So I'm pretty new to tuning but I've done my research so I think I have a decent understanding of how the Cobb AP works. I loaded up stage 1 on my stock '08 gsr and took some data. Now the stage one has target load boost/fuel values that peak in the 180's at WOT. Add in the offset of 100 and I'm expecting to see logged values close to 280. Every time I pull tho, I'm maxing out in the 230's. Boost isn't even reaching 22psi. I played around with the coarse WGDC (the fine WGDC is already pinned by 3500 rpm) but it doesn't seem to do much. This sound normal to anyone? Anyone have any suggestions?

 

Weird, I could've sworn the max value in the Target Engine Load is 159. Anyways, the maximum correction the solenoids will make would be 5%, this is set by the boost solenoid correction table (dunno the name in AP). So this means if your target is 280 and you only hit 230, it would only add 5% to your WGDC.

But before you make any corrections to your maps, how are you doing your pulls? Make sure you are in 4th or 5th gear starting at a roll at around 2000 RPM and go WOT from there. If you don't do this, you wont be able to reach your max loads.

 

Thanks for the info. I think the max engine load varies depending on the software you use. I think ATR tops out in the 190s (plus offset). Regarding the WGDC correction, I actually increased the correction percentage from 5% to 10%. Not sure of how good of an idea this was but I was getting desperate. Regardless, it didn't help as I'm pretty sure it only corrects Fine WGDC, which is maxed out at peak boost anyway (high 3000s, low 4000s)

I figured the turbo would never be able to catch up if I started a pull over 3000 rpm so I've been starting runs from about 2500-2800 RPM. It's tough for me to make a decent pull in the city without attracting too much attention.

Anything else I can do to reach my target? I even tried increasing offset to set the target even higher...no luck though...

 

Well I solved half of my problem. The ATR help manual says Table A of the Coarse WGDC tables is what the ECU reads at WOT. Well after taking a look at a few logs I noticed it didn't matter what I changed in table A the WGDC wasn't changing. So I changed all of the tables and managed to get my boost close to 23 psi. So far so good.

The only problem now is my logged Load Boost/Fuel is still in the 230s, even with the slight increase in boost pressure. Anyone know how to fix this or if this is even a problem? It might make it easier if I knew just how the ECU calculated load boost/fuel.

I can post a log if anyone thinks it'll be useful.

 

Depending on your weather, you will also hit different loads. I wouldn't worry about what exact load your are hitting as long as you think your boost levels are ok. Load will vary, and I think it's hard for a stock (stage 1) car to hit 280 loads in typical environments. I hit 220-240 load in third gear depending on the weather (running 22-23.5 psi), but I'm at high elevation so my peak load will usually be lower than others at sea level.

 

Very true. I forgot how much of a role ambient temperature and pressure will play in achieving a target load. Thanks for the help.

 

Cobb changed it for some reason or another, they also offset it all by 36 (lowest you can go, no 0) for some reason.

"if it's not broken, don't...."

maybe the "engineers" where bored.

- Bryan

 

Odd that they would offset it........ So I guess the values would start from 36 with a max of 195 or so? Since the op's target is set at 180, that would be 15 lower than maximum. So in normal terms, his target would be 159-15 which is 144. Add his offset of 100 and the target would be 244 which sounds about right for a stock turbo

No idea why they would mess with the scaling........

 

Looks to be ~32, not 36.

ATR shows 32 as the lowest for all my tables. If I max, it's 190.75, subtract 32 gives me 158.75 (160.4 being the ECUFlash max) -- 31.35.. close enough.