nhockett

I have a datalogger and a boost controller. I want to push boost over 16 psi. What do I look at on the data logger to do this? I believe it is the knock and the air fuel ratio. Help from anyone who has done this before would be greatly appreciated. Thanks in advance

kjewer1

We need 2 things. What logger, and what gen car.

On a 1g, you can see knock. Since you mentioned it, I'll assume you have a 1g. Knock counts from 0-3 the ECU will ignore. From 3-7 it will hold timing. Over 7 counts and it will start to pull timing back. Max is somewhere around 43 counts of knock. If you are seeing over 20 something is wrong. Too much timing, too much boost, too lean, etc. 0-10 is good. 0-5 is better.

On a 2g, you cant log knock unless you have DSMlink chip/logger. So you have to look at timing. On stock injectors timing should rise to ~16-17 degrees by redline, maybe a bit more if you are on a small turbo and/or low boost. With larger injectors you can see up to 24-25 degrees at redline. IF its lower than where it "should" be then you are getting knock. Etc

You can also log O2 voltage, but use this number carefully. Knock is still the important number. But in most cases 2Gs will be at ~.92-94 volts on pump gas, and 1Gs will be between .88 and .92.

__________________
Kevin Jewer
POS RWD - 8.9 at 156, 1.20
2005 EVO RS - 11.52 at 121, 1.59

www.POSracing.net

nhockett

I have a 1g and do not know what program ( apparently it is a bootleg version) On my palm pilot it has 4 letters MMCD. On the stock boost level I am usually at 1-5. Regularly it goes up to 14 and if I down shift it goes up to 43. Sometimes in the middle of the power band it hits 20-30. This doesn't seem right to me. When I increase boost the numbers go up immediately to 20+ I have not checked 02 voltage yet. I have a turbo xs mbc. Am I to look at peak knock levels? Average? The downshift numbers do not concern me that much. This engine is new and I do not want to fry it. Thanks

kjewer1

You dont want knokc to get high, ever. So you wouldnt be looking at an average, etc. If it only goes high above say 6k rpm, then add fuel in that range, etc. If you dont have fuel control, you can only bring it down by lowering boost. For your particular setup that is. Things like better intercoolers etc will reduce knock even at higher boost levels. IF knock counts are below 7ish, then you are ok. If it only goes high occasionaly, that shit happens. SOmetimes a mchanical sound will trigger it, or after a few pulls the intercooler may be heatsoaked, etc. Always use high octane gas, and keep knock counts below 10, and you should be fine.

__________________
Kevin Jewer
POS RWD - 8.9 at 156, 1.20
2005 EVO RS - 11.52 at 121, 1.59

www.POSracing.net