Hi,
Wanted to know what air fuel ratio you guys with the Comptech SC are at.

I am at 13:1 to 13:3 at WOT.

Seems to me that it is a bit rich. Wanted to see what every one thought.

Thanks
Rich

 

Definitely lean for FI.

I used to run 13-13:5 WOT for roughly 5,000 miles, this was with VAFC tune. Although I never ran into any issues, I never had that reassurance that the engine would last.

I'm currently running 11.5 WOT and running with confidence. Usually with FI, people try to target 12:0. Running rich with FI would be below 11:0. I'm tuning with AEM EMS.

I believe N/A motors run at 13:5 WOT.

I would definitely up the fuel pressure through the FPR.

Good luck.

 

I run at 12 to 12.5 at WOT with my Comptech supercharger.

 

Same with me...12.0 to 12.5.

 

OK,


I am asking because I have the AEM wideband air fuel ratio.

My car back fires after I let off the gas. So if that is lean why is it back firing?

I talked to AEM the guy said "14.75 is were you want it" ?

Now I'm

 

I used to have backfire when my A/F was in the 13's. This was caused by the testpipe. I use to run it to redline an let off, this would cause a torch type backfire.
Now, I back fire every time I shift hard hitting redline.

Definitely try to lower you A/F readings to under 12.5. The best thing to do is to dyno it and tune it via emanage or aem ems.

AEM probably misunderstood you, try calling them back to confirm.

 

13?? yikes, you need to bring that down to at least 12. Back when I was ridiculously turbocharged I ran at 11.7-12.5 under full boost (11psi). When I was all motor (12:1 compression) I ran a little leaner a/f (around 12.5-13) which your able to get away with. You should only be at 14.75 at idle, never while under WOT, thats just ridiculous!

 

Thanks guys.

 

Sometimes when you backfire you can shoot to much gas through the intake and out the valves and the heat from the exhaust manifold could have you backfire as well too.

 

Yup much too lean, want to be around 12's.