Superman09

iTrader: (65)

Hey everyone, my 99 Trans Am is in the works for a pair of 60mm turbos that will be put on this winter. However i have come to a big fork in the road.... My transmission is currently a bone stock 4l60-e with stock torque converter and everything.... that needs to be changed, it won't work well with stock stall and will probably kaboom as the 4l60-e's are known for. I have 3 options, and I'll give you some background on the car to help me decide which set up to go with.

Car is a 99 Trans Am, twin 60's, stock motor for now, forged next season will come. 500 rwhp is the goal on stock motor and 650+ on forged motor. Car is a STREET car and will only see the track once a month or so and those times will be just for fun to race some buddies and see how she runs. Car will be driven on only nice days and such, but mainly is a street warrior. I don't take it on long trips or drives and am not concerned with gas mileage considering this is a performance car.

So there is some info, here are the choices...

1.) Send out my 4l60-E to get built to the hills and install a pro yank 3400 converter and trans cooler.

2.) Swap out my 4l60-E for a M6 and get a nice clutch to hold the power.

3.) Swap out my 4l60-E for a TH-400 with reverse manual valvebody and all the other fun parts.

I really can't decide on any of them, and each has their ups and downs. Here are some of my personal thoughts...

-I could have the most fun with a M6 for the street, except there is the fact that i suck at driving a manual and would need practice, but i'm sure with practice i could get it down easy and be rowin gears in know time.

-TH-400 seems like a solid unit, but more of a track/race car set up, seems that it may be difficult to find a super street set up for it, only 3 gears, etc.

-4l60-E seems like a solid choice, fun with the torque converter but maybe not as fun as a M6 would be, would be a hellova lot better at the track, don't have to worry about missing a gear, but even the best of the best have been known to fail and they are known to be money pits having to keep on needing to be rebuilt.

With that in mind, maybe you guys can give me your input as to what you think would be the right choice for me! Thanks for reading and thanks in advance for your time to read this long thread and for your advice.

2000 Tran Zam

iTrader: (2)

My advice, if this is mainly a weekend car or just something to enjoy, do what makes you feel the best.

My choice would be for an m6. I know you dont have the most experience with it, but if your not looking to race for money or at the track too often, it will be the most fun of all choices (based off my experience).

It will take a little time to get used to the clutch, but whats the fun in having a car shift for you when you can do it yourself?

and as far as your power goals, 500 rwhp on twin t60's will be absolutely no problem, prob run like 6-8 lbs on it with an m6 and get there.

As far as your stroked motor goes, if your only looking for 650rwhp, your wasting those turbos...

You can get 650rwhp out of a single t70, maybe even a lil smaller and spool time would be much better.

Unless you plan on making close to 1000rwhp on race fuel, if you plan on sticking with a TT setup, I would run like twin t44's or something similar to what the incon kit put out.

Of coarse thats just my opinion, but to each their own

ABeasst

iTrader: (5)

built M6 and 4l80 are the only ways I'll run my car.

smokinHawk

iTrader: (48)

two questions for you
1) do you want to go fast
or
2) do you want to break trannies?

Th400 if you chose #1

RyanJ

4L80-E

Do it once.

Superman09

iTrader: (65)

Also i'm going to say right now that i don't want the 4l80-e. I have ruled it out as i do not want to hack up the car to fit it. SO out of those 3 please tell me what you think. Thanks!

I want my car to be fast, but it is not a race car. I do not want to break trannys, lol.

With an M6, what clutch are you fast boosted guys using with good results and nice use?

FUroundeye

iTrader: (6)

You'll have to hack up the car for the TH400 just as much as the 4L80E, so...

obZidian

iTrader: (2)

a good, solid clutch for that m6 would be a textralia.

as for the 4l80e... im not sure where you read that you have to hack your car apart to install one. That isn't true at all. The trans should fit right with a new crossmember/transmount bracket, and a new driveshaft. Other parts are a converter, some wiring harness to match the 80e, longer dipstick, reflashing your pcm to match the 4l80e parameters, etc. It really isnt much and you dont have to hack the trans tunnel to pieces to get it to fit. There is probably as much, but no more, involved going from an auto to a m6.

I would suggest, if your gonna stay auto, DO NOT stay with the 4l60e. It will just disappoint you. I had to rebuild mine 3 times, everytime with the BEST stuff you can throw at a 4l60e. Now, i know rossler has a few successful 4l60's.. BUT, its a trans that has blown under stock power, you cannot WOT shift it into 4th unless you want to replace your 3-4clutch pack sooner than expected, 3-1 WOT/4-2 WOT are tough... etc.

To me, its not worth it beyond stock. If you still dont want the 4l80e, go for the th400, but my first choice would be the 4l80e. Almost the same cost as swaping to a M6 but an auto that usually holds 700lbs trq STOCK and with 4 foward gears.

goodl luck!!

Superman09

iTrader: (65)

hmm awesome news there. I'm going to look into a 4l80-E a little more. Thanks for the info!

Josh@KY-Turbo

iTrader: (120)

I voted the 4L60E. I did the 4L80E on my last build. get a 97 up trans and have it built. Yank x-member. Slight tunnel clearnacing. 4L80E veter. And the TCI TCU controller. All in all it cost me about $3600. Expensive, but would hold anything and keep the OD. You can get a full manual 4L80E and not have to worry about the TCI controller. I think you can get the factory PCM to control it also.

2000 Tran Zam

iTrader: (2)

i heard 4l80E's that were built costs like 5k...

Josh@KY-Turbo

iTrader: (120)

For a full tilt version like the Ohio Boys run yes. Billet input shafts and all.

For the average turbo car you dont need one like that. A performance rebuilt 4L80E is good to 800+ft/lbs pretty easy. No need to have a full race trans in a car that will spend 90% of its time on the street.

obZidian

iTrader: (2)

you can have a built 4l80e cost that much...

but, i just picked one up for way less, fash00 ws getting rid of his and got a solid trans, cryo'd for way less than 5k. cannot remember but closer to 2k than 3k.

god, i gotta start writing this stuff down!!!

Superman09

iTrader: (65)

How much power do you think a stock 4l80-e could hold? Also, are you guys buying these trannies used from truck guys or new... if so from where? Thanks!

Josh@KY-Turbo

iTrader: (120)

I bought mine off ebay for $375 and spent like $1200 on the rebuild. A stock one is good for 700ft/lbs of touque. I just had upgrded clutches and steels put in mine along with new solenoids and such.

bearcat

anyone know if a 4l80 will bolt up to an lt1?

NHRAMAN

iTrader: (1)

How about a TH-400 + a Gear Venders unit....

ty_ty13

iTrader: (42)

what the hell are you thinking.... a th400 would be the best for a turbo setup... i mean ****... you can run 3.08 gears or 2.73 gears with a turbo and still be super fast..... those highway gears help load the turbo any way.... especailly if you plan on running on any kind of MT DR or GR DR....

just make sure and get a 9'' rear that way you can get much more gears to choose from....

i love my th350 i just wish i had gotten a 9'' cause you can get a spool with 3.42 which is what i really want with my 408 blower car...


i say your foolish if you dont get a th400 .... build it once and dont worry about it... plus you can launch a turbo easier/harder with a auto tranny...

obZidian

iTrader: (2)

a 4l80e is geared exactly like a th400, but with a od gear, with i believe is a .79/.78

with those same gears (3.080/2.73) you'll still be super fast, WITH a fourth od gear, electronic lockup converter if you so wish to run a lockup, hold equal amounts of power, did i mention it has an extra gear and have all the options you would have with that th400.

Th400 for is more strip than street. Rpms to high for street/highway driving. That is why i got the 4l80e.

Now, a th400 with a gear vendor is a great idea, actually, my initial setup. BUT, i was looking at the way the gear vendor was shifting and decided agains't it. Also, its the same price, almost, as a built to the hilt 4l80e so you decide.

Jammer

iTrader: (1)

Im on 4l60 # 4 in 2 seasons and maybe a total of 1500 miles.. I find it quick and easy to swap, but starting over, i'd suggest a 4l80 as well. As far as a converter, a 3400 is too much in my opinion, as all the torque once you have a built motor might cause you to stall closer to 5k or higher when wot... When I had similar turbos on my Cas kit and a TCS 3200 stall, at 17 lbs of boost the converter didnt stall untill almost 6k rpm.
I now run a converter from a 6 cyl Envoy and I launch well and drive around easy. I also would recommend a lock-up converter if you street drive alot. The auto will likely result is notable better track times and consistancy for you.