Wednesday Results

[GNAT87]

So we were working on the car yesterday and ended up getting it on the dyno. After a few pulls we maxed the 60lb injectors out. So finally i found some 83's picked them up and put them in. At the end of the day after tuning and getting the car dialed in the 83's are at 92% duty cycle. I figured with the mods i have i couldnt come close to maxing the 83's out and especially at my power level...I was looking at dyno numbers and see people on the board with anywhere from 450 to 500 rwhp with 60's and even one had 42.5's pushing somewhere around 460 at the wheels. You guys thing there could be a problem anywhere?

Also anyone close to my numbers got track times yet?(see signature) Its a full weight car...just trying to get an idea of what to expect this weekend

Thanks everyone for the help in advance

Wasnt sure where to post this type of thread

 

[John Wilde]

What is your fuel pressure doing at max boost?
To me it sounds like your fuel pump is junk.
IMO you are not making enough power to have those injectors
at 92% DC. I am too tired to do the math but those injectors
should be good for over 800RWHP.

 

[ITSNOTAGN]

agreed, the 60lbs'ers are good enough to get you into the low 10's/hi 9's, and 83's, like john said will do some serious power. According to my EFI calculator, at 11.5:1 AFR, 6 83lb injectors will go close to 1000whp at 100%. You my friend just wasted your money, look at your fuel pressure.
Gary

 

[GNAT87]

I will check the pressure today. What in tank pumps are you guys running? I have a single walbro 340. Do yall think that could be it? Should I look for the double pumper?

 

[ITSNOTAGN]

A single 340 is good to 600whp on most applications. If its not up to par, then you either have a loose line in the tank or the pump is bad. Hope you get it sorted out
Also what i do if i suspect a problem is hotwire the pump on and close the FPR, it should max out a 100psi guage and then some. If it doesnt drop the tank and check the inner hose for tightness, and repeat. If still not good change the pump.
Gary

 

[gnmaster2004]

I had a similar problem, there was not enough voltage at the injectors.
I bought a inj. hot wire harness from Racetronics, now i have 14 volts
at the inj. and a lot less duty cycle.

 

[we-4brett]

the car has a fast on it and i cant see the injectors not having enough voltage. but possible.

 

[HighPSI]

You may want to consider getting a pressure sender and logging the fuel pressure. Your setup appears similar to the GM High Tech buildup. We hit 559 rwhp at the same boost with the same turbo. We were only using 72's at a much lower duty cycle.

 

[GNAT87]

wow...i need to figure it out... Do you know where i could find that GM write up?

 

[we-4brett]

im thinking it has to be a problem with fuel delivery as well. either the car has low fuel pressure or it is running out of fuel pump in the higher boost levels. possibly could be a injector voltage problem, but just dont see that with a fast set up. im thinking it may need twin pumps or the fuel pressure raised. what do yall usually run the fuel pressure at with about this set up??

 

[we-4brett]

A single 340 is good to 600whp on most applications. If its not up to par, then you either have a loose line in the tank or the pump is bad. Hope you get it sorted out
Also what i do if i suspect a problem is hotwire the pump on and close the FPR, it should max out a 100psi guage and then some. If it doesnt drop the tank and check the inner hose for tightness, and repeat. If still not good change the pump.
Gary

may drop the tank and check the line from the pump to the feed line. i have had alot of problems with that in one of my customers cars.

 

[John Wilde]

Change the fuel filter too.
That is cheap and only takes a couple minutes.

 

[jetmech]

Im running low 11's on the 60's at about 90% duty cycle at around 26-27# boost. But my bottom end has 130k on it

 

[John Wilde]

Also can you please post the dyno sheet?
I am curious why the RPM was limited to 4800.
Did you data log the dyno pulls?
I bet Cal could point you in the right direction.

 

[Quick6'n'-K.C.]

Im running low 11's on the 60's at about 90% duty cycle at around 26-27# boost. But my bottom end has 130k on it

Odd, car in my sig with the same turbo and boost numbers is running about 90% duty cycle with 009's, also running low 11s. I am using a tad bit of methanol to cool the intake air temps.

Are you sure your pump isnt weak? You must have ported heads and a heavier car??

Take it easy
BW

 

[GNAT87]

Guys yall are great and thanks for the help ....BAD NEWS...so i was at the track earlier and on my first run something went wrong, way wrong. I left the line got about half track and white smoke started poring out of my exaust. I stopped at the end, poped the hood and oil was blown everywhere but mainly on the passenger side. Its knocking bad now. I put in on a trailer and got it home. I checked the oil and it was black so im guessing it wasnt a head gasket. Any help would be greatly appreciated on guessing what might have happened. Me and we4brett might start pulling the motor appart next week. Weve got pinks coming in late march so im going to do my best to get it back on the road....What i would like to do is find the problems, fix them, maybe new heads and a roller cam, clean everything up, and talk to Cal about getting it tuned by him down at there shop

 

[HighPSI]

wow...i need to figure it out... Do you know where i could find that GM write up?

GM High-Tech April 2007

Part VI - Tech - Power Trip - 559 HP 550 TQ - GM High-Tech Performance Magazine

 

[HighPSI]

What i would like to do is find the problems, fix them, maybe new heads and a roller cam, clean everything up, and talk to Cal about getting it tuned by him down at there shop

Sorry to hear about your luck. Let me know what I can do.

 

[John Wilde]

Guys yall are great and thanks for the help ....BAD NEWS...so i was at the track earlier and on my first run something went wrong, way wrong. I left the line got about half track and white smoke started poring out of my exaust. I stopped at the end, poped the hood and oil was blown everywhere but mainly on the passenger side. Its knocking bad now. I put in on a trailer and got it home. I checked the oil and it was black so im guessing it wasnt a head gasket. Any help would be greatly appreciated on guessing what might have happened. Me and we4brett might start pulling the motor appart next week. Weve got pinks coming in late march so im going to do my best to get it back on the road....What i would like to do is find the problems, fix them, maybe new heads and a roller cam, clean everything up, and talk to Cal about getting it tuned by him down at there shop

Man I feel so bad for you!
I was going to send you a pm about not running the car until you had the issue resolved but was taking care of my son all morning.
When you get the motor back together please have someone go over everything with a fine tooth comb.

 

[GNAT87]

This next week were going to start the work. I will let yall know how things turn out. If the motor ends up coming out of the car I am definatly doing the upgrades ive been looking forward to and going with a girdle or billet main caps. Which do yall think? Cal I will hopefully be contacting you in the near future for a few parts and maybe talk to you about tuning the car if your available, thanks for the link too...Thanks everyone for the support

Taylor