sinful7

iTrader: (1)

I have a fd rx7 with a turbo ls1 in it that should make around 630-680whp after properly tuned.. I need an auto trans to go behind it.. the car wont be raced much but id lie if it will never see the drag strip.. im figuring 3-4 passes a year.. and im serious lol.. but it will see some spiriting driivng around town and on the highway.. some say the 4l60e wont hold up even if built.. and the 4l80e is maybe too large to fit in the trans tunnel of the fd rx7.. so im in a weird spot.. i want an overdrive auto trans that will work and perform like a raped ape!

anyone got any ideas on what is true and what is not true.. I have been a m6 guy for a long time so im new to the auto world basically.. I need your guys help..

I scored a 4l60e stock trans, and a 3600 rpm lock up stall converter the other day the stall is brand new, but the trns is used.. no biggy since i would prob rebuild it anyways.. but anyone got thoughts on what can be done to hold this power on the street and minor strip duties?

gt35built

iTrader: (1)

4l80e would be the better option in the long run, but first determine if it will fit or not.

you can get a 60e to hold that amount of power by a reputable sponsor on this site, but you do hear a lot of stories of them getting toasted.

Call some sponsors. (FLT, Performabuilt, Finishline) You will find a lot of good feedback from forum members about each builder.

3.8redbird

iTrader: (3)

4l60e will need to be built to the hilt. 5 pinion planetary alto clutches. the works. Then a good durable highspeed balanced driveshaft

what rear and tire? gear?

sinful7

iTrader: (1)

i have a 8.8 irs with 3.55 gears and im running 275/40zr17's in the back and remind you this is in a 2800 pound rx7.

4l80e wont fit.. too big i measured.. im stuck with a 4l60e or a t350 setup but i really want to keep overdrive..

3.8redbird

iTrader: (3)

gear vendors overdrive on a th350?

sinful7

iTrader: (1)

how didnt I see this answer coming?? sigh... thanks for your answer but im looking for a single transmission that has it all in one case.. lke a 4l60e or a 700r4 or 200r4 etc... not a t350 with aftermarket stuff attached to the tail etc.. but thanks for the help anyways.

ChucksZ06

iTrader: (9)

I think with your light wt and that size tire you would be fine with a built 4l60. The turbos help also. The high torque at lower engine speeds and sticky tires are what really trashes the autos.

fun Pain

I say MAKE the 80e fit it isn't that much bigger, I put one in my thirdgen, when everyone told me that i would have to beat the hell out my tunnel,,, nope not one mark on my tunnel even used the same drive shaft. I know it won't be that easy but it will be worth it.

FastKat

iTrader: (10)

What about all the 6Lx0E variants? Would one of those work?

FirebirdSS

iTrader: (7)

Think you would do just fine with a built 4l60e.

ArkBird96

No it won't work. Not with an LS1. Those 6LXXE transmissions depend on the computer from a newer LS3(?) engine, not an LS1. AFAIK no one makes an aftermarket computer that will work with it. Not yet at least.

Austin@HPE

Rpm transmission level 6 4l60 hands down i have personally ran it to over 850rwhp and 50-60 mid 9 passes at 750rwhp. PM i can get you a good price.

3.8redbird

iTrader: (3)

TCI makes a 6 speed auto derived from the 4L80e. It wont fit due to this but they do sell a computer for it. Might it work?

ArkBird96

I think all it does is apply the OD in the 80e in certain gears and they also change the gear ratio. You will NOT get the 2 OD gears with this setup, just one OD. Also, they make a stand-alone controller for it, so that will work. The 6L80e is a different animal. It relies on both a TCM and an engine computer for the Gen IV engines to work properly.

3.8redbird

iTrader: (3)

Thanks for the insight. I have read some up on it and know it only has 1 OD but didnt know much about the 6L80e

transaman98

iTrader: (16)

4L60E will hold up with a car that light. Make sure its built by a reputable shop and you won't have any problems.

poorhousenext

You might want to check with Mast Motorsports. They are running a 6L90E with their ECU/ECM since back in 2008.

Might want to check out out their build thread below.

https://ls1tech.com/forums/conversio...ng-hauler.html

I kind of follow the 6L80/90E builds and updates.

Here is picture of my 6L80E/LS7 build in a 66 Corvette. A 4L80E is a piece of cake to install compared to 6l80E. I'm using a 4L80E based trans in my 64 Corvette Pro Touring Build because it has better gear splits than the 6L80E so you can keep engine in it's power band when downshifting.



Build Thread here.
https://ls1tech.com/forums/conversio...e-project.html

The 64 vette with 4L80E based trans build is a Pro Touring class build. This car has a 4.0" wider tract than the stock bodied 66. It only has a 2400-2500 TC Stall because it's not built to just go in a straight line. Being able to downshift thru gears is more important than being able to just put trans in D and launch. The 66 is really just a cruise around look good car with 6 sp auto and LS7 engine to give it a cool factor.

http://www.digitalcorvettes.com/foru...d.php?t=130528

I see no need for two overdrive gears. If you look at TCI's 6sp and compare it's first 4 gear splits to both GM 6L80/90 and a 4 or 5 speed manual, it matches up to the manual and beats the 6L80/90e as it limits you to 3 gears.

To down shift into 1st you just about have to be stopped, are have damn good ears are you will over rev engine in a heart beat.

The only downside to TCI's 6 speed is it's lack of engine braking to help save your brakes. Course that's not a problem for most here, as they only drag/street straight line race.

Will the TCI 6 sp hold up? Probably better that either the 6L80 or 90 at this time. Do a little research on cost of converting to a 4L80e and that $6000.00 dollar price that includes paddle shifters, TCU, wire harness, etc. and you may find it's price is not that bad. Throw in the Limited Lifetime Warranty and it starts to look a lot better. By the way, you can find one priced on web, vendor here for less, around $5500 are less.

Just the thoughts of a man with an open mind.