This is the set up I want to run. It's awesome torque on the low end while the turbo's spool up and then when the superchargers max out the turbo's have hit full spool and take over. I've been doing some trolling but have yet to find someone else with a similar system. If I do it will it be a one-of-a-kind?
This is the set up I want to run. It's awesome torque on the low end while the turbo's spool up and then when the superchargers max out the turbo's have hit full spool and take over. I've been doing some trolling but have yet to find someone else with a similar system. If I do it will it be a one-of-a-kind?
A nice setup in fantasy, but entirely impractical. The supercharger is belt driven and therefore parasitic in nature to top end engine power. There is not way to "disengage" it's parasitic effect on the engine due to the belt driven nature of it.
A twin turbo setup is nice, but space becomes an issue without removing the trunk.
A far better solution would be to use a single large turbo with a controlled nitrous burst to spool the turbo up off the line allowing the exhaust to catch up.
In the mid to late '80s someone already did a twin turbo, supercharger combo. NOT for a fiero per se, but I'm pretty sure this set-up was used in a red chevy euro sport. (It also had Michigan plates.)
Hotrod, carcraft, and popular hotrodding all featured it at some time or another.
(If you want to hear about something UNIQUE, One dude built a 55, or 57 chevy belair with .......7 TURBOS in it!) FREAKY.
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01:51 AM
eph_kay Member
Posts: 943 From: Independence, MO Registered: Apr 2006
Sorry to get technical, but the 57 belair had 8 turbos, 1 per cylinder, still crazy.
And currently Hennessey runs a twin turbo and supercharged set up on the ford GTs, when I asked they claimed that the car make more power that way than with a custom intake, both setups were rated at 1000hp, so I would guess it was cheaper to just keep the supercharger, aka more profit....
Also, twin supercharger setups have been done, but usually on huge motors that need that many superchargers to flow the air they need.
I am not sure if it is a good or bad thing, but the 3800 doesn't need that much air to make more power than is practical in a fiero, and by the time a perfect twin supercharger setup or even a twinscrew supercharger set up "maxed out" so will the 3800.
Mostly just my opinion, I say get a 3800 in you car, drive it, then do a top swap or turbo it, and then see if you need more from there.
Well no such thing as a stupid question. Just stupid answers. Thank you to those that actually took the time to answer my question with a decent answer. It is appreciated. The 3800 isn't going to be stock either. I plan to bore it out, have over-sized pistons, racing camshaft, better built heads and so forth. My aim is 800 HP. My first plans were for a single twin screw supercharger and 2 turbo's (1 to each manifold). T25 Turbo's. They're rated to 27 PSI and claim to make up to 600 HP. I have my doubts about them. I think they may be too small. Can anyone recommend a larger turbo? Any thoughts on the T76 Turbo's? They're a real bargain on Ebay. Pretty much $1 per HP 494.54 plus shipping
Well no such thing as a stupid question. Just stupid answers. Thank you to those that actually took the time to answer my question with a decent answer. It is appreciated. The 3800 isn't going to be stock either. I plan to bore it out, have over-sized pistons, racing camshaft, better built heads and so forth. My aim is 800 HP. My first plans were for a single twin screw supercharger and 2 turbo's (1 to each manifold). T25 Turbo's. They're rated to 27 PSI and claim to make up to 600 HP. I have my doubts about them. I think they may be too small. Can anyone recommend a larger turbo? Any thoughts on the T76 Turbo's? They're a real bargain on Ebay. Pretty much $1 per HP 494.54 plus shipping
From this post I can tell that you have A LOT of research ahead of you and I wouldn't buy anything until you no longer have any questions.
No need to **** up the bottom end. A cam, heads and a single 76mm turbo will get you there, no problem.
Rated PSI does not determine the turbo's power potential. Hell, mine is rated at 70psi
quote
It's awesome torque on the low end
Turbo's provide more low end torque than a supercharger, period.
At the point of compression he's considering he's going to need a custom dart racing block, all drop forged and cryo treated internals with oil channels custom fabricated in; complete custom heads, an intake and exhaust system that won't fit in a fiero without removing the trunk lid (4 inch pipe being required for that ridiculous amount of airflow,) water/methanol injection before each turbo outlet, a full blower, a completelly new suspension, full slicks, a wheelie bar, another 1000 pounds of weight, a stretched frame to change the center of gravity, a custom body to fit the new frame, a second mortgage on the house, and fierox will still beat him in the 1/4.
More does not equal better. Peak of efficiency equals better.
[This message has been edited by jasonfox (edited 12-20-2010).]
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05:28 AM
rcp builders Member
Posts: 736 From: north port, Fl. Registered: Apr 2007
In theory it sounds good but actually done you will realize it's a waste of money. You may be unique but power wise you can get the exact results from a single turbo setup. A friend on another forum twin charged a sunfire gt with a 2.4. It sure looked pretty but he dumped 4k into both setups and misc. Things for the motor, and yet the car is a "one of a kind" its still slower than many other j bodies with a single turbo setup. So its up to you its YOUR money. Not mine.
Please read this a a positive, contributory response.
A little math at the outset will help you plan your path.
A naturally aspirated 3800 makes roughly 200 HP at atmospheric pressure. 800 / 200 = 4, so you will need 4 ATM of pressure, 3 above atmospheric, 14.7 X 3 = 44.1 PSI to the intake valves.
The next problem, and my greatest disappointment, is airflow. You would need to flow a HUGE amount of air. I do not know of an existing head for the 3800, not even the ZZP aluminum head, that will flow enough air. Even with maximum porting I don't think that the valve arrangement will permit the airflow needed to support 800 HP.
If you can find heads that will support the flow, 800 HP could happen.
------------------ Steve AT 88GTP DOT com 88 GT\3800 SC\L67\L26\4T65E-HD NIC Cam\Comp Cam Hi-Tech 1.8 rockers\Rhoads XL Lifters eBay Headers\Magnaflow Camaro muffler, 3.4 pulley DH Tune
Wanna go faster?
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09:28 AM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
Maximum crank horsepower on stock heads is probably around the 700 mark.. I am close, if not there already... others have been a bit beyond 700 crank with the same SINGLE SMALL turbo I have. reference my car: http://www.youtube.com/watch?v=tW6fxDyyn0M
quote
A naturally aspirated 3800 makes roughly 200 HP at atmospheric pressure. 800 / 200 = 4, so you will need 4 ATM of pressure, 3 above atmospheric, 14.7 X 3 = 44.1 PSI to the intake valves.
While completely correct, I would like to add a bit more "apples to apples" on this, as a "n/a 3800" is not particularly directly compared with a turbo motor. First off, a simple cam and exhaust package, as well as some tricky tuning, will push a n/a 3800 into the 250 crank HP department at peak flow. Many things were done to the 3800 to more or less limit peak power, and flatten the curve significantly to provide as much grandpa hauling power at 2500rpms as possible. A few changes to the intake geometry, a clean intake setup, and a flat fuel curve, will provide some good power, and make the "pressure above ATM" equation a bit more realistic, as it has been proven that a heavily modified 3800 (with a stock lower rotating assembly) makes 950-1000HP at 26psi with a ~T76 turbo. 250hp+14PSI = 500hp. 250+28psi = 750hp. I am making that 750hp on 22-23psi due to the ability to take advantage of very cool and dense intake charge air, and a massive amount of octane increase letting me run a serious amount of ignition timing as well. You will probably find that most results have been similar to the "math" when you are strictly running 93 octane fuel.
Aftermarket (iron and alum) heads have been pushed past the 800 mark, on stock lower ends.
These threads have always confused me in terms of "having more low end power"..... I mean, I make probably 575-600whp, and its enough power that slicks will not hold anything in a situation where I would need MORE low end power...I mean i am making PEAK power shortly after 4000rpms, although I do have a slightly tighter low rpm cam... Its way more than enough, and I wouldnt think any situation of cam, turbo, etc, is going to give me "not enough" low end power. If you are going to try to bring "turbo lag" into this thread... there are about a billion easy ways to fix that issue, that does not involve 2 superchargers.
Some debunking of horrible information in this thread includes:
quote
There is not way to "disengage" it's parasitic effect on the engine due to the belt driven nature of it.
False, if the pressure on the top and bottom of the supercharger is the same, you are basically only using power to spin the blades in a neutral environment, probably a 2-3HP loss, maybe less. Considering this, wither you have 1 or 2 superchargers, neither is going to significantly change your drive-ability, as a 800HP turbo is going to spool VERY fast under any amount of load. If you were considering running a larger than 10.5 slick all the time, and had a whole truckload of confidence in your transmission... I suppose there would be a mild use for a blower helping things, but I have a feeling 1 blower would be just as good as 2.
quote
Any thoughts on the T76 Turbo's?
A true T76 turbo is good for 1000HP, most likely more if it is a up to date wheel design. I believe I found what you consider a T76 on ebay, and it appears to be the real deal GT4202 clone... which is good for at least 1000hp on its own.
[This message has been edited by darkhorizon (edited 12-20-2010).]
All im going to say is it is possible, ZZP made a twincharged kit for the gtp's it is not that hard to do.If you really wanted a "twin turbo" you probably could make something work... but the supercharger will give you the instant low end torque you are wanting at low rpm.And if you use the boost bypas like the stock 3800 uses you can reduce the drag on the motor for when the turbo spools.But that will require a custom tune for the bypass system, but zzp can do it or would probably let you know how.
And you can get 800hp look at the grand nationals.... or go to google and look for TTGT that zzp had it ran a 8sec pass, but you need a lot of $$$$$$$
Originally posted by darkhorizon: False, if the pressure on the top and bottom of the supercharger is the same, you are basically only using power to spin the blades in a neutral environment, probably a 2-3HP loss, maybe less. Considering this, wither you have 1 or 2 superchargers, neither is going to significantly change your drive-ability, as a 800HP turbo is going to spool VERY fast under any amount of load. If you were considering running a larger than 10.5 slick all the time, and had a whole truckload of confidence in your transmission... I suppose there would be a mild use for a blower helping things, but I have a feeling 1 blower would be just as good as 2.
The rotation of the impellers is tied directly to the rotation of the pulley on the supercharger, no? If I am incorrect forgive me. Being, to the best of my knowledge, that the rotation of the impeller is fixed with the rotation of the pulley that is driven by your vehicle, the increase of airflow beyond the rate of the impellers due to the spooling of the turbos after reaching peak exhaust flow would create violent turbulence, possibly enough to destroy the supercharger impeller resulting in major damage.
If my understanding of this is incorrect, my apologies. I definitely tip my hat to you at your impressive knowledge of modifying a 3800.
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12:27 PM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
The trick with POSITIVE DISPLACEMENT blowers, is the fact that they move air, regardless of pressure. If you equalize the pressure above and below the blower (via a "smart" bypass system) then you are going to effectively turn the blower into a ram, more so than a blower. It takes very little to turn a blower in a zero pressure displacement enviornment, it would perform like it was in a vacuum, if you want to visualize it that way.
The trick with POSITIVE DISPLACEMENT blowers, is the fact that they move air, regardless of pressure. If you equalize the pressure above and below the blower (via a "smart" bypass system) then you are going to effectively turn the blower into a ram, more so than a blower. It takes very little to turn a blower in a zero pressure displacement enviornment, it would perform like it was in a vacuum, if you want to visualize it that way.
The trick with POSITIVE DISPLACEMENT blowers, is the fact that they move air, regardless of pressure. If you equalize the pressure above and below the blower (via a "smart" bypass system) then you are going to effectively turn the blower into a ram, more so than a blower. It takes very little to turn a blower in a zero pressure displacement enviornment, it would perform like it was in a vacuum, if you want to visualize it that way.
Great knowledge, thanks! Something useful came from this thread.
I looked into doing a dual supercharger, and as Dark says earlier, it doesn't give you much advantage. Here's my math from another thread:
Well, I did do some math and have arrived at the sad conclusion that superchargers are criminally inefficient. It does make sense to run two chargers in parallel, rather than one at the same level.
Here's the stock guess: To make 260 HP, you need to intake about 722 m^3/hr, resulting in 6.7 PSIG (1.42 PR) of boost. This is in the 60% efficiency range of the Gen5 M90.
With one charger: To make 350 HP, you need to intake 970 m^3/hr (or 34% more air than stock, which is about a 2.8" pully, I think) at 13.5 PSIG (1.91 PR), and is in the 54% efficiency range.
The advantage of going with twin chargers: Intake is reduced by 1/2 for each charger, with the PR staying the same. The intake volume is now at 485 m^3/hr, and the efficiency is in the 56% efficiency range. Two superchargers for 2% more efficiency? *Le sigh*
I'm not convinced that sequential would be much better either.
What isn't shown is any higher PR above 2.0. This is where you could really make some power. If, suppose we could run a 2.2 PR (18 PSI), we could make 410 HP and some crazy torque way low in the RPMs. This would definately require intercooling as it would appear to be in the 56-54% eff. range.
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11:28 PM
Dec 21st, 2010
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
The one project I want to see and I would deem really effective would be a sequential supercharged CSC blower system, using something like a D1SC or the like. For those that do not know the characteristics of a CSC... It is basically like a belt driven turbo, which means it HAS to lag based on RPM. The more RPMS you make, the more you compound the airflow, so it results in a very peaky airflow curve vs rpm, leaving very little airflow at low rpms.
During a day to day operation, the M90 blower will do a surprising amount of work before the sluggish CSC comes on (assuming is pulley'd for peak efficiency). You would get a flat ~300hp before the CSC came into its own around per say 4500rpms, and give you 400+ from 4500rpms onward. Apples to apples the CSC system would probably be harder to make big big power with, but it would for sure be "unique" and "engineering-ly effective".
Only side effect would be some insane exhaust requirements.. So it would be prohibitively difficult to make something quiet.
I looked into doing a dual supercharger, and as Dark says earlier, it doesn't give you much advantage. Here's my math from another thread:
Well, I did do some math and have arrived at the sad conclusion that superchargers are criminally inefficient. It does make sense to run two chargers in parallel, rather than one at the same level.
Here's the stock guess: To make 260 HP, you need to intake about 722 m^3/hr, resulting in 6.7 PSIG (1.42 PR) of boost. This is in the 60% efficiency range of the Gen5 M90.
With one charger: To make 350 HP, you need to intake 970 m^3/hr (or 34% more air than stock, which is about a 2.8" pully, I think) at 13.5 PSIG (1.91 PR), and is in the 54% efficiency range.
The advantage of going with twin chargers: Intake is reduced by 1/2 for each charger, with the PR staying the same. The intake volume is now at 485 m^3/hr, and the efficiency is in the 56% efficiency range. Two superchargers for 2% more efficiency? *Le sigh*
I'm not convinced that sequential would be much better either.
What isn't shown is any higher PR above 2.0. This is where you could really make some power. If, suppose we could run a 2.2 PR (18 PSI), we could make 410 HP and some crazy torque way low in the RPMs. This would definately require intercooling as it would appear to be in the 56-54% eff. range.
This is why turbos are more useable in day to day driving. OE's use superchargers because grandpas need lots of torque to drive around the bingo parking lot...
Originally posted by Will: This is why turbos are more useable in day to day driving. OE's use superchargers because grandpas need lots of torque to drive around the bingo parking lot...
That's why they just put V8s in Cadillacs. Turbos are more usable in "day to day driving" because the turbo will very rarely get used anyway. Most people who own vehicles with OEM turbos or superchargers just think "oh it's better because it says turbo or supercharged on the side." And OE superchargers are much more rare now than 5-10 years ago. GM only puts them on a few higher end V8s now. All the lower end cars with forced induction are turboed. And the upper-mid range is getting direct injected V6. The OE use of forced induction on low end cars is purely marketing ploy.
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11:15 AM
gmctyphoon1992 Member
Posts: 693 From: Lighthouse Pt, Florida Registered: Jun 2010
i got an idea.. why make it complicated with a twin supercharged twin turbo charged engine... why not just run a single turbo like a T-76 or a turbonetics off a twin screw supercharger or even a single screw supercharger... a single turbo system will tend to give you more boost anyways wont it? from what i know thats why many have converted to single turbos on their supras to get more boost... plus it frees up the engine bay a bit and on top of all that you would probably be getting the same power if not more than quad charged motor.... i think it gets to a point of doing too much when you could simplify and run much more efficiently...you would still be getting the same turbo-supercharged effect but less piping and less hassles... idk thats my impared .02
[This message has been edited by gmctyphoon1992 (edited 12-21-2010).]
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12:27 PM
Kemp3 Member
Posts: 282 From: Carmel Valley CA, USA Registered: Sep 2007
To start out I would like to say a big thank you. To all of you. For putting up with my relatively amateur knowledge. The twin supercharger idea was crazy I know. I was trolling youtube and seen a Ford Lightning sporting the twin supercharger set-up and immediately an idea spawned. I have come to the realization that I will start with the buick 3800 and on the side begin a build of the TA performance v6. I am going to stick with the v6 for the ease of swap in between the 2 v6's. Kemp3 you are amazing. That is exactly what I was looking for. Finally one good idea came from this thread... Back at ya buddy (you know who you are) I also want to swap the transmission for the G6. I was looking at the ones offered by V8Archie.com Yays or nays? The m90 supercharger. What does everyone think of it? Is there another I should be looking at? cost VS durability and longevity? Someone made mention about my twin turbo idea. I believe it was along the lines of running one large one with a smaller one. The effect being similar to running a supercharger and one large turbo. Can anyone expand on this idea?
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11:32 PM
Dec 22nd, 2010
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
buick 3.8 is not the same as a S2 3800... The stock S2 3800 out performs all "built" 3.8's, and honestly I dont think many of the "stage 2" buicks have done anything extra special compared to what the S2 guys have done.
Originally posted by 86_Fiero: Someone made mention about my twin turbo idea. I believe it was along the lines of running one large one with a smaller one. The effect being similar to running a supercharger and one large turbo. Can anyone expand on this idea?
The general classic idea for running twin turbos is you run one smaller one that spools very fast, and a larger one that provides all the top end power, and you avoid lag because the small one spools up fast and gets you using forced air sooner.
The general classic idea for running twin turbos is you run one smaller one that spools very fast, and a larger one that provides all the top end power, and you avoid lag because the small one spools up fast and gets you using forced air sooner.
OMG PEOPLE, "TWIN" turbo means using two of same turbos. You guys are thinking of sequential tubro or "biturbo".
Originally posted by Justinbart: OMG PEOPLE, "TWIN" turbo means using two of same turbos. You guys are thinking of sequential tubro or "biturbo".
OMFG EVERYONE IS NOT PERFECT AND SOMETIMES THEY MAKE TYPOS.
ffs. So I meant to type "two" instead of "twin." Straighten your panties. He was asking about why someone suggested two turbos of different size and said "twin" and I typed that while reading and typing at the same time. Trust me kid, you ain't perfect either; so get over yourself alreaady.
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12:59 PM
Kemp3 Member
Posts: 282 From: Carmel Valley CA, USA Registered: Sep 2007
you are going to need one special trans build to deal with 700Hp , I have a NSX 5 speed in my car with a Tilton twin disk clutch. I find the gearing from this trans to be perfect , if I did it again I would probably go with a 6 speed instead of 5 .
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06:12 PM
PFF
System Bot
katore8105 Member
Posts: 1519 From: Upstate NY US Registered: Dec 2009
86_Fiero, go to http://www.clubgp.com and spend a few months digesting all the information there. Some good advice was given to me once of reading up, starting with a stock engine and learning to tune 1st. Then start modding while learning to tune as you go. If you are going to heavily mod a 3800 some day, you need to learn how to tune and what all the values mean. There you will learn what is what, to do and what not to do, nomenclature, different build options, best power for $s spent, and the physics behind high performance 3800s.
You will find all the information you need and more by just reading on Club GP. Be advised that there is no rating system there and people will make it clear they know when you are wrong in whatever method amuses them. You should have next to no questions about anything 3800 related if you just read what hundreds of people have already covered many many times. Then when you are ready to stuff it all in a Fiero, come back here and read the many 3800 build up threads and how to fabricate what you need to make it work.
Edit to add: FYI the last year of my life in my spare time when not working on my car has been spent reading on CGP and PFF like it's my job. I'm just now starting to purchase aftermarket 3800 parts.
[This message has been edited by katore8105 (edited 12-22-2010).]
wish i could excuse a whole post that was wrong as a typo.... anyway none of this is ever going to happen and seems like a waste of time other then the talk on theory.
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08:13 PM
RotrexFiero Member
Posts: 3692 From: Pittsburgh, PA Registered: Jul 2002
Wow, why dont you just get two 3800sc's, two rated torque converters (like on a go cart), and mount one engine on each wheel. Bet that has never been done before. For maximum fuel economy you can run just one engine, and then when you want to race fire up the other engine.
Sorry, just trying to be funny.
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08:38 PM
sardonyx247 Member
Posts: 5032 From: Nevada, USA Registered: Jun 2003
The single supercharger/turbo setup has been done, by people who couldn't fab up an intake, even in Fieros. a dual supercharger/turbo, well that is just tossing money around/away. If you ever drive a well tuned turbo car, you will never want a supercharger again. and by well tuned I don't mean a laggy OEM turbo'd 4cyl car.
quote
Originally posted by darkhorizon:
buick 3.8 is not the same as a S2 3800... The stock S2 3800 out performs all "built" 3.8's, and honestly I dont think many of the "stage 2" buicks have done anything extra special compared to what the S2 guys have done.
Gotta call BS on this one, you can't say ALL, (well you can say anything you want, doesn't mean it's true.) considering the "worlds fastest V6 6.98sec 1/4" is a buick 3.8, NOT a 3800 AND another example is my ex-father in laws GN, 997TQ and 860ish HP I have seen the dyno. Stage two block built by Kenny Bell. oh and he has NO lag, he launches at 21PSI
quote
Originally posted by 86_Fiero:
I also want to swap the transmission for the G6. I was looking at the ones offered by V8Archie.com Yays or nays?
With the new info now out about the F23 transmission, I would go with that. the G6 trannys are getting broke behind stock engines. So why waste $3000+ on a trans that will just break. If you want to just be able to say you have a 6 speed, just get a shifter sticker, as I doubt you would ever let anyone drive your Fiero to the point they would need the 6th gear. ------------------ "DRIVE IT LIKE A FIERO" '84 Fiero, engine to be determined '87Blue GT 3.4L Swap Completed!!!!!!!! Boosted!!!!!!! ^^^^ Now in the Construction Zone^^^^ Las Vegas Fiero Club Parts/Sales/Service/Club Fiero Road Club Of Northern Nevada
[This message has been edited by sardonyx247 (edited 12-22-2010).]
Gotta call BS on this one, you can't say ALL, (well you can say anything you want, doesn't mean it's true.) considering the "worlds fastest V6 6.98sec 1/4" is a buick 3.8, NOT a 3800 AND another example is my ex-father in laws GN, 997TQ and 860ish HP I have seen the dyno. Stage two block built by Kenny Bell. oh and he has NO lag, he launches at 21PSI
Woah killer, I made my claim of "didnt do anything extra special" vague for just this reason. I know that they have been pushed, but they probably have been pushed by tens of thousands of dollars... I mean its a custom built racing block..
The last dyno our (series2) only "pushing it" guy did was 870whp through a loose automatic. Modlist is, aluminum heads molded after stock heads (no significant changes), a semi fancy intake manifold, and a 72mm turbo. He launches on 21psi too!
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08:08 AM
Will Member
Posts: 14278 From: Where you least expect me Registered: Jun 2000
the g6 6-speed "supposively" only holds up to 300 or so horsepower is what most people were telling me.. im sure it could be built up though and you would need a hell of alot stronger clutch to hold 800hp... also i wonder if tremec will make a front wheel drive 6-speed that would be original from what i know...or would it be? who knows... by the way why not just start with a built V8 instead of a built V6 im not being negative i just want know? maybe its cost effective? Because than you could have the torque down low until that huge turbo spulls... of course you could modify the exhaust housing to have little lag? just throwing suggestions i thought would be interesting to consider