HI EVERYONE, I HAVE A 87 RX7 NON-TURBO. I JUST PUT A INTAKE AND CUSTOM CAT BACK AND THE DP IS 3" BIG. BUT NOW MY CAR IS SLOWER THEN BEFORE. WHEN THE CAR AFTER 3,000RPM WAS LIKE THE ENGINE IS DEAD. SO CAN SOME ONE TELL ME WHY.........??
THNAK YOU!!!

 

where in ny are you from?

 

GOATSLONG: IM FORM BK

 

3 inch is too much for a NA...and dp's are only for turbo's

 

SO HOW BIG DO U THINK THAT I CAN PUT IT ON.............THANKZZZZZZZ

 

Your 6th ports no longer work, as they were dependent on your stock exhaust backpressure to operate before, the 6th ports open at about 4000rpm, now they are staying closed.

Do a search for 6th ports for more explanation on their operation, and ways to continue using them now, youll have to rig something up...

 

What is 6th ports...?? Should i put a converters back??

 

Like I told you the 6th ports normally open due to backpressure generateed by the stock cats. Now there is not much backpresure, so no 6th ports. The 6ports are a set of 2(5th and 6th) intake runners that remain closed until a set of actuators is triggered by 2psi or more of air pressure, when the extend an arm, rotate a sleeve inside the block, and open the extra set of ports for top end. They stay closed until the air pressure makes them open, and you no longer have any air pressure.

Like I said, do a search and a lot of reading for the information you want. Im not about to sit here and type out what has been covered hundreds of times before, and the information is still archived in this forum, you just have to go find it. You are only one of thousands with nonturbo cars that have this problem, and many have found various ways to make them work again. You might just want to wire them open(remove actuators and use wire to hold open), even though it'll hurt your boittom end.

 

I run a header and 3" exhaust on my N/A. You need to do what he says and get them wired open. You lose bottom end, but to me I got my top end power. I also have a K&N, ported intake, TB mod, electric fan, and air pump removed, everything that could basically be taken off the motor.