mr2 questions

[I-Eat-Civics]

my friend just bought an mr2 and it got beat by a stock spec V. there has to be something wrong with it. It runs fine and he drives better than me. Is there maybe a way the turbo was turned down? cuz i mean even if it was ragged on bad it shouldve still beat the spec v. and how many lbs of boost can u push on a stock mr 2. IT's a 1991.

[ac427cpe]

are you sure it's a turbo? and are you sure it's the fault of the car?

[JekylandHyde]

I test-driven some amazingly beat turbo MR2s that ran terribly.

As for your boost question, I would not go over 15 psi with the factory turbo. If you upgrade the turbo and make the necessary modifications to the rest of the system you can run a lot of boost. I am currently racing at 23-24.5 psi on a 100% original engine with 200,222 miles.

[I-Eat-Civics]

Originally Posted by JekylandHyde

I test-driven some amazingly beat turbo MR2s that ran terribly.

As for your boost question, I would not go over 15 psi with the factory turbo. If you upgrade the turbo and make the necessary modifications to the rest of the system you can run a lot of boost. I am currently racing at 23-24.5 psi on a 100% original engine with 200,222 miles.

well is it possible the boost is turned down, cuz i might be getting it. and its there a stock watsegate on them?

[I-Eat-Civics]

Originally Posted by JekylandHyde

I test-driven some amazingly beat turbo MR2s that ran terribly.

As for your boost question, I would not go over 15 psi with the factory turbo. If you upgrade the turbo and make the necessary modifications to the rest of the system you can run a lot of boost. I am currently racing at 23-24.5 psi on a 100% original engine with 200,222 miles.

o yea and if its not the boost what can be done for them to run better cuz it only has 119 k

[JekylandHyde]

I've never heard of a turbo without a wastegate ... so yes, they do have a wastegate

The biggest place used MR2s lose power is the ignition. I suggest buying brand new TOYOTA cap, rotor and wires once a year. Get your self some new NGK copper plugs or the Toyota platinum plugs if you are not really modified yet.

I have seen MR2s down as much as 30 rwhp because of these parts.

I would also do a fuel filter, air filter and oil change and see where that gets you.

Stick a boost gauge in there so you know how much boost you are running.
It is possible that you are stuck in "low boost mode" which would only be 7 psi or so.

OEM boost should hit 11.98 psi, but under certain circumstance the ECU limits you to 7.

[NSX-R]

What kind of tires does the MR2 have?

[I-Eat-Civics]

Originally Posted by JekylandHyde

I've never heard of a turbo without a wastegate ... so yes, they do have a wastegate

The biggest place used MR2s lose power is the ignition. I suggest buying brand new TOYOTA cap, rotor and wires once a year. Get your self some new NGK copper plugs or the Toyota platinum plugs if you are not really modified yet.

I have seen MR2s down as much as 30 rwhp because of these parts.

I would also do a fuel filter, air filter and oil change and see where that gets you.

Stick a boost gauge in there so you know how much boost you are running.
It is possible that you are stuck in "low boost mode" which would only be 7 psi or so.

OEM boost should hit 11.98 psi, but under certain circumstance the ECU limits you to 7.

what would make the ecu limit the boost?

[JekylandHyde]

*coolant temps to low
*ambient temps to low
*detonation (knock)
*others that I may not be aware of

I would also check to make sure the TVIS is opening up. If that does not open, you are only running on 4 intake valves per cylinder instead of 4.

Have you checked the codes?

What date is painted on the ignition wires?
I would really start there first.

[TRD2000]

hi temps seem to do the trick too Jeff...

[Im JDM Yo]

Date? I thought 1998 meant 1998cc's.

[TRD2000]

ok, i'm hanging here, what exactly is a spec v? cause the only one i know it the gt-r skyline, if so there's really no surprises so it has to be something else right?

[JekylandHyde]

TRD2000, hi temps increases the probabilty of knock/detonation which is my 3rd bullet above.
The ECU does not limit boost pressure based just on high ambient/coolant temps ... you have to start experiencing knock first.

[I-Eat-Civics]

Originally Posted by TRD2000

ok, i'm hanging here, what exactly is a spec v? cause the only one i know it the gt-r skyline, if so there's really no surprises so it has to be something else right?

a spec v is a nissan sentra se-r spec v 2.5 l cvtc 6 spd with 175 hp and its a 4 door

[TRD2000]

ahhh ok, got ya now, wouldn't have guessed that one! thanks civics!

I just knew when it got REAL hot it didn't get boost (observation) handy to know its knock not temp, Thanks Jeff