Possible Air Starvation?

[S15_Spec_R]

This probably sounds silly but I was wondering if the above could occur. My circumstances are HKS Mushroom IC sitting by the strut facing the wing and a FMIC. When I push it at around 110+mph I get some hesitation/holding back. I'm running 1bar and stadard tubby, 740 injectors, apexi ecu power fc, splitfire coils. The car still goes on to higher speeds but I was thinking that due to the lack of air flow this could be the problem.

Maybe its the mapping as it was done by a tuner on the road and I have had mixed responses as to which is the best (rolling road or actual road). Thanks, Keith

 

[Rosscoss]

You will probs find that it's the mapping of your engine or boosting problems. Your actuator may not be holding boost. You may need to uprate you actuator and then get it remaped :thumbs:

 

[Auss15]

Are you still using the stock rubber turbo intake pipe?

 

[craig8585]

Does it maintain 1.0 bar when it hesitates?

 

[S15_Spec_R]

Cheers for your replies.

Ross and Craig, I am using samco hosing then its a SS pipe to the HKS mushroom filter (I not fussed on the filter but the tuner said it was as good as the ARC one I wanted, however with the FMIC pipes it would not fit).

Yes it holds 1bar on the defi gauge and on playback I cant see anything that contradicts that. The only thing that changes on hard driving is my oil and water temp, they both go from 70 c to 80 c but no higher.

This doesnt happen under the 100 mph so I thought it could be lack of air due to the force of the outer air going over and under and no direct channel for air to an isolated filter, as we know they suck a lot of air. I also have a SS manifold which I have wraps for but not fitted yet.

 

[Auss15]

Would be worth fitting a Z32 AFM if you haven't got one now :thumbs:

 

[S15_Spec_R]

I had my AFM removed when the ECU was upgraded - it was recommended by the tuner due to AFM's being potentially unreliable?

 

[craig8585]

If its holding 1bar when it starts hesitating then I wouldn't think it could be air starvation as the boost would surely drop? Is the boost creeping at all in the higher gears (5th and 6th)?

What form of boost control are you using too?

 

[S15_Spec_R]

Possibly but its so small and quick that the needle response shows but I assume this slight movement is due to the increase in rpm and the actuator doing its job?

1 through 5th are all 1bar but 6th seems to hold around 1.2bar.