99gst_racer
Moderator
- 11,976
- 1,542
- Apr 5, 2003
-
Coloma,
Michigan
I had some fun on the dyno yesterday. It was a 2WD Dynojet, so I dropped the t-case and driveshaft and hit the road. The very first pull blew the tires clean off on the rollers before we even hit 6K rpms. Love that torque! We eventually had to turn the tire pressures down to 20 psi and use some sort of spray on aerosol traction promoter to get traction. Immediately, the clutch began to slip in the 5000-6700 RPM range and slowly catching back up. I'm pushing this ACT 2600 well beyond what it's rated for and I'm surprised it's done as well as it has thus far. But, it's time for a twin disk. The blank areas on the dynograph are where the rollers weren't accurately reading due to the clutch. And when it caught, it still wasn't catching 100%.
Despite the slipping clutch, I was still able to squeeze out 609 WHP and 541 ft/lbs torque. This was at 47 PSI! But, the final pull also answered my question of whether or not the head was warped from overheating at the shootout. The head gasket popped somewhere between cylinders 2 and 3 and was pissing a stream of coolant out the back of the block. So, I'll have the head resurfaced this time around and should be all set. And I'll have to get a better clutch before I can see true and complete curves and peaks.
This power curve is gnarly! This is exactly why it's an absolute blast to drive around on the street.
We did some math and we feel it would have peaked in the 680-700 WHP range had the clutch held. And we would have started the pulls at a much lower RPM, but that was putting the clutch in an even tighter headlock.
Datalog attached.
Despite the slipping clutch, I was still able to squeeze out 609 WHP and 541 ft/lbs torque. This was at 47 PSI! But, the final pull also answered my question of whether or not the head was warped from overheating at the shootout. The head gasket popped somewhere between cylinders 2 and 3 and was pissing a stream of coolant out the back of the block. So, I'll have the head resurfaced this time around and should be all set. And I'll have to get a better clutch before I can see true and complete curves and peaks.
This power curve is gnarly! This is exactly why it's an absolute blast to drive around on the street.
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We did some math and we feel it would have peaked in the 680-700 WHP range had the clutch held. And we would have started the pulls at a much lower RPM, but that was putting the clutch in an even tighter headlock.
Datalog attached.
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