I don't know much about rotary engines this is my first one, I'm going to put a 2.5 inch single outlet straight pipe and was wandering if I should leave the cats or can I take them off without looseing power? I allready cleaned out the first two and left the main one alone

 

Removing them will bring out a little bit more power, no need to worry about losing power from that.

 

thanks, oh yeah one more question is the exuaghst return line needed to be welded back in to pipe if it's straight piped

 

i believe it should be because on certain models it actuates the 5th and 6th ports... we will need more info about your car before we give you a positive yes or no though... i'm sure someone can tell you for sure once you give us the year of your car

 

the year is 1988

 

any more advice

 

correcty me if im wrong but, removing the cats on a n/a would not effect the funtion of the 5th and 6th ports. Only turbo II motors rely on the back pressure to activate them.

 

iirc the difference is not na and turbo but s4 and s5. the s4 (what he has) needs the back pressure to activate them, the s5 opens at a set rpm.

 

Turbo motors dont even have auxilary 5/6 ports, 5/6 ports are only on nonturbo models. Turbo motors have 4 port intake design.

You can setup the 5/6 ports to open with the airpump instead of exhaust backpressure read this writeup to see how

http://rotaryresurrection.com/2ndgen...actuation.html

The better more expensive method is to get an electric airpump and an rpm switch, and use them to open the ports.

If you want link for that I can give you it.


The other option is to leave the stock main cat/split air pipe and everything should work fine given you have enuogh backpressure to open the 5/6 ports.

 

thanks for the advice I'm more than likley going to use the stock air pump to activate ports