BlackVert
15 Year Member
so he pulled out at 4000 rpm? there is the problem right there. if he takes it up to 5500 or so, the horsepower numbers will be alot higher
If the vibration was bad enough at 4k for a dyno operator to stop the pull...look at replacing the HB or check your drivshaft.
14.7 A/F is generally not were people on the tuning forums have seen the best power production. The general range people seem to notice a sweet spot is in the 12.8-13.2 range N/A.
If it put down 190rwhp at 4k rpm and the pull was stopped. I would sort out the reason the pull was stopped before I was worried about 190rwhp at 4k...that is not too bad.
When I mean A/F is on its 14.7.....not all the time but the amounts are were they spose to be tuned with a chip, The gauge is off so The fuel pressure is about 40 and the guy said he set it to were it needed to be with his fuel gauge. I bought the balancer new about 5 monthes ago and had it balanced with the rotating assembly within 5 grams. But when the car idles it is kinda a lil ruff and you can feel a little vibration at the idle and when the car is reved a little. And there is a slight vib. when cruizin but I think that is the drive shaft maybe unbalanced? it is an auto shaft. This guy is the only dyno around these parts and I don't think he is the best.... But I will post the dyno sheet tonight, I also found out today that he only brought it up to 4000rpm ( because of vib.) when on the dyno so that would add a lil more power right? its spose to be 5500. but the power stops at 191whp and is a steady line acrost the sheet, with no slop in the charts.
Hold the phone, crisis averted. If he let out at 4000rpms, that's your problem right there. 190rwhp is about dead on for 4000 rpms.
Kurt
No, I'm afraid that's still low.
191rwhp @ 4000rpm = 251rwtq
He should be making over 300rwtq.
The engine was internally balanced. The RWTQ at 4000 is 255. Not sure of the clutch balance but did not vibrate when it was on my other car and was only used for about 2000 miles with the same flywheel. Just got done pressure testing the cylinders and the first one is about 100 and the rest are 120, This was a dry test with the TB closed. I Checked the torque on the heads and also the lifters and everything seemed fine. What is the next step from there? Also wondering if this could be a possible vibration maker? and what are the long term problems problems if one cylinder has a lower compression then the others? The Rings are new moly rings and installed the right way so I dont think it's them (no blue smoke) and there is no mix of oil and coolent in eather locations, so not the head gasket? So my guess would be one of the valves?
The rockers are on a pedistol mount and dont need ajusting, they just tighten down on the gt40's