General This car is kicking my butt. Please help.

[DallasN2O]

90 Laser, 2g pistons, 2g maf, Walbro 255, Aero AFPR, SAFC (I currently have it, but it's not installed... Don't think it will do me any good.).

edit: I also have 550cc's.

No boost leaks.

Base timing set to 5*, shows ~8* ungrounded.

New knock sensor, with teflon tape, torqued to around 7 ft-lbs.

Base fuel pressure at 45lbs

I can run 7lbs of boost and get no knocks (or very low, 1-2cts occasionally)

I turn it up to 13-15, I get LOTS of knock. Sometimes. I'll gas on it, as soon as we come into full boost around 3.5k or so, 30+ sometimes 43 counts of knock.

BUT, if I let off, and get back in it- SOMETIMES it will go way. It'll show 5 counts and it'll slowly drop back to 0 all the way to redline.

This problem is kicking my ass. Should I retard base timing some? I really don't know where to start with this.

If I need to provide more info let me know.

 

[RadDsm]

I think it's a combination of the 2g pistons and maf with the 1g timing map.

You should have some larger injectors than stock, and put in the safc. Once you do those 2 things and tune, you shouldn't have any problems with knock.

Your fuel pressure is also a bit higher than it should be, I'm assuming you did this to try and combat the knock? If you don't have a wbo2, pick one up before you do anything fuel wise.

 

[DallasN2O]

Actually last night the AFC was installed and functioning- We made many pulls, but could NEVER get the knock to go away. Tried almost everything from -10% to +30%. +25% or so seemed to be the sweet spot, we were only getting 43counts of knock every third pull. =/

I didn't mention the AFC runs because I thought the car should be able to run 15psi or so WITHOUT the AFC, I didn't want to overcomplicate the situation.

edit: And I do have 550CC's, forgot to mention. I did raise the fuel pressure to combat the knock. I was getting knock with 35 base FP @ 7lbs. =/

 

[RadDsm]

Do you have any way to monitor your afr's? If so, what are they?

If you are logging these runs with anything, you can also throw one up.

 

[DallasN2O]

Currently no wideband. I'm really only wanting 13's out of this car- I'd prefer to not purchase one right now.

I can post some logs later this evening.

http://www.dsmtuners.com/forums/tuning-engine-management/286426-help-settings-after-2g-maf-1g.html

Sounds very familliar.

 

[LiquidX]

A wideband is essential for any tuning. I suggest like others have said, get a wideband. Either the AEM UEGO or Innovate LC-1. You need to know how lean or rich you are running and you cannot be guessing when trying to tune your car.