To evaluate the MAP at WOT, you need to compare it with the barometric pressure. Did you also get that off the data log? Do they print it on the timeslip? Is there any possibility that there was a "low pressure" front in the area (usually accompanied by rain, so not likely)? If not, the standard barometer at 1,200-ft is about 97kPa, so you are losing 7kPa in the intake track. Thats about 2"Hg, and that seems like a lot to lose. Anything in the intake track could be contributing to the pressure loss. The TB would be a contributor.

 

Fred, if the barometer is printed on a timeslip, how do you calculate kPa, better yet what is "kPa" for us beginners? And how do you go about reading the kPa, Datalog? Care to elaborate to me. Thanks!

 

The "pascal" is a metric system measure of pressure. 100 kPa (kilo pascals) = 1 bar = 14.5psia = 29.53"Hg. 14.5psia is the "standard" metric system atmospheric pressure. In the English system, "one atmosphere" = 14.7psia = 29.92"Hg = 101.4kPa.

You can read the barometer and the MAP from your PCM with a scanner. You can measure vacuum with a vacuum gauge, read the barometer, and calculate MAP if you don't have a scanner.

MAP + Vacuum = Barometer

Barometer - MAP = Vacuum

 

Im not sure if the datalog shows barometer reading, i will check that when i get home. The logged runs i have arent from the the night i raced, not that my track gives weather conditions anyway.

 

Discovered some major problems on the dyno today.


My A/F was 18:1. The tuner said he had never seen a car that lean before.

I put a fuel gauge on it and at idle i have 40 psi, but WOT it drops to about 20psi. After a new filter it still drops to about 30psi.

What do you think, pump or regulator??? WHich to replace first?

Car put down 318hp and 350tq. It was a dynojet and those numbers are corrected.

 

God dam! 18:1 and no fuel pressure at WOT!!!! Well I think you found the problem.

Bret

 

Yeah, im going to put a fuel pump in it, verify the pressure and try to get back to the dyno maybe next saturday.

Im glad i didnt wait to long to get to the dyno.

 

not sure if anyone mentioned this in the thread, but arent those TR6's for nitrous?

ive read people with nitrous setups say they lost power n/a with the TR6 plugs.

i think the TR55 is better for n/a.

 

yup...I did also. We had to shoot about 4 degrees more of timing just to get the cylinder to proper operating temp. Swapped to the Tr55, and pulled the 4 degrees back out, and made the same power that the TR6 with +4 did.

 

update

http://web.camaross.com/forums/showthread.php?t=354880