2001 GS-R: Engine rebuild, other refreshments

[aw614]

Is there any reason I should get one of these intake manifolds? Although I think S2 has a bad reputation here because of the forum issues several years ago.

https://4pistonracing.com/collections/i ... tra-street

https://4pistonracing.com/collections/i ... kunk2ultra

I am just using the Skunk2/Gen 1 blox ITR clone intake manifold. I know the Gen II skunk2 is better, but I really prefer that OEM+ look the gen 1 has and I can run the stock ITR intake tube into my Mugen intake.

[GeHonda]

Is there any reason I should get one of these intake manifolds? Although I think S2 has a bad reputation here because of the forum issues several years ago.

https://4pistonracing.com/collections/i ... tra-street

https://4pistonracing.com/collections/i ... kunk2ultra

I am just using the Skunk2/Gen 1 blox ITR clone intake manifold. I know the Gen II skunk2 is better, but I really prefer that OEM+ look the gen 1 has and I can run the stock ITR intake tube into my Mugen intake.

I have the same G1 SK2 unit for my GSR P72 head. It looks like a P73 manifold to the untrained eye.

[Dave7CDMTYPER]

The racing intake manifold looks gorgeous. Imagine that with 4Piston porting.

[DC231]

Is there any reason I should get one of these intake manifolds? Although I think S2 has a bad reputation here because of the forum issues several years ago.

https://4pistonracing.com/collections/i ... tra-street

https://4pistonracing.com/collections/i ... kunk2ultra

The ultra race is way too big of a plenum for what you need. It's great for WOT high RPM shifting drag racing. You will suffer a lot in the mid range with a manifold that large.

The street version would be much better for your build but you may have issues with it not having enough clearance from the firewall if all the original equipment is still there.

The ITR intake manifold is top of the line for having the best throttle response and mid range power over aftermarket manifolds while still holding it's own on the top side.

[JDMJNKY]

Almost passed eh? What did you end up doing to pass?

Yes inspiring video! That will most likely be very similar to my engine setup. 200whp would be super great. Is that your car? In the comments it says it is a gsr motor stock valvetrain with P30 pistons. That's impressive, and my engine is gonna be way cooler than that anyway.

That makes me wonder. That car was untuned on stock obd2 ecu. Impressive that it was running so well without a tune. Would that car pass smog in that condition? For my car, maybe I'd put in stock ecu to pass smog, then back to the tuned ecu after that.

Yeah almost passed, it was my car, But I did not see it through to pass ref. With a stock header and a new cat it would have passed for sure. Iirc my low speed HCs were just off the charts.

As long as they have no reason to fail you visually, I believe it’ll pass smog, that and all cel’s must be off. The car was on a VAFC tune.

[Dave7CDMTYPER]

On the first build, I should have trusted my gut over my friend's and gone with the tighter piston ring gap and follow the manual on piston ring orientation. After I redid things on the current engine, I don't have the smoke or the crazy consumption the previous setup had. I still consume some, but a whole 5 quart jug of oil will last me 2.5k to 3000 miles and not 1000 miles with a mix of autocross, an occasional track day and driving to and from events. And I don't have a dirty bumper full of oil. Now instead of oil that gets on my bumper, it's just dirt, (who knew, but the rear end gets as dirty as my GTI does with just dirt). Both motors made identical power, but one doesn't smoke Both made around 180 whp, which I am fine with.
...

Thank you for that writeup! It's very helpful, and I will do my best to pay attention to those details.

The ultra race is way too big of a plenum for what you need. It's great for WOT high RPM shifting drag racing. You will suffer a lot in the mid range with a manifold that large.

The street version would be much better for your build but you may have issues with it not having enough clearance from the firewall if all the original equipment is still there.

The ITR intake manifold is top of the line for having the best throttle response and mid range power over aftermarket manifolds while still holding it's own on the top side.

Ok great info thank you! I've heard about using the ITR manifold, but it does need some modification to fit onto gsr head.

[Dave7CDMTYPER]

Yeah almost passed, it was my car, But I did not see it through to pass ref. With a stock header and a new cat it would have passed for sure. Iirc my low speed HCs were just off the charts.

As long as they have no reason to fail you visually, I believe it’ll pass smog, that and all cel’s must be off. The car was on a VAFC tune.

Ok great to know, that's very helpful. If I had the S2 intake manifold, that probably wouldn't help with visual inspection.

[JDMJNKY]

Ok great to know, that's very helpful. If I had the S2 intake manifold, that probably wouldn't help with visual inspection.

They're supposedly carb legal, if it is the CARB EO one you'll be fine. If you can locate a gen I they look just like an ITR IM. That will surely pass.

[Dave7CDMTYPER]

Ok great to know, that's very helpful. If I had the S2 intake manifold, that probably wouldn't help with visual inspection.

They're supposedly carb legal, if it is the CARB EO one you'll be fine. If you can locate a gen I they look just like an ITR IM. That will surely pass.

Ok sweet!

[Stin1]

Ok great to know, that's very helpful. If I had the S2 intake manifold, that probably wouldn't help with visual inspection.

The original skunk works manifold were some type redrill on the type r manifold.
They're supposedly carb legal, if it is the CARB EO one you'll be fine. If you can locate a gen I they look just like an ITR IM. That will surely pass.

Ok sweet!