quote Originally posted by vamper68: at 5500 in 5th gear i get an easy 150 and thats with a fairly stock 2.8 it might take me almost a mile but its fun

In this thread
https://www.fiero.nl/forum/Forum2/HTML/056763.html

quote Originally posted by vamper68: i laugh in the face of danger. as my car sits right now i can get it up to and hold over 140 at 5000 rpm this is with a fairly stock 2.8 motor in a fast back body the only problem i have had with stability (mind you that it gets better at the higher speeds) is i have had a headlight door open up at about 145 i plan to "pin them down for faster speeds" i doubt that my fiero has much over 200 hp and does not run the best in the world

Sorry Vamper, BS needs to be called out before it goes too far.....

[This message has been edited by crzyone (edited 01-08-2005).]

OK Oreif….

Let’s start with some assumptions. The link you provided is similar to a hundred other’s on the net…and not one of them is accurate. The math is all wrong for a variety of reasons. Let’s just stick to the ones related to the Fiero.

First, tire size. The biggest problem with tire size assumptions is that one manufacturer’s 215/60/R15 tire is NOT the same size and another’s. You would think it would be so, but it ain’t. Also, the auto manufacturer’s recommended tire pressure is NOT the same as the maximum recommended tire pressure on the side wall of the tire. The recommended tire pressure fof the Formula and GT REAR tires is 30 PSI cold. The link you provided gave a figure of 801.59 rotations per mile for a 215/60/R15 tire. This is a good “par” estimate but it is not exact.

I took the trouble to do the exact calculations for the Fiero Tires long ago and did the calculations for optimum tire pressure for maximum speed on the day I tested the car at Lake Edwards. Keep in mid these calculations take into account the atmospheric temperature of the day. It is normal for tire pressures to increase 30-60 kilopascals (4-8PSI) when the tires get hot. The Stock Fiero came with Eagle GT +4 tires. ‘215’ is the width of the tire in millimeters, The Profile (or aspect ratio) is ‘60‘. This is calculated by dividing the section height by the section width and multiplying by 100. ‘15’ is the rim size in inches. The GT+4 is a 240-A-B, H-rated tire (top speed 130 MPH), with a load rating of 95 (1521 pounds). Because the GT+4 is a ‘B’ rated tire in terms of temp. it is more susceptible to pressure variations.

To make a long story short, desired speed range (top speed in our discussion) is:

Normal Max load -{( % load decrease) X ((normal max load)}= new max load
Inflation increase required + normal max inflation = new inflation pressure

The figures come out of Goodyear’s Engineering Data Book page L-2 and worked out to be 33.8 PSI with a tread deflection of -.201’ diameter.

From this we calculate tire diameter of 25.2 -.201= 25.0/2= a radius of 12.50 inches.
Circumference =2(3.1415)12.50= 78.54inches.

1 Statute Miles is 5280 feet. 5280x12 = 63,360 inches

63,360/78.54= 806.72 miles per rotation for Eagle GT+4 tires at 33.8 PSI cold

Now that we have an accurate MPR number the rest is easy:

Revolutions Per Minute x Minutes Per Hour gives us engine revolutions per hour

Divide this by the OVERALL RATIO!!! NOTHING ELSE IS RELEVANT!!! So take your 3.61s and 3.35s and heave ‘em out the window. The OVERAL RATIO is all that matters.

divide this number by revolutions per mile to get Miles Per Hour.

((4300x60)/2.60)/806.72 = 123.01 mph Top Speed

Gee, what a surprise. Theory and Reality collide.

Now we get to the final assumption and that is the Revolutions per minute of 4300.

The maximum available force exerted on a drive gear is based on a rather simple concept. I like to use the example of a ‘see-saw’. If you have a neutrally balanced ‘see-saw’ with the fulcrum in the middle then ANY amount of force will move the ‘see-saw’. A transmission gear is simply a circular ‘see-saw’. Anything under or over neutrall balance will be the equivalent of a taller gear or an overdrive gear. If a gear is an overdrive gear MORE force is required to lift the ‘see-saw’. Since the car has mass and tires have friction and wind has resistance the car can’t be moved with “ANY” amount of force. What this means is that the fulcrum is not in the middle OR you have some opposing force on the other end of your ‘see-saw’ requiring extra force on your side to move it.

NOW…by changing gear ratios (ie, swapping an Isuzu for a Getrag) you are effectively changing the location of the fulcrum in an attempt to find a more optimal distribution of opposing forces (engine HP on your end; aerodynamics, friction, etc. on the other end) making it possible for you to lift the ‘see-saw’ higher without using any more force. If you weigh 200 lbs and you sit on your end of the ‘see-saw’ then 200 lbs is the limit of your available force. In the same way that 135 BHP is the limit of the available force for the Fiero 2.8 liter engine. In fact, I have heard the 140hp myth for years and have yet to see anyone prove it. In fact, the 1988 Fiero Press release dated August 5, 1987 (which I have an original copy of) states, “The standard powerful 2.8L MFI V-6 engine coupled with the GM Muncie/Getrag 5-speed transaxle gives the 135 horsepower vehicle a 0-60 time of about 8.0 seconds.” In fact, you will not find ONE peice of GM literature with anything more than 135 hp written on it. And I have seen people’s data sheets from dyno days that show the REAL horsepower to be far LESS than 135. Do a “dyno day” search on Pennocks. Like I said, I am not interested in myths, opinions, guesses, or assumptions, show me the dyno chart and I’ll change my position. Without these, the Fiero is a 135 hp engine.

As for the REAL Indy, I’ve owned 4 Indy’s over the years, I’ve personally examined two of the original 3 Indy’s up close, am building an identical SD-4 engine as we speak, and have one of the most complete libraries on the car. The Real INDY did NOT use the stock 4-Speed Muncie Tranny. It used a “special close ratio transmission” (from the INDY press release, yes, I have an original of that too) with more durable gears of different ratios for the added horsepower with a 3.66:1 final drive ratio, not 3.65. It had 232 horsepower at 6500 RPM and had an average lap speed of 136 MPH. Top speed was 144. It also had 225/50VR16 tires in the back. Plug THAT into your calculator! It managed to go 144 MPH because it had the horsepower to do so, not because of the gearing. And as for the areodynamics, ot was the lowering of the car that I was talking about. It dropped the cd down to .34.

In short, the Fiero’s top speed in stock trim is 123.77 MPH with a nearly optimally tuned tranny. Changing to the Isuzu tranny might give a 2 MPH advantage due to gearing since the car still has the same weight, HP, and Tires. But the RPMs will not increase enough to overcome the advantage due to the power limitations of the engine AND the increased resistance of drag, and friction for each mile per hour faster you go.

Go to the test track and prove me wrong.

[This message has been edited by Toddster (edited 01-08-2005).]

For the GM literature, find an 88 owners manual, it clearly states 140hp.

[This message has been edited by 88gtNewb (edited 01-08-2005).]

quote Originally posted by 88gtNewb: For the GM literature, find an 88 owners manual, it clearly states 140hp.

Got One, you are right. Page 6-4 it states "140 HP at 5200 RPM".

Just the same, all other literature states 135 hp and I have never seen a dyno reading come even close to that. I tend to believe that the HP rating is a marketing thing more than reality. I'd prefer to see a dyno sheet.

Toddster... you realize the 140 claimed is at the flywheel right? Putting the wheel hp around 115-120. You have to take into account driveline loss. Most cars are advertized with flywheel hp, it sounds better. Thought you would know that.

quote Originally posted by Toddster: To make a long story short, desired speed range (top speed in our discussion) is: Normal Max load -{( % load decrease) X ((normal max load)}= new max load Inflation increase required + normal max inflation = new inflation pressure The figures come out of Goodyear’s Engineering Data Book page L-2 and worked out to be 33.8 PSI with a tread deflection of -.201’ diameter. From this we calculate tire diameter of 25.2 -.201= 25.0/2= a radius of 12.50 inches. Circumference =2(3.1415)12.50= 78.54inches. 1 Statute Miles is 5280 feet. 5280x12 = 63,360 inches 63,360/78.54= 806.72 miles per rotation for Eagle GT+4 tires at 33.8 PSI cold Now that we have an accurate MPR number the rest is easy: Revolutions Per Minute x Minutes Per Hour gives us engine revolutions per hour <------------WRONG!!!! Divide this by the OVERALL RATIO!!! NOTHING ELSE IS RELEVANT!!! So take your 3.61s and 3.35s and heave ‘em out the window. The OVERAL RATIO is all that matters. divide this number by revolutions per mile to get Miles Per Hour. ((4300x60)/2.60)/806.72 = 123.01 mph Top Speed Gee, what a surprise. Theory and Reality collide. Now we get to the final assumption and that is the Revolutions per minute of 4300.

Nice math, thanks for proving how wrong you are. It's not ENGINE RPM's, the equation above tells me that the TIRE spins 4300 RPM at 123.01MPH.
It has nothing to do with the RPM's of the engine!!! This is where the gear ratios have an effect.
Calculating backwards the ENGINE's RPM would be 4650 RPM's If the engines RPM stayed the same and the gear ratio lowers, The TIRE RPM increases. Same force is applied to the 5th gear, RPM is a constant and top end miles per hour increases at a rate of 1mph per .02 ratio change.

Nice try though, Thanks for playing.

quote Originally posted by Toddster: The maximum available force exerted on a drive gear is based on a rather simple concept. I like to use the example of a ‘see-saw’. If you have a neutrally balanced ‘see-saw’ with the fulcrum in the middle then ANY amount of force will move the ‘see-saw’. A transmission gear is simply a circular ‘see-saw’. Anything under or over neutrall balance will be the equivalent of a taller gear or an overdrive gear. If a gear is an overdrive gear MORE force is required to lift the ‘see-saw’. Since the car has mass and tires have friction and wind has resistance the car can’t be moved with “ANY” amount of force. What this means is that the fulcrum is not in the middle OR you have some opposing force on the other end of your ‘see-saw’ requiring extra force on your side to move it. NOW…by changing gear ratios (ie, swapping an Isuzu for a Getrag) you are effectively changing the location of the fulcrum in an attempt to find a more optimal distribution of opposing forces (engine HP on your end; aerodynamics, friction, etc. on the other end) making it possible for you to lift the ‘see-saw’ higher without using any more force. If you weigh 200 lbs and you sit on your end of the ‘see-saw’ then 200 lbs is the limit of your available force. In the same way that 135 BHP is the limit of the available force for the Fiero 2.8 liter engine. In fact, I have heard the 140hp myth for years and have yet to see anyone prove it. In fact, the 1988 Fiero Press release dated August 5, 1987 (which I have an original copy of) states, “The standard powerful 2.8L MFI V-6 engine coupled with the GM Muncie/Getrag 5-speed transaxle gives the 135 horsepower vehicle a 0-60 time of about 8.0 seconds.” In fact, you will not find ONE peice of GM literature with anything more than 135 hp written on it. And I have seen people’s data sheets from dyno days that show the REAL horsepower to be far LESS than 135. Do a “dyno day” search on Pennocks. Like I said, I am not interested in myths, opinions, guesses, or assumptions, show me the dyno chart and I’ll change my position. Without these, the Fiero is a 135 hp engine.

Nice fulcrum explanation, You are right about the added force to the overdrive gear, But you forgot to take into account that the differential ratio lessens the force needed.

As for "real" horsepower of the 2.8L:
from 1985 to 1987 the engines were mechanically the exact same. Although the 1985/1986 were rated at 140hp @ 5200 rpm and the 1987 was rated at 135 @ 4500 rpm. So why is the RPM different? In 1988 the only difference was they used an internally balanced crankshaft instead of externally balanced, ALL OTHER PARTS WERE THE SAME. Like I said earlier the only difference in the ratings was for EPA ratings and nothing to do with the true horsepower of the engine.

As for testing on a chassis dyno, The chassis dyno is very inaccurate at measuring crankshaft horsepower. Since your a person of "facts"
I had an engine dynoed on an engine stand, The trans was rebuilt and tested on a trans dyno. The entire set-up was placed on a chassis dyno and there was over a 12% error when calculating crankshaft horsepower to what the engine dyno actually showed.
A chassis dyno is only good for measuring how much power gets to the ground and how fast the car will go time vs distance using power at the wheels and vehicle weight. (drag racing)

Just to add to your "press release" facts, The 1985 Fiero GT press release shows 0-60 as 7.6 seconds, the curb weight as 2572 lbs, and the engine is rated at 140hp @ 5200rpm.

quote Originally posted by Toddster: As for the REAL Indy, I’ve owned 4 Indy’s over the years, I’ve personally examined two of the original 3 Indy’s up close, am building an identical SD-4 engine as we speak, and have one of the most complete libraries on the car. The Real INDY did NOT use the stock 4-Speed Muncie Tranny. It used a “special close ratio transmission” (from the INDY press release, yes, I have an original of that too) with more durable gears of different ratios for the added horsepower with a 3.66:1 final drive ratio, not 3.65. It had 232 horsepower at 6500 RPM and had an average lap speed of 136 MPH. Top speed was 144. It also had 225/50VR16 tires in the back. Plug THAT into your calculator! It managed to go 144 MPH because it had the horsepower to do so, not because of the gearing. And as for the areodynamics, ot was the lowering of the car that I was talking about. It dropped the cd down to .34.

Taken from the 1985 Fiero GT press release:
"The all new Fiero GT comes with a close-ratio 4-spd transmission (the same one used on the famous Pace Car that paced the Indy 500.)"

The reason they called it "special" in the Pace Car press release was it was not a "STOCK 1984" transmission.

As per your request, I plugged in the numbers and had a top end speed of 146.85907mph.

As for the differential, there isn't much difference between a 3.66 and a 3.65 except the 3.66 was in a "press release" stated by a PR person, and the 3.65 was what was stated by the people who actually built the Pace car for the race, But you seem to believe the PR people.

Oh wait that's right you still think that tire rpm and engine rpm are the same.

quote Originally posted by Toddster: In short, the Fiero’s top speed in stock trim is 123.77 MPH with a nearly optimally tuned tranny. Changing to the Isuzu tranny might give a 2 MPH advantage due to gearing since the car still has the same weight, HP, and Tires. But the RPMs will not increase enough to overcome the advantage due to the power limitations of the engine AND the increased resistance of drag, and friction for each mile per hour faster you go. Go to the test track and prove me wrong.

I don't need to go to a track to prove you wrong, You have just done it mathematically all by yourself.
Again, Thanks for playing.

[This message has been edited by Oreif (edited 01-08-2005).]

quote Originally posted by Oreif: Nice math, thanks for proving how wrong you are. It's not ENGINE RPM's, the equation above tells me that the TIRE spins 4300 RPM at 123.01MPH. It has nothing to do with the RPM's of the engine!!! This is where the gear ratios have an effect. Calculating backwards the ENGINE's RPM would be 4650 RPM's If the engines RPM stayed the same and the gear ratio lowers, The TIRE RPM increases. Same force is applied to the 5th gear, RPM is a constant and top end miles per hour increases at a rate of 1mph per .02 ratio change. Nice try though, Thanks for playing

oh boy.....

I had to re-post this so everybody can read the part where you claim engine RPM has nothing to do with speed. BTW, i think you mean 'affect' not 'effect'.

The TIRE does not spin at 4300 RPMs, the ENGINE DOES!

Follow along closely Oreif, this isn't that hard a concept to grasp:

1) The engine spins and drives the main shaft of the tranny
2) The main shaft of the tranny is connected to a gear (5th gear for our little experiment)
3) 5th gear is connected to the differential. The ratio of the engine revolutions to the two gears is 2.60:1. This is called the final ratio. So for every 2.60 revolutions of the engine, the differential spins once. Follow me?
4) The differential is connected to the wheel and spins the tire which has a circumferance of 78.54 inches at 33.8 PSI. (Circumferance varies with pressure as discussed in my last post). And, as I hope I don't need to point-out, circumferance = 2(pi)R (see note below)

Sooooooooooooooo.....

Every 2.60 REVOLUTIONS of the engine (yep, it IS related to speed) turns the differential 1.00 times (in 5th gear) which spins the tire 1.00 times too. If the car travels 78.54 inches for every 2.60 revolutions of the engine then 78.54 / 2.60 = 30.21 inches per engine revolution! Still with me?

30.21 X 4300 (engine revolutions per minute) = 129,893.08 inches per minute travelled

divide by 12 inches in a foot and we get 10,824.42 feet per minute travelled

divide by 5280 feet in a statute mile and we get 2.05 miles per minute

multiply this by 60 minutes in a hour and we get 123.00 miles per hour

I REALLY hope this ends this discussion. I can't think of how to make it any clearer.

Since there is obviously nothing wrong with my math, the ONLY issue here is whether my assertion that the maximum RPMs the stock 2.8 can manage with a getrag tranny attached is 4300 or not.

My assertion is based on personal racing experience and is backed up by every magazine article, technical manual, and test report out there. Think it can spin faster? SHOW ME THE PROOF. But stop trying to tell everyone that my math is off.

And comments like "Nice try, thanks for playing" rank right up there with "Oh God please don't tell me we have to go through the physics again...PLEASE!." But at least I'm not being hypocritical about being intolerant.

I've got every one of those magazine articles you mentioned. And lots more, like John Schinella's personal notebook maked "GM Confidential". It's 3.66:1 I'll get more into this later. Gotta rug rat to put to bed.

Note: the only other variable in my equation is tire circumferance which is not only dependant on pressure but on the actual manufacturer. It is true that one maker of a 215/60/R15 tire will not have a tire exactly the same size as another makers 215/60/R15. Go to www.1010tires.com to confirm that, they state it right on their tire calculator page. This site is usefull for tire size comparisons in a general sense --> http://www.miata.net/garage/tirecalc.html But I have the Goodyear engineering data on the Eagle GT+4 which provides the exact numbers. for the stock Fiero tire and those are the numbers used here.

[This message has been edited by Toddster (edited 01-10-2005).]

wow

quote Originally posted by crzyone: Toddster... you realize the 140 claimed is at the flywheel right? Putting the wheel hp around 115-120. You have to take into account driveline loss. Most cars are advertized with flywheel hp, it sounds better. Thought you would know that.

I do. Loss through the tranny is about 25%. I take that into account.

[This message has been edited by Toddster (edited 01-10-2005).]

With a manual trani I would say the loss is quite a bit less than 25%, more like 15%

quote Originally posted by crzyone: With a manual trani I would say the loss is quite a bit less than 25%, more like 15%

Yep, it's around 15%, SLP engineering says is right in around a 17% drivetrain loss through a M282 Getrag /Muncie 5 spd.

Hmm, if your 2.8L Fiero can't pull over 4300 RPM in 5th gear, ya best go get it fixed cause something is wrong with the engine.

quote Originally posted by jelly2m8: Hmm, if your 2.8L Fiero can't pull over 4300 RPM in 5th gear, ya best go get it fixed cause something is wrong with the engine.

Nope, nothing is wrong. it is operating at peak efficiency for a "Stock" 2.8 and exactly the same as every other Fiero out there including yours. If you think your "Stock" Fiero can rev higher than 4300 in 5th gear then you'ld better get your tach fixed.

quote Originally posted by Toddster: Sooooooooooooooo..... Every 2.60 REVOLUTIONS of the engine (yep, it IS related to speed) turns the differential 1.00 times (in 5th gear) which spins the tire 1.00 times too. If the car travels 78.54 inches for every 2.60 revolutions of the engine then 78.54 / 2.60 = 30.21 inches per engine revolution! Still with me?

AHH, Your right that the 4300 is not Tire RPM, I apologize for mis-reading your math.
But you still have a variable in your formula that doesn't change when the differetial ratio changes.
The problem is the 2.60 is NOT the same with all differential ratio's!
For every revolution of the engine 5th gear turns .78 times. (overdrive)
For every 3.61 turns of the differential gear, the tire spins 1 revolution. It actually works out to be 2.63 overall final drive.
Your "2.60" is the overall drive ratio of 5th gear and the differential drive combined. Which is fine, But this number changes when either the gear or the differential ratio's change.
This number would be a lot higher if you were in any of the lower gears due to the much higher ratio of each gear (1st thru 4th) and the diff ratio stays the same, So how come the number doesn't change in your equation when the diff ratio changes and the gear stays the same????
Change the diff ratio to 3.32 or 2.78 and the "2.60" number changes accordingly. This is where your flaw is:

With a 2.78 the "2.60" should be 2.13
With a 3.32 the "2.60" should be 2.42
So ((4300x60)/2.13)/806.72 = 150.14 MPH
or ((4300x60)/2.42)/806.72 = 132.15 MPH

You can't seriously think that regardless of which differential ratio the overall final drive of "2.60" stays the same???

quote Originally posted by Toddster: I REALLY hope this ends this discussion. I can't think of how to make it any clearer. Since there is obviously nothing wrong with my math, the ONLY issue here is whether my assertion that the maximum RPMs the stock 2.8 can manage with a getrag tranny attached is 4300 or not. My assertion is based on personal racing experience and is backed up by every magazine article, technical manual, and test report out there. Think it can spin faster? SHOW ME THE PROOF. But stop trying to tell everyone that my math is off.

Can you explain the Motor Trend testing of two IDENTICAL 1984 Fiero's one with a 3.32 final drive 4-cyl going 120mph and an SE going 105mph with a 4.10 4-spd? Your "personal racing experience" is only based on 1 car with 1 trans. Not all stock Fiero transmissions have the same differential drive. (meaning between styles Isuzu, Getrag, Muncie, and the TH125's)

Again, Sorry I stated your math was wrong, It's not wrong, You just forgot that the overall drive ratio varies between transmissions differential ratio's, so the formula is right, just the data you entered is only good for your particular overall drive and you do not properly change the overall drive ratio data when the differential ratio changes.

Edit:
Just located some Factual data. Gary Wirtzburg's "Fiero" book Page 110
Final overall ratio's of ALL transmissions. (final gear + differential)
1984 4-spd economy 2.42
1984 4-spd 4.11 gear 3.32
1984 Auto trans 3.18
1985-1988 Isuzu 5-sp 2.48
1985-1986 V-6 4-spd 2.96
1985-1986 Auto 3.35 or 3.65 for GT
1987-1988 V-6 5-spd 2.60
1987-1988 Auto 3.33 or 2.84 with 4-cyl.
So a V-6 with the Isuzu trans at 4300rpm goes 128.9mph ( 6mph increase just changing transmissions)
Now say the car is traveling down a highway with a slight down grade with a tailwind and the driver gets to 4500rpm or even the fact his stock 2.8L runs better than yours did, He's now doing 134.95mph. Given a speedo normally has an error of +/- 2% he could claim "about 135mph" and be correct.
Your racing was flat, level, and no wind.
Did you have your engine dyno'd on an engine dyno to prove it was at the 140hp rating?
Was the car chassis dyno'd to show what it was putting to the ground? There are a few stock dyno's posted in the archives and they go from 112hp to 122hp at the tires. Where did yours fall into? The entire point is you are making claims that your testing is the absolute benchmark and sorry it is not.

So now would you believe a Fiero using stock parts can go 135mph?

I've had my first 86 SE V-6 up to 5500rpm in 4th gear with a set of BFG Euro T/A's on aftermarket wheels.
According to the BFG website Revs of the tire and the final drive, It was doing 138.02mph. (NOTE: the engine was stock)
Car and Driver had a 1986 GT hit 131mph same engine, same trans, fastback body.
That works out to be about 100 rpm less with the tire size difference and CD of the body.

[This message has been edited by Oreif (edited 01-10-2005).]

quote Originally posted by Toddster: Anyone claiming to have gone 135 in a stock fiero (getrag or isuzu) either has a bad tach and/or filter, bad speedo, bad VSS, bad ECM, or is just embellishing.

or had a tailwind, or had a slight downhill, or had slightly higher compression slightly low oil level with thin oil and slightly better fuel mix making slightly more HP

quote Originally posted by Toddster: Show me the times slips and I'll retract.

absolutely idiotic - asking people to post a timeslip from a topspeed run? where the hell would they manage that?
no matter what your car did there are a lot of other variables to other peoples stock fieros - along with the actual ambient conditions that it happened in..

prove that someone elses stock Fiero can't.. its just your educated opinion.. if it was a more obvious statement like no stock fiero will hit 160 then sure.

no matter how wrong you are you will never admit it - so this pissing match thats been going on is pointless..

[This message has been edited by Kohburn (edited 01-10-2005).]

Sorry Todd, hate to break it to you, but your Formula is not the bench mark. I could whip up a dozen 2.8L powered Fiero's that will pull over 4300 rpm in 5th. Contrary to popular belief the stock guages aren't as inacurate as you and other make them out to be.

I haven't a clue how fast my particular 2.8L Fiero is, nor do I care, but at least I know it's faster than your Formula.

Every year or so someone comes in here and asks how fast a stock V6 Fiero is and everytime you tell the same story over and over. Every time most people call your story out. Not only that, your story info is over 10 years old, are ya sure their equipment was 100% that day?, did you see the calibration slips for the timing equipment?

Look I don't care if my 2.8L Fiero goes 180 mph, or 80 mph, but I know my V6 Fiero and many many others I have worked on / driven work a heck of alot better than yours, just because yours has a problem and won't pull over 4300, doesn't mean the rest of the Fieros in the world won't, and your theory on the tach suddenly being inaccurate after 4300 is pure BS. I've tested the tach on several Fiero's with a scan tool, and a high end Snap -On digitial advance timing light and the highest deriviation I've seen with either was only slightly over 170 RPM.

BTW I'm leaving your rating positive, I think your full of BS on this, but other than me disagreeing with you on this, I respect you for the most part.

The fiero tach is very accurate. I have 2 tachs in my fiero. The stock in dash, and another aftermarket one that runs off of a sensor that fits on a spark plug wire.

The 2 are within 20rpm of eachother at any rpm, I only got the aftermarket tach becuase my tdc will go to 7200rpm and the stocker is only good for 6500.

I had my 86GT with a stock 2.8 with 85,000 miles on it at 5400rpm in 4th gear. This is a 3.65 4 speed muncie. The spedometer seemed to read around 125-130mph. The car still had some throttle left. 123mph is not the top speed of all fieros. It is not the theoretical top speed.

I would assume a formula would have worse drag than a 85GT. The 85 also has better gearing for a 2.8 top speed run.

There are enough people in this thread that have gone over 123mph, myself included.

quote The problem is the 2.60 is NOT the same with all differential ratio's! For every revolution of the engine 5th gear turns .78 times. (overdrive) For every 3.61 turns of the differential gear, the tire spins 1 revolution. It actually works out to be 2.63 overall final drive. Your "2.60" is the overall drive ratio of 5th gear and the differential drive combined. Which is fine, But this number changes when either the gear or the differential ratio's change. This number would be a lot higher if you were in any of the lower gears due to the much higher ratio of each gear (1st thru 4th) and the diff ratio stays the same, So how come the number doesn't change in your equation when the diff ratio changes and the gear stays the same???? Change the diff ratio to 3.32 or 2.78 and the "2.60" number changes accordingly. This is where your flaw is: With a 2.78 the "2.60" should be 2.13 With a 3.32 the "2.60" should be 2.42 So ((4300x60)/2.13)/806.72 = 150.14 MPH or ((4300x60)/2.42)/806.72 = 132.15 MPH

There is no flaw here. You are forgetting that your engine has limited horsepower. Remember the 'see-saw' analogy? Your examples keep insisting that moving the fulcrum of the see-saw will have no effect on the amount of force required to push your end down.

It just ain't so.

quote You can't seriously think that regardless of which differential ratio the overall final drive of "2.60" stays the same???

yes I can because we are talking about a STOCK fiero. Unles you have a Getrag with a quick change differential then the final drive ratio is 2.60....and if you do have a quick change Getrag, where can I get one?

quote Can you explain the Motor Trend testing of two IDENTICAL 1984 Fiero's one with a 3.32 final drive 4-cyl going 120mph and an SE going 105mph with a 4.10 4-spd? Your "personal racing experience" is only based on 1 car with 1 trans. Not all stock Fiero transmissions have the same differential drive. (meaning between styles Isuzu, Getrag, Muncie, and the TH125's) Again, Sorry I stated your math was wrong, It's not wrong, You just forgot that the overall drive ratio varies between transmissions differential ratio's, so the formula is right, just the data you entered is only good for your particular overall drive and you do not properly change the overall drive ratio data when the differential ratio changes.

I didn't forget the drive ratio. You forgot that horsepower is a constant. A change in gearing will increase the rolling resistance of the car and your engine will top out at a lower RPM than it did before.

quote Edit: Just located some Factual data. Gary Wirtzburg's "Fiero" book Page 110 Final overall ratio's of ALL transmissions. (final gear + differential) 1984 4-spd economy 2.42 1984 4-spd 4.11 gear 3.32 1984 Auto trans 3.18 1985-1988 Isuzu 5-sp 2.48 1985-1986 V-6 4-spd 2.96 1985-1986 Auto 3.35 or 3.65 for GT 1987-1988 V-6 5-spd 2.60 1987-1988 Auto 3.33 or 2.84 with 4-cyl.

Gary's book has several errors not the least of which is claiming that the final drive ration for the 1988 coupe is 2.60 when in fact it is 2.48. I prefer to rely on the Pontiac data.

quote So a V-6 with the Isuzu trans at 4300rpm goes 128.9mph ( 6mph increase just changing transmissions) Now say the car is traveling down a highway with a slight down grade with a tailwind and the driver gets to 4500rpm or even the fact his stock 2.8L runs better than yours did, He's now doing 134.95mph. Given a speedo normally has an error of +/- 2% he could claim "about 135mph" and be correct.

A 60 MPH tail wind (near hurricane force) is good for 1MPH. And as for adding 6MPH, again, you have failed to consider the limited horsepower of your car. 2 MPH...TOPS.

quote So now would you believe a Fiero using stock parts can go 135mph?

You still don't get it Oreif. You are living in a theoretical world..and a flawed one at that. The Fiero's top speed is 123 MPH. Period. I've owned over 20 fieros over the years including 7 Formulas. Not one of them (in stock form) ever topped 124 MPH. Not one!

quote Car and Driver had a 1986 GT hit 131mph same engine, same trans, fastback body. That works out to be about 100 rpm less with the tire size difference and CD of the body.

No they didn't. I have every C&D article on teh fiero and their best performance "ESTIMATED" was 125 MPH. Actual test best was 123.

And Jelly, You have never had your 1988 Fiero over 4300 in 5th gear unless the car in modified. Sorry. the Fiero Tach is notoriously INACCURATE. Just read Oliver Schotz page. Why do you think Rodney Dickman makes a fortune selling new home-made tach filters? Your Tach is in need of repair.

I'm pretty sure that if i was running an aero nose and had the decklid on in the pic i posted with maybe some lowering springs I bet i would've been faster than 123.77mph .Considering a few days ago i had the speedo well beyond the 120mph mark, with no tailwind,no hills (i live in Delaware).

I just thought of something.... I'm running ported heads and intake so i guess that takes me out of the stock category huh? Ooops

[This message has been edited by FIEROPHREK (edited 01-10-2005).]

quote Originally posted by Toddster: There is no flaw here. You are forgetting that your engine has limited horsepower. Remember the 'see-saw' analogy? Your examples keep insisting that moving the fulcrum of the see-saw will have no effect on the amount of force required to push your end down.

But you do not know what the actual horsepower was at the crankshaft or to the wheels of the car you tested 10 years ago. The 140hp rating is NOT an exact figure. Mass-production engines can vary by as much as 8%. The other thing you are forgetting is a 1986/1987 SE and GT both weigh less than the 1988 Formula. So since there is less weight to move, higher RPM is attained. There is nothing theoretical about it. Even a 1987 SE weighs over 100lbs less with a V-6 and Getrag. So it has less rolling resistance and by your own reasoning should be able to go faster than 4300rpm in 5th gear.

quote Originally posted by Toddster: yes I can because we are talking about a STOCK fiero. Unles you have a Getrag with a quick change differential then the final drive ratio is 2.60....and if you do have a quick change Getrag, where can I get one?

That is incorrect. The OVERALL FINAL DRIVE of the STOCK 1985 and the 1986 is 2.96. Using your math formula and knowing a 1986 V-6 STOCK SE or GT can top RPM's in 4th gear up to 5500rpm is proof right there. I've been in numerous STOCK Fiero's with a V-6 4-spd and have been over 5000rpm in 4th. Again the weight of the cars has an effect as well and the earlier V-6 cars weigh less. Not all Fiero's are identical in weight, overall drive ratio, and CD of a 1988 Formula.
The 1988 Formula is NOT the ONLY STOCK Fiero. A 1985 SE had the V-6 option and only weighed 2520 (1985 GT only weighs 2580) as opposed to the Formula weight of 2808.
The Formula is NOT the fastest STOCK Fiero either.
I would put money down that a STOCK V-6 with the getrag 5-spd can exceed 4300rpm in 5th gear.

quote Originally posted by Toddster: I didn't forget the drive ratio. You forgot that horsepower is a constant. A change in gearing will increase the rolling resistance of the car and your engine will top out at a lower RPM than it did before.

I have looked at you math formula again, There is nothing in it that the rolling resistance can change. You do not include the weight of the vehicle nor do you include the hardness/softness of the tires. A harder compound of rubber will decrease rolling resistance. Rolling resistance is not the same between a GT, SE, or Formula.
As for horsepower/torque, I have yet to see anything anywhere that says 140hp stops at 123.77mph. I do know of many cars with less or the same horsepower that have gone faster.

quote Originally posted by Toddster: Gary's book has several errors not the least of which is claiming that the final drive ration for the 1988 coupe is 2.60 when in fact it is 2.48. I prefer to rely on the Pontiac data.

You'd better look at the data I posted again, The 4th line down:
1985-1988 Isuzu 5-spd is 2.48
The 2.60 is ONLY the Getrag 5-spd.

quote Originally posted by Toddster: You still don't get it Oreif. You are living in a theoretical world..and a flawed one at that. The Fiero's top speed is 123 MPH. Period. I've owned over 20 fieros over the years including 7 Formulas. Not one of them (in stock form) ever topped 124 MPH. Not one!

I am using the same math formula you are using. The "limited horsepower" you claim is pretty sad. The Fiero has 140hp and 170ft/lbs of torque in a 2.8L V-6.
There are many cars out there that have the same weight of the vehicle (or heavier) with the less or the same horsepower/torque going faster than 124mph for a top speed.
A 2002 BMW Mini weighs 2780lbs has a 5-spd 4-cyl with 114hp and 109ft/lbs of torque (this is NOT the "S") and a top speed of 125mph. So how does a car about the same weight with 36hp less and 61 ft/lbs of torque less go faster if the Fiero is limited by horsepower? A 1984 Fiero with 92hp and 135 ft/lbs of torque went 120mph, So your trying to say 48hp more and 35 ft/lbs of torque only gains you 3mph?????????
You are baselining the entire top end of ALL Fiero's on just one run of a 1988 Formula 10 years ago. You are the one who has no accurate data on any other version of a STOCK Fiero's.

quote Originally posted by Oreif: Well I went thru a bunch of old magazines and guess what I found? Sept 1983 Motor Trend 1984 coupe 4-spd trans with 3.32 final drive 0-60 10.5 seconds, top speed 120mph, 1/4 mile 17.7 @ 75mph (This is with a 92hp 2.5L 4-cyl) They show an SE with top speed of 105mph using the 4.10 4-spd. with 0-60 being 10.1 and 1/4 mile being 17.4@ 76mph Weight is shown at 2460 lbs Notice to Toddster, That is a 15mph difference by just changing the final drive and documented in Motor Trend Magazine. Not a 2mph difference as you thought. So Motor Trend went to the track in 1983 and proved you wrong 21 years ago. Feb 1986 Car and Driver 1986 GT 4-spd with 3.65 final drive, weight 2696 lbs, 0-60 7.5 seconds, top speed 131mph, 1/4 mile 15.9@ 85mph Nov 1987 Car and Driver 1988 Formula 5-spd with 3.61 final drive, weight 2805 lbs, 0-60 8.2 seconds, top speed 123mph, 1/4 mile 16.0@ 85mph The 2 above were the same magazine. Just for the fun of it: June 1985 Car and Driver SD-4 IMSA Pace Car 2.7L 232hp, 3.65 final drive, Weight 2505, 0-60 6.3 seconds, top speed 161mph 1/4 mile 14.7 @ 93mph June 1985 Car and Driver GTU Race car, 2.7L 275hp, 3.66 final drive, Weight 2106, 0-60 4.0 seconds, top speed 192mph, 1/4 mile 12.3 @ 112mph. Notice to Toddster, The aftermarket racing trans did have a 3.66 differential ratio, Maybe your press release person mixed up the Pace car with the IMSA GTU car when writing it or maybe they were going to use the aftermarket trans and swapped in the trans for the V-6 at the last minute.

What can I say Oreif? I'm really disappointed in you. I thought we were engaging in a serious discussion. I had no idea you would resort to outright lying.

I checked my copies of these magazines and the Sept 1983 Motor Trend states, "Curiously, however, at absolute tops end, calculated to be around 120 MPH..." Uh yeah, calculated by a bunch of Motor Trend desk jockeys with no clue. NO actual test result.

But Road and Track and Car and Driver of the SAME month and year estimated top speed to be 103 and 104 respectively for the 4 banger.

The Feb 1986 issue of Car and Driver actually lists the V-6 Fiero's top speed as 123 mph at 5050 RPM with the 4-speed Muncie and it states this in TWO locations. Didn't see your 131 claim anywhere in that article. But it seems that you borrowed that number for the next article.

And the most egregious BS of all is your total fabrication of numbers from the June 1985 Car and Driver. The SD-4 had a TESTED TOP SPEED of 131 mph. Yep, a Super Duty 4 light weight race car peaked at 131. And the GTU had a top speed of 161 MPH. The 192 figure you quoted is now where in the article.

For the record:

The March 1987 issue of Automobile Magazine ACTUALLY test drove the Fiero and the result was 120 MPH top speed.

The April 1988 Issue of Popular Hot Rodding tested the Formula...Top Speed was 122 MPH

The December 1985 issue of Sports Car Monthly tested the 85 GT at 125 MPH...must had a tail wind

The August 1986 issue of Road and Track has the top speed at 123 MPH

I can go on and on. I have not found ONE article that shows ANY fiero listed with a top speed of over 125 and even THAT is probably an error.

I don't mind being wrong if you can provide REAL proof. I do mind being told I'm wrong out of some...I dunno, ego thing? maybe? And given phonied-up sources and stats in the desparate hope that I won't look it up. It does both of us a disservice and serves only to confuse readers of this thread who are ACTUALLY TRYING TO LEARN SOMETHING.

Top Speed is 123.77

[This message has been edited by Toddster (edited 01-11-2005).]

Uhhh... You guys seriously think weight has any affect on top speed? Weight determines how fast your car will get to top speed, not the speed its self. It may have a small affect on rolling resistance through your wheel bearings, but thats it.

Rolling resistance and wind resistance are the ONLY factors in top speed. Weight is only inirtia.

If you have a 60mph tail wind you will not only go 1mph faster, that is utter bullshit.

Again, your engine is fighting wind resistance and rolling resistance only. Accelerating mass is not a factor in top speed, it will only determine how long it takes to get there.

Wind resistance is exponential. It is the MAJOR factor in top speed. This is why the car that broke the sound barrier used 2 frigin huge jet engines. Not because the car weighed so much, its because of wind.
--------------------------------------
My GT went over 123mph.

quote But you do not know what the actual horsepower was at the crankshaft or to the wheels of the car you tested 10 years ago. The 140hp rating is NOT an exact figure. Mass-production engines can vary by as much as 8%.

Says who? And no BS sources this time. It is my understanding that stock engines vary as little as 3%.

quote The other thing you are forgetting is a 1986/1987 SE and GT both weigh less than the 1988 Formula.

No I'm not and NO THEY DON'T! The 85 GT had a curb weight of 2728 pounds. The Formula was 2775, nearly identical.

quote That is incorrect. The OVERALL FINAL DRIVE of the STOCK 1985 and the 1986 is 2.96. Using your math formula and knowing a 1986 V-6 STOCK SE or GT can top RPM's in 4th gear up to 5500rpm is proof right there.

NOT in 4th Gear it can't. 5500 RPM in 4th? NO WAY! 5000 RPMs tops.

quote I have looked at you math formula again, There is nothing in it that the rolling resistance can change. You do not include the weight of the vehicle nor do you include the hardness/softness of the tires. A harder compound of rubber will decrease rolling resistance. Rolling resistance is not the same between a GT, SE, or Formula. As for horsepower/torque, I have yet to see anything anywhere that says 140hp stops at 123.77mph. I do know of many cars with less or the same horsepower that have gone faster.

Are you arguing just cause you like too? This is really not that hard to understand Oreif.

OK...back to the see-saw. Horsepower is a constant (can we at least agree on THAT?) The force applied to one end of the see-saw is going to be constant. The fulcrum is the gearing and the weight on the other end is friction, wind resistance, and other opposing forces. If you move the fulcrum (change your gearing) you are ALSO chainging the weight on the other end of the see-saw because the faster you go, the harder it is to push through the air and to overcome your tire friction. Capice? THUS just changing your gearing will NOT make you go faster UNLESS your engine tranny combo is not optimized to begin with. And the fact is that the getrag is a very efficient tranny. There is VERY little room for speed gains through gearing or tire changes, 2 MPH...maybe 3. That's it. If you want to go faster you need more power. See? not hard.

quote You'd better look at the data I posted again, The 4th line down: 1985-1988 Isuzu 5-spd is 2.48 The 2.60 is ONLY the Getrag 5-spd.

you'ld better look again. That is exactly what I said. The 1988 "coupe" came with the Isuzu.

quote I am using the same math formula you are using. The "limited horsepower" you claim is pretty sad. The Fiero has 140hp and 170ft/lbs of torque in a 2.8L V-6.

You are just using it wrong. And what do you mean "sad". The horsepower of the car is the horsepower of the car! It's part of the math, a part you keep ignoring.

quote There are many cars out there that have the same weight of the vehicle (or heavier) with the less or the same horsepower/torque going faster than 124mph for a top speed. A 2002 BMW Mini weighs 2780lbs has a 5-spd 4-cyl with 114hp and 109ft/lbs of torque (this is NOT the "S") and a top speed of 125mph. So how does a car about the same weight with 36hp less and 61 ft/lbs of torque less go faster if the Fiero is limited by horsepower?

No there arn't. I do not know about the BMW. But assuming your numbers aren't made up BS again then it may have better aerodynamics or more efficent tires. I'll look it up.

quote A 1984 Fiero with 92hp and 135 ft/lbs of torque went 120mph,

No, it didn't! as per my previous post. It went 103.

quote So your trying to say 48hp more and 35 ft/lbs of torque only gains you 3mph????????? You are baselining the entire top end of ALL Fiero's on just one run of a 1988 Formula 10 years ago. You are the one who has no accurate data on any other version of a STOCK Fiero's.

Coming from someone who has NO DATA AT ALL that sounds very funny.

quote Originally posted by Toddster: Stop talking and start listening. Go get a book and look up the definition of horsepower. It is the measure of force required to lift 1 pound 1 foot in the air. Hence, By definition, the more weight you have, the more horsepower you need to move it.

I hate jumping into arguements (and in this one, I can't decide who's right ).. but this made me smack my head in disbelief.

First, horsepower is not a force. Horsepower is a measure of work. Specifically, a rate of work. One hp gives you the ability to lift 550 pounds one foot in the air in one second.

Secondly, while more weight will cause more rolling resistance, (and require more force to move it).. it does not require more power to move it. A fiero engine could move a battleship to 123mph if there were no friction (wind, and uhh... I guess rolling if it had wheels) and enough gears.

That is all. <leaves the room>

quote Originally posted by Toddster: Weight has no factor in top speed? Then why can't your Fiero engine drive a battleship up to 123 MPH Einstein? According to your logic all it needs is enough time to get up to that speed.

Who is the dummy....? Try to think before you speak before you sound like a complete retard.

A battleship has how much wind plus water resistance? EXACTLY!! If a battleship had the same drag coefficient as a fiero, yes eventually the mighty 140hp fiero engine would get it to 130mph. Has nothing to do with weight, dummy.

As for how you came up with hp... my god man.... I think you mixed up some torque with some hp. TORQUE is a measurement of force 1 foot from the center of the driveshaft. If a motor can exert 170lbs of force 1 foot from the driveshaft it makes 170lb/ft. Horsepower is a function of torque vs rpm. The higher the rpm sustained with the same amount of torque, the higher the horsepower. Horsepower is work. Go read a book.

ok EINSTEIN, make me a formula for top speed of a fiero that uses wheel hp and drag. This will give you a fiero top speed. It has nothing to do with drive ratios.... I don't care where the fat guy sits on your teetertoddster.....

And for the record, a fiero with a dyno of 120hp is actually around 140 at the flywheel. Stop saying the fiero does not make that hp number. Its a well known fact a fiero will dyno around 115-120hp at the wheels. This means with 15% driveline loss taken into account, the fiero makes 140 FLYWHEEL HORSEPOWER.

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Buy a fiero, become a mechanic

[This message has been edited by crzyone (edited 01-11-2005).]

Look, We all understand about the fulcrum. The problem isn't gearing or the fulcrum, The problem is you keep assuming that ALL Fiero's are exactly the same as your Formula. This is the variable you are not taking into account. Earlier Fiero's weigh LESS. Different brands of tires in STOCK sizes have LESS rolling resistance. Especially newer compounds.
Example:
1987 SE with V-6 5-spd. Even going by your weight, is minimum 50lbs less. Using new tires with less rolling resistance the car gets 200 rpm more because of the lower weight, better aero-dynamic nose, and less rolling resistance of the car. Going by your math formula we get: 128.72mph.
Just like before where you refuse to change the overall drive ratio for different transmissions, you are not taking into account reduced rolling resistance of newer compound tires and less weight of earlier Fiero's.
I had my first 1986 V-6 4-spd Fiero in 4th gear and the engine over 5000rpm, I know it was faster than 123.77mph
The car was timed at 126mph using a Police VASCAR set-up. That is more than you "2mph max" and that was with a higher overall drive ratio than the getrag.

Just looked up the weight of my 1986 SE in the 1986 Pontiac service manual.
Curb Weight: 2680 lbs (manual trans) 2728 (auto)
There is about a 50lbs difference between the auto and manual. So my guess is the 1988 Formula weight you posted is the manual trans but the weight of the GT is the auto trans as the 1986 SE is nearly identical to the 1985 GT.

123.77mph is not the top speed of ALL Fiero's, a 1986 V-6 4-spd Fiero was timed at 126mph in October of 1987. That alone dispells your 123.77mph limit.

[This message has been edited by Oreif (edited 01-11-2005).]

quote Originally posted by Toddster: I didn't forget the drive ratio. You forgot that horsepower is a constant. A change in gearing will increase the rolling resistance of the car and your engine will top out at a lower RPM than it did before.

when you change the drive ratio you change the RPM at which the engine is at at a given speed.. this also changes the HP at that given speed.. in the fiero with its lower powerband this can increase its top speed

[This message has been edited by Kohburn (edited 01-11-2005).]

I was going back thru this thread and watched YellowFiero's video. (BTW ~ Yellowfiero, Nice Vid! )

Now everyone look back and count how many times Toddster stated a V-6 getrag 5-spd Fiero cannot get more than 4300 RPM in 5th gear. Now go look at the video below and pause it at 0.53 and clearly read the tach.

Now go back and use Todd's math formula but change the 4300 rpm to 4700 rpm and you also need to change the 806.72 (stock tire revs) to 796.01 for Yellowfiero's 235/45R17 rear tires.

What? His tach MUST be off since Todd says this is a physical impossibility! A Fiero can't go 136.25mph! (note his tire size.)
The 2.8L can never push a getrag 5spd's 5th gear past 4300rpm right Todd? Maybe he photoshopped it? Yeah he edited his video to move the tach higher. Oh wait maybe it was the K&N air filter and oil filter that gave the car a 13 mile an hour gain. HMM maybe it's because of his larger diameter tires, But wait his horsepower didn't change and it takes more power to turn larger tires. Wait lets see if we change to stock tire size HMM.. If he had stock tires he would only be doing 134.44mph. That is still 11mph faster than Todd's Formula.

So Todd here you go Video Proof of a Fiero going over 13mph faster than your Formula. The tach reads 4700rpm that is 400rpm higher then your "claimed" limit. I can prove with dyno runs performed by Travis (1FST2M6) that a K&N air filter and an Ocelot Exhaust offer less than a 2hp gain so his "mods" have no effect. Also note this was in a GT. The CD of a Formula is .357 But a fastback GT has a HIGHER CD of .365 So it has more drag to overcome than a Formula bodied car. Oh and it can't be the tires because you said, "There is VERY little room for speed gains through gearing or tire changes, 2 MPH...maybe 3." which is only true for the tires.
So now what excuse do you have?

Download 17 MB AVI file

Edited to use the correct RPM of 4700.

[This message has been edited by Oreif (edited 01-11-2005).]

quote Originally posted by Toddster: Go get a book and look up the definition of horsepower. It is the measure of force required to lift 1 pound 1 foot in the air.

wrong,

You should take your own advice and read that book. One horsepower is approximately 30000 ft.lbs of work per minute, ie, it's a unit of "work", not simply force. All factors involved: time, weight, and distance.

Damn, I guess I learned something in physics class way back when

Dave

quote Originally posted by Oreif: I was going back thru this thread and watched YellowFiero's video. (BTW ~ Yellowfiero, Nice Vid! )

good call - i forgot about his video

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quote Originally posted by Toddster: Stop talking and start listening. Go get a book and look up the definition of horsepower. It is the measure of force required to lift 1 pound 1 foot in the air. Hence, By definition, the more weight you have, the more horsepower you need to move it.

Your book has a typo, then. Moving a 1 pound mass 1 foot in distance requires 1 lb-ft of TORQUE. It is not, I repeat, NOT, a measure of horsepower. By definition the more weight you have the more TORQUE you need to move it. If you want it moved faster, you need more horsepower.

Torque is the amount of work done.
Horsepower is how fast that amount gets done.

If it takes x horsepower to move a mass y distance in z seconds, it takes twice the horsepower to move the same mass the same distance in half the time.

You're making some incorrect assumptions, Todd, and even if your number crunching is accurate, you're putting in garbage numbers due to the bad assumptions.

quote Originally posted by Oreif: I was going back thru this thread and watched YellowFiero's video. (BTW ~ Yellowfiero, Nice Vid! )

That's Mr. Yellowstone to you

http://www.sjbaker.org/telamom/speed_math.html

Orief, I know what your saying about weight adds alittle bit of rolling resistance but it can be overcome by increasing tire pressure.

Ultimatly, top speed is drag limited. Toddsters formula does not even take grag into consideration, which is completely wrong.

quote Originally posted by Formula88: Looks like 4700 rpm to me.

Thanks for the snapshot of the video, I corrected the math above.

quote Originally posted by Toddster: And like I already said, a 60 MPH tail wind is good for a whooping 1 MPH! Come one guys. stop making silly assumptions and do some damned math or testing! I HAVE! 123.77...tops

the math is why we argue - that along with all the asumptions you make and variables you leave out

is that what you did the top speed run in? mismatched body panels, extreme camber and wide tires? (don't forget tire width can effect your CD as well as rolling resistance)

[This message has been edited by Kohburn (edited 01-11-2005).]