Hi, i have builted new exhaust on my rx-7 non turbo (downpipe to back), 2,5" pipe`s, one presilencer and two backsilencer`s. I have removed the split air pipe and blocked split air pipe connection, removed cat and the air pump belt. In finland we dont have emission test`s on rotary engines so i dont need that system.

Engine is working great but now idle speed is bounce about 600rpm to 900rpm and there is some backfire on pipes?!?!?. How do i get my idle speed steady?Do i have remove or block something else?Why there is backfire??? Please help me guys! ! !

BTW,the sound of my exhaust is great and i think there is couble horsepower more ;D

Sorry my bad english and it would be great if someone can help me and send the instruction`s and maybe photos that what should i do. My email is: udo69me@hotmail.com

 

Backfire = exhaust leak. What year RX-7 are we talking about here?

Mario III

 

If your car is an S4, blocking off the split air pipe is keeping exhaust backpressure from opening the auxilliary ports. Result: 25 hp lost.

If your car is an S5, disabling the air pump is keeping it from actuating your aux ports as well as the variable dynamic intake (VDI). Result: 40 hp lost.

The factory service manuals or training manuals can give you a better break down of these systems (http://www.rotaryheads.com/PDF/2nd_gen/).

As for the bouncing idle, it could be your TPS needs to be adjusted, though it's really not related to exhaust. http://howto.globalvicinity.com/gv_w...i=58&co=1&vi=1. A vacuum leak is also a possiblity for this problem.

 

Its 1988 non turbo model ( 146hp) and i dont think theres any lost`s in horsepower`s..so u are telling me that i should put the split air pipe and air compressor back on working?!?!?

 

Yes, you need to reattach the split air pipe. The small (~6mm) vacuum line coming off of it connects to the auxilliary port actuators. Without it connected, your aux ports will not open at 3800rpm like they are supposed to. The result is 25hp lost in the top end. If you didn't feel a loss in power, they probably never worked in the first place.

The air pump and ACV can be removed. Do a search of the 2nd gen section for "emissions removal". A lot of people have done this.

 

ok...but do i have to put that split air pipe back in the main pipe?can i only remove the block which is in split air pipe connection??

 

what about on a turbo II? I want to remove my air pump but wasn't sure about the 5th and 6th ports on that model.

 

See attached pictures for help on that. The split air pipe is labeled. Connection "A" is the vacuum line that connects to the auxiliary port actuators. "B" is the check valve that keeps exhaust gas from entering the ACV. Just plug them both back in.

Turbo motors have 4 ports, not 6 like an NA. You can remove your air pump, but you will need a double alternator pulley. As I mentioned, the water pump pulley will slip without 2 belts.

 

Thank you for the pictures this is what I was looking for. I was trying to figure out what the a and b parts were in the FSM. Thank you for the thorough picture and enhancing the FSM sample