Ok, last night I was tuning my friends SS S/C. We got the timing down, to zero knock with the occational 1.2 or whatever spike here and there. The tune I gave him had the PE table starting at 1.30, then moving gradually towards the end at which is was 1.27.
When we were scanning his car for knock, I also looked at the IDC which was at like 78% at 5000 rpm. I looked at the commanded AFR, and it would start out at 11.4, then go to 11.1, then 10.8, then at about 6500 rpm it drop to 10.1!!! WTF!?!? Its like his car was completely ignoring the PE table! I looked and his stoich AFR was 14.699 whatever, so it wasn't changed or anything. I don't get it! Now I don't know if the COT would effect it THAT much, bit since he still has a cat I left the COT alone. Could the COT be why his car is being so stupid???

Bump :D

Remove cat over temp and piston protection if you wanna fine tune PE. Running 10-1 is gonna melt that cat.

Also if your MAF isn't recalibrated, A/F is going to be all over the place while in PE.

Also, you're going to have to redo timing again. After you lean it out, you'll probably start seeing knock again. Always tune fuel first.

Remove cat over temp and piston protection if you wanna fine tune PE. Running 10-1 is gonna melt that cat.

Also if your MAF isn't recalibrated, A/F is going to be all over the place while in PE.

Also, you're going to have to redo timing again. After you lean it out, you'll probably start seeing knock again. Always tune fuel first.

Piston protection is set to 7000. Also I didn't really think the fuel was gonna be outta wack, so I just started timing adjustments. Also He won't see knock, I'm sure of it... its only running 15 degrees! :lol: Just a safe 91 octane tune. We also calibrated the MAF table too.

What are the steps involved in calibrating the MAF curve?

Set the car to run in Open Loop with DFCO disabled. Go for a drive logging with the "MAF-A/F ratio error" histogram loaded. Make sure you have the MAF (Hz) PID loaded. Highlight the results of the log and place them into the editor by multiplying by % into your current MAF curve.

bit off topic but I was wondering if there was any info on this stuff anywhere a tuning book? It would be nice to know how to do some of this stuff and what max or optimum timing and fuel ration # are.

Ok, first you can't go by the commanded AFR!! unless you have a wideband and they are dead on!

Second, your PE numbers are affected by your VE Table. What you want to do is first tune your VE table in SD tuning, then work on the PE. I mean you can do it without touching the VE table, but your PE is going to be up and down and not smooth at all.

also your friend needs 60lb injectors if he's hitting 78% duty at only 5000rpm.

Let's not blow up any more engines:nono:

bit off topic but I was wondering if there was any info on this stuff anywhere a tuning book? It would be nice to know how to do some of this stuff and what max or optimum timing and fuel ration # are.

Read the RLforum and HP tuners forums.

max AFR on supercharged vehicle 12.0, recommended 11.6-11.8

Timing on 94 octane 20-22*

Timing on race gas or water-methanol injection 24-26*