bikeordie092

iTrader: (2)

ok.. so sometimes i have this trouble with my car backfiring right as i start it.. i swear it was only after i revved the motor and cut it off....

well today it backfired once, then the next time i went to start it the muffler farkin exploded! exploded as in didnt sound like a regular backfire, sounded louder than a gun. there was nothing stuck in the end of it.. my question is, how the hell does something like that happen?!


here is a video i took after the fact:

rwatson5651

iTrader: (5)

I have always wanted to see the inside of one of those!!!!!!

My only guess would be raw gas finding its way into the exhaust system, I bet that was one "Oh ****" moment!!

I would check my carb closely to make sure its not flooding and then check the ignition system to make sure everything is getting combusted when it supposed to.

2 cents

coldy13

LOL, first I've heard of it happening to someone else That happened to me back when I first got my rx-7. Rwatson has it right, fuel getting into the exhaust, start the car...and BOOOOOOOM!!! It's just the way the engine is designed, when you flood it trying to start the car, the rotors are going to slosh a bit of fuel out the exhaust ports, that plus other exhaust leaks that let fresh air into the exhaust = boom.

bikeordie092

iTrader: (2)

ive never had any flooding issues, tho... it was as soon (or damn close) as i hit the ignition. the timing is good, double and triple checked....

bikeordie092

iTrader: (2)

"oh ****" doesnt even begin to explain lol... the car started up shortly after i let everything quit smoldering, loud as hell now lol

coldy13

That'll throw a bit of fuel into the exhaust too.

It happened to me the same way, as soon as the engine cranked, muffler went boom.

XanderMan

instead of a Vanity Plate saying RX7Zoom ..opt for RX7BOOM ..lol all in good fun ..luckily there wasnt a small animal close by !

85rotarypower

Removed the muffler on my 79 due to a leak near the inlet side of the muffler. I cut it open to see what its all about inside there and there was obvious damage due to backfiring. This is when the thermal reactor and all related parts were still on the car. Damage was primarily around the inlet side of the muffler. The pipe internally had come loose in the baffles it would usually be attached to. On top of this, the inlet baffle (where the pipe goes in) and the baffle just inside that (about 4-5 inches in if I recall correctly) were both deformed. Muffler was leaking due to rust at the seams.

I know I took pictures of the internals, have to see if I can find them.

mazdaverx713b

iTrader: (91)

with an afternmarket exhaust system you will see a lot of backfiring.. however the aftermarket mufflers are known for splitting and are not quite as thick of a design as the oem units. a cheap aftermarket muffler will almost always fail on a 7. go with the good stuff from RB, stay with the original muffler or plan on buying a muffler every year or so.

bikeordie092

iTrader: (2)

yeah i have no emissions stuff or anything on the car, the PO removed it all... how well does the 12a do with little to no back pressure? i think for now (till after DGRR) im going to put a coffee can style muffler on it. granted itll be loud, but itll be legal lol

coldy13

I'd stay away from the coffee can type, the cheap one I had made my car louder than a straight pipe... If you want a cheap one to get you by, I'd get one of these Thrush Turbo Mufflers - JEGS I've had them on my BMW and my sisters Saturn for a few years now, I wouldn't expect it to hold up forever on a rotary but it should keep the noise reasonable until you can get a RB muffler on there, the universal mufflers aren't that expensive either http://www.racingbeat.com/RX7-1986-1...sal-Parts.html

bikeordie092

iTrader: (2)

We actually sell the thrush mufflers at work(autozone) I was just thinking less back pressure=less explosion lol

nff

mine did the same thing:


i also registered a 115db in the cabin on this run. (the thing you see sliding off the dash)

also less restriction for the most part on rotarys equils more efficency.

bikeordie092

iTrader: (2)

nice, lol idk, i guess i just hadnt ever heard of this happening... now i know its not all that special lol

nff

also look at your title under your name. lol oh the irony.

bikeordie092

iTrader: (2)

U know, I never even saw that. That's great lol

Jingkun

iTrader: (4)

Lol this should free up some horsepower

Mine backfires all the time. Ive got a rb header and muffler and a straight pipe where the cat would be. I hear glass packs are the way to go for a replacement though JK DONT DO THAT

Cookboy

iTrader: (10)

I just put one of these on, with an RB presilencer and a 22" magnaflow as a midpipe. Sounds great, very mellow, no baffles.

rx7lives

Look at it this way, you have less back pressure.

PreviouslyPlastic

iTrader: (1)

I wonder if this is what has happened to my muffler.
Externally it looks fine and was installed by the previous owner at a "muffler shop".
I've been trying to quiet my SA down and even with a "conventional" muffler it seems loud as hell.

nff

get under the car and give your muffler a hug. you'll find out if its blown out or not. also check your pipe you may have a leak.

not the best sounding but its within legal limits.