I have researched this by searching the forum, and found lots of interesting information. Seems like I ought to be convinced that removing the air pump isn't the best idea, but I am persistent, if nothing else...

So I have a 1993 RX7 R1, with no cats or any functional emissions control equipment whatsoever. Further, my ECU doesn't even know what an air pump is. Obviously, the air pump is no longer of any use. If there were no other considerations, the decision here would be obvious - remove the air pump, save some weight, less sh*t bolted to the engine.

However, it isn't that simple. Removing the air pump pulley significantly reduces the contact area of the belt on the water pump and alternator pulleys. I have seen the Greddy pulleys, which supposedly help some due to larger diameter and some sort of extra grippiness on the water pump pulley. However, I am not looking to underdrive the accessories, rather I am looking to remove the air pump! With the stock pulleys, it looks to be a pretty bad idea to simply remove the air pump and run a shorter belt - maybe not for daily driving on the street, but for a racecar, I would certainly not want to push it like that, particularly for wet races.

So here is the real question: anyone here running/ran the pulleys on a 3rd gen on the track, and if so, have you ever noticed any problems? Any increase in coolant temp on hot days on track? Ever had the battery die mysteriously/suddenly? Any info would be greatly appreciated.

 

Garfinkle has made an idler to replace the air pump that has an alum pulley that is bigger than the air pump pulley ( to slow it down for less drag and wear ) .And he has under drive pulleys. so the water pump is well in contact with the belt. Just design and make one for your self .

 

Hmmm, that is more along the lines of what I am looking for - a solution just to remove the air pump, without any changes to anything else.

However, time is not a luxury I have, so I can't just design and fabricate something. Is there anyone that maybe sells something like this?

 

ask duboisr, Garfinkle is always coming up with doo-dad's he'd probably make you one

 

Replacing the pulleys with under drive pulleys Ex. Greddy pulleys will not make a noticeable difference in battery power. It will however reduce cavitation of the water pump casused by a smaller pulley. When In creasing the size of the pulley it slows the water pump and therefore reduces cavitation and more effectively cools the vehicle.