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Discussion Starter #1 (Edited)
I am making tentative plans to covert my '97 Auto to a single turbo setup in January of this coming year. The car has about 30,000 miles on it. I have yet to actually decide on a turbo, however it will most likely be along the lines of an SP-66 or 63, point being that is will be capable of near 600 rwhp in an auto. Obviously the stock tranny is not going to like this type of power and I need some suggestions as to how to go about dealing with this. I am sort of having an internal debate as to whether or not to upgrade the tranny (probably to an SP tranny due to the success rate) at the same time even though it is running fine currently. The upside to upgrading now would be no worries, while the upside of waiting would be easier on the wallet. The downside to doing it now would be that my stock tranny is running great and it would cost $$$ for the upgrade, and the downside of waiting would be if it breaks withing 1-2 months I will have wished I had just had it done while the car was already out of commission at the shop.

OK, I currently have a B&M tranny cooler and PI converter.

I guess my first question, which is difficult to answer, is how long will the stock tranny put up with a turbo setup like this? Is it going to go out on me the first pass I make on the track at high boost or can I reasonably expect better?

If I choose not to upgrade the transmission, eventualy it will give out. Is it possible to break the stock tranny to the point of complete failure instantaneoulsy, or will it likely give out over a time period and be driveable at least to the shop? Will either of these leave me with a greater expense bill than if I had decided to upgrade it when it was running fine?

Can I break anything else on the car as a direct result of the stock tranny going out and choosing not to upgrade it until it fails? Basically, would choosing to wait until the stock one gives out be stressing any other part other than the tranny and converter?

Finally, in your opinion, weighing the cost of upgrading the tranny (which is obviously diferent for every person), would you elect to upgrade it at the same time or be more inclined to simply wait until it falis? Why?

Thanks in advance.
 

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I'm not an auto guy, but I'll take a stab at it.

Seems to me what breaks autos is torque, and heat. If you deal with the heat issues by using a good, fan-equipped tranny cooler, and refrain from either running high boost, or using it all the time on the street then the stock tranny could last a while before the inevitable upgrade.

My guess is the clutch packs will start to slip first, you'll start banging into the rev limiter when the car shifts from 1st to 2nd. This would be an early warning sign to get ready to drop the transmission for a rebuild.

How much boost (torque) do you plan on running on the street, are you going to drag the car often?

Remember, this advice is worth what it cost. :)

I bet you could get away with the stocker for a good while if you don't run it hard.

Edited to remove reference to stock converter, noticed you have the PI
 

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supreme,

I have an '98 auto and have owned 4 total mkiv's,all autos
except 1 na i got in trade,all have hit the rev limiter after
downpipe,and exhaust were added so i dont think it was
a sign of tranny failure,it just revs up faster,it changes gears
@ 6800,rev limiter is @ 7200 i think,so before our smooth
changing tranny can make the change 400 rpm have went by,
anyway i have a sp57 on the way,and im sure gonna keep the
factory tranny for now,i also have less than 30k on car,i have a
pi 3800 and cooler mounted directly in front of clutch fan,

randy
 
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