ROSSCNEW

I got a hks hiper exhaust after fitting it i have started getting a flat spot about about 3600 revs.

Anyone else had this problem

Its a Sti8 jap import.

Dark Blue Mark

Just a back box?

MB

ROSSCNEW

Back box and decat only one cat removed

Dark Blue Mark

Hmm, if you'd disturbed the o2 sensor, it might explain it at lower revs.

Not very familiar with the STi8 thb, so id be guessing. It maybe worth a reset of the ECU if you can, see if it learns its way around it.

MB

Bob Rawle

because the turbo is spooling earlier the closed loop delay is probably hanging on too long on part throttle while boosting ie its still running at stoich on boost.

bob

Bob Rawle

the front sensor controls the stoich fueling not the rear one. it can't learn around it if thats what it is

bob

Dark Blue Mark

Interesting... I had heard the HKS freed up a lot of backpressure. I remember John Banks getting quite significant BHP gains over some of the other systems too... Guess thats only cured by a remap, Bob?

MB

ROSSCNEW

How do you do that on the new age impreza's

Dark Blue Mark

Do what?

MB

ROSSCNEW

Reset the ecu

ROSSCNEW

how much roughly for a remap?

Bob Rawle

Yup afraid so, or find some other way of reducing turbo spool however that sort of defeats the object so to speak.

bob

Dark Blue Mark

Not sure if you can reset it on STi8 without a SECS or dealer intervention? As Bob says, the ECU wont do anything to adjust if it is due to early spool.

MB