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Went to the dyno today to see how the car does but had a little trouble. Doing 4th gear runs the engine would rev up to around 6000 rpm where it would just kind of stay, the operator wasn't sure what the reason could be. Rev limiter is set to 6800 and it does hit this on the street.
The car runs great, but the results are a little disappointing and I'm not sure that they make sense or if something was wrong?
Car has 26" tires and 4.10 gears, engine is an LS1/M6 mafless, mods as follows:
- 228/228 .600 112 lsa
- PAC dual springs .660
- LS7 Lifters
- 7.4 Pushrods
- Stock 799 heads
- Stock LS1 Intake
- Catless 1 7/8 Headers, Speed Engineering true duals
- Melling high pressure pump
- SLP FloPac
- 11.8-12.2 afr, 24-26 degrees timing
The graph is in mph, the horsepower and torque scales are the same.
Does anybody have any ideas? Does the torque reading seem low? What does the small spike in torque at the end of the run where it doesn't want to accelerate anymore mean?
I'd recommend checking your header primaries - possible dead or partial cylinder.
You mean check the temperatures? Good idea, should it be just at hot idle or after some spirited driving?
Originally Posted by Mike@Diablosport
I see 2 pulls that ended at different places, RPM on the graph would really help.
I'll see about getting some of the runs with with engine speed. These are just the two he sent me when I asked, I did 8 or so while there. Is it just a few clicks away for the shop or will I need to run again?
You mean check the temperatures? Good idea, should it be just at hot idle or after some spirited driving?
I'll see about getting some of the runs with with engine speed. These are just the two he sent me when I asked, I did 8 or so while there. Is it just a few clicks away for the shop or will I need to run again?
any time you want. Just to make sure all the primaries are all about the same temperature
Going to see about putting it back on the dyno next weekend and actually saving my hpt logs and getting graphs with engine speed this time. I've read that the f-body tach is a little slow so maybe I really was at the rev limit? That doesn't explain the poor torque though, surely the LS1 intake isn't entirely to blame? I will be looking for an LS6 intake anyway.
I'll look into doing a leak down and compression test too I think. Should also mention coils are at least 2 years old, plugs are one step colder factory gapped tr6 iridiums and it has brand new msd wires.
As for primary temperature, they were all within 20f of eachother (190-210f).
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