legacycentral bbs

Hi there everyone! I have a question that i kinda need some sort of answer for.

How much torque can the stock 4eat in my 93 SS handle?

I ask such a question because im swapping some perty high power parts in.

Im thinking that i can get around an easy 250wtq

So have many people ran some torque into a 4eat?? I just cant seem to find a nice answer.


Tommio

I think that will depend on the condition of the 4EAT. If its got 150,000 miles on it, it may not be in the best of shape to handle that kind of power. If it's new, that shouldn't be a problem.

Well. I have 180,000KM's on her.
I will dump ALL the fluid out of the trans and diffs before i do my mods.
The list of mods for the motor are these BTW:

Garrett GT28RS Disco potato! and yes its BB
550cc yellow toppers with rails
Walbro 255
Jecs maf
AWIC
EWG
AEM FIC

I dont know how good that would be for a trans with 180,000kms on it tho.

Thoughs???

Tommio

Really all you can do is try. There's not much you're going to be able to do other than have the trans rebuilt. So you can either do it now, or leave the trans as is, see how it runs, and if it grenades have it rebuilt or put a used one in.

One thing some people overlook is the torque converter. The lock clutches can and do wear out....they are not servicable in the torque converter and when they wear out....you really just need a new torque converter.

I got Angel up to 285 horse, no clue what the torque was. The transmition finally gave out due to improper maintanence at the hands of Jiffy lube, rather than being over worked.

In my opinion you really need to be putting some serious power down to overpower a 4EAT. or.... you know, racing/abusive use. However at these power levels the 4eat cant compensate and your running little more than FWD once the wheels come loose under heavy throttle. **EDIT** the last being said after the trans blew due to Jiffy lube and AAMCO doing poor rebuilds, so a propper 4EAT might respond better

I'm not an expert. just sharing my personal experiences.

One thing I would definitely recommend is an external trans cooler and running good synthetic ATF.

HI,

My .02.

#1 The Turbo 4eat is the same (except for final drive ratio) as what was used on the SVX, which made 230HP/ft-lbs @ the Crank. As you may know they frequently fail, but not sure if that's due to bad design, lack of maintenance, or both. THIS SITE points to design - not sufficiently cooled:

The 4EAT transmission installed in the Subaru SVX (also in the Legacy, Nissan Pathfinder, and Mazda MPV) suffers from one fatal problem: HEAT.

* Radiator-based transmission cooler can't keep the transmission fluid cool enough
* Transmission is poorly designed and does not allow the lubricant to flow through it to keep parts lubricated (thus friction causing heat)
* Unusually high overdrive places additional side loads on bearings generating heat
* AWD system puts strain on the transmission causing even more heat

#2 I had a turbo 4EAT in my '90 w/my EJ22T. I ran it for the last 2 years w/the Revtronix chip which was dyno'd @ 230 Torque @ the Wheels. I used a tranny cooler and it was fine 'til this last summer when I went for the 'rob tuned' EJ20 ECU and most likely now around 250-275 ft-lbs @ the wheels. I lost 2nd gear about 1 month ago....drove it around town in 3rd- Manual mode just fine, and drove in D on the freeway Ok also, before I started my 5-speed swap.

From what I've read the 4EAT is a strong transmission, if maintained and kept cool.....not sure my experience disproves that or not.

Td

Thanks very very much for all the great info!

Now i know what im going to do here.

Get a transmission cooler installed
Change the trans fluid to the Subaru six synthetic HP stuffs.

and if it blows... i will call IPT for a rebuild.

Redline D4 is also a very good ATF. That's what I used before switching to MT.