I was on the Dyno Last Friday getting some tuning done and I was told that the Vig convertor was slipping badly on the Dyno on the first run. One the first run with no adjustments my car made 427RWHP and ~550REARWTQ, actually the highest level of torque was at 572RWTQ when the convertor started slipping. The car with the current cam and boost should have made power too about ~5600rpms but because of the converter slipping it took a nose dive at 5100rpms. One the first run, the guy dynoing my car said that immediately before we looked at the graph that the converter is taking a dump and is not holding, he could feel/hear it when he was mashing the pedal down. On the second run, it was pretty much gone, it would not put the power down to the rear wheels, only like 270 REAR Wheel HP. I was shocked to know that this would happen to a vig converter so I wanted to see if this has ever happened to anyone else. The car is at Dynotech Performance shop now and the trans is getting a full shake down but the popular consencious is that the converter is the culprit, the trans was built with better parts to handle 650Flywheel HP from Dynotech performance with better clutch bands, sun beast shell, shift kit etc, etc. If it would have held up the car would have made somewhere in the niehborhood of 450RWHP and mabee more cause they were able to add some more timing and the motor loved it. Byran Herter was the one that did my Dyno tuning and he said if I could have gotten a clean run the car should make AT LEAST 450+ REAR wheel HP with the converter holding and the extra timing he added after it made 427RWHP.

Anyways, I just wanted to see if anyone has ever experienced this with a vig converter.

Thanks,
Claude

 

I would have the trany checked first because if the 3-4 clutch set up is not perfect it will slip. You will know when you drop the pan if it is the trany. I have been racing these converters for a long time and have never had a problem yet. If the trany is gone with a lot of metal in the oil I would send the converter back to PI to be cleaned and checked. One way or the other you may want to sent it back any way to be checked.

I have been racing the 4L60E since 96 in a 96 Trans-Am. I hooked up with Pro-Built last year and for the first time I made a whole season with no trany problems. I was running consistant 10.20s with a 1.32 60ft with this car and when I took the trany down this winter I put back together with the same cltuches. I make an avrage of 500-600 runs a year on the car.

 

Thanks for the reply broh...I am having them check the entire trans out this week. The one thing that I found funny is that the car now feels slushy in all gears, before when I burnt out 3-4 gear, the car still shifted fine in first and second and did not feel slushy as it does now. Plus the guys at the Dyno was almost convinced it was the converter. I guess I will know for sure later this week when I hear back from Dyno tech.

What kinda of clutch-bands are you using for 3-4 Gear?
Alto? or Raybestos?

Thx,
Claude

 

I forgot to ask you, how much does your car weigh and how much was the price your trans ?

Thanks,
Claude

 

Lock the convertor and redyno. Then you'll know for sure if it's the convertor or not. If it still slips when the convertor is locked, it's a tranny problem.