sti69

iTrader: (1)

Hi Guys we all know that optimax has stopped. Well my 94 STI has been running sweet with optimax and octane booster but since hemel hampsted went up ive had to switch to tesco 99

My question is that tonight the car has started to boost to 1.5bar (on optimax it ran between 1 to 1.2bar with no probs!) and during hard accelaration through the gears the boost is all over the place ie. 1 to 1.5bar and i hit fuel cut

any ideas!

leonpoole

It could be due to the weather getting cold. Mine always starts to overboost at this time of year

dj219957

overboosting is more likely to be due to weather change rather a fuel change. Cant see how fuel would cause overboost???

Bob Rawle

It can, better fuel more exhaust gas velocity from more effective combustion (different burn) and hence the over boost. Turbo is more lively from it and boost dynamics struggling to control.

bob

dj219957

I stand corrected
What he said then

sti69

iTrader: (1)

So do you think my car is going to be better suited to tesco's 99 with octane booster (even though its overboosting!) or should i go back to optimax when its back at the pumps?

Also how do you control the boost dynamics if it continues to overboost - would an ecu reset help because of the change of petrol?

Sooo many questions and its not 2006 yet!!!