When is it suppose to taper? My evo holds 19psi all the way to redline.

Only mod i have is a K&N Filter and a Autometer CF Boost Gauge.

 

Do your evos over there run 20 psi stock to make 271 hp? JDM evos (pretty much all of them i think) only run 13-14 psi stock to make 276 hp. Are the evos over there restricted or something?

 

When I first got my car.. and installed my boost gauge, I discovered that my boost didn't taper (I had run a 12.93 once at the track and never made any additional runs) Here's whre it gets interesting, my car was bone stock, and always ran very strong.. Then I took my car in for service at the dealer and it didn't run as strong.. I noticed it was tapering.. Since there was nothing written on the invoice since it was a regular oil service and tire rotation.. I think either the solenoid was not functioning correctly, and it was replaced in my case, or it was stuck either open or closed.. and then started working.. The other possibility is the car had a different OE Flash, or it had a defect, and they reflashed the car without telling me.

I have since modified the car, and I run a turboXS utec, using the stock solenoid for boost control which works just fine now.. But it was interesting and never found an explaination for what it was..

The only thing I know for certain about my car is I got one of the first cars ever delivered in the northeast (Long Island)

No good in speculation, but I can only guess that its an anomoly in the ECU or solenoid, or something that "slipped through the cracks"

Some cars are also strong runners, and aren't nearly as knock prone as other cars.. My car definitely seems like one of them, so perhaps that could have something to do with it.

 

yes, 19psi stock tapering to 16.5psi (According to documented sources)

Its likely that thanks to the better gas, you can run less boost and more aggressive timing and make up for the difference.. I always assumed the evo's ran the same boost regardless of country though.. I do know the EVO RS turbo was titanium and in some years, some had a 10.5 nozzle as opposed to the 9.8 in the US Domestic car.. All of those things will obviously reflect different numbers.