Why is my 2.5 str not hitting hard?
Thread Starter
TECH Enthusiast
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Joined: Jul 2005
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From: Rain Island, NY
Why is my 2.5 str not hitting hard? I have 2.73 gears, SS3600 2.5 str i just installed, & stock power. Today i was testing the converter out. It is 90 degrees out and the nittos are sticky.
The firts hole shot did not break the tires loose & it felt soft. The 2nd time it did break loose & still felt soft. Punching it from 20 did not break loose. WTF?
Could this be torque management? Does this have to do with the reduced HP from the converter? Or just the way it is for the set up i have now?
The firts hole shot did not break the tires loose & it felt soft. The 2nd time it did break loose & still felt soft. Punching it from 20 did not break loose. WTF?
Could this be torque management? Does this have to do with the reduced HP from the converter? Or just the way it is for the set up i have now?
I wasn't really that impressed with the 2.5/2.73 combo in my car either. I agree that a tune will help but your not going to have the car sideways from a 20mph roll. Just hit the nitrous next time and it will feel better. 
On The Tree
Joined: Sep 2004
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Hmmm I think my str is 2.7 in my TCI and with the 3.42 gears it felt insane when I installed it in January, in the summer it feels pretty good still, but nothing compared to that 0 degree winter air 
Very impressive for what little I have done!
Very impressive for what little I have done! I ran nittos at the track with full bolt-ons (ST 3500 converter) plus 3.23s and got well heated nittos to stick. I realize you are on the street, but the whole object of good tires is too stick. I'm not surprised that in hot weather those tires actually hold on a 2.73 car.
If the car hesitated, I'd look at TM as the culprit. If the rpms jumped up and the car pulled solidly from the punch, the converter is doing its job. At a 20 mph punch, the torque multiplication is a lot lower than 2.5 because your output shaft is not anywhere near zero rpm.
I'm not sure by "soft" you mean weak, or you didn't feel a violent launch. Even a high STR converter should launch smooth. It would be nice to see your current 60'. Its a lot easier to see problems when you have the before & after.
If the car hesitated, I'd look at TM as the culprit. If the rpms jumped up and the car pulled solidly from the punch, the converter is doing its job. At a 20 mph punch, the torque multiplication is a lot lower than 2.5 because your output shaft is not anywhere near zero rpm.
I'm not sure by "soft" you mean weak, or you didn't feel a violent launch. Even a high STR converter should launch smooth. It would be nice to see your current 60'. Its a lot easier to see problems when you have the before & after.
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Originally Posted by THE LAST Z
Ill try it on a cooler day next time....see what happens. It wasent a "violent launch" like your saying ragtop 99.
The car should not need a tune to notice the effects, I have not, and mine hits hard enough to where I have to be careful with the throttle on launch (Nittos also) or I am spinning bad. It hits fairly hard I would say.
Are you stalling it up, or flashing it? That can make a big difference. I break loose on even a half-throttle flash (without any tire warm-up though, I don't think it would if they were sticky).
Are you stalling it up, or flashing it? That can make a big difference. I break loose on even a half-throttle flash (without any tire warm-up though, I don't think it would if they were sticky).