Boost "hunting" With Pfc Boost Control Kit

[jmac]

Noticed recently that during sustained high-load runs in 4th and 5th gears by boost seems to "hunt", as in it'll hit the max boost setting in the Boost Control menu on the PowerFC but then drop back a little and build again (see pic).

It's not boost cut or a coil problem (been there done that) but it *just* backs off enough to be noticeable.

Any suggestions whether I could change any boost control settings (duty cycle adjustment?) or is this more a mechanical/wastgate issue?

Current setup is as in my sig, set to 1.1 kg/cm2, duty cycle 66. It's a reliable tune otherwise with no issues.

Thanks guys!

[paulr33]

alter the duty cycle

if it comes on too hard, decrease the number

if it doesnt come on hard enough, increase it

its a ratio for open:closed for the solenoid

it also has a fuel cut if you exceed target boost by 0.25kgcm2

[jmac]

Ok, will give it a try. It's not overboosting, just backing off gently by a couple of PSI then going back up. It was a cold day too... hadn't noticed it before at race meets etc where it's hotter.

Cheers Paul!

[rob82]

Ok, will give it a try. It's not overboosting, just backing off gently by a couple of PSI then going back up. It was a cold day too... hadn't noticed it before at race meets etc where it's hotter.

Cheers Paul!

Make sure the length of pipe from your wategate to the boost control solenoid and from boost source to solenoid is as short as possible. Also where is your boost source - please tell me it doesn't get vacuum.

Edited August 9, 2006 by rob82