Hi, i have G35 05 coupe with GTM stg2 tt kit, oem maf, stock block.

The car run fine & dyno curve are good but ont the street, when i have boost peak @ 8psi (WG set @ 6) the car hesitate 1sec...

-Timing is near to 55 in this range on Osiris timing map, I tried with 44 & less but still have this trouble...i can see timing fall to -1 degre & i see knock strenght when a datalog but i also tried to raise my High det. timing to the same value of low det. ...same thing..engine hesitate, timing fall for 1 sec ?

Any idea ?

Sorry for my english

 

how many hp are u pushing? ( ie how much wind are you making lol)
i ask because you said stock maf.

 

425hp 395lbs
According to GTM, the original maf is good even has 500HP with their setup

I thing oem piping is 2.75'' & GTM is 3'', need to readjust maf table? When i datalog, the trace line will never go to end of base fuel schedule table...

thx for the help!

 

I.just bought a new Maf at the recc of my tuner as he says they don't do well over 400 HP.

 

Chances are your MAF is maxing out did you log the voltage? I had a similar hesitation issue with PMAS that took zeroizing the fuel comp table and tuning entirely by MAF. Total PITA but it runs like a champ now.

 

Lol.. I'm.pretty proud to have guessed closely.

 

I'll datalog them tomorrow
GTM told me the oem maf should be ok up to 500hp.. I need to re tune oem maf or install a hpx?

 

If the MAF isn't maxing out (> 4.6volts) then I guess stay with it... but I've never seen much more than 400whp with OEM MAF without an enlarged housing, ect.

 

Your right guy's !
I maxed my maf... 5V @ 8psi.
Still have some questions..

-HPX or Uprev GT maf ?

-Idle bounce after engine start, tried to raise & remove some timing, still bounce..

-If i want check my log after saved them, i lose some sensor value...every value on maf sensor..V, GM/S, accel. ped. pos., inj duty..... normal ?

thx!

 

Either will be fine, but keep in mind you need a full retune after changing it out.

Idle bounce can be caused by a few things, usually tune related. I flattened my MAF table out a bit in the idle voltage areas to combat it.

Don't know about your last question.

 

Ok, thanks!
I ordered Uprev GT maf

For my idle bounce..i see in my datalog bank2 O2 sensor isn't stable like bank1 and correction bounce between 97-125% ...I'll order a new O2 sensor