Hello, I have a Cobb tuning devise on my 07 HR. I have long tube headers and long tube intakes on it with the 2+ stage tune installed. I have a hesitation at 2500 - 3000 rpm's with medium to high throttle, but none at light throttle. Has anyone else had this? How did you tune it out? less ignition? Less ex. ca, advance? No check engine lights or anything. All else is fine. Thanks for your help.

 

that cobb data logs.. do so and post the print out.

 

sounds like a lean spot. have you checked your afr's in the rpm ranges where it hesitates?

you can also email cobb and download their tuner software to make and adjust your own tunes on your own computer.

i have yet to venture into tuning it myself.

datalogging a run or two will show you why.

the preloaded maps on the cobb were tuned on cars without intakes and definitely not headers. you're probably running lean if anything.

 

^ the stage 2+ map is meant for heavy breathing mods ie plenum and headers etc.
i agree it sounds like a a lean spot tho..
I ran it as well on my car before my bearing died. stage 2+ map richens it up quite a bit tho.. run the AFR mode while you drive and watch when that hesitation occurs, whats the AFR? lol.

 

guess youre right about the headers i forgot about that. but intakes were never a part of their tunes i believe.

either way, i have long tube intakes, catback, and art pipes and im having lean spots at 1/4 throttle. WOT is close to 13 at times.. hoping to get upreved soon.

were you boosted on the cobb?!

 

No boost. Just these two mods plus cobb. I did set it to air fuel on a ride last night and your right. It does lean out in that spot around 15.3, when the rest of the rev range is 13.5-14.0 I haven't used the pro tune software yet. Is it anything like KPRO for RSX-S, because that is my prior experience. BTW this is in a G35 sedan.

 

I run a Cobb tune on my 08 HR, and also have long tube intakes (Injen). You are going to want to run a custom tune on your car because of the intakes. The Cobb off the shelf maps were made with the intent of running the stock airboxes.

Basically, your car needs to have the MAF information altered a bit. Because of the change in the intake geometry and other things, the true amount of air brought in does not reflect the values examined by the MAFs (or at least this was the case for myself, and my friend who tuned my car's 07 Z). Because of this, both he and I originally had issues with fuel, because even though the car added the appropriate fuel for the air observed, this was not the correct amount of fuel (and injector pulse I believe? forgive me if I made a mistake in terms, he's the tuning whiz) for the air actually pulled in. My car ran lean. With a custom tune, you will notice a difference in power and throttle response especially (my favorite part). If you are having issues, I can get in contact with my friend to ask him some questions for you (he's tuned around 6-10 Z's with the cobb units now and used to do etuning for Z's on their boards), and could give you one of my maps to use as a base line for the MAF recalibration if you are interested. If I can be of any help to you, just post up in here or send me a PM!

 

Is tuning the MAF very difficult. I looked through the tuning manual and saw the LTFT indicator of MAF being out of tune. My LTFT is usually around 108-112, with spikes at 120+. Is your base map a 2+ or a 2 cobb map?

 

Cobbs off the shelf maps suck if you have anything but stock intakes. Tune it yourself or have it tuned professionally.