I had the stock exhausts on there with the catalytic converter, cut out the converter and put some brand new racing beat exhausts and it pops loud. Someone said its pretty normal just wanna make sure?

 

State your car in future tech questions please...and less back pressure as you have no cat on it is usually what causes your "backfire"..
Now you just need stickers..Hotdogs flamedbroiled here ---->>>>> (tail pipe entrance..)..lol!

 

Mine backfires. I do have a cat, but I don't believe it is working too well.

Im running a 79' 12A.

 

richchchchch

 

It's not running rich at all. I've set the idle properly.

The reason it backfires is not because of the mixture, but because of the age of the engine+an inherent flaw in the design of the Wankel.

If you aren't running a fuel injected engine, it still takes a sip of gas even though the ignition is turning off as the engine spins down. This little bit of mixture is more than enough to ignite when it goes over the exhaust.

 

Mine does it whenever i warm up the car. Is this normal?

 

Ideally...no. it's not supposed to.

I beg to differ. Back fires have a lot to do with air/fuel mixture.

 

I get this in my FD. Only mod is a catback. Don't get it too often, so it's not too bad!

 

Backfires can be costly when a muffler explodes. It can happen; trust me.

 

its normal mine its the same

 

I wonder if there is any way to stop this from happening. Even if i stop the "accelerated warm up" it crackles and backfires a bit upon warming up.

 

Its normal. What size exhaust pipe are you running?

 

i tink you are the first person dont liked :P

 

Is it really normal? I don't remember my brother's FD doing it but mine does too. At least until it gets up to operating temp.

 

Some backfires on a wankel when it's spooling down just after letting off the acceleration pedal are normal. I've never heard one backfire during warm up.

Low fuel pressure can cause this. Check fuel filters, pumps, and any other obstacles in the fuel lines.
Catalytic converter removal/damage will cause it. Specifically in the RX7 when an air injection system in the exhaust.This creates a combustion in the exhaust system and the the lower resistance of a damaged/removed exhaust allows the combustion to take place immediately.
An air leak into your intake can mess up your AFR and cause this as well.

 

never knew low fuel pressure could cause this. it actually seems really counter intuitive

 

My 92 FD has Knight Sports Metal Cat. but Backfire not happen. (the engine is stock) Generally without Cat. makes backfire~~

 

It throws off your AFR and when some of the resistance in the fuel line seizes it can dump more fuel than necessary. I've seen it happen before.