I did a 3rd gear pull as suggested. I think there're maybe room for improvement since it went so smooth and almost knock-free.

Should I add timing since fuel seem to be already lean for 91 oct?

Also notice that my FueldTrim_Mid is a off (67% versus 100 and 108%) comparing to the HIGH and LOW trims. What can I do about it?

Boost peaked at 22psi, RNR GT35r with all bolt ons, stock block, 91oct. Thank in advance.

 

I would richen the AFR from 6000 rpm on and make the AFR end up @ 11-10.9 by 7500 rpm. A bit too lean for 91 octane gas. That should take care of your 1-2 counts of knock.

If you want to figure out your fuel trims then use Mitsulogger or modify your Evoscan xml file to work like the one in Mitsulogger.

 

This is a bit off topic but I was under the impression that target AFR didn't really have much to do with octane level, ie whether you are running C16 or 91 Oct you should aim for 11.0-12.5 (depending on how big your ***** are).

Octane level directly affects the amount of timing you can run...

 

Thanks.

 

Well, the better quality gas, the less gas you need to prevent knock... so they go hand in hand. That's why race fuel or meth injection use 12:1 or leaner safely... they don't need to dump more fuel to prevent knock.

 

rather than running overly rich because of 91 octane I prefer to adjust the timing, however, I wouldn't change anything for a 1-2 count of knock on a single run.

the bigger question in that log is why is your load diving with a 35R?

also your mid fuel trim is likely hosed because the injector scaling/latencies aren't right.

 

Mellon,
thank for the reply. I'm not sure why my load is decreasing in higher RPM (from 260+ down to 240+) but I was thinking it's normal. Is it?

I'm also thinking my injector scaling/latencies aren't right as well. Here is mine on the Precision 880cc (I got it from the injector scaling thread):
Scaling: 750
4.69 3.624
7.03 1.992
9.38 1.344
11.72 0.984
14.06 0.744
16.41 0.576
18.68 0.456

What should I change to try fixing my fuel trim?

 

most of my customers with 35R's work their way up towards redline and do not fall off. I would be suspicious of the wastegate or boost controller...wouldn't be a bad idea to pressure test the system also.

oof, I don't like your cc size or latencies...keep in mind that what worked well for one car never works well for another ignore what other people use and give the car what it wants. Keep in mind that when you get the injectors scaled correctly your WOT portion of the fuel map is likely to be way off now

 

seems to me that with all the money going into these larger turbo kits why f with 91 oct gas? If you can't get 93 then go to the track with a couple of cans or wherever and get 100 or 105 and bump up your crappy 91 to a level your larger turbo is happy with.....Alot of guys where I live just buy race gas and write it off as the price to play.

 

^^^I do run c16 but 91 is for daily drive. I started tuning the car myself with ecuflash so I'll like to start out with 91 first. You don't want to waste the gas driving around on expense race gas don't you. With 91 oct, 400 whp is enough for me on the street but thank for your kind random comment and assumption.

 

sorry