82mazdarx7

I just got my new engine in from Pineapple racing. But I noticed this problem with my last motor. When you rev up the motor, when the rpms are going down, you here this pop pop pop pop like a back fire. But I dont think it is back firing. I dont know if rotary engines can even back fire. Well anyone have any ideas. I have seen other rx7s do the same thing and am wondering what the hell it is.


Brad

sonic_rx7_84

It's normal, the rotary engine likes to dump a little bit of gas down the exhaust which causes the gas to ignite in the exhaust system causing the poping noise. Happens with mine, and most of everyone I talk to.

peejay

That 's what a rotary SHOULD do.

sonic_rx7_84

yeah but not as bad as your rex did midtrip to columbus.

peejay

You should've heard the '80 popping and banging all the time... it was rather fun

The '85 rarely does it... will have to fix that

sonic_rx7_84

I'll be a very happy man to hear that popping sound again, wont be long-> new engine coming soon!

82mazdarx7

Thats good. I really didnt think that anything was wrong. Just didnt know what the hell it was

8000RPMzEZ

Put the car in 1st gear and go to like 4 to 5k rpmz and stay in first gear and let off the gas, if it pops and all that, check your timing. More than likely it is off. I have never heard that this is a normal sound for a seven.

Mike

nimrodTT

Exhaust afterburn on decel is normal for a rotary. Though timing can affect it because the effective burn time in the compressed chamber can change, it's still normal.

82mazdarx7

its only when I am in nutral and rev it up. I cant really hear it while it is in gear.