Jaguarx7

Got an RB Road Race Header for my '88 vert, and was wondering how I can make my ACV work while using the header. Racing Beat says for s4 cars you have to remove the ACV because the header/engine flange blocks up the port which porvides fresh air to the stock exaust manifold, and with the port blocked the ACV wil not function correctly. I'd really like to keep my acv because it runs my aux. ports and VDI (yes, VDI), and times their opening quite well. So my thought is to drill a hole in the flange to unblock the fresh air port and vent it to open air.

I would appreciate any and all feedback on this idea, as well as any other ideas you may have to make the acv work.

Mint87RX7

well you have to realize that even though your ports and vdi work great now, once you put a header on there your not going to have as much pressure in there so they wont work the same even if you do get the acv hooked up. i would suggest searching for alternatives to run your ports. i have mine ran off the airpump with an rpm switch.

Jaguarx7

I don't think lack of pressure will be a problem, but rather too much pressure. The solonoids will direct air to where I need it when I need it. My problem now is too much pressure. The air formerly routed to the manifold fresh air port now has nowhere to go and is causing my ports to open way too early. Perhaps it would help to say that I'm running the ports/vdi off the ACV air dump hose located at the bottom of the ACV. As I understand it, the air is only directed to the manifold fresh air port at lower RPMs (when I don't need it), at higher RPMs it's diverted to the air dump hose (where my port actuators get it) and through the relief air silencer.

Jaguarx7

Any other thoughts?

Jaguarx7

bump?

Jaguarx7

Mabey another bump might help.

HAILERS

Something does not add up here. The Split Air Pipe gets a very small amount of the airpumps air. MOST goes to thru the checkvalve b/t the acv and the intake manifold.

With a fully warmed up engine, you should get only a whisp of air out the acv's dump nipple on the bottom of the acv. If THAT is where your picking off the air for the auxillary port actuation and your getting a lot of air out of it at idle, then something is amiss with either the relief solenoid or switching solenoid.

If it's in the dump hose that your picking off the source of air for the auxillary ports, it should not be supplying air there until approx 3850 rpm.

I probably just misread your post and disregard this post if it's enormously in error.

Jaguarx7

First, thank you for replying. The air that goes through the check valve goes into the exaust manifold, when you install a header that port (the fresh air port) is blocked by the header/engine flange. Since that air can no longer go to the exaust manifold it has nowhere to go but the ACV air dump.