F22A4 intake to F22A6 intake

[Bravo-man]

Hey guys I'm new here, this is my second 91 and and I have a A4 motor just want to know if doing this mod is worth the 35$ I spent for a A6 intake thanks.

[deevergote]

Definitely. The A6 intake manifold flows much better... of course, to make proper use of it, you'll need the F22A6 ECU, as well as the IAB control box that is located under the manifold. The F22A6 camshaft would be best to take advantage of the ECU's tuning as well.

If you ever come across an H23 intake manifold, that's an even better upgrade. You can take the plenum and throttle body from the H23 manifold and put it on the F22A6 manifold's runners (that makes for a much easier swap down the road, once the A6 manifold is installed)

[Tippey764]

Easily worth the trouble

But before you put it on, make sure you clean out all the carbon buildup and the EGR before you install the intake manifold on the car

Also if you remove the fuel rail then expect to buy new fuel injector seals

Obviously you will also need an intake manifold gasket set. If you order the intake manifold gasket at like advanced auto or pepboys make sure its the right one first. When i did my swap they gave me an a1/a4 gasket because their systems didn't know the differences beyond motor sizes.

[Bravo-man]

On the Iab I thought you could just gut the internals or is that not good? And thanks for the help I already did the disc brake swap that was fun. Oh on edit all i can find is auto cams is this ok or do I reall need one off a manual trans.

[deevergote]

As far as I know, the cams do not differ between auto and manual... the only difference is between the A1/A4 and A6 motors.

You CAN gut the IAB, and you can also hook it up to operate solely on vacuum... but you won't get the full effect of it. Gutted, you will lose some low-end power. The point of the system is to maintain velocity in the intake runners... and having too much room to flow air will result in a stagnant/turbulent airflow pattern.

[Bravo-man]

Oh I see now the ecu could I get that reprogramed they only have the auto trans ecu's and was thinking in getting better tuning.

[deevergote]

You cannot reprogram an Accord ECU. You can use a Civic ECU, but we're getting into pretty complicated territory there. Many people on here have done it, but it requires a good deal of knowledge to do so (and enough mods to your engine to make it worthwhile)... OR, it requires a bit of cash to pay someone that knows what they're doing to do it for you. Many people think you can just slap a chip in there (as the shady ebay sellers would have you believe), but that really is not an option.

The auto ECU will work. The only real difference in the way it operates is that it is programmed to give a little extra gas when the auto transmission shifts. I'm not even sure that would occur without input from the auto transmission computer.

[Bravo-man]

Ok on the A6 cam I thought that the manual trans was more aggressive then the auto, that was going from a A4 cam manual to a A6 cam auto , so it it will still be better going to a A6 cam auto then staying with the A4 cam manual?

[gloryaccordy]

I would get the top half of an OBD1 H22 or H23 intake manifold to fully round it out

[deevergote]

Ok on the A6 cam I thought that the manual trans was more aggressive then the auto, that was going from a A4 cam manual to a A6 cam auto , so it it will still be better going to a A6 cam auto then staying with the A4 cam manual?

Double-check the Honda part numbers to ensure the parts between auto and manual are not different, but I'm pretty sure it doesn't make a difference between the two motors. The only engine that this community cares about that has a difference in the camshaft profile between auto and manual is the F20B... to my knowledge, anyway.