Transmission types and capabilities?

[wyomingste]

I am working on building a performance LHO (3.1 N/A) i know alot of people will disagree with this but its my decision knowing that i might be happier with a DOHC or 3.1 turbo..

 

What are the different types of transmissions that will fit in my car (91 STE Grand prix LHO.

 

I currently have the TH440T-4 (4T60) and i want a transmission that will handle about 800+ horse power (not going to make that much but the stronger the trans the better in my opinion.

 

What would everyone think about capability and strenght (including reliability) of the following transmissions? Experience or reasearch is helpful, just want to get the best for my money and setup.

 

TH440T-4 (4T60)?

4T60E?

4T65?

4T65E?

4L80E?

3L80?

4T40?

4T45?

4L60E?

4L60?

4T80?

 

Thanks for the help that anyone can offer (i'm also searching online every chance i get for options and opinions)

Eric

[Guest TurboSedan]

4L80E?

3L80?

4L60E?

4L60

 

 

unless you're converting to rear wheel drive you can forget about those four.

[Tru2Chevy]

Don't forget the TH125 - little 3 speed workhorse trans.

 

- Justin

[THe_DeTAiL3R]

5-speed

 

out of the automatics

 

4T65e built up or a 4T65e-HD (from GTP)

[manitcor]

yeah

 

t65 or t65-hd are your best bets if you have the choice. the t60 can be built to take power too but not as much as the t65.

 

You also have some manual options as far as GM T-mont gearboxes go.

 

Getrag 282

Getrag 284

Whatever is in the new G6 (not sure what its called)

 

there may be others im not aware of.

[Prospeeder]

Ya no *L** trans, the L is for Longitudly (sp?) mounted engines (RWD except for the retarded chryslers use FWD Longitudivly mounted engines), and the T on the ones are for Transversly mounted engines (FWD usually)

[DaveFromColorado]

4T60-E = boat anchor. Unless you build it up with good parts (not super high end, but better then stock) these units are fairly useless if you're making any power.

 

--Dave.

[fastbird232]

Ya no *L** trans, the L is for Longitudly (sp?) mounted engines (RWD except for the retarded chryslers use FWD Longitudivly mounted engines), and the T on the ones are for Transversly mounted engines (FWD usually)

 

Fixed.

[Prospeeder]

Ya no *L** trans, the L is for Longitudly (sp?) mounted engines (RWD except for the retarded chryslers use FWD Longitudivly mounted engines), and the T on the ones are for Transversly mounted engines (FWD usually)

 

Fixed.

 

Whoops! And when i made it, i as trying to make sure i didnt get my T and L mixed up, lol

[mfewtrail]

If you're sticking to a NA 3.1 build, you're not going to have to do very much to the transaxle...a basic rebuild with a few upgrades would work fine for you. Afterall, I doubt you'll break 200hp at the crankshaft...let alone 800.

[Prospeeder]

i dont see an N/A 3.1 making more than 200hp

[wyomingste]

never know, i might get lucky and make it past 400 my goal (with the help of a local performance shop). I've brought him a list of the parts i might use and he says it has a possibility of upwards of 300 without nitrous (i'm going to run alcohol not gasoline and bump the compression up to about 11-13.5:1 also using a nitrous kit that should add about 150 horsepower, he is looking to see if the nitrous is going to be to much at that compression and if it is what a safe compression would be.)

 

I'm mainly looking for the transmission strength because i plan to use a 2800 RPM stall or a transmission brake to help with the launches of the car.

 

If i can't break at least 300+ with the naturally asperated (going to run extensive simulations with different parts) i'm going to go with a turbocharged motor (or twin with a custom hood making room for the extra turbo and anything else) (also want to run nitrous on it) and still with the same plan to run it on only alcohol. If anyone has done research on the alluminum heads with alcohol what were the results, is it possible to run alcohol on these heads (they will have extensive work done... LS1 springs, Larger Valves, Full port and pollish, 7 angle valve job, 1.7-8 rocker arms, complete combustion chamber balance... basically everything possible for the price I set per head (3000 each is the max i will spend on the heads)

 

Didn't know what the L and T ment on the transmissions but it never hurts to ask and get an answer right?

 

Thanks for the help so far,

[TeeJay3800]

Thumbs down on the nitrous, but I think it's cool whenever someone wants to seriously build up a 3.1. More power to ya!

[Guest TurboSedan]

whatever you do.....i would seriously consider forgetting about the LH0 and starting with a +00 3400. they can be had for under $500 with only 50,000 miles on them and they will bolt right in. you can find them anywhere. you could run it on your existing wiring harness with some minor changes and you can still use the 3.1 ECM (though it will need to be tuned of course). or you could run it on the newer OBD-2 3400 SFI electronics and PCM and use a DHP Powertuner. i really don't know anything about the newer OBD-2 stuff and DHP Powertuner though. just a suggestion.

 

just my opinion, but the only way to get real power out of a 3.1 LH0 engine is by shoving boost through it, and even then it's going to be severely limited thanks to the intake/heads not being able to support anything near what you want HP wise. i could be wrong but i just don't see it happening. at the very least it's not very practical. just my opinion of course.

 

...and 4T65 all the way. you'll have to use newer electronics or piggy back system if you want to use the 4T65-E HD in your car.

 

i don't think anyone here with a 60* V6 is making nearly 400hp even with a turbo. if anyone is coming close it's Tim G (turbo 3.4 DOHC) and Curtis Walker (extensively modified 3.1 Turbo).

[digitaloutsider]

I totally agree with TurboSedan. If you want to stay with a naturally aspirated pushrod and want to be in the 60 Degree family, I HIGHLY suggest starting with a 3400, or even better, a 3500. The LH0 will never make anywhere near 400 HP without some form of boost. Period. You can go ahead and quote me on that too. If someone is able to do it for LESS than it would cost to fabricate a complete working turbo system that pushes 400 HP, I'll reimburse you for the costs.

 

If you don't care about staying with a 60 Degree, look into a Series II 3800 N/A (L36). There are L36's in 13's over on ClubGP with no boost. The engines just have a vast vast aftermarket, something our 60 Degrees don't really have.

 

The bottom line is, if you want a fast car with no boost, throw the LH0 in the nearest dumpster. It's a poor choice. Hell, even if you want boost, look at the TGP guys who put out big numbers and notice this: half of the parts on their engines didn't come from the original 3.1 Gen II under the hood.

[Guest TurboSedan]

Hell, even if you want boost, look at the TGP guys who put out big numbers and notice this: half of the parts on their engines didn't come from the original 3.1 Gen II under the hood.

 

maybe i read this wrong, but i'm one of the TGP guys putting out bigger (well...bigger than most dyno-wise anyway). just about everything on the engine is original GEN-II 3.1 stuff right down to the entire shortblock. the only things that aren't (in my case) are minor things like the MBC, K&N, BOV and chip.

[Guest TurboSedan]

found this from Curtis Walker:

 

I dynoed the car, 310.2 wheel HP At 7 psi. Ran it at the track, calculated the HP at 430 wheel HP at 16 psi, smoked the tranny

 

note: that tranny was a Getrag 282 but keep in mind it is seeing HIGH hp/tq not to mention HIGH RPMs.

 

wheel torque was 290 @ 7 psi. So, wheel torque might be around 400 @ 16 psi.

 

not exactly dyno proven at 16psi, but given Curtis's experience i'd believe those numbers. keep in mind that is an EXTENSIVELY modified GEN-II 3.1 using a T4 .68 A/R P-trim Turbine and 60-1 compressor.

 

+ 400whp can be done on a GEN-II 3.1 (shortblock). BUT....doing it NA....no way.

[dbtk2]

The bottom line is, if you want a fast car with no boost, throw the LH0 in the nearest dumpster. It's a poor choice. Hell, even if you want boost, look at the TGP guys who put out big numbers and notice this: half of the parts on their engines didn't come from the original 3.1 Gen II under the hood.

 

Huh....thats funny. I believe there are only two TGP owners here that don't have pretty much all Gen II parts on their engines. Jud and I have 3x00 topends and thats about it. Big numbers can be had with the Gen II topend, I just needed headgaskets anyways so I changed my topend while I had it apart. I mean, my lumina was pretty much a stock TGP engine with ud pulley, roller rockers, and a chip, and it ran pretty damn good. 14.4's is not bad. That car was Gen II, no arguing that at all.

 

I mean....look at my STOCK dyno numbers. IMO those are big numbers and my car had a K&N filter and no cat and thats it...

 

Shawn

[digitaloutsider]

Post edited. Forget it.