andymoraitis
15+ Year Contributor
- 3,241
- 153
- Jan 25, 2004
-
Utica,
Michigan
I was wondering if some of you more experienced tuners could give me your feedback in an attempt to solve some of the issues I'm having. Here's the short mod list to save you time
Big 16G at 20psi
Stock SMIC
Full 3" exhaust with 3" high flow cat
ACT 2100 w/chromoly flywheel
FIC 550cc injectors
Injen Intake
Buschur Upper I/C pipe
1G Bov
Walbro 190
Keydiver Stage III chip w/EPROM ECU
Now, to the problems. I've tracked this car twice and both times I had poor results in terms of getting any serious top end performance from it. The first time, I ran 14.0 @16psi and trapped 100 MPH. The second time, I tried a better track and ran 13.6 @20 psi trapping the same 100 MPH. While I have launch issues which may be due to an improperly broken in clutch (best 60' is 1.98 and I KNOW how to launch), the slow traps are bothering me. In an effort to check everything, I did a boost leak test and the system held 20psi for 30 seconds easily. Compression across all four is 175-175-180-175.
I consulted with Jeff at DSM Chips and his feeling is the car is running too rich and that we can adjust for it in the chip. FYI, he runs the factory A/F at 9.5:1 with maximum timing of 16 degrees. I recently replaced all plugs with fresh NGK's before running it again and upon removal, all of them had some carbon fouling around the lower threads and around the insulator. The inside of the tailpipe is black and if I rev it to 3K, it will splatter black garbage all over the driveway. In addition, I also get some mild rich backfires when shifting between 3500-4000 RPM in any gear.
Anyway, we're adjusting the chip, and Jeff worked all night and created three new chips for me:
1. 11:1 A/F with max 16 degrees timing
2. 11:1 A/F with max 22-23 degrees timing (for race fuel)
3. 10.5:1 A/F with increased timing (I'm assuming somewhere around 18-19 degrees)
I'll be picking up a logger in the next week so that I can have a better read of what's happening, however I wanted to ask the people who are making strong horsepower on their stock blocks what A/F ratio they tune for. I've corresponded with David Buschur and he thinks 11:1 is still too rich, but then again, I can turn up the boost to lean it out on pump gas (as long as I encounter no knock).
Any feedback on the optimal tuning ratio would be helpful. While I understand that there's no perfect combo, I'd like to feedback from the experienced tuners on what they shoot for so that I have a baseline.
Thanks!
Andy
Big 16G at 20psi
Stock SMIC
Full 3" exhaust with 3" high flow cat
ACT 2100 w/chromoly flywheel
FIC 550cc injectors
Injen Intake
Buschur Upper I/C pipe
1G Bov
Walbro 190
Keydiver Stage III chip w/EPROM ECU
Now, to the problems. I've tracked this car twice and both times I had poor results in terms of getting any serious top end performance from it. The first time, I ran 14.0 @16psi and trapped 100 MPH. The second time, I tried a better track and ran 13.6 @20 psi trapping the same 100 MPH. While I have launch issues which may be due to an improperly broken in clutch (best 60' is 1.98 and I KNOW how to launch), the slow traps are bothering me. In an effort to check everything, I did a boost leak test and the system held 20psi for 30 seconds easily. Compression across all four is 175-175-180-175.
I consulted with Jeff at DSM Chips and his feeling is the car is running too rich and that we can adjust for it in the chip. FYI, he runs the factory A/F at 9.5:1 with maximum timing of 16 degrees. I recently replaced all plugs with fresh NGK's before running it again and upon removal, all of them had some carbon fouling around the lower threads and around the insulator. The inside of the tailpipe is black and if I rev it to 3K, it will splatter black garbage all over the driveway. In addition, I also get some mild rich backfires when shifting between 3500-4000 RPM in any gear.
Anyway, we're adjusting the chip, and Jeff worked all night and created three new chips for me:
1. 11:1 A/F with max 16 degrees timing
2. 11:1 A/F with max 22-23 degrees timing (for race fuel)
3. 10.5:1 A/F with increased timing (I'm assuming somewhere around 18-19 degrees)
I'll be picking up a logger in the next week so that I can have a better read of what's happening, however I wanted to ask the people who are making strong horsepower on their stock blocks what A/F ratio they tune for. I've corresponded with David Buschur and he thinks 11:1 is still too rich, but then again, I can turn up the boost to lean it out on pump gas (as long as I encounter no knock).
Any feedback on the optimal tuning ratio would be helpful. While I understand that there's no perfect combo, I'd like to feedback from the experienced tuners on what they shoot for so that I have a baseline.
Thanks!
Andy