I've been working on porting out one of the stock manifolds since there isn't really a decent price aftermarket manifold available yet for the H22. I've have basically joined the two runners in the intake bypass manifold together into one large runner. about a half hour with a recipricating saw and some smoothing out with a die grinder is all i've done so far. I"m gonna do some more polishing to make the bridges smooth and rounded.

 

good idea just dont go too over board!!!

 

This has been done before and I think there was even a dyno taken.

 

Yeah i don't understand why there hasn't been a really nice manifold for street h22 motors. Good work on the manifold. You will probably see like 3-4 hp gains.

 

I have only heard of overall power loss with this procedure. Hope you prove it wrong with some dynos of before and after. Hate to think that all that hard work was done to destroy any well thought out research from Japan.

Maybe I will try it too!

 

you just created a bunch of turbulence in your intake system should have just ported the throttle body to 70mm and left the rest stock......

 

I cant see that helping much at all, but actually killing your power AT LEAST until 4500 or so.

That is worse than just keeping the secondaries open all the time, and doing that kills your low end. Dyno proven.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdmcivicferio &raquo;</TD></TR><TR><TD CLASS="quote">you just created a bunch of turbulence in your intake system should have just ported the throttle body to 70mm and left the rest stock......</TD></TR></TABLE>

ok buddy, but he is going to smooth everything out. should that not help?

and those that say that it kills hp, show a dyno to back up your statement. please enlighten us.

mr mike let us know how it turns out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SUB-0 H23 &raquo;</TD></TR><TR><TD CLASS="quote">
and those that say that it kills hp, show a dyno to back up your statement. please enlighten us.
</TD></TR></TABLE>

I did the test first hand on the dyno. It was my *** standing beside the roller plugging the vacuum line with my hand so I remember it bright as day. Honda tuned it perfectly because the H22 lost power until they would have normally opened.

 

yeah i'm gonna get it dynoed again pretty soon. but i'll have a couple more mods then my last dyno. My last dyno was done with slight porting to the 8 holes and the IAB plate removed. I did not see any trq lose in the lower end but really need to improve higher end flow.

 

If you are planning to mod the stock IM rather than construct a new unit or buy an aftermarket piece heres something for you to try...

fill the hole in between the Square and the circle openings on the the casted plate at the top of the runners. Port the squared opening to match the circle opening that sits just in front of it...

Like this...



Photoshop special

run 8 velocity stacks/air horns that sit level with the plate floor. The only portion of the velocity stack/air horn that should be portruding is the actual rolled trumpet portion, almost like a speed bump surrounding the openings.

You may have to fab a new plate or add material here and there... Its all depending on whos doing it and their preferences in fabrication.

The thing I like about the runners of the H22 is the fact that they run a large taper. I think the only downside of the H22 IM is the mid to uper half, the runner entries and the plenum itself.

heres a pic of the velocity stacks/air horns...



The only difference from the way they are in this pic is the fact that in this pic, they are roughly above the surface or in this case the adapter floor.



The height above the plate floor on the prelude IM isnt needed with these so your going to have to machine off quite a bit to level them.







Modified by Rick Solis at 4:56 PM 5/21/2004

 

You really don't want to keep the high surface area and the radical turn which is why our manifold sucks from the get go. Though I found that port matching and cleaning up the ports on a stock engined manifold yeilds literally nothing.

 

I yanked the secondary box and ported the **** out of mine way more than that about 6 months ago..... there's always someone who's done it before you!......... anyway, don't bother if your NA.... you won't like the results.... if you're fully built and have a standalone like me..... the port work will help SOME, but i've found that the most power is made in the portwork of the cylinderheads.