Styx

I would like to add forced induction of some sort to my 2002 auto IS. The problem lies in wether to add a turbo or a supercherger. I am not looking for an enormous amount of horsepower...between 300-350 would be nice. I have heard that there are problems with adding a turbo to the auto tranny, but superchargers do not seem to add much in the way of horsepower. Any suggestions or problems that you guys have faced when adding F/I to an auto tranny? Thanks...

Styx

Does anyone out there have a turbo kit on their automatic IS?

bchau_gt

I don't have a turbo kit, but I do have a supercharger kit on an auto IS.

Now, when you say you want between 300 and 350 horsepower, is that at the wheels or flywheel power? In either case, both supercharger and turbo kits can produce that power. So the stress on the auto tranny shouldn't be that different.

You can always have potential tranny problems when you add forced induction, regardless of what kind of power you put down. That's my opinion. Some factors to consider are:
* Your driving style (do you floor it from light to light, or do you drive like a "normal" person? )
* The amount of power you do end up putting down
* Whether you will be upgrading your tranny with things like a valve body upgrade and tranny cooler, or maybe even a 3rd gear sprag replacement

I haven't had any issues with my tranny yet with over 3000 miles with my kit. I also do not drive like a maniac, nor do I floor it too often (though I may start after my car is tuned this weekend ).

There also may be a different amount of stress placed on the tranny depending on whether you have a turbo or a supercharger. Since a turbo spools up to maximum boost at a lower RPM, there may be added stress on the tranny for a larger RPM range than compared to a supercharger, which does not achieve max boost until redline. I'm not sure about this though.

Some people have also said that the auto tranny can reliably hold up to 350rwhp, some say less, but the auto tranny is stronger than the manual tranny. Then again, I've known of some people who killed their tranny with well under 300rwhp.

I think the way you drive is very key to how long the tranny will last. However, adding a valve body upgrade and a tranny cooler may help extend the life of the transmission. I'd still like to add a tranny cooler myself.

rominl

iTrader: (4)

both blower and turbo can achieve that power number at the wheels easy, no problem at all. and from what i have read so far, the auto tranny can probably handle to about 350rwhp no problem. anything more than that you want to upgrade your tranny. true or not, i dont know, buti have read a few people saying the same thing before

Styx

Define "upgrade your tranny". Will the usual valve upgrade offered by SRT, TurboEast...most other companies...will that do the trick? Most people say that with the addition of the valve upgrade and a transmission cooler the automatic transmission should be good to go. I just don't want to find out the hard way that they were wrong.

bchau_gt

The only auto transmission upgrades I know about are:
* Valve body upgrade (I have the TurboEast upgrade and like it)
* Auto tranny oil cooler
* 3rd gear sprag upgrade (I believe only PFS offers this, and possibly only to their existing customers)

Aside from that, you can get a full race tranny built I believe. You should be okay, with the above upgrades as long as you don't drive the car hard all the time.

rominl

iTrader: (4)

for an auto tranny that's what i would expect to do too. if there is a next step it would be a whole new stronger tranny imho

bchau_gt

Good point, you can always just do a tranny swap, but it's not cheap. This also brings up a good question. Something I'm not sure about is whether it's possible to swap the Supra TT auto tranny into the IS. I haven't read much on it, but I'm wondering if it can bolt up with only minor custom fabrication work and ECU compatibility issues. Anybody here know?

isman

The stock auto tranny with just a valve body & tranny cooler can hold easily 350whp of boosted duties. I've had my stock auto fully built with clutch packs, plates, sprags, along with valve body, tranny cooler and torque converter with work with. It held perfectly for 450-500whp hard hard use with my SRT stage 3 set up. It held up to 700whp on the dyno, there after it started to slip (either the torque converter or tranny...). Now, I have a 6spd v160 Supra TT tranny swaped. Bottom line the stock auto tranny is quite beefy, and will hold plenty for duties around 350whp. Good luck.

rominl

iTrader: (4)

don't hold me to it but i think it's not totally direct swap.

tsopranoMB

great post.....you have signifigant experiance with it....

I'm confident in my auto tranny upgrades...we'll see how much power it holds on both the dyno and the street/track....