Ok I am a newbie to this site and to the turbo RX7 so be gentle I just bought a 87 Turbo II, it has 100k but has a 30k motor in it (for only $2500). It ran perfect when I bought it a month ago when it was bone stock. I have scince put a cone style filter (with adapter plate) which it ran fine after that. Then I had the cats removed runing 2 1/4 pipe all the back with two straight through muffs. This is when the prob started. It is defitely faster but at about 5000 rpm the hp cuts out for a couple of seconds then comes back on. It doesnt do this all the time just sparaticly. it almost feels like the fuel is being cut off and on i still have the stock boost guage which I know is probaly not correct so I do not knowif boost is spiking. Does anyone have any ideas on what could be causing the prob. And one more thing this does not happen during normal driving only during hard accelartion/boost
thanks in advance

 

You are hitting fuel cut. Pretty good way to blow your motor.

 

You need a FCD bad. Mazdatrix and racing beat have them. Or you could pick up a used one from the partstrader or something.

 

Definately get an FCD, that is your problem, the ECU is programmed to cut out fuel once you hit a certain PSI, to protect it from blowing up. If you get a FCD, I'd suggest upgrading the fuel pump to an FD fuel pump, or a walbro 255lph. Try to get a FCD with a higher clamping voltage then what racingbeat sells.

Or else you could try making your own FCD.
http://www.teamfc3s.org/info/articles/fcd/diy_fcd.htm
That is a link to a writeup on how-to make your own.

 

Thanks guys, I had a feeling it was a factory govener but man thats lame to cut fuel at high boost...
And forgive my ignorance but what is a "FCD"...

 

fuel cut defencer

 

Read the article I posted, and it should give you a good background on the whole deal about fuel cut and fcd's, and maybe you can save a couple bucks and make your own.