Taropatch

I can see my fuel pressure while idling but i am unable to see real time. I can get a sensor and gauge in the cabin, but Im unsure if RR is capable of logging more than one additional signal.

Hello all, I am having trouble finding the cause of my current issue.

I rebuilt my 05 OBXT last summer and had an uneventful break-in period. I then began tuning the car with the guys over at cryo and without making that much power we were maxing out the MAF on the stock air box. I thought this was strange because almost every post I have read on the forum states that the stock air box is capable of 300ish hp. The logs were not putting up much more than stock boost. Fast forward and I changed the air box to the Cobb intake with enclosure and now were back with the same issue just with more boost and it has begun to lean out at the high end causing knock. I have double check all connections, smoke tested it, and it looks to be getting good vacuum numbers so I don't think it has anything to do with that.  I installed a new MAF during the rebuild and have cleaned it a few times since with out any change. I have zero issues with normal driving, but generally keep it out of boost.  

 

To summarize current issues are: 

1. MAF sensor maxing out  (looking at the tune it has been scaled up 13%)

 2. leaning out at higher RPM 

3. and the knock around 3800

 

 

Here is the short list of relevant mods:

RA short block

Rebuilt stock B25 heads

all new vacuum lines and in bay fuel lines 

new in tank fuel filter 

 

Fuel:

DW 750cc injectors 

Tomei FPR set to 3 bar

DW 65c pump

 

intake: 

stock manifold with phenolic spacers 

and TGV flap delete 

Grimmspeed top mount intercooler 

Kinugawa 16g  

Mishimoto turbo inlet 

Cobb intake 

Grimmspeed BCS

Exhaust:

Stock headers with Grimmspeed cross over 

some aftermarket catless uppipe

Grimmspeed down pipe 

and custom catback exhaust 

 

Here is the last log after I made sure everything was tight. I probably wont make another pull until I find an issue.

Any help is appreciated!

 

 

R2 3rd gear pull after fix.xlsx

I swapped the front O2 sensor out and just like that the problem is fixed. Did some logging to be sure that was the only problem. Everything looks good while cruising and no more leaning out when doing a third gear pull.

Interesting that it didn't throw a code with that front sensor malfunctioning.

Ok, thanks for taking the time to look at it. I'll try swap out the front O2 sensor tomorrow when i get home from work.

ok here is the log with the added parameter:

https://docs.google.com/spreadsheets/d/1v04XsFcmQAaZydyUx8unsPTz7O9CiSkVR4rYri4oj4I/edit?usp=sharing

 

I'm not sure how that relates to to the measured AFR. Is the CL target fueling the requested fuel like the final fueling base? or is it final estimated AFR after corrections in relation to the current measured AFR?

 

Thanks

awefulwaffle:

It didn't feel a like there was any loss of power while doing the pull. fuel pressure is great at idle and is set to factory specs so should be adequate for stock tune.

 

I have attached the stock boost table I pulled from RR and will go log a cruising run with the added parameter of CL fueling target.

 

Thanks

Hey all I have been having an issue with my OBXT surging when cruising. It happens in all gears. Usually around 3k rpm its most noticeable and only if I am holding the throttle in one spot.

 

The engine is stock except DW65c pump and Tomei FPR (added after the issues began, thinking it was fuel related)

Competition clutch "stock" replacement with SMFW.

 

LGT suspension geometry conversion and full refresh of bushings and coils front to back.

 

 

Today I did some logging and during a cruise the AFR is fluctuating from 11-18 without any change in throttle input. In a 3rd gear pull its leaning out to 20.33 and now it's parked until I can figure it out. I was thinking maybe a post MAF leak but couldn't find any yet.

 

Anybody have issues with this before? I have been unable to find a thread addressing this.

 

 

 

 

 

here are the logs:

Cruising: https://docs.google.com/spreadsheets/d/1vZstxaAro40Ks2ZI1yxb_RbfNPZj7JDDdKR2l56qdic/edit?usp=sharing

 

3rd gear pull:

https://docs.google.com/spreadsheets/d/1Ct4bmL7FL9L9UlofDehYj4SR_UGC5uRUp7SHNnrCbBk/edit?usp=sharing