transaman98

iTrader: (16)

So I am deciding what tranny I want to run in my car. Obviously I already have a 4L60e, so I am trying to decide wether to beef up my current tranny or swap it out for a TH400. I was wondering if you guys could tell me what the pro's and cons are for each tranny and which one would be better for a street car that occasionally sees the track. Thanks.

ChocoTaco369

you won't want a th400. it has no overdrive. if you drive over 50mph you're gonna be in some **** gas wise. no to mention, you'd lose like 50hp by getting a th400 because it's extremely parasitic and the 4L60E has MUCH better gearing. you'll lose a lot of speed with a th400. a th400, from what i've gathered, should only be used in 700+ horsepower strip cars. once you get into that power range, the parasitic loss won't matter and for the strip, you don't need overdrive.

if you're going to be doing a lot of street driving, a 4L60E or a 4L80E will be your best choice. the 4L80E has overdrive and just like a th400 can take 700hp all day every day if it's built properly. the con is it's very heavy and expensive.

if you're making under 500rwhp a 4L60E should suit you just fine. just make sure you get one from a good builder like rock-on or FLT. if you just rebuild your stocker with a few better parts it's not gonna hold. you're gonna need a full-on race built 4L60E (costs around 2 grand), but if it's built PROPERLY, it can take a beating so i've heard. just in stock form it's a junk trans.

revtime

iTrader: (1)

Wow, have you ever had a TH400? Have you ever driven a car with gears and a TH400 with a decent stall?
Lose 50 HP? My car went faster with the TH400, no changes to the motor.........tell me how I lost 50 HP.
Better gearing? give me a break, the spread in a 60E is horrible compared to the TH400. The only good thing about it is the steep first gear, and that will actually cripple you without traction.
I will give you overdrive, on the hiway its a nice thing but I will take the high RPMs over rebuilding the tranny every 20 thousand miles (my expierance only).
If the car is a weekend toy then throw in the TH400, if its a daily driver then I would go with a built 60E.

Not trying to be a dick, but that was some straight up misinformation right there.

LSWon00

iTrader: (3)

I have to agree with revtime above. I don't have a TH400 but its on the list of things when the 60E takes a crap. OD can be had through an aftermarket tailshaft if I'm not mistaken. Yeah the OD units aren't cheap but neither is a 60E or a 60E rebuild for that matter.

SSilverSSurfer

iTrader: (8)

th400 way more bullet proof than the 4l60 if you plan on hitting the strip alot, downside no overdrive but whocares

ChocoTaco369

he's using it on his STREET CAR that will see the strip. getting a TH400 is a BIG mistake. he says he will occassionally see the track. you're gonna ruin his daily driver to go to the track twice a year?

and again, i believe the 4L60E is geared lower.

i've heard of people losing around 50hp with a TH400 swap. but maybe that's an M6 conversion. either way, no one should argue you'll lose SOME hp. i just feel giving up OD is a very bad move for a street car. it's gonna kill your wallet and kill your engine.

revtime

iTrader: (1)

Everyone is entitled to their opinion.

For me the TH400 was the single best thing I have ever done to the car.
And I said in my first post that if its a daily driver I would not put a TH400 in it.

transaman98

iTrader: (16)

should i just put up a poll on the question?

Zombie

iTrader: (2)

I run a th400 and put about 100-200 miles on my car a week. 2nd best mod I've done to the car (first was the turbo).

Chocotaco, just because a dyno reads lower after a transmission swap doesn't mean jack, you need to run the car at the track. Dyno's are not for racing, they are a tool for tuning, they also do not tell the whole story. I've seen graphs of a turbo mustang losing 200 rwhp on the dyno swapping from a T56 to a Th400, he ran a better ET with better MPH at the strip.

Transamman, if you are keeping the car fairly mild then a 4l60 is probably your best bet. Th400s become a good choice when you start to make a ton of power. You do have to give up overdrive, my answer to that was 2.75 gears though.

11SECDWS6

iTrader: (3)

This is straight of of the Timeslip Database here on LS1tech (so you can verify):

RWHP...........Wght..........MPH...........ET..... .....Transmission

444..............3000..........132.3.......10.14.. ..........TH400

470..............3100..........134.96......9.96... ..........TH400

491..............3390..........129..........10.28. ...........TH400

413..............2950..........128.48......10.295. .........TH400

As you can see, these are no dyno queens, but damn sure git-r-done at the track.

Dyno queen = 4L60E

Track queen = Turbo 400/Turbo 350/Powerglide

z28pat

iTrader: (10)

I am wondering the same thing transaman98 is wondering,
if you had to choose for a street/daily driven car that goes to the track 4 to 5 times a year, would you still choose the TH400?,
I know it's no question for a track car that the th400 is the one, but having no Overdrive sounds like a real pain.


pat

11SECDWS6

iTrader: (3)

4L80E would be the way to go if you wanted to keep overdrive and be bullet proof also. But you'll have to pay $$$$$

Joel_SS

iTrader: (8)

While those are great numbers.. Look at the wieght they are all stripped.. I bet every one of them was trailored to the track.

But for a daily driver and occansion trip to the track a build 60e should be just fine.

Zombie

iTrader: (2)

For under 500 HP I agree. If I could have had OD and lockup for cheap I would have, but it's hard to do things cheap when you make big power.

11SECDWS6

iTrader: (3)

Not really, my ws6 has zero weight removed and weighs 3550 lbs. Thats only 550 lbs heavier than say, the first car that ran a 10.14 @ 3000 lbs. They say that 100 lbs = approximately .1 seconds off your et, so at stock weight, that would still make that car a 10 second car w/ just 444 rwhp.

I drove mine to the track tonight w/ TH400 and all. 35 miles one way. Temp got alittle hot, but not too bad. Drove all the way back w/ absolutely no problems.

Thats not what I understand. Just talking around w/ people at the track, I personally know a few people that went through 4L60E's left and right. Even built ones. I know of one person on this board who is well known that has gone through seven 4L60E's before he finally went to a 'glide.