MOSTDELUXE

iTrader: (3)

Iam putting a turbo 400 with a brake in my car and was wondering if anyone has track times? difference in 60ft and e.t. And if it ate anymore power.

sevanseriesta

iTrader: (34)

people see quite a bit of difference in 1/4 mile times, but you will lost power on the Dyno! People have lost as much as 70HP on a dyno

MOSTDELUXE

iTrader: (3)

what kind of difference in et?

john kilgore

the th400 has 2.48 first gear ratio and the 4L60 has 3.06 first. maybe a 2.75 first from ATI would help.

ChocoTaco369

I've heard of people losing literally 90 rwhp Seriously. Of course, that person was pretty heavily modded...but then again, if you weren't heavily modded, you wouldn't need a TH400

performabuilt

iTrader: (25)

I dont know the amount of loss but the internals are quit a bit heavier. so there will be some loss. As for et the biggest loss might be the 60ft due to the higher first ratio.

Z ROADSTER

Pretty big loss in power & pretty big increase in weight. The only experiance I've had with the turbo 400 wasn't good.Eats horsepower & torque and believe it or not , its not as reliable as the turbo 350. Everything about the TH-350 is better than the 400. And thats the real truth .

XpEdItIoUs

iTrader: (44)

You guys have to realize that a th400 is unlocked. Just because you make less power on a dyno with a th400, it dosn't mean you car gets slower

PBA

"Pretty big loss in power & pretty big increase in weight. The only experience I've had with the turbo 400 wasn't good. Eats horsepower & torque and believe it or not, its not as reliable as the turbo 350. Everything about the TH-350 is better than the 400. And thats the real truth."

It is just the opposite, when it comes to reliability. The TH400 will eat up a little more HP than a TH350 in a vehicle that has a very high numerical rear end ratio. It is very hard to do a direct comparison on a dyno because of the torque converter. When you can make a transmission change at the drags and use the same torque converter, then you can see the differences. There are so many little things that can be done to help out the transmission from eating so much HP. Each transmission can be helped out by using lighter parts, roller bearings in certain areas, lowering main line pressure after the 2-3 shift occurs, Turbulator type steels in the 2nd & 3rd gear clutch packs, and the low/reverse clutch in the TH350, reducing the amount of clutches used in the low/reverse area in the TH 350, etc. The TH400 uses a low/reverse band and once it is off there is no drag as when compared to the low/reverse clutches in a TH350 which eat up more HP the higher the rpm.

revtime

iTrader: (1)

I would LOVE for you to back that up with technical info. LOVE IT.

I know my car got faster with the TH400 because I started beating guys I could not beat when the 60E was in it. I don't have times yet to prove it beyond a doubt but everyone agrees the car got faster.

Z ROADSTER

Stock 350 compared to a stock 400 , both behind a small block , which one would have the weight & horsepower advantage ? And as to which trans is the most dependable , in my experience the TH350 out performed my TH400 & outlasted the 400.
Now you mention the " 60E " which never entered the equation. I'm just speaking from my past experiences with the two tranny's. Not trying to start an argument here.

XpEdItIoUs

iTrader: (44)

Why do the big horsepower guys use a 400 then if its not as reliable?

ncnumber8

iTrader: (1)

Your mph might be down w/ a TH400 but your et will be as good or quicker w/ the 400. As far as a 350 outlasting a 400, thats a new one for me. A friend of mine builds 350/400 on the side (to feed his racing addiction) and he said even a stock 400 will outlast a built 350 in most cases. That depends alot on who builds the 350 though.

revtime

iTrader: (1)

There is a difference between an arguement and a debate. I love to debate.

Now, weight and horsepower I will give you to a certain point as once you get to enough horsepower that it kills the TH350 then the weight and horsepower advantage gained you nothing.
I have no idea what condition your TH350 and TH400 that your basing your expierence on were in.
I do know that if you compare apples to apples the TH400 will last longer and take more abuse than a TH350 both built street/strip.
Having said that I have seen built TH350s take alot of power but I have seen TH400s get criminally abused and suffer no ill effects.
I have had both over the years and my current Rossler TH400 has convinced me beyond a shadow of a doubt that I can have reliability, performance, with no compromises.
Well to be honest the OD gear is the only compromise and I am getting used to it being gone.