H23 Intake manifold

[deevergote]

It's also most likely stuck pretty well to a paper gasket.


People say the hybrid is better, but there have been no official tests to prove it. It's all theoretical. Try it and see which you like better.
Also, replacing JUST the plenum is much less of a hassle. You don't have to deal with the gasket (which is a pain in the ass to scrape off... if you do that, replace it with a Bisimoto gasket... more performance)

[Tippey764]

It's also most likely stuck pretty well to a paper gasket.


People say the hybrid is better, but there have been no official tests to prove it. It's all theoretical. Try it and see which you like better.
Also, replacing JUST the plenum is much less of a hassle. You don't have to deal with the gasket (which is a pain in the ass to scrape off... if you do that, replace it with a Bisimoto gasket... more performance)

I am definetly taking my lower end off. I want to clean the EGR out and it will make it 100x easier. I think im going to use the h23 bottom end because i cant have any down time while i swap manifolds and clean up stuff thus leaving my car disabled. I want to remove the old one and put the new one in and be on my way.

[Chico Suave]

IMO for an all motor car its best to run the A6 runners with the h23 upper plenum and TB because the A6 has longer runners which help with torque especially when combined with the h23 plenums increase volume over the a6.

to the OP its not 100% nessassary to run the ECU and the butterflys can be run open at all times and added power will still be utilized. I really dont see the point in controlling them when they are open at full throttle anyways.

Just an FYI the A6 runners are shorter than H23 runner. Shorter=better top end, Longer=better torque. Also yes it is not needed to have the ECU to open the butterflies you can just have the vac line hooked straight to the plenum but will open at WOT and hurts your low end of the power band. The ECU has the secondaries open up at 4600 rpm to allow you to get the most out of your power band both torque and horsepower, so it is ideal to have the PT6 ECU with the IAB black box.

It is you car OP hope this helps you out. Also to get to the bolt on the back of the bottom of the runners you can get to it without lifting the car in the air, just take off the intake and you will be able to see the support bracket and be able to reach the bolt as well. Good Luck

[Charliehstle209]

Just an FYI the A6 runners are shorter than H23 runner. Shorter=better top end, Longer=better torque. Also yes it is not needed to have the ECU to open the butterflies you can just have the vac line hooked straight to the plenum but will open at WOT and hurts your low end of the power band. The ECU has the secondaries open up at 4600 rpm to allow you to get the most out of your power band both torque and horsepower, so it is ideal to have the PT6 ECU with the IAB black box.

thanks a bunch for this, Chico! just picked up a complete H23 IM for $21.

any thoughts of butterfly delete? or is it tunable to open around 3000rpm...?

gl on your IM pull ASTCB7, its not too bad. yes you'll have to get under the car to remove the brace from the block to the manifold. then a 12mm on the block nuts

[turbo90accord]

H23 is longer its has been covered before here posts 6-10

[Deetz]

H23 is longer its has been covered before here posts 6-10

I just read threw that whole thread, not one person has dyno'd this swap proving any power gain. They sure have a lot of measurements in there, but that doesn't mean power. In fact, it may just shift the powerband.

I sure would like to see a before and after. I have a whole H23 intakes, TB, fuel rial injectors, ect.....but won't do the swap unless i know something can be had by it.

Last time i tried a manifold swap was a B20Z crv engine in my civic. everyone said to go to an integra unit, i did an lost power.

Another example was a B16A with Type R intake manifold. The R manifold had bigger runners, but all it did was loose velocity which resulted in a loss of power over a smaller B16 manifold.

So, does this whole H23 manifold swap actually make power????

[deevergote]

The H23 manifold has a larger throttle body and plenum, while retaining a similar runner diameter to the F22A6, along with the IAB system that the F22A6 has. More airflow without losing velocity. It honestly SHOULD make more power.

A dyno would be nice... but very few members here can afford to dyno their cars, unfortunately. Those that do only do so when they have significant mods done.

[kellogg_racing_]

so it is ideal to have the PT6 ECU with the IAB black box.

Will the p12 ecu control the IAB's too? I've been told the p12 get more power then the pt6 does...

[splitsecondcb]

Will the p12 ecu control the IAB's too? I've been told the p12 get more power then the pt6 does...

the p12 is only good for performance when your running a f22a1 or f22a4, or else you can also run it with a sohc f20a, it is more useless to run a p12 with a f22a6 because it won't open the butterfly unless your using a vacuum line to open up the butterfly at wot, i know one of the member was riding like that but don't know if you would get any gain from it or lose sufficient powers.

[kellogg_racing_]

the p12 is only good for performance when your running a f22a1 or f22a4, or else you can also run it with a sohc f20a, it is more useless to run a p12 with a f22a6 because it won't open the butterfly unless your using a vacuum line to open up the butterfly at wot, i know one of the member was riding like that but don't know if you would get any gain from it or lose sufficient powers.

Ahh I see. Either get the p12 or the h23 plenum and pt6. Either way, I'll be doing some research. Thanks for the clarifications though!