Hi there,
thinking of building a b17a for boost, resleeving it to 84.5 mm to give me more displacement and still have a good r/s ratio for revving high. I want to use a large turbo that really comes on only by 5.5-6k rpm and screams like hell till 9500 rpm, and I guess my question is, what type of camshaft should I use in this application? I know crower offers custom ground billet cams for 650 if no one makes a proper camshaft for this, but I'm hoping someone does.

 

I really don't think you'll gain much by revving that high. Save yourself some dough and get some ITR cams, set your revlimiter to a much more mortal 8500 and go from there. You don't need to rev the snot out of it to get power when you're boosted.

 

Stay away from ITR cams as they have too much duration. Turbo motors benefit from big lift & short duration to move as much air as possible without blow-by. I have personally seen 2 1.8's making 400+ whp on mild boost running GSR cams.

Rich

 

That is just a myth. ITR cams if properly tuned can make more power than GSRs. The extra duration helps fill the cylinder and you can tune them slightly to get rid of the overlap. BTW, at high RPMS, where boost builds the most, the amount overlap becomes less and less since the engine is turning faster.

 

Im using Spoon Cams on my turbo ITR motor.
Signal uses Spec A's on their turbo B16B chop top

 

I think Crane Cams makes some good cams for your application you can check out there web site to make sure.

 

overlap is bad at low RPMs due to blow by, however, like Jared mentioned at really high RPM, the inertia of the air makes it harder to blow by since its lazy to move in and out of the cylinders, at least that idea works for an NA engine, with a turbo there is the whole boost factor, but it depends also on how much boost your running..most will day GSR cams are good, i think ITR cams are better, and CTR cams IMO arent a good idea, unless you know how to tune...Web makes turbo specific cams also.

 

Check out Webcams-maybe?

 

Most of the Japanese tuners that run turbos on hondas recomend the TODA A's ...? Food for thought