Lemmy

I have a MY02 STi Type UK which has a PE sports cat exhaust system, uprated fuel pump and an Ecutek remap carried out by PE about a year ago. Directly after the remap the PE rolling road indicated 319 hp and 292 lbft on Esso SUL. Over the next few days the performance felt liked it improved due to the ecu’s self learning. Therefore I was surprised when 2 months later PE’s rolling road showed 309 hp and 293 lbft on Optimax. Matt Collier had his DeltaDash hooked up for that rolling road run and it showed that all ecu parameters were fine – the advanced multiplier was at 16. Therefore I put the lower power down to higher ambient temperatures and Optimax.

However, at the recent G-force rolling road day I only got 299 hp and ~280 lbft on Esso SUL. The lambda ratio and boost (1.3 bar on rollers) seemed the same as usual.

So I seem to have lost 20 hp in a year with no further engine or exhaust changes to the car, except an extra 12,000 miles and three oil changes. Can anyone explain this?

willgill

iTrader: (1)

Different RR?

that can account for a bit of it

WREXY

Yes ambient temps play a role and no two dynos will give the same output. You wouldn't have lost any power if you were to dyno the car at the same dyno and in same ambient temps as on day one.

Bob Rawle

Just because the advance multiplier was the same doen't mean it was running the same ignition, it has an ign learning map which can take a further 3 degrees (that I know of, possibly 4) out of the timing without moving the adv multiplier, thats enough to reduce your power output noticeably however a car would produce a differing figure on differing days even on the same rolling road due to local conditions at the time. PE and Gforce are actually quite comparable, not had my car on both yet but plan to vist G force soon after the prosport day on the 29th.
Also bear in mind that fuel quality varies batch to batch although Esso SUL is one of the more consistent.

cheers

bob