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Best trans for 4.9 swap by Dizzixx
Started on: 12-03-2007 01:23 PM
Replies: 61
Last post by: Fieroseverywhere on 06-08-2008 01:36 AM
Dizzixx
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Report this Post12-03-2007 01:23 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
So I just bought an 87GT and I intend for it to become my project car. I have decided I want to go the route of a 4.9 because I want torque with some HP as well. Also it is supposed to be simple and cheap all of which work for me. I would like to know which transmission is best to use and why, also where I might be able to get one (IE which cars to look for that have a specific final drive that arnt the fiero)

So far I have found that most people favor the Getrag. Is there a significant difference in drivability of the two , getrag vs isuzu, on a 4.9 swapped car. Also is there any reason to even consider the 4spd muncie?
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Report this Post12-03-2007 02:58 PM Click Here to See the Profile for J GunsettClick Here to visit J Gunsett's HomePageClick Here to Email J GunsettSend a Private Message to J GunsettDirect Link to This Post
I would say no to a 4spd muncie. I used one for about 2 years and you will be turning 2700 RPMs at about 70 MPH. If I had it all to do over again I would have keep the Caddy auto transmission hooked up on the 4.9. 5 speed is better than the 4 speed, and the 6 speed is the best of the manual transmissions.

Jack

------------------
If you can not run with the big dogs, stay on the porch!

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Dizzixx
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Report this Post12-03-2007 05:45 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
Does the automatic make tranction control easier? Are there issues using a Isuzu? If I understand correctly they are easier to come by. And I have been watching the thread on Cryoing things and I think I will probably invest in doing it , its inexspensive and I double it will cause an problems so in any case I would at least have piece of mind. Where does the 4.9 rev too and where is its powerband? What is the best final drive for it, and what about 1-2 gears arnt they too short in the 6 speed?
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Report this Post12-03-2007 06:21 PM Click Here to See the Profile for aaronrusClick Here to Email aaronrusSend a Private Message to aaronrusDirect Link to This Post
 
quote
Originally posted by Dizzixx:

Does the automatic make tranction control easier? Are there issues using a Isuzu? If I understand correctly they are easier to come by. And I have been watching the thread on Cryoing things and I think I will probably invest in doing it , its inexspensive and I double it will cause an problems so in any case I would at least have piece of mind. Where does the 4.9 rev too and where is its powerband? What is the best final drive for it, and what about 1-2 gears arnt they too short in the 6 speed?


stick with the 4t60e tranny, it is infinately better than any of the manual trannies, UNLESS you find an econo 4 speed and swap the gears into an '85 or later casing...
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Dizzixx
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Report this Post12-03-2007 07:22 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
What about using a 4T65E-HD? Is it compatable?
Is the torque converter on the 4T60E adjustable? Anyone have a working tapshift? What makes it better? If someone where to present some empiracal evidence rather than just opinion I would be more inclined to consider it as an option. What does the 4T60E come on? Does it reqiure a ECM flash or can you use the caddy or fiero ecm?

Can it even handle 300 ft pnds trq?
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Report this Post12-03-2007 08:04 PM Click Here to See the Profile for project34Send a Private Message to project34Direct Link to This Post
 
quote
Originally posted by Dizzixx:
Where does the 4.9 rev too and where is its powerband?

To help answer those questions, here are some dyno results posted on another thread ( http://www.fiero.nl/forum/Forum2/HTML/087941.html ) by FieroMaster88 for his 4.9L swap, which happens to use the intake manifold from an Allante:

 
quote
Originally posted by FieroMaster88:



Because the 4.9L is a torquey, but not particularly high-revving engine (as suggested by those dyno results), the 4.9L swap seems somewhat better suited for an automatic rather than a manual trans.

Hopefully others also have some 4.9L dyno results they'll post.
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Report this Post12-03-2007 08:52 PM Click Here to See the Profile for Fiero BrickSend a Private Message to Fiero BrickDirect Link to This Post
As much as I dislike automatic transmissions, I would use the 4t60 if I had a 4.9.

If you really want to use a manual transmission with the 4.9, I would track down an economy-geared 4 speed and swap its guts into the much stronger 85 or 86 4 speed case. I think the gearing with the economy final drive would be acceptable, if not as good as the 4t60's.
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Report this Post12-03-2007 09:24 PM Click Here to See the Profile for aaronrusClick Here to Email aaronrusSend a Private Message to aaronrusDirect Link to This Post
 
quote
Originally posted by Dizzixx:

What about using a 4T65E-HD? Is it compatable?
Is the torque converter on the 4T60E adjustable? Anyone have a working tapshift? What makes it better? If someone where to present some empiracal evidence rather than just opinion I would be more inclined to consider it as an option. What does the 4T60E come on? Does it reqiure a ECM flash or can you use the caddy or fiero ecm?

Can it even handle 300 ft pnds trq?


all caddies that come with the 4.9L come with the 4t60e tranny..its a heavy duty version of the tranny designed to take the extra TQ of the 4.9 engines

the caddy computer will not control the 4t65eHD tranny. you will spend alot of extra money getting the 4t65e to work with the caddy, and it is really unnecessary...

and yes, you CAN install a higher rpm stall on the 4t60e/4.9L setup, but i wouldnt, the one that it comes with is perfect for it and the caddy's powerband.

before you install the caddy engine, i would highly recommend getting the delta cam's drop-in hi-lift camshaft for the 4.9L, it really wakes up that motor..its liek $150 with a core exchange me thinks..

ohh,and when it comes time to program the caddy ecm for use in a fiero, i can mod yoru chip with many custom parameters for a very small fee. email me at stickpony@gmail.com for more details
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Dizzixx
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Report this Post12-04-2007 01:21 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
Given the fact that the 4T60e is allready bolted on the engine when I pull it at a yard, and the relatively minimal cost of rebuilding an auto, and from what I hear the ease of that job. You guys have me convinced. I suppose if I dont like it I would have time to hunt down an econo 4 spd. What is the econo final drive? How fast will the engine be turning over at 75-80? Can the muncie handle it even with the redesigned housing? Can the 4T60e use the standard automatic shifter in the fiero? The 87 I intend to use as the project car is an auto.
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Report this Post12-04-2007 01:34 PM Click Here to See the Profile for Arns85GTClick Here to Email Arns85GTSend a Private Message to Arns85GTDirect Link to This Post
The 4 speed 3.65 Muncie tranny is the strongest Fiero tranny and it has an excellent gear ratio for giddy-up-go. You would need a plenty strong clutch for spirited driving with the 4.9.

That said, I believe the 4T60 tranny is much better for the application. You have better overdrive and it handles the torque for day to day streetlight action a whole lot better.

Arn
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Report this Post12-04-2007 03:40 PM Click Here to See the Profile for v8fiero400Click Here to visit v8fiero400's HomePageClick Here to Email v8fiero400Send a Private Message to v8fiero400Direct Link to This Post
I have a 4.9 with the isusu 5 speed. It is lots of fun to drive and good on gas..... The only thing I don't like is first gear... As soon as you get going you have to shift to second. If the road is flat and I'm not in a hurry then I prefer to start out in 2nd which almost makes it a 4 speed!
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Dizzixx
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Report this Post12-04-2007 03:48 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
How is it on the freeway rev wise? Whats the final drive on the isuzu vs. the final drive of the econo 4 spd and the getrag?
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Fieroseverywhere
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Report this Post12-04-2007 03:54 PM Click Here to See the Profile for FieroseverywhereClick Here to Email FieroseverywhereSend a Private Message to FieroseverywhereDirect Link to This Post
Interesting Dyno results. I have not seen that one yet.

According to the chart that 4.9 put out 259 ftlbs of torque at 2100 RPM.

Pretty impressive for a motor you can get and install for next to nothing, relatively speaking. I am going with a isuzu also since it came from the same car as my 88 cradle. I have a muncie and another isuzu sitting in case it is needed also. I know the 4t60e is better suited to the 4.9 but I just can't drive an auto. Now the 6 speed sounds like the perfect tranny for me. Still waiting to hear some MPG estimates with a 4.9 though. I would guess low to mid 30's but who knows for sure. What you getting Jscott?
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Dizzixx
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Report this Post12-04-2007 04:29 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
 
quote
Originally posted by Fieroseverywhere:

Interesting Dyno results. I have not seen that one yet.

According to the chart that 4.9 put out 259 ftlbs of torque at 2100 RPM.



???

As far as tranny choice goes, it looks like you can relate to my dilema then. I am just trying to decide if it is worth hunting for a 4.9 with the 4T60e on it or hunt for a 4.9 and seperately hunt for a getrag or isuzu.

What benefits do the late model getrag and isuzus have (early-mid 90s) the ones with the internal slave cylinder or w/e are they strong, better ratios, better shifting ??? Basicly why bother updating rather then find an older one, especially when the new throwout bearing is freaking 120 a pop?
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Report this Post12-04-2007 07:13 PM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaDirect Link to This Post
IMO, the best trans choice for the 4.9L is the 4T60e transmisson that came with it. The gear ratios match the strong low end of the power band and provide the best gas mileage. Bear in mind that the 4.9L is a bottom end (not top end) power machine. You want to keep the revs below 4500 RPM to stay in the power zone and cruise on the highway at 2000 RPM and not 3000 RPM. If you use anything like 3:33 FDR gearing, you will have a strong 1/8 mile performer but poor highway mileage and 1/4 mile performance. The 4.9L has its limitations but in a Fiero you've got one quick stoplight to stoplight car, real strong for the street, but marginally competitive for the 1/4 mile. However, for the price it just can't be beat.

------------------
87GT - with 3800SC Series III engine, 4T65eHD
87GT - 3.4L Turbocharged engine, modified TH125H
" I'M ON THE LOOSE WITHOUT THE JUICE "

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Fieroseverywhere
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Report this Post12-04-2007 07:29 PM Click Here to See the Profile for FieroseverywhereClick Here to Email FieroseverywhereSend a Private Message to FieroseverywhereDirect Link to This Post
 
quote
Originally posted by Dizzixx:


???

As far as tranny choice goes, it looks like you can relate to my dilema then. I am just trying to decide if it is worth hunting for a 4.9 with the 4T60e on it or hunt for a 4.9 and seperately hunt for a getrag or isuzu.

What benefits do the late model getrag and isuzus have (early-mid 90s) the ones with the internal slave cylinder or w/e are they strong, better ratios, better shifting ??? Basicly why bother updating rather then find an older one, especially when the new throwout bearing is freaking 120 a pop?


When it comes down to it it really depends on your driving habits and preference. The 4.9 has been proved to work will all fiero trannies, the 6 speed, and the 4t60 & 4t60e. If you plan on racing it or just abusing it often then you might want to go with a stronger tranny to start with. If you are a calmer driver then an isuzu will probably be fine for your purpose. It will give you some go when you want but probably wont take constant abuse, even cryo'd. The getrag will take more but cost and availability come into play. I know little about the FWD getrag so I won't go there. The muncie is pretty common, easy to find, and plenty strong but your gas mileage will suffer. The auto trannies are the most common, strongest and are best suited to the RPM range of the motor but its not really about the motor its about how you drive it. What would be best suited to you? What tranny is in the car now? This could also be a determining factor as a change from manual to auto and vise versa is quite a bit more difficult.

The 6 speed is largely untested paired to the 4.9. You will get good gas mileage and supposedly it is stronger then the getrag. With less people running them you could run into problems that were unknown before. Should get great gas mileage and have good acceleration but cost is a factor. Until the axel situation is figured out it will remain the road less traveled. Also now with GM discontinuing it they will become less common. The one that I know of that is running with a 4.9 was done by Archie and we have yet to get some good feedback on how its working out and the gas mileage its getting.

[This message has been edited by Fieroseverywhere (edited 12-04-2007).]

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Will
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Report this Post12-04-2007 07:49 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillDirect Link to This Post
The Economy 4 speed has a 3.32 final an .72 top gear and 3.73ish first gear.
The V6 4 speed has a 3.65 final, .81 top gear and 3.35 first gear.
The best 4 speed would be a hybrid of the V6 case & 1st/2nd gear with the economy 3rd, 4th and final.

The Fiero Isuzu final drive is 3.35 with .72 top gear. I don't think any other GM applications of the Isuzu trans have the 3.35 final, however.
The Isuzu first gear is very short and 2nd gear has a tendency to shed its teeth when used with a powerful engine.

Getrag has 3.61 final.
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Report this Post12-04-2007 09:06 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Direct Link to This Post
I had the 4T60e...Hated It

Changed to the F40 Six Speed.



Fieroseverywhere - Too soon to know about gas mileage. The car is parked in Wisconsin for a few more weeks.

[This message has been edited by jscott1 (edited 12-04-2007).]

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Dizzixx
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Report this Post12-04-2007 09:10 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
Well I will abuse it more than I should so that probably eliminates the Isuzu unless I find one dirt cheap allready pulled out of a car or something. The 4T60e is still up there but I really think I would simply be happier with a standard trans. So that leaves the Munci 4 spd econo and the Getrag 5 in the running.

What is reqiured to do a manual swap? Install clutch pedal, master cylinder, clutch lines, slave cylinder, trans, shifter assembly, shift and select cables. Am I forgeting anything?

Could somone explain how these gear ratio numbers work. It would seem for fuel economy you want a smaller number. That is pretty much the extent of my knowledge I thought it was a ratio of the number of times the engine turns to the number of times the axle turns but whats with the extra number 3.32 and .72, 3.65 and .81?
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Report this Post12-04-2007 10:38 PM Click Here to See the Profile for FieroseverywhereClick Here to Email FieroseverywhereSend a Private Message to FieroseverywhereDirect Link to This Post
 
quote
Originally posted by jscott1:

I had the 4T60e...Hated It

Changed to the F40 Six Speed.

Fieroseverywhere - Too soon to know about gas mileage. The car is parked in Wisconsin for a few more weeks.



I understand. No flaming intended. Projects like this take time to get everything tested throughly. I am just waiting to hear the results before I make a final decision on whether to go with a 6 speed or stick with a 5. Until the....

 
quote
Originally posted by Dizzixx:

Well I will abuse it more than I should so that probably eliminates the Isuzu unless I find one dirt cheap allready pulled out of a car or something. The 4T60e is still up there but I really think I would simply be happier with a standard trans. So that leaves the Munci 4 spd econo and the Getrag 5 in the running.

What is reqiured to do a manual swap? Install clutch pedal, master cylinder, clutch lines, slave cylinder, trans, shifter assembly, shift and select cables. Am I forgeting anything?

Could somone explain how these gear ratio numbers work. It would seem for fuel economy you want a smaller number. That is pretty much the extent of my knowledge I thought it was a ratio of the number of times the engine turns to the number of times the axle turns but whats with the extra number 3.32 and .72, 3.65 and .81?


If you are going to beat on it I would avoid the isuzu. Though they are cheap and easy to find you will probably end up paying more in the long run throught replacement costs.

I think you pretty much covered everything for the auto to manual swap with the exception of the shift surround. You will also need to buy or modify a flywheel to work with the 4.9 as a manual since they were never equipped from the factory. This can bring quite a bit more cost then just doing the 4t60e. If you have a tight budget then this may not be much of an option. The cost of that change can add up fast with the required parts. The car can always be switched at a later date.

I'm probably not the best person to explain the gear ratios. I'm more of an engine, suspension, and brakes type of guy myself. Maybe Will can chime in with his infinate knowledge.
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Report this Post12-04-2007 11:08 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Direct Link to This Post
 
quote
Originally posted by Fieroseverywhere:


I think you pretty much covered everything for the auto to manual swap with the exception of the shift surround. You will also need to buy or modify a flywheel to work with the 4.9 as a manual since they were never equipped from the factory. This can bring quite a bit more cost then just doing the 4t60e. If you have a tight budget then this may not be much of an option. The cost of that change can add up fast with the required parts. The car can always be switched at a later date.



If you are on a tight budget then swapping to a manual is not going to be the best way. And the 6 Speed is definitely not for the cost conscious. There are many G6 specific parts you need. If you have the time to scout out parts, maybe not too bad, but new those parts are pricey. The flywheel turned out to be the least of my concerns.

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Report this Post12-04-2007 11:25 PM Click Here to See the Profile for FieroseverywhereClick Here to Email FieroseverywhereSend a Private Message to FieroseverywhereDirect Link to This Post
 
quote
Originally posted by jscott1:

The flywheel turned out to be the least of my concerns.


That doesn't suprise me one bit.

I can't even imagine the cost associated with going from an auto to a 6 speed manual. I would figure somewhere close to what WCF charges for their NSX 6 speed swap. Don't know what it cost you but luckily my car is already a manual so the cost wouldn't be as much for me.
Still that is what makes your car unique and that is worth the price. Gas mileage savings should pay for the swap in a few years also.

[This message has been edited by Fieroseverywhere (edited 12-04-2007).]

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Dizzixx
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Report this Post12-04-2007 11:52 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
Well I actually allready have everything but the swap motor and tranny itself, and of course its components, but the ones I listed I have.

I have an 85 donor car that I pulled the tranny from to get my 84 working again but I still have its , clutch pedal, clutch lines, shifter assem, shifter surround (assuming you mean the interior bits?), clucth master cyl, and a slave can be purchased cheap (used the original to go with the swapped tranny) and then I need to get cables which are exspensive unless you can find them used. But I am not too worried about cost, if it comes down to being 200-400 more but I am %100 happier I can live with that.
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Report this Post12-05-2007 12:41 AM Click Here to See the Profile for befarrerClick Here to Email befarrerSend a Private Message to befarrerDirect Link to This Post
If you go with a 5-speed, you will be best to go with a 5-speed shifter, which was never installed on an 84 Fiero. You would also need a clutch, and the mentioned flywheel mod, those 2 together will probably get close to the $400 mark, you would also need both axles. The clutch line is a pain to install from what I have heard, there is also some wiring changes for the reverse light, and neutral/clutch switch. Getrac parts are the hardest to find, as far as cables and clutch slave is concerned.
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Capt Fiero
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Report this Post12-05-2007 01:20 AM Click Here to See the Profile for Capt FieroClick Here to visit Capt Fiero's HomePageClick Here to Email Capt FieroSend a Private Message to Capt FieroDirect Link to This Post
Not sure if we can post jpe images, but will see if this works.

If you want a quick and dirty run down on ratio's, http://captfiero.com/transratios.htm its kinda an idiots guide to gears on the Fiero manual trans. My 85GT was an Auto and I converted it to a 4spd, then later converted it to an Isuzu 5spd and have blown 4, 5spd tranaxles and 2 clutches on my 4.9. Its currently sitting in my garage awaiting yet another 5spd to be installed. At this point it would have been cheaper for me to just install a 6spd to start out with. I would never dream of installing a 3.65 4spd in the car, it would hate long freeway drives. With the Isuzu I have driven in it from Vancouver BC Canada down through Oregon and back several times, and pulled off 30mpg out of it. So the taller the gears the better with the 4.9.



------------------
85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

[This message has been edited by Capt Fiero (edited 12-05-2007).]

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Report this Post12-05-2007 02:24 AM Click Here to See the Profile for FierOmarClick Here to Email FierOmarSend a Private Message to FierOmarDirect Link to This Post
Since your 87 GT already has an auto trans, I would stick with the 4T60e that comes with the 4.9. And so you know, the Cadillac gearing was matched to a 205-70-15 tire which is 26.3" diameter. Using a smaller diameter tire will have the effect of lowering the gear ratio. But, you don't have to stay with the same size tire. For example, Hankook's H105 is available in a 235-50-17 which is also 26.3" diameter (I would match with 215-50-17 in front). A stock Cadillac could move pretty well with its gearing matched to the tire diameter, and yet, Cadillac claimed 16 City and 25 highway MPG. The only difference would be that your car would weigh about 800-900 lbs less. You would have less money invested in the project, leaving you enough to do a Lebaron brake swap that would leave you with very capable performance.

FWIW, if using a 26" diameter tire, the 3.65 Muncie 4 speed would be turning 2500 rpm at 65 mph, and 3000 rpm at 78 mph. The econo 4 speed would be turning 2000 rpm at 65 mph, and 2500 rpm at 80 mph. The Isuzu in 5th gear would be about 1 mph less than the econo trans.

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FierOmar

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Report this Post12-05-2007 04:25 AM Click Here to See the Profile for aaronrusClick Here to Email aaronrusSend a Private Message to aaronrusDirect Link to This Post
 
quote
Originally posted by Will:

.


RPO MY8 MT2 MG2 M19 M17
Fin 3.32 3.35 3.61 4.10 3.65
1st 3.53 3.73 3.50 3.53 3.31
2nd 1.95 2.04 2.05 1.95 1.95
3rd 1.24 1.45 1.38 1.24 1.24
4th 0.73 1.03 0.94 0.81 0.81
5th x.xx 0.74 0.72 x.xx x.xx
Rev 3.42 3.50 3.41 3.42 3.42

[This message has been edited by aaronrus (edited 12-05-2007).]

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BJR
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Report this Post12-05-2007 09:14 AM Click Here to See the Profile for BJRClick Here to Email BJRSend a Private Message to BJRDirect Link to This Post
How can you tell a 1984 economy trans with the hiway gears in it, from the other 4 speed used in 84? Is there some numbers on the case or some other identifying thing to look for?
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FierOmar
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Report this Post12-05-2007 10:20 AM Click Here to See the Profile for FierOmarClick Here to Email FierOmarSend a Private Message to FierOmarDirect Link to This Post
 
quote
Originally posted by Capt Fiero:

Not sure if we can post jpe images, but will see if this works.

If you want a quick and dirty run down on ratio's, http://captfiero.com/transratios.htm its kinda an idiots guide to gears on the Fiero manual trans. My 85GT was an Auto and I converted it to a 4spd, then later converted it to an Isuzu 5spd and have blown 4, 5spd tranaxles and 2 clutches on my 4.9. Its currently sitting in my garage awaiting yet another 5spd to be installed. At this point it would have been cheaper for me to just install a 6spd to start out with. I would never dream of installing a 3.65 4spd in the car, it would hate long freeway drives. With the Isuzu I have driven in it from Vancouver BC Canada down through Oregon and back several times, and pulled off 30mpg out of it. So the taller the gears the better with the 4.9.




Nice chart, but you may want to add a few:

Hybrid: econo (MY8) final drive (3.32) in M17:
3.31 1.95 1.24 0.81 (gear ratio)
10.99 6.47 4.12 2.69 (overall)

Quad 4 Getrag w/ 3.61 FD:
3.50 2.19 1.38 1.03 0.81 (gear ratio)
12.64 7.91 4.98 3.72 2.93 (overall)

F40 6 speed w/3.55 FD:
3.77 2.04 1.32 0.95 0.76 0.62 (gear ratio)
13.38 7.24 4.68 3.37 2.70 2.20 (overall)

/ / /

I think it was Doug Chase that posted this a few years ago:

mph @ 6000 rpm, using 825 rev/mile tires:
MY8 36 66 103 176
M19 29 53 84 128
M17 35 60 94 144
MG2 34 57 85 125 163
MT2 34 62 87 123 171

Note: 215-60-15 (stock V6 Fiero rear tire) turns approx 825 rev/mile

You can make your own chart for any tire size. But for now, using the above chart with the same tire, the 3000 rpm speeds would be exactly 1/2 of those listed above; the 2000 rpm speeds would be 1/3 of those listed above, etc.


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[This message has been edited by FierOmar (edited 12-05-2007).]

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FierOmar
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Report this Post12-05-2007 11:06 AM Click Here to See the Profile for FierOmarClick Here to Email FierOmarSend a Private Message to FierOmarDirect Link to This Post
And here is a good source for information on the automatic transmissions offered by GM. http://www.gmtuners.com/gmtransinfo.htm

The 4.9 came with 3 different overall FD ratios: 2.73, 2.97 and 3.33. Thus, multiplying by the 4th gear ratio (0.705), the overall final drive ratios would be 1.92, 2.09 and 2.34 respectively. The highest gear in the 6 speed has an overall ratio of 2.20.

IMHO, the biggest problem with the 4T60e is the extra weight.

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Dizzixx
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Report this Post12-05-2007 11:42 AM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
 
quote
Originally posted by befarrer:

If you go with a 5-speed, you will be best to go with a 5-speed shifter, which was never installed on an 84 Fiero. You would also need a clutch, and the mentioned flywheel mod, those 2 together will probably get close to the $400 mark, you would also need both axles. The clutch line is a pain to install from what I have heard, there is also some wiring changes for the reverse light, and neutral/clutch switch. Getrac parts are the hardest to find, as far as cables and clutch slave is concerned.


The 85 is the donor car, allthough I used the shifter assem in the 84, it still has the other components. Including the axles.

How much more does the auto weigh compaired to the manual? What is the redline on the 4.9? And why are getrags so hard to find/exspensive?

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Report this Post12-05-2007 12:49 PM Click Here to See the Profile for Mickey_MooseClick Here to visit Mickey_Moose's HomePageClick Here to Email Mickey_MooseSend a Private Message to Mickey_MooseDirect Link to This Post
 
quote
Originally posted by Dizzixx:
What is reqiured to do a manual swap? Install clutch pedal, master cylinder, clutch lines, slave cylinder, trans, shifter assembly, shift and select cables. Am I forgeting anything?


...to complete the swap you will also need the steering column and associated wiring - clutch, axles and flywheel.

Been driving my Izusu 4.9 daily for 3 years now with no transmission problems. The tranny was disassembled and checked over before it was used to verify that is was good to begin with.

The 4 speed has a better 1st gear than either of the 5 speeds with the 4.9.

The best transmission to use would be the one that was built for it - with anything else, are are making due with it and putting up with it's issues.

I would not be too worried about the final drive ratio if you plan on beating on the car - it does not matter if it runs at 1500 rpm at 70 mph, the basic fact is if you are going to beat on it, it WILL suck the fuel tank dry in a hurray reguardless of the final drive. I can go anywhere from 450km per tank down to 160 km per tank depending on how it gets driven (usually I am in the 250km/tank range).

 
quote
Originally posted by Dizzixx:
What is the redline on the 4.9? And why are getrags so hard to find/exspensive?



I believe the factory redline of the 4.9 is something like 5200 (or 5400) rpm - but it runs out of poop way before then (as shown inthe above dyno chart) and yes it is a noticable drop off.

Fiero Getrags are hard to find becuase they are rare - basically only 2 model years had them. If you want the Getrag, you would be better to go with one of the FWD ones and either use Rodney's conversion kit, or build your own.

[This message has been edited by Mickey_Moose (edited 12-05-2007).]

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Report this Post12-05-2007 12:53 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
I suppose what you say about fuel efficiancy is true. Why do you need to swap out the steering column? I understand there are differences, like the finger release and what not, but is it really essential to get it to work? I mean I have those parts as well, but that does make a difference as far as time goes.
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Report this Post12-05-2007 01:03 PM Click Here to See the Profile for Mickey_MooseClick Here to visit Mickey_Moose's HomePageClick Here to Email Mickey_MooseSend a Private Message to Mickey_MooseDirect Link to This Post
 
quote
Originally posted by Dizzixx:
I suppose what you say about fuel efficiancy is true. Why do you need to swap out the steering column? I understand there are differences, like the finger release and what not, but is it really essential to get it to work? I mean I have those parts as well, but that does make a difference as far as time goes.


It really only takes 10-15 minutes to swap the column (4 bolts holding the column up, one on the shaft and the couple of plugs) - there is a switch on the column that is different between the 2 so that car can not be started in any gear except park and neutral on an auto car, and when the clutch is not pressed on a standard car. If you have to have the car inspected, this may be on the list of the things they test. I think there was something else, but I don't recall it at the moment.

If you are worried about the amount of time spent on a column swap, then you are in for a surprise when it comes to doing the 4.9 wiring (unless you buy a premade harness) and building all the little brackets and such since no one sells a complete install kit anymore.

[This message has been edited by Mickey_Moose (edited 12-05-2007).]

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Report this Post12-05-2007 01:06 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Direct Link to This Post
You don't need to swap the steering column. That little lever is the only difference and that lever is useless in my opinion.

The theory is that if you need to shut the engine off while the car is in motion the lever prevents you from locking the steering wheel. The problem is your fingers get so used to flipping the lever if you ever need that capability it won't be there. I was pulling my Indy into the garage and I shut the engine off quickly(overheating) and I inadvertently locked the steering wheel.
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Report this Post12-05-2007 01:10 PM Click Here to See the Profile for jscott1Send a Private Message to jscott1Direct Link to This Post

jscott1

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I don't think the park/ neutral switch is on the column...I thought it was on the tranny.
?
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Report this Post12-05-2007 01:10 PM Click Here to See the Profile for DizzixxClick Here to Email DizzixxSend a Private Message to DizzixxDirect Link to This Post
The brackets I am not worried about but the wiring I was considering inviting somone in the local club to do at cost or something, or calling the fiero factory and asking if they would sell a wiring harness setup for whichever ECU I wanted to use. I understand it would cost more, but I dont want to be plauged with electrical problems becuase I didnt know what I was doing, not that I am unfamillar with a soldering iron just think sometimes its better to leave certain things to the professionals.

Maybe thats the difference, the auto uses the shifter to tell when it is in park and its wired to the column and the manual uses the tranny??seems like a strange way to do things but you never know

[This message has been edited by Dizzixx (edited 12-05-2007).]

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Mickey_Moose
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Report this Post12-05-2007 01:13 PM Click Here to See the Profile for Mickey_MooseClick Here to visit Mickey_Moose's HomePageClick Here to Email Mickey_MooseSend a Private Message to Mickey_MooseDirect Link to This Post
 
quote
Originally posted by jscott1:
I don't think the park/ neutral switch is on the column...I thought it was on the tranny.
?


Maybe so, I am just going by what someone else told me...I am sure it was meantioned there was a difference in the switch on the column

Maybe I should have said, yes the auto column would work, but if you wanted to be complete, then change the column.

[This message has been edited by Mickey_Moose (edited 12-05-2007).]

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Will
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Report this Post12-05-2007 03:33 PM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillDirect Link to This Post
 
quote
Originally posted by jscott1:

You don't need to swap the steering column. That little lever is the only difference and that lever is useless in my opinion.


There is a cable from the automatic shifter that operates a mechanical interlock on the auto trans steering column. This prevents the key from being removed (or the wheel locked) with the car in gear.

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Report this Post12-05-2007 08:35 PM Click Here to See the Profile for FieroseverywhereClick Here to Email FieroseverywhereSend a Private Message to FieroseverywhereDirect Link to This Post
One bonus to the caddy ECM is the ability to program the tire size in. This can allow you to fine tune your ratio a little for gas mileage or performance purposes. A nice little feature IMO.

I, personally, am going with a 215/60-16 front and 235/60-16 rear. They are a very common tire size that is available in about 12-15 different makes including some studdless snow tires. I know some of you will say they will look like truck tires, here is my rebutal..

The pontiac in the background is running 225-60-16's. The picture was taken for the bike, of course.

I think they will fill the wheel well better, give me better gas mileage, and a slightly higher top speed and the expence of some tranny killing low end torque. Point is with the caddy ECM you are not limited to the same outer diameter as your original fiero tires. Freedom to choose your size and aspect ratio is a good thing. Just watch how big they get, you dont want to have to put a lift kit on your fiero to run bigger tires. I'm glad I get to keep my 60 series tires, I like the ride they give. I am also compensating for the added weight by using light weight wheels (~12.5lbs). Unsprung weight will be about 2 lbs less per wheel total over the stock 215/60-14, even with the brake upgrade and other mods.

[This message has been edited by Fieroseverywhere (edited 12-05-2007).]

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