ok i have a 94 gsr that is stock that i wanted to beef up a little bit, so i bought type r pistons, rings, rods and new bearings. i also bought all the itr head internals like cams and valvetrain with a skunk2 intake manifold. im just waiting to save up enough money to put all this in. also having a p&p done. what kind of numbers should i be looking at when i get all this together. is i gonna be exactly the samed numbers a regular type r is putting down or is it gonna have a little more horsepower, and what type of header do you guys suggest? do i need better fuel management for this? thanks to all.

 

I cannot stress this enough! Fuel managment is critical! Tunning is everything...

With that in mind, use a header designed for mid to high rpm power. Stock ITR is a 4-2-1 design. I would suggest a 4-1 header, but this depends how low your car is. Do you already have a catback & highflow cat? What other mods do you have already?

 

pretty much my car is all stock as it sits right now, just waiting to put all these parts in. i want to put everything in at once instead of doing it piece by piece. also have a stock exhaust, looking for something quiet till i get down on it if you know what i mean. with everthing that i have and a good tune with a decent exaust, do you think i might hit 200 to the wheels?

 

Your goal is deffinately possible, but it will talke a strong tune. Mabye you could get CTR pistons and bump the compression a little more. Or use an aftermarket valveterain. Either way, your on the right track.

As for the exhaust, I recomend Apexi WS2 or the RSR. Deffinately get a catback. If you search around you'll find reviews & opinions on different exhaust systems.

 

well i still have everything new in the box so i can prolly take them back. what kind of comp do the ctr pistons have and will they bolt directly in like the itrs? also does it matter what the year on the piston is? either way il look and see, but its a little easier talking to someone who knows. what kind of valvetrain do you recomend? what kind of fuel management is good to go with and should i bump up my injectors and fuel pump? is there any thing else that i am missing? thanks, just trying to hit atleast the 200whp mark but 220 would be better!

i read that the ctr pistons have 12;1 comp. is this too high for a daily driver on pump gas? also seeing on another forum that the ctr were hitting the oil squirters and broke them, dont know might stay with the itrs that i got, but what about the valvetrain though, thanks

 

You could be right about the CTR pistons. I don't see the block squirters getting in the way, but its possible. I believe they will yeild between 11:1 - 12:1 cr. I might be wrong. Most of my knowledge comes from a turbo build i've been working on for a long time, so your needs are a bit different than mine. Im positive they will fit, and ive heard many say there completely streetable.

If you're just going to stay with the ITR pistons, you could get the head milled, and use flat faced valves for higher compression. Skunk 2, Omnipower, Rocket Motorsports, and Supertech all have some good products. Lots of people have used ferrea valve components with great success. I can tell you that if you plan on using aftermarket camshafts and revving to there full potential, you will need some aftermarket valvesprings & retainers. For tunning, go with whichever best suits your budget & application. Chrome, Uberdata, AEM EMS, Neptune, ZDyne.

If you need more info, you might direct your questions to the Engine Tech & Tunning forum. They will have better advice for your N/A buildup there. Good luck!

Best tunning info.
http://www.pgmfi.org/

Here is, in my opinion, a great N/A buildup guide.
http://www.c-speedracing.com/howto/nabuild/nabuild.php

 

PCT pistons will yield a 13:1 compression. You will have to pull an assload of timing to safely run those on pump gas.

PR3 pistons yield 11.2:1 and JDM ITR pistons yield 11.5:1, so those would be better choices for pump friendly compression ratios.

 

p30 or jdm p73 pistons would be ideal for your setup. both would put you in the 11.5ish:1 range. 200whp with itr cams is certainly doable, but would require a very good tune. if you want more than 200whp, you'll need to look into bigger cams and matching valvetrain. i like the rm m22x, and skunk2 pro1.

you'll also want a good flowing header with a 2.5" collector and matching 2.5" exhaust to prevent bottlenecks. then something to tune with. there are many options out there so i'll leave the research up to you.