Air fuel ratio in MY03 STi PPP
A question for you techie fellows please. I recently had my motor as above on a dyno. Figures (corrected to flywheel) were 288BHP (7000rpm) with 285 lb/ft (4500rpm). All of the MY03/04 PPP's tested were similarly (or more) short of the mark. A MY01 PPP bugeye got 300BHP/300lb/ft (no other mods). A P1 (no mods) did exactly what it says on the tin 275/240. This RR has a good setup with great front and topmount fan provision, it was a cold day with Optimax. Do you think this is a dissapointing figure? The other consideration is that the very knowlegable and experienced technician said that I was running really rich 10:1. Their seems to be a VERY wide margin of safety there in terms of knock. The only engine mods on my car are STi panel filter and a TSL group N deresonated centre section and back box. Any comments would be welcome. Thanks in advance.
Hugh.
Hugh.
Scooby Regular
Joined: Dec 2002
Posts: 1,986
Likes: 0
From: Southampton*** MY02 STi, Black/Blue Mica Prodrive Style, mildly modded :) :). ***
All I know is that my MY02 STI PPP has never reached 300/299 on a RR. Best I ever got was 289/285.
One word: Heat Soak (ok two words
)
And the PPP map senses inlet temps and will not give you full power.
My worst bhp on a RR was 265, only just above standard.
I mailed Prodrive and the answer back was all about inlet temp, ambient temps, heat soak etc etc.
So i guess, if you are going to RR it, you need to be able to measure these temps and do the dyno run once you know the inlet temps are low enough, and not sky high, otherwise yes, the car will hold back.
Just my thoughts
One word: Heat Soak (ok two words
)And the PPP map senses inlet temps and will not give you full power.
My worst bhp on a RR was 265, only just above standard.
I mailed Prodrive and the answer back was all about inlet temp, ambient temps, heat soak etc etc.
So i guess, if you are going to RR it, you need to be able to measure these temps and do the dyno run once you know the inlet temps are low enough, and not sky high, otherwise yes, the car will hold back.
Just my thoughts
Thanks for that. I didn't notice that my mate seems to be having discussion about my motors AFR with John Banks in General Technical!
http://bbs.scoobynet.co.uk/showthread.php?t=376914
Thanks to everyone for their thoughts.
Hugh.
http://bbs.scoobynet.co.uk/showthread.php?t=376914
Thanks to everyone for their thoughts.
Hugh.
Thread
Thread Starter
Forum
Replies
Last Post




