Fast Too
Enthusiast
It all looks fine until you go above 12 in the 4900 to 6000 range. I would get that fixed if possible. Under boost you shouldn't have an A/F greater than 12 or detonation may result.
Squealing pulley (?) after Paxton S/C install
- Thread starter Billy Coons
- Start date
Billy Coons
Enthusiast
Now the dyno shop and DC both said just the opposite: (I believe, but I'm getting old and senile), that down low it was running rich and up top was good (considering the cats lean out the exhaust by up to .5-1.0 on the A/F a bit). 
Fast Too
Enthusiast
It is a bit rich down low, I agree with that but should be okay if your not going to tune your SS Box. 12:9 though is very lean on a boosted car however.
Billy Coons
Enthusiast
Well hopefully DC can clean it up a bit more for me. Shipping it to them on Monday... 
Hi Billy. Can you post the A/F chart? It is not unusual toward the end of a dyno run when the pedal is lifted for there to be a leaner presentation. I believe your numbers are OK. I also don't think that being a little rich down low means much. At any rate, it will only take Dan Cragin a minute to look at your chart and tell you whether you actually need anything done. By the way, you mentioned the high flow cats leaning out the A/F. Are you sure that this is true at lower RPM's? I remember that with my Roe supercharged 99 GTS, the high flow cats did not process the fuel in the exhaust as well as the stock cats at lower RPM ( below about 2000RPM ) when boost had not fully kicked in yet. With Paxton cars, which I currently have, boost does not really come on significantly until about 3300 RPM.
Billy Coons
Enthusiast
Hello, I'm unable to post the dyno sheet as it's a 3.5meg .pdf file and the uploader does not accept it. I can email it to you if you'd like? Maybe you have a way to post it here?
As for the numbers, Dan told me he wanted to clean it up a bit down low because he felt it was a bit rich. He also said he was satisfied with the higher A/F ratio at the top end.
Car runs like a ***** ape, so it doesn't feel bad..but we did notice the torque actually dropped at the lower RPM's after the install. Too rich? Higher flow exhaust?
Bill
As for the numbers, Dan told me he wanted to clean it up a bit down low because he felt it was a bit rich. He also said he was satisfied with the higher A/F ratio at the top end.
Car runs like a ***** ape, so it doesn't feel bad..but we did notice the torque actually dropped at the lower RPM's after the install. Too rich? Higher flow exhaust?
Bill
"As for the numbers, Dan told me he wanted to clean it up a bit down low because he felt it was a bit rich. He also said he was satisfied with the higher A/F ratio at the top end."
If he said it, you can count on it being true. Please email me the chart anyway. I am curious. I will PM you my private email.
Best,
Bob
If he said it, you can count on it being true. Please email me the chart anyway. I am curious. I will PM you my private email.
Best,
Bob
Billy Coons
Enthusiast
Bob, dyno sheets emailed. Thanks! Computer is getting sent out Monday. -Bill
Fast Too
Enthusiast
Good luck Billy, Bobpantax is providing you good insight and recommendations. Hope all turns out well. I have an A/F gauge in the car, and that is something you might want to consider in the future. Relatively easy and cheap to install and could save you an engine failure down the road should one of those paxton fuel pumps fail and you go lean unbeknown to you. As Bob said it is normal for the car to go lean at the end when getting off of the car, but in my application it goes very rich for a second before doing so as the injector pulses cannot keep up with the VEC signal.
Billy Coons
Enthusiast
Thanks! On my dash above the radio console, I have the AutoMeter DSS shift light, Boost Gauge and wide band A/F ratio guage, and they read dead on with the dyno during our pulls. Very happy with the gauges. Only wish someone make a nice 3 gauge dash pod or a-pillar for the SRT-10's. Generic ones wouldn't work, had to use individual cups. :-(
Fast Too
Enthusiast
Very smart move on the gauges. I am looking for a good double pod as I want a boost gauge in the car. Something interesting you said though, if your reading dead on with the dyno, then how can the CATs be accounting for a leaner mixture up high? The **** for the wideband should be installed upstream of the CAT
Billy Coons
Enthusiast
Very smart move on the gauges. I am looking for a good double pod as I want a boost gauge in the car. Something interesting you said though, if your reading dead on with the dyno, then how can the CATs be accounting for a leaner mixture up high? The **** for the wideband should be installed upstream of the CAT
Now that's a darn good question! Looking back, I was staring at the A/F gauges during the runs. Afterward, I compared what i remembered seeing to what was on the sheet, and it looked pretty consistent. Could have been some minor differences though. Oh well.
