Buahahaha
Didn't mean to get anyone butt hurt.
Good luck, happy Friday

 

just keep being immature, you're doing a good job at it. it must come natural to you.

 

it gets old after awhile.. i believe in the saying.. 'Do unto others as you would have them do unto you'.. i never disrespected that member in my life, so there's no reason for him to come trolling in here and disrespecting me.

 

Huh? I liked the OP's question. I don't know the answer though. I had never thought about it before. WTF why are you telling people what to do on here anyway, dude?

 

Tom the heads should be pretty much the same including flow rates. The really only diff. In a us spec and a jdm is the SAS and related parts ie turbo. Different turbine material and shaft. Our us spec is an almost exact carry over from the VII. Us was supposed to get it but it would not pass EPA standards with the SAS. Or safety standards from DOT. BAM 400 extra pounds!!

 

I don't know if this is relative or not, but it's possible the USDM evos were underpowered compared to other international models. The USDM evo is advertised as 271 hp (can someone confirm please).

When the evo 4 was released (1996) it was advertised at 276 hp and power is reported (by sources other than Mitsubishi) to have increased with each model but still be advertised* as 276 hp. Estimates for the evo 9 were in excess of 330 hp. So if the evo 8 was 320 hp, that is a significant difference to 271 hp.

I've pondered this several times in the past but never bothered to ask anything, I've wondered 3 possibilities.

1. USDM evo is advertised at 271 hp but is actually higher.
2. USDM evos have a different tune to comply with emissions. (As a side note, tuners in NZ claim a 60 whp gain with a walbro 255 and tune).
3. USDM evos have different hardware. (Could explain the MAP sensor)

So if the USDM evos have different hardware, it is possible that Mitsubishi used a different head, doesn't make sense to me but a lot of things don't .

*As per the gentleman's agreement between japanese car manufacturers, power will not be advertised higher than 206kw/276hp. Actual power output was not restricted.

 

Used to be 320hp back in the day. Reason why the 300zx, 3000gt vr4, and supra tt were all advertised at 320hp (flywheel). Meanwhile, supras were putting down over 300whp stock lol

 

AJ

you see the trouble you are causing!

tscomp,

I have absolutely no definitive answers for you.

If my friend (one of your newest most annoying customers) caused this, we get that cancer causing gasoline from South America here not the EPA friendly 93 "****" you get in the states . While it could very well be revised coolant passages in the head making the combustion chamber less knock prone it could be that we just get "great" 93 here?

The latter is wishful thinking on my part no doubt lol

 

the fuel honestly doesn't seem to bad from what i could see. it could be a true 93 octane. ive worked with much worse fuels here in the states.

his tunes basically done, just gonna add another degree or so uptop so he gets that additional power back that we lost. aside from that it gained quite a bit downlow.

did you get a ride in his car yet?

 

and you guys get the special models also. the FQ's and stuff. and your very rare wagon that you have.

 

thanks for this information.

 

I haven't no. I told him i would be the laptop holder for the next logging session though

I need to sort out my car's issue of not logging fuel trims. Gonna go for a nice long drive and see if they show up

 

Good luck with tht

 

bad o2 sensor maybe? make sure the car is registering a proper airflow hz as well.

 

I am in need of a new cylinder head for my evo 8 so I am definately interested in this info. If there is something fundamentally better in the jdm head, like revised fluid passages or some such, then it may be worth it for me. I havent seen much talk about jdm heads on this forum so I hadnt given it much thought before. Overseas gets all the cool stuff so I wouldnt be surprised if they are different.