Dyno update from STM tuning
Its been a long day and I won’t have time to share all the details yet. I haven’t looked over the logs carefully enough but at the end of the day we are out of injectors. We were seeing 95 to 100 percent duty cycle and the link said we were at 52.9lbs/min flow so although we could turn the boost up for a quarter mile run it wouldn’t work for road racing.
We did a bunch of pulls at 22psi and then one at 24psi. The next pull we tried for 25psi but it hit 30psi instead. On that run Emery got off the gas at 6000rpms. That run made 372hp and was climbing fast. It was also without any knock.
We pulled the plug because the oil leak on the turbo drain line was getting worse and with the injectors running at there max and the turbo already at over 52lb/min there was no point. We also didn’t run the car past 7500rpms and in fact we did most of the tuning running up to only 5500rpms. The goal was to get it running right before we turned up the wick. That’s why there were a bunch of 300hp numbers coming out.
At the end of the day the car is running 25psi on pump and meth making 355hp on a Mustang dyno scaled for a 4000lb car. If the scaling was set to the cars real weight the numbers would have been higher but I am not a big fan of dyno numbers. I know two cars that came off that dyno that made at least 60hp less that run 11.9′s at 115mph. That puts us firmly in the 120′s where I wanted to be.
There are a few things that could wring out more power from the car. First is injectors. It will make power at 100% duty cycle but I think the torque curve showed the break down in the spray patten. 850cc or even 950cc would be better suited for the job. On a good note guess how much power it takes to max out 660′s? Over 400hp to the wheels so we are in a good place. Cam gears would help and so would a better set of cams. The car has 272/264 HKS and I think they ad to the fat torque curve but more exhaust cam would help.
I’ll work on a blog with more details tomorrow but for now I am happy and the One Lap VR4 is fast.
