LLman

I have a question. Can I remove split air pipe & block off both ends.
What effect has it and do I have to do anything else doing it.

thnx.
LLman

thomasmeisch

Don't plug it. Cut it off at the rubber part that goes into the engine. If it was in the way it won't be now and you wont have any probs

LLman

But what does the split air pipe actually do?

LLman

Samps

If you still have cats on your car leave the SAP in tact or your cat will clog up in a hurry. The SAP is used to supply air to the cat, to warm it up.

NCsublime

Yeah, I have mine removed. I'd leave the rubber piece that connects to the engine on, and plug it somehow (I used the cap off of some tire spray-I put it in backwards, and zip tied it. I haven't gotten around to taping it up yet. Anyway, as previously stated, it's purpose is to inject air into the cats to reduce emissions. I have a block-off plate for the end of the SAP if anyone needs it. I got it from RB thinking it would fit onto the engine block, but it ends up that it goes on the end of the SAP. I didn't want mine hanging up under the car, so I removed it completely and therefore don't need the block-off.

-Derek

derek_fullerx@hotmail.com

Turblown

iTrader: (12)

So is it ok to plug the hole that goes to the engine? I noticed vacuum pressure sucking there. I don't have cats either..

NCsublime

Yeah, but the "hole" that come off the engine is actually extended about 2 inches (like a hollow tube attached to the block). I'd leave the rubber hose on that fits over the tube, and just plug it up. It's easier to work with that way, and it will be quite secure. I had the tube capped off with a rubber cap, but it ended up shooting off somewhere and is now lost.


-Derek

fasthack

do you have to plug it? does anyone know the effects of plugging it?

NCsublime

I don't know any specific benefits, but it can't hurt. I don't know why RB would sell a block off plate if it was useless.

-Derek

SpeedRacer

The blockoff plates are for the CAT side of the SAP, not the engine side. I plugged mine, but that was after running without it plugged for 1.5 years. Probably doesn't matter. I just stuck a cork in the tube extending off the engine, and use a clamp to secure it. I have about 4 corks now on my car blocking different passages.

NZConvertible

The air pump supplies air to the cat via the split air pipe. The cat requires the extra oxygen for the catalysts to work (not to heat it up, the exhaust gases do that). Without the extra air the stock cat will clog fast and kill performance. You should pull the air pump, ACV, SAP and cat all together, because they all require each other and are useless if you pull just one. If you need a cat in your area, replace it with an aftermarket one that doesn't require air injection.

NCsublime

Yeah, I never really thought about using a cork. I have a lid for a spray bottle shoved into the hose that connects to the engine, and then zip tied it so it was tight. I'll tape it up someday. . .

I understand that the block off plate is for the cat side and not the engine side. I just wish I would have known that before I bought it. That is the reason I'm not using it. I already custom fabbed a block off plate for the cat side. I wanted to totally remove the SAP. If I would have known it was for the cat side, then I wouldn't have wasted my money on it. It's removed now anyway so the blockoff plate is useless.

-Derek

NCsublime

How is the air pump rendered useless with the removal of the SAP and cats? I don't have either, but still have my air pump for auxillary port actuation and ACV for who knows what reason, and my air pump still works. I do, however, see how the others would be useless, but not the air pump (not on 89-91 FCs anyway).

SpeedRacer

You are correct, the airpump is still needed for 6-port actuation, VDI actuation and for the AAF(anti-afterburn valve) which is in the ACV. You also can't remove the ACV if you want your 6-ports and VDI to work. Although if you have a Series 4 engine, then you might as well get rid of everything at once.

rxspeed87

doesn't the racing beat header and pre-silencer provide enough pressure to open up the 6-ports so you can remove the airpump and all that nasty stuff

NCsublime

Only on 86-88 models. The 89-91 require pressure from the air pump or a different method of activation.

LLman

So if I remove SAP ,ACV and airpump then its ok?
btw I have 87 N/A

LLman

NZConvertible

OK, I'll clarify what I meant. I have a turbo so I wasn't thinking about 6-port and VDI actuation. If you remove the air pump, everything else is useless and can come off, but the stock cat must come off if it has no extra air supplied to it.