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Discussion Starter #1
I have a couple of questions about torque converters, I am running a 83 Grand Prix with a 454 chevy, 425 hp, 4.56 gears,Mosser 12 bolt, 238/540 cam, 31x14x15 inch tires and weight is 3000. I had this motor in my vette with a 2800 stall, ran great 12.85 1/4 mile at 103 mph, car weighed 4000 with 3.73 gear. Now in the new car I am running a 3300 to 3500 stall with balloon plate for 150 shot of nos. I have not run the nos yet, I can't get the car to stall above 2300, 60 foot times are bad at 1.6 leaves the line like a dog and runs 1/4 in 12.65 at 101 mph. Can anyone tell me what might be wrong? I sent the converter back to the company that made it they said they loosened it up, but still acts the same. Should I go to a 4.11 gear? New at building drag cars any help would be appriciated.
THANKS
 

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Going up in gear will effectively tighten the converter. What do you mean you can't get the 3,500 out of it? Are you trying to footbraake the car to its rated "stall" rpm? If so, it doens't wokr like that as it will wind up being alot lower and won;t see the full flash rpm until the engine is under a load. Cruise around in high gear at like 20 mph and throttle it hard while watching the tach and see where the tach goes before the car really wants to plant you in the seat and move. That will tell you where the converter goes unde a load, but since the converter doesn't see that much of a load in low gear while footbraking you won't see the true flash rpm. The added gear will help the launch, but tighten the converter a bit, so you will need to have it setup for the 4.10 gear. The adjustment inside of it is different when they set them up for specific applications and gearing.
 

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Discussion Starter #3
Kris, yes you are right I was trying to foot brake the car. Can you tell me why my speed and times seem to be off? Is it the gears, or can the converter not be performing at its max because of not useing the Nos? Thanks for the reply that helps me understand how the converter works.
 

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It is the converter. If it flashes to 3500, it will do so under a load and you won;t see it when footbraking the car. Do the drive test in high gear and throttle it and see where it goes beofre the car picks up and goes. It could just be a real tight 3,500. You have a real mild engine combination, so with a 150 hit, the converter should flash to about 3800-4k, which will be nice for a 6-6200 shift point. You can go looser on the converter with a low flash rpm to help the car leave and e/t better. But it is the converter that is keeping you from e/t'ing well. If you go with more gear, which it may like as well, you will tighten the converter and will need one that now flashes higher and is looser to make up for it. 3.73 is not alot of gear for a 4k lb car. But if streetability is a concerne, and you shift low, use it and run the right converter.
 

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Discussion Starter #6
Thanks for the reply guys!! The 2800 stall is in my vette it would foot brake to 2500 to 2800. The car I have the 3300 to 3500 stall has 4.56 gears and still leaves the line slow I will check the stall in high gear as Kris said and see where I'm at. The car also does not seem to pull as hard on top end with this converter, but it is set up to run the NOS and I haven't ran it yet I was trying to get the car set up first.
 
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