High HP and AUTO trans

[92pearltt]

Has anyone ran a high horsepower car coupled with an auto trans. I am really thinking about swapping an auto into my fwd drag car in the making. I would just like to know if anyone knows how much power the FWD trans can handle. Also is the AWD auto trans stronger and can I swap it to FWD like the getrags? Does an AEM standalone have the ability to control the auto or do I still need a tcu. I am kind of an automatic trans noob so help me out if you can.

Imperfect drop me some knowledge lol.

[MR2]

Nelson would be a place to start.

[IPD]

neither nelson nor chris have experience with high HP FWD ATX, afaik. in fact, i'd say 11secFWD is probably the most knowledgeable member we've got. http://www.3sgto.org/garage_vehicle.php?do=view_vehicle&id=39

you can check my blog on here for some of my thoughts on the matter. succintly, the ATX in the 3/s is a mechanical duplicate of that in the 1/2g DSM's. there are guys who have gotten 8's out of them with welded VCU's. the only real achilles-heel is OD--and anyone who has raced them will tell to use it as minimally as possible, if at all. it appears to be sufficient for normal driving, but it really isn't designed to handle power shifting in a high HP application.

FWD and AWD ATX's are the same; you're not going to get more or less durability from switching--and you can't convert (even if you could, since they're identical, it's a rather pointless idea...especially given the difficulty in finding a 3/s compatible one).

i don't know AEM well enough to know if you can run extras like the trans off it. my guess is you'll simply have to use the TCU & tell the AEM or ECU to send the readouts that the TCU needs (there's about three of them). both nelson and chris ran AWD ATX's in manual-shift mode--so they won't really be able to help you out much with the wiring aspect.

p.s.
fwiw, if you want to primarily run drags with the car, get a custom-stall torque-converter with a stall of 3500-4500 rpms. it will make the car shitty for casual driving, but the effect at the dragstrip is definite. my guess is that it's probably good to set the stall at a MINIMUM as high as the rpm band where your turbos spool. add a translab shift kit, end clutch kit, and a nice-sized trans-cooler (i'm going with c3's 2" + fan cooler). here's one of the shops you can start asking around at:

Transmissions (http://www.sheptrans.com/transmissions/index.htm)

IPT is a good place to buy--if you're having the work done by yourself. i've heard mixed-signals about level 10. dsmtuners is a great place to ask around.

[Ninja Performance]

No, the 3S AEM does not do ATX control.
IPT sucks (IMO)
Get the TC restalled and brazed at Hughes in AZ. They are the shit.
Run full ine pressure and use 2 toggles to shift thru the 4 gears.
The input shaft will snap at high HP hard shifts. 500HP and under shouldn't be an issue

-Chris

[n2nsanity]

you're welcome to buy mine if you want
was in a 94sl i got from another member
said he had like $5k invested into it
i think 10k on a rebuild, shift kit, high stall tq converter and lsd
i did a 5spd conversion, so it's just sitting in my garage
also have the fwd atx axles. i have a 92 5spd mtx, so i couldn't use them
and the atx engine harness and tcu
i'd let it all go for stupid cheap if you're interested

i had trouble getting everything to work, so i'm unsure of the condition
i really wanted to see what it could do, but i got impatient and did the mtx conversion instead

pm me for more info if you're interested

[IPD]

No, the 3S AEM does not do ATX control.
IPT sucks (IMO)
Get the TC restalled and brazed at Hughes in AZ. They are the shit.
Run full ine pressure and use 2 toggles to shift thru the 4 gears.
The input shaft will snap at high HP hard shifts. 500HP and under shouldn't be an issue

-Chris

i think IPT is ok if you're just buying the translab shift kit & clutch packs from them--but that's about it. for a torque converter, i'd buy one NEW--not a rebuild. i forget the name of the place i was looking at, but DSM tuners can probably point you in the right direction.

p.s.
due to incessant nay-saying...i've pretty much decided i'm going to run stock internals on my trans until it shits the bed. if it can hold up to 500+ awhp of dd & a few 1/4 passes--that'll pretty much be the end of discussion, as far as i'm concerned.

[Ninja Performance]

Stock internals will be fine for 500HP. Use full line pressure. Use Hughes to restall and braze. You will be fine. IPT did our first "high performance build" and when it blew we rebuilt it ourselves. Turned out the special clutch packs were off the shelf aftermarket units, like NAPA. Nothing special. And the stall was never right. So we started rebuilding ourselves and sent the TQ to hughes and things improved big time.

-Chris

[IPD]

Stock internals will be fine for 500HP. Use full line pressure. Use Hughes to restall and braze. You will be fine. IPT did our first "high performance build" and when it blew we rebuilt it ourselves. Turned out the special clutch packs were off the shelf aftermarket units, like NAPA. Nothing special. And the stall was never right. So we started rebuilding ourselves and sent the TQ to hughes and things improved big time.

-Chris

yes. i would rather pay brett to build it than IPT. that said, IPT sourcing just the clutch packs/translab stuff is probably just as good as anywhere. i've never ran across anything definitively proving that "clutch pack A" is superior to "clutch pack B". if you know of something, i'd like to hear it. the biggest "difference" i've heard between any of the stuff on the market is a kit having 4 vs 5 clutch packs included.

p.s.

here's where i would shop for a torque converter. DSM tuners seem to think rather highly of this place:

http://www.converter.com/

[Ninja Performance]

yes. i would rather pay brett to build it than IPT. that said, IPT sourcing just the clutch packs/translab stuff is probably just as good as anywhere. i've never ran across anything definitively proving that "clutch pack A" is superior to "clutch pack B". if you know of something, i'd like to hear it. the biggest "difference" i've heard between any of the stuff on the market is a kit having 4 vs 5 clutch packs included.

p.s.

here's where i would shop for a torque converter. DSM tuners seem to think rather highly of this place:

Precision Industries (http://www.converter.com/)

Bret graduated, mech engineering, and has a real job now.

-Chris

[IPD]

Bret graduated, mech engineering, and has a real job now.

-Chris

:cry:

he was the best. 3sx just isn't what it used to be. my three favorite dudes are all gone now. i'm definitely going to have to look elsewhere now. :suspect:

[ilian51378]

Old thread, but I need the info... I am planning on installing 19Ts on my ATX AWD GTO and wanted to know if the tranny would hold up for daily driving. I am not going to go to the drag strip and abuse it. The only thing I have done to the trans is a cooler from IPT - I got the biggest one. I also bought an end clutch kit, just in case mine craps out. I plan on running about 8psi of boost for now, but I might decide to go up one day if that would be safe for the tranny. I have had the turbos on the car for the past four months with no issues. I have also installed paddle shifters. What do you guys think?

[familyMAN]

I was advised to install a trans lab shift kit also. $50-60ish off ebay. That is supposed to be great for increased reliability and shifting of course. Then for racing, do the blue wire/kiggly mod for full line pressure shifts. (I'm going with a shift box since I don't have a TCU like you.)

[IPD]

My w4a33 shit the bed. Not too surprised, since it was used when i installed it, but i got a solid couple years out of it. Shooter has my old rebuilt FWD trans--I hope it's still going strong.

I'm still looking for a shop to do the work, but the list of what i'm contemplating:

-clutch packs
-end clutch kit
-translab shift kit
-jacks spider center differential (rated for up to ~600awhp--welded is recommend above that)
-precision industries 2500rpm stall converter
-larger/thicker trans cooler
-(undecided) Quaife front LSD

I'm hoping I can find a shop that will do all the labor for under a grand.

[ilian51378]

I was advised to install a trans lab shift kit also. $50-60ish off ebay. That is supposed to be great for increased reliability and shifting of course. Then for racing, do the blue wire/kiggly mod for full line pressure shifts. (I'm going with a shift box since I don't have a TCU like you.)

I have a shift box in my car that I can use as a stand alone or with the TCU. I have a switch that lets me use the trans in an auto or manual mode. The shift box always does full line pressure shifts.

[ilian51378]

My w4a33 shit the bed. Not too surprised, since it was used when i installed it, but i got a solid couple years out of it. Shooter has my old rebuilt FWD trans--I hope it's still going strong.

I'm still looking for a shop to do the work, but the list of what i'm contemplating:

-clutch packs
-end clutch kit
-translab shift kit
-jacks spider center differential (rated for up to ~600awhp--welded is recommend above that)
-precision industries 2500rpm stall converter
-larger/thicker trans cooler
-(undecided) Quaife front LSD

I'm hoping I can find a shop that will do all the labor for under a grand.

How much HP did you run it with?

[IPD]

On my existing setup? It's probably around 250awhp. I think a stock ATX is plenty strong to handle that. A used ATX, like mine, you can't ever tell. People do stupid shit like neutral-drops in these cars....because regarded stick-shift fanboi. If you have a tip-top stock ATX & a cooler, I wouldn't worry about it until well past the 300awhp mark.

[familyMAN]

Other site has a dr650 car running 10's on bone stock auto from a jdm importer. Didn't even change the filter. Just full line pressure with toggle shifting.

[ilian51378]

Other site has a dr650 car running 10's on bone stock auto from a jdm importer. Didn't even change the filter. Just full line pressure with toggle shifting.

Okay, I will get a pair of 19Ts and hope all works out fine...

[thor'svr4]

No, the 3S AEM does not do ATX control.
IPT sucks (IMO)
Get the TC restalled and brazed at Hughes in AZ. They are the shit.
Run full ine pressure and use 2 toggles to shift thru the 4 gears.
The input shaft will snap at high HP hard shifts. 500HP and under shouldn't be an issue

-Chris

Is there any way at all to get an AWD ATX to handle higher hp for extended periods of time? Ive been told the OD shaft (?) and input shaft are weak but is there nothing us AWD guys can do for 500+ awhp daily drivers? any 300M versions of the shafts available? or awd DSM tranny that might hold?

I would love nothing more than to have an AWD ATX tranny with a high stall converter, manual valve body (or shift box/switches) and a transbrake. I even tried looking up nelsons tranny setup but i think hes running some shep dsm tranny and shep apparently isnt doing dsm's anymore... im guessing im SOL.

[familyMAN]

The awd DSM internals and our internals are EXACTLY the same. With full line pressure 1,2,3 gears will handle 500awhp no problem. The only issue is WOT shifting into OD. That's why Nelson has his car set up to rev so he can rev out 3rd gear. Many 500awhp and under OD is even fine.

If you want to upgrade... trans lab shift kit and end clutch upgrade. Maybe main clutch kit too. None of that is expensive and IPT has YouTube vids online.

[IPD]

^ Agreed. You can get all of the stuff you need to beef up the tranny for <$500. Differentials and Converter will cost a tad more.

My original intention was to run a stock W4A33 on my 500+ AWHP build, just to underscore how capable they can be. I still believe they are; I just feel that you take your chances any time you install a used trans--and mine finally gave up the ghost after 2+ years.

Shep doesn't do ATX's...and hasn't for quite some time (if ever). Kiggley recommended English Racing, so it's between them, IPT and Level 10 if you want to ship it out and have someone else do the work for you. Problem is, I don't believe any of them offer a center-differential spider upgrade (like Jack's sells), and will instead WELD the center differential. That's not something you want on a DD. I wouldn't trust Quaife center differential either (there's a LOT of stories about them breaking). Quaife fronts should work splendidly though.