Corprin

Like said before, if you have the motor apart, and the tools there why not just do it then!!!





Honda's vtec system runs off cams that look normal, but have an aditional lobe. Take the DOHC vtec cam, has 8 lobes for the standard "low power" profile, and a more agressive lobe for the "vtec" setting. There are 3 rockers, the two normal, and the extra that rides on the larger lobe. When the car reaches a set RPM the computer tells a solonoid to lock all three rockers together. this makes the two lower rockers to fallow the larger profile. Therefor makeing the valves open longer, and wider, making more power.



Cam tuning consists of a few parts;

Duration - amount of time the cam is open, measured in degrees of rotation

Lift - amount the valves opens from full closed to full open, measured in inch, or mm's

Ramp - the face of the lobe between the full open and full closed, this depicts how fast the valves moves from closed to open measured in degree of rotation

overlap - the amount of of time both intake and exhaust valve(s) are open at the same time. Measured in degree of rotation.



If you would like a lesson on what it all means, and how it all ties together, please feel free to PM me.

jspecracer7

either way, once you port, you will lose some of the smooth "idle" that a stock engine would normally have. You go to high on the exhaust, you'll increase overlap. If you take the intake ports down more, you'll increase overlap. However, if I had to choose, I'd heavily exhaust port it and clean up the intake ports.

Racer X

So your saying that porting the intake isn't really all that big of a deal?Just do the exhaust then?

toddp31

I did my exhaust and just cleaned up the intakes, hopefully it will be enough to spool the t-88. Idle is 900-1000

jspecracer7

I'm saying intake porting is more dangerous...You DO NOT WANT TO HIT THE WATER JACKET...Clean it up a little and do a big exhaust port. You'll make good power and still be safe.

GoRacer

OK, so that sounds like you are answering "yes" to my last question: Small intake and large exhaust street ports?

BigTurbo74

so what do you mean heavily port the exhaust? i was planning on taking it down around 2mm and smooth it to fit flush with the stock sleeve

IGY

On a turbo rotary you will see more gain from exhaust porting only, than intake porting only. The way I look at is you are forcing air in with a turbo, but if it can't get out you aren't going anywhere. Now if you go crazy with the exhaust porting and don't do any intake porting you can cause problems also. If you are worried about screwing something up, I would find someone that knows what they are doing, or just do the slight exhaust port and clean up the intake.

BDC

Agreed.



B