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How do you make a exhaust crackle/pop - 289 V8

13K views 14 replies 10 participants last post by  kenash 
#1 ·
Hi,

I am currently trying to find a exhaust set-up. I am planning on keeping duals (no H or X pipe) with cherry bombs or flow master 40 series. (Looking for loud, aggressive and uneven tone)

I would like my exhaust system to crackle and pop on the overrun. Is it something to do with exhaust or is it unburnt fuel?

In any case, I would like to know how to make my car do it.

It is a 1965 Mustang with 289 V8 and stock auto transmission

Thanks for any help.
 
#2 ·
It'll probably happen on its own with an aggressive cam, though it has happened to me on a smogger 351 (sans EGR and the ignition system was failing). A long duration cam will put extra fuel and air into the exhaust due to the intake and exhaust valves briefly being open at the same time. So, my advice would be to build for power and the sound will come. In my opinion, the best sounding engines are the ones that are built to a purpose. The sound is coincidental, but glorious. Think circle track cars.
 
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#3 ·
The only time your car will make a crackle, whether it is due because of a cam or overfueling will be during engine braking. Also if you incorporated an x into your mid section it will pull more unburned fuel out of the cylinder and promote "scavenging." If you are also looking for an agressive tone, dont go with any mufflers that are chambered. Most uneven tone sounds come from mufflers that are packed with a filler, fiberglass, that is a cherry bomb or magnaflow. Good luck.
 
#5 ·
I think 6stang is dead on. Your exhaust type has a lot to do with the distinctive 'cackle' it sounds like you're after. A set of glasspack mufflers (I.E. - Cherry bombs or Thrush) after being used for a bit will have the sound you want. Adding air leaks to induce backfires may not be necessary at all.

Chambered exhaust or good 'turbo' mufflers (classic Magnaflows) will never have the vicious snarl you're looking for. At best, they'll sound like Black Cat firecrackers in a trash can, on decel. There's something magic about a Ford smallblock with a pair of cheap glasspack mufflers on.

https://youtu.be/qVzRIQ2HGV0?t=20

I know he's got his exhaust kicking out to the sides, but it's much the same with them coming right out the back. Also, putting the glass packs close to the headers will be louder than if you put them out on the ends of the pipes, generally speaking.

It only gets 'better' when they are old and the fiberglass matting is no longer fluffy and sound-absorptive. The downside is that you'll get all kinds of highway drone at some RPMs, so long road trips without earplugs aren't recommended.

If you *really* want to wake the neighbors, weld flanges directly to the glasspacks and bolt them to the headers. I had my Cougar set up that way with some old Blackjack Aluma-Kote headers for a while, and my car could break the sound barrier just idling...

... I didn't keep it that way very long. But it did sound fun.
 
#7 ·
Thanks for the replies.

I would like to put setup onto the car where I can interchange the Glasspack with the Flowmaster 40 series is I find it too loud and uncomfortable.

Are there any glass packs which have same mounting and dimensions as a flow master 40 series?

Only other option is electronic cut-out??
 
#9 ·
Cutouts usually don't cackle, and neither will Flowmasters. It's something to do with the way the unburned hydrocarbons and o2 mix inside the baffles of the glasspacks that cause it. Perhaps it works like the flame holder in a jet engine, allowing ignition and making the small explosions happen, instead of just shooting flames out the exhaust?

Exhaust leaks (in my past experience) were great for massive backfires and blowing mufflers apart, but I've never heard 'em make any sound but KABOOM. Maybe your experience will vary.

Personally, I *hate* chambered exhaust. It's like bolting a coffee can on your tailpipe. You get a big echo, and a hollow sound. I know, I'm an old fart, and flowmasters are all the rage with new cars. Everyone these days has 'em. But I still don't like 'em. That gutted tin-can sound is not for me!
 
#11 ·
I would like my exhaust system to crackle and pop on the overrun. Is it something to do with exhaust or is it unburnt fuel?

In any case, I would like to know how to make my car do it.
With good tuning a small block will backfire slightly when you let off the gas while cruising. Is that the sound that you are looking for?
 
#12 ·
^^^^^^

Just keep leaning it out and / or introduce some air into the exhaust with your ice pick, and you will have no problem getting that combustion pop pop pop in the exhaust system.

Funny, most people try to get rid of that.....


Z
 
#13 ·
If I didn't know already that you know your stuff so well, Zray, I'd worry about you... ;)

My dad's uncle was a funny guy. He had an old Ford truck with glasspacks, from the late 50s. He always said that he didn't want a fancy funeral, but when he died, he wanted to be put in an old pine box and loaded into his old truck. He also asked his boys to rack the pipes on that truck of his one last time on the way to the funeral.

They did.

The savage snarl of a healthy motor with a pair of cheap glasspacks will always hold a special place in my heart. Rest in peace, Martin Wells.
 
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