You don't have to port it 5mm to see a difference. The inside surface of the throttlebody is rough and unfinished when it comes from the factory.

all you have to do is grind the inside surface down a little bit, more twards the outside, and less twards the butterfly, and then polish it so that it is completely smooth.... It'll be smoother and a bit bigger than stock, hence, more induction....

 

More induction even if the butterfly stays the same size?

 

Ummm... don't think this is entirely true... while you may see some increase due to less resistance the restriction of the butterfly is where the gain is really at. A butt dyno cannot feel a simple polish on TB i've done this before and nothing... didn't even show on dyno. I've heard of this before though... mostly on V-6 and v-8's where there are more noticeable gains on such things. The Throttle body from RRM is 5MM larger than stock but also machined in entrance to allow better draft and in back of butterfly its machined to condense charge better. Thus not only do you see an increase in overall air intake but a more denser charge from the vortex effect. On N/A with full exhaust and intake mods the TB is noticeable especially at higher RPM's and on the low end where full exhausts take away. On Forced induction it's gians are substaintial. If you guys are leary of TB because of price try to smooth/polish it out and see if your happy. If not then get it. Remember that the TB for our car is like $500 even at a discount place. Thus if you screw it up good luck... maybe getting a professionally machined one is best!

 

Yes, this is true, I've done it on two cars, A mustang GT and a 3000GT. And yes, it made a big difference. I also ported and polished the intake manifold....

But, I'm starting to realize, that our cars will never be "fast." I didn't really realize it when I bought it, but without adding a turbo, which

a. voids any factory warrantee (then what's the point of owning a new car)

b. Shortens the life of an originally non-turbo engine.

So, if you guys really think it's worth it to spend $500 for an extra 2-5 hp, and no cosmetic gain whatsoever, go for it. I just don't think it's worth the cash!

 

a. The new car smell.

b. Not to any extent that you should be concerned about unless you don't build and care for it properly. If you're running 6 psi (properly) don't expect any severe premature wear. If you're running 9 psi constantly (even properly) on stock internals and expecting no problems then chances are you're going to be in for a suprise.

I'm still not even boosting properly. My car needs tuning like you would not believe, but I have no doubt in my mind that it was all worth it.

EDIT: And my engine and drivetrain warranty can suck my ***. If my rear control arms go you best believe I expect Mitsubishi to cover my unmodified suspension.

 

Oh yeah. One thing I forgot to address was throttle response. The bored throttle body (when my car was NA) and a slight tightening of my trottle cable made a noticable difference in my throttle response. I stepped on the accelerator, I moved. No sluggishness, no lag. I'm not saying to go out and buy one, I'm not saying not to, but there are definitely some decent pros to weigh against the big con (cost).

 

I have the RRM TB and I love it. I have a CAI , test pipe and axle back and the TB gave all of those a lil kick in the backside. I noticed a difference after 4000 RPM mostly.

 

how much is it to polish a TB, and how much is it to polish and bore and INTAKE MANIFOLD.

THNX, Brendan

 

Port/polish Tb and manifold could run you 300-500 depending on shop. It's expensive for such little gain on these cars. Only real way to gain is to get bigger TB. Just because we are four cylinders. Port and polish actually has little effect on our cars NA motor. But on turbo its a big difference.

As for voiding warranty on motor... RRM kit will soon be carb certified... if that's true than mitsu will have to cover warranty issues right? I'm not for sure but I believe this is true.

 

If a part is CARB certified, then mitsubishi cannot void the warrenty unless the part directly causes the failure. This is true in the case of emitions. If you car does not pass emitions and all of you parts are certified, mitsu must fix whatever is wrong. Now if you have a turbo or what not and blow your engine, sorry you get to pay for that one.

 

Are you sure you're not mixing up CARB with SEMA? I'm admittedly talking out of my *** here, but CARB is just emissions whereas SEMA is the org. for all certified aftermarket parts.

 

hmmm... i wonder who here knows that Guru Del is an environmental major who works with epa for certifying legalities on automobiles... Also is the guy getting kits CARB certed! Oh wait i know the answer... i know the answer! HA! Just messing with ya Hobie!

 

Is it worth to do it on a stock TB. I know it won't give more HP, just want to know if it would be worth it, and if yes could you tell me how to. I'll take a look at it tomorow, but if you've done it, you can probably help me on that one.

 

damn boe i knew the answer too. both sema and carb requirements state that a vendor must fix anything that i wrong. where to two differ is in california: an aftermarket part that is carb certified may not allow the manufacturer to void the warenty of an emissions related system.

 

has anyone checked to see if our TB is the same as the ones on mirages? IF they are, I'd be willing to bet you could find a bored out TB for a mirage for cheaper than RRMs