I have been planning on upgrading my throttle body to a larger one and having the intake manifold port matched to the TB. I was wondering if it would be worth it to have the whole intake manifold port and pollished instead?

I heard that the interior of the intake maniforld is supposed to be rough to improve air fule mixture and that a port and polish will not be that beneficial. Please pitch in your two cents about it.

 

I would leave the interior of the Manifold alone and only do the ports.

Port match the trottle body side and when you get the head P&P get the manifold Port matched again.

 

Ok, so it's true about the rough interrior of the intake manifold being better then a smooth surface?

 

i believe you want the air to be somewhat turbulant inside the intake manifold...if the airflow is too smooth it wont pick up as much of the fuel thats being sprayed and it would just pool...


[Modified by FnkyChnkyMnky, 1:22 AM 7/16/2002]

 

you don't want turbulence in the plenum tho, you just want enough at the inlets (err.. outlets! =P) to promote fuel atomization. you need enough where the air will grab the fuel and help carry it into the cylinders.. i'd leave the manifold alone, the possible gains made won't warrant the cost..

 

how about get a skank2 manifold, and mod ur ecu to forget about the butterfly..

or you can mod the itr IM to fit instead.

 

If you P&P your gonna loose some HP unless you have a pretty built motor!

 

How you figure?

135 hp out of a D15B7 with just bolt ons, must not have HURT it much.

 

I took an idea and a file to my GSR manifold. I also added an ITR exhaust cam and a few other mods. On stock exhaust still... yet when I looked at my dyno once I figured out my cam gears... man. There was one pull at +8, +3 and 19BTDC where I made almost 125 at 5252rpm and 159.8/123 thats with all stock stuff mind you. before that, I had 118 at 5250 on CTR/GSR but I never tuned the cam. I figure unless I have ECU tuning I wont get to see all of what my manifold to do, also need to raise the VTEC point to say 4850 or so, get a header, proper cat back etc... my motor is having issues right now... but it will be back and stronger... with the P72 IM

oh yea... its late and Im kindsa tired. I opened the secondaries and tapered the stack on the inside so #1 sees the same angle as #4 as much as I could by reducing the profile of the internal plate, opened the openings about 1cm each so they they look like this ()()()() instead of o o o o !! when I first hit IAB opening, there was a difference even on the stock map. I also knifedged the TB butterfly without changing the size, the same to the internal ones as well to reduce the profile on them. I also adjusted the snap to the plate so the air flows more to the runner than straight into the roof of the wall. The TB got a tapering 70-60-68 as well. Then, I portmatched the IM to the TB at 68 and smoothed it out. Seems to
be working fine! I added a hondata gasket (works best on turbo) and bypassed the TB coolant.


[Modified by MikeSarr_GSR, 9:06 AM 7/28/2002]