MalibuJack

iTrader: (5)

Well.. my experience with the air filter was the same, it seemed to lose power after I installed it.. after a few days it was normal again when the computer learned.. In open loop, it shouldn't feel any different anyway.. I notice occasionally my car feels low on power compared to other days.. The best guess I can figure for that reason is humidity and temp are having an effect and at part throttle closed loop, the ECU has to learn a little to adjust..

It seems like my car ran a little stronger immediately after an ECU reset.. then settled down to what I was used to afterwards.. However a boost gauge is definitely a troubleshooting requirement because your only pondering possibilities now..

Hypreshr

iTrader: (4)

Nope, like I said, no engine mods on my car. This def has nothing to do with temp, humidity and all that. Right now it's about 30-40 degrees colder than the first few weeks I had my car. Also, I had my brother drive the thing for only his second time, (First was when the car was running strong) and he said it feels ALOT weaker. Boost gauge coming.....

raywong

I am pretty sure the Jap Evo's are spec at 280hp. It is a gentlemen's agreement between the car makers. All WRX, GTR, EVO, 350Z... are 280hp. However there is no restriction for torque. You can expect the next EVO and WRX to have the same 280hp and higher torque.

90GSX-03EVO

iTrader: (27)

Did you bend the honeycomb on the MAS? Even a small bit of damage will rape the hell out of the performance and make the car drive like ***. If you did, pull the MAS, get an allen wrench of the same size as each honeycomb hole and use it to push the bends back straight again.

I have the BR MAS pipe and filter and the car has a stock feel according to my butt dyno. Sounds a hell of a lot stronger, though.

Josh

90GSX-03EVO

iTrader: (27)

You should screw with the guy since he was such a dick. Hook up the boost gauge to the wrong spot so that it only shows like 14 psi max. Have him troubleshoot that. He should have got on the phone with the tech support that they have. I guess he either had too much on him mind or maybe he had too much pride to admit that he didn't know.

Josh

raywong

what is MAS?

90GSX-03EVO

iTrader: (27)

Mass air sensor. It meters the volume of air that comes in to the car so that it can add sufficient fuel to avoid running lean and melting pistons.

On the Evo 7 and 8, follow the intake track. You have the ram air scoop, the top part of the air filter box, the actual air filter, then the lower part of the air filter box. After that, there is a box that has a wire harness plugged into it, then it goes to the rubber acordian-style pipe that goes to the compressor of the turbo. Now, back up. The box that had the wire harness plugged into it....That is the MAS.

Josh

Oscar

EVO VII Japan Boost Spec: 14.5 psi ave
USA EVO VIII Boost Spec: 18 psi ave.

The USA EVO VIII lacks of the ACD, AYC, the 6-speed gearbox and weighs 70kg more so at the very beginning they are not the same EVO.
The engine software should be different as the LEV emissions regulations are quite different also. Do not forget those cars are designed to run petrol with higher octane levels as well as lower sulfur levels.

JT-KGY

iTrader: (3)

Are the number of cats different?
How about position of the cats?

90GSX-03EVO

iTrader: (27)

Higher RON octane, but lower rating by our standards. Their 100 octane would be about like our 91 octane. It is like the difference between horsepower made on a dyno and SAE corrected HP numbers made on that same dyno.

I think htey run lower boost because of the weaker gas. With higher boost, there is more chance of knock, so they just make the power other ways.

I wouldn't complain that we got screwed or whatever because the US Evo isn't the same as the overseas Evo. At least we still have the 4G63 and 16g. Look at the STi. They went with a 2.5 motor, so part support will be a LOT slower for that car than with a Evo with a powerplant that has been in the US for over a decade.


Josh

jemm

iTrader: (2)

Those figures for the jdm evo 7 are not correct. Boosts to 1.3 bar(18.8) and rolls off to 1.1 bar (~16psi). Those are for a stock Evo 7 GSR and are actual readings from a jdm 7 on 90 pump octane gas (95RON). These are in keeping with what is typically experienced by other owners locally & overseas.

jemm

iTrader: (2)

The 100 RON (Road octane#) fuel that is available in Japan is equivalent to 91 MON (Motor Octane#). Pumps in the USA quote their numbers as PON (pump octane number#) which is (RON+MON/2). Japanese 100 RON fuel has the same octane rating as 95 usa pump octane gas.

We run jdm and export (euro spec) Evos down here (with excellent reliability) on 90 pump octane (95 RON) fuel.

eevoo

iTrader: (10)

I agree with above - get a boost gauge. One other thing my friend told me, and it's true. You just get used to the power. My car feels "slow" after I drive it for a few days. I drive my fiances RSX, then get back in and it's like the WRC . Also, the car feels much faster from the passenger seat I think. Not saying you don't have a problem, just something to consider (maybe I'm nuts). Good luck getting it worked out!

jemm

iTrader: (2)

1 Cat in the same place as yours.

The GSR which is only supposed to be sold as a japanese domestic model only, has ONE o2 sensor on the downpipe. The RS2 which is the official export model to europe and the caribbean etc.. has another o2 senor post cat.

Remember that emission standards in Japan are not as tough as those in the States, in fact they are roughly equivalent to your 1988 Federal standards!!

raywong

The JDM 7 here are 280hp, 5-speed, ADC, AYC, 14.5psi. That's what we have here in Hong Kong.