Exhaust Popping Sound

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straightlinespeed

straightlinespeed

Sometimes I pretend to be normal
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Hi guys, I've always been curious what people do to get there cars to pop backfire, get that rap sound when they are cruising and then let off the gas. Is that from the exhaust they are running or what???
 
Yup , what he said. I had glass packs on my 72 318 Demon-sounded like gunfire when decelerating on a freeway off ramp. That and leaking carb and old tired valves.
 
If you want to backfire one...get going pretty fast then shut ignition off with gas pedal down then turn it back on..but be careful..it can do some damage.If you're talking about the rumble when letting off gas the exhaust system has a lot to do with it.
 
Retard the ignition timing & run it a little rich if you just want to make it backfire. I don't recommend it as far as tuning it goes, but if poppin is what you want then...
 
No, I really dont want the sound. Sometimes I like it, but it would drive me nuts. I'll keep my engine running right. If I had a complete beater I might consider it.
 
Good one brother!
Teach the youngin's how to blow their mufflers apart (the one's drivin' old carbureted stuff)...Oh and it helps pumping the **** outta the pedal while you're at it!

All kidding aside, one of my buddies just got pulled over doing it in his old D350...

If yer lookin' for all that poppity pop pop on trailing throttle, that's a combination of exhaust system (like the the glasspacks) and maybe a header leak allowing some fresh air into the exhaust, or an excessively lean condition when you chop the throttle, causing it ( the lean condition causes a mixture that either doesn't ignite in the combustion chamber or only partially burns, then re-ignites in the exhaust).

:cheers::cheers::cheers::cheers::cheers:
 
i get it in Flowmasters when they make enough back pressure. top end of the rpm range and let off nothing fancy there
 
Back in Time said:
If you want to backfire one...get going pretty fast then shut ignition off with gas pedal down then turn it back on..but be careful..it can do some damage.If you're talking about the rumble when letting off gas the exhaust system has a lot to do with it.
Click to expand...

Some would be shocked to see just how large a muffler will get when they blow it up like this. You can only get away with this is glasspacks.
 
Exhaust leak in the manifold or headers near head can cause it if you are running a bit rich. Every time I have had a less than perfectly tuned hot rod (IE always) and it got a leak near the head in the exhaust, it would pop out the tail pipe when let off the exhaust.
 
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