The three US EVO VIIIs we've tested (under nearly identical conditions) put down right around 180 wheel hp. That's only ~20 more wheel hp than a stock WRX. Hence my concern about the 271hp rating. Thes dyno figures would suggest closer to 255hp, IMHO.
A few interesting findings:
Peak hp occurs around 5500rpm, not the claimed 6500rpm. Peak torque is right around 4000rpm.
One of the three cars we tested ran 2psi less boost (17 tapering to 15 vs. 19 tapering to 17) than the others. It had a one month earlier build date (1/03 vs. 2/03), FWIW. It ended up making the same power as the other two higher boosting EVOs but with slightly less torque in the low end and midrange.
Our EVO VIII, for some reason, only has a 1bar MAP sensor. Strange seeing it in a turbo car that runs 19psi of boost. I would expect nothing less than a 3bar unit for the car. With the 1 bar MAP sensor, it maxs out (reads a full 5v) at 0psi of boost. Bizarre and pretty useless, as far as I can see. While I didn't check the other cars we tested, I suspect they are similarly equipped.
The car is especially knock prone at certain engine speeds. At least it is on the lovely 91 octane gas we run in CA.
The car runs a frequency-based MAF sensor. Not the usual 0-5v types seen on most other cars.
The car is under-advanced above 5500rpm. Adding just 1-2 degrees of timing at high rpm bumped hp by over 10 wheel hp without any detectible knock.
The EVO VIII's factory ECU is a bit more sophisticated that the older EVOs which had no type of active knock correction or smart ignition learning capabilities. Even the processor on the board is bigger These new ECU smarts will present more complications on the tuning end. But that's what we do so we consider it a challenge.
The EVO, like the WRX, is suseptible to MAF misreadings through intake modifications. We measured some pretty wild MAF errors when trying out different intake configurations.
There's a lot more info we've dug up during our tune-a-thon. Some of it we'd like to keep to ourselves for now and some we'll elaborate on on our website (http://www.vishnutuning.com/lancer.htm
). There's nothing there right now but a pretty picture. Give us a couple of days and it'll start filling out. It's past midnight and we just came back from our first test drive of our mildly tuned EVO Lots more info to come....
PS. As mentioned earlier, all testing on all EVOs were done on 91 octane gas. I did test our car with slightly higher octane (by mixing in a couple of gallons of 100 octane) and found significant gains (6-9 more wheel hp). But still shy, IMHO, of the factory's claim. I think the car's short gearing, great turbo response, and strong midrange torque make it feel quite a bit more powerful than it really is. Still an awesome car. And it's bound to get only better as we get a handle on how to make more power safely.
PSS. Also, keep in mind that these numbers are from our Dyno Dynamics dyno which, while arguably more accurate, reads more conservatively (lower) than Dynopacks and Dynojets. While it's the best dyno for tuning, it's not the best "big number generator" that some people like