Tuning new Mass Air and 30lb injectors

289 · 11-21-2006, 11:33 PM

Hi I was wondering can anyone help me tune my 89 GT. I just put a new 76mm Mass Air and 30lb injectors. The motor has a Steeda #19 Blower/Nos cam, Elderbrock performer RPM intake 65mm TB full 2.5 exhaust with mid length headers, stock heads, and I'm running a 155lph pump and I have an adjustable regulator. I was running my stock Mass air with 19lb injectors at about 40psi at idle. Can I just bring my pressure down.
Thanks

Jeff Chambers · 11-22-2006, 07:34 AM

Shouldn't be any need to adjust anything if the MAF and injectors are calibrated. The calibration works to keep the necessary pulsewidth throughout the entire operating range. That being said, the calibration curve of the MAF is key. ProM had pretty bad calibrations, Granatelli's have been pretty good and the PMAS are even better. C&L tend to be a little lean in the lower range. The best thing you can do is find a competent tuner in your area and have the entire combination tuned with a custom PCM calibration (chip). When I tune a car, I always set the FP to 39-40 with the vac off and base timing at 10-degrees. All adjustments are then taken care of in the custom programming for optimum performance and driveability.

USMC302 · 11-24-2006, 08:05 PM

It would be better determined with a wideband as well. Which is what tuner would use. You could also always use the old track testing method, start around 42psi, and bring it down a quarter turn after every pass, watch your MPH and when you start to slow down, bring it back up a quarter turn and your there. Good luck!

11-22-2006, 07:34 AM	#2
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Re: Tuning new Mass Air and 30lb injectors Shouldn't be any need to adjust anything if the MAF and injectors are calibrated. The calibration works to keep the necessary pulsewidth throughout the entire operating range. That being said, the calibration curve of the MAF is key. ProM had pretty bad calibrations, Granatelli's have been pretty good and the PMAS are even better. C&L tend to be a little lean in the lower range. The best thing you can do is find a competent tuner in your area and have the entire combination tuned with a custom PCM calibration (chip). When I tune a car, I always set the FP to 39-40 with the vac off and base timing at 10-degrees. All adjustments are then taken care of in the custom programming for optimum performance and driveability. __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"

11-24-2006, 08:05 PM	#3
USMC302 Registered Member Join Date: Apr 2001 Location: Gallatin, Tn Posts: 1,326	Re: Tuning new Mass Air and 30lb injectors It would be better determined with a wideband as well. Which is what tuner would use. You could also always use the old track testing method, start around 42psi, and bring it down a quarter turn after every pass, watch your MPH and when you start to slow down, bring it back up a quarter turn and your there. Good luck! __________________

11-21-2006, 11:33 PM	#1
289 Registered Member Join Date: Jan 2000 Location: Mount Joy, PA , U.S. Posts: 198	Tuning new Mass Air and 30lb injectors Hi I was wondering can anyone help me tune my 89 GT. I just put a new 76mm Mass Air and 30lb injectors. The motor has a Steeda #19 Blower/Nos cam, Elderbrock performer RPM intake 65mm TB full 2.5 exhaust with mid length headers, stock heads, and I'm running a 155lph pump and I have an adjustable regulator. I was running my stock Mass air with 19lb injectors at about 40psi at idle. Can I just bring my pressure down. Thanks