Hey all, first post. For curiosity sake, how much aftermarket power can be safely added to a GT with an auto tranny? I remember reading that someone had mentioned a 30% rule. With that in mind a 90HP increase would max you out. I just read the specs on a Saleen and they sell the supercharged model with either tranny.

Also, how would one go about upgrading the auto tranny to reliablly handle more power? Thx.

 

I don't know about the rules for adding power to a trans, but this trans probably doesn't have any aftermarket heavy duty parts available for it. It also didn't start out as a heavy duty trans, being based on the C3, if I recall correctly. I share your concerns, as I have an auto on order, but question this trans' durability behind a V8.

An aux trans cooler would be the first mod I'd make to the car.

 

I asked the same question over on a forum where they know almost everything and never did get an answer. If Bryan goes through with his mods and adds the blower we will all fine out. Hurry up Bryan.
ROLL ON

 

Thanks guys,
Since I never seem to leave well enough alone when it comes to cars. I'm afraid that if i order the auto, I'll be trading it in for a manual later. I've been watching this forum to see what works and what doesn't. So guess we'll just watch and see.

 

Typically, components in a car are designed with a 10-20% extra margin.

So I'd speculate the transmission would work indefinitely at 330-360hp (at the crank). That is not to say it will not perform fine at higher levels, but I would not say "indefinitely."

Since this tranny is a fleet tranny used in the T-Bird and LS, it may actually have been over-designed even more, in anticipation of using it in beefier vehicles.