Exhaust Cackling

[The DoN]

You know when like you hear a badass Camaro rollin down the street and they let off the on the gas and the exhaust just cackle sounds like they're breaking all kinds of glass. What kind of exhaust would I need for me to do that?

[WhiteBrow24]

2inch straight pipe.... if you have a 2wd truck, cut that Y pipe off and put 2 pipes that are straight all the way back, that sucker will snap crackle and pop

[mgrotel]

ok, whats the best way to not have that crackle, cause i hate the shat

[WhiteBrow24]

ok, whats the best way to not have that crackle, cause i hate the shat

haha a properly setup exhaust, true dual high flow cats, decent muffler (magnaflo) bigger pipes probably 2 3/4 pipe maybe 3 inch.

and a properly placed X or H pipe

[silveradoguy98]

i've got 2" true duals with two 14" glasspacks, and it crackles more than anything i've ever heard.

[Bama2door]

ok, whats the best way to not have that crackle, cause i hate the shat

werd...i have straight pipes now and the crackling at high rpm is starting to piss me off. I may try the new super 44's to help it out.

[The DoN]

well its time for me to get a new exhaust setup because the previous owner had them bend out to the sides and they are up a little bit, so where the pipes meet the muffler, its all rusted and getting ready to break apart. I was thinking smoke stacks but I dont have a diesel and it wouldnt be cool if only white smoke came out lol. No but seriously I think Im going to do new headers and no cat and glasspack mufflers 3" piping all the way.

[1Bad454]

Interesting article here:
It is normal for many high performance exhaust systems to moderately backfire or pop when the throttle is closed from mid-to-high rpm. In fact, one should expect a well-tuned high performance engine to "pop" and "crackle" when the throttle is closed at high rpm.

The popping is a result of the air/fuel mixture becoming very lean when the throttle is closed and the engine is rotating well above idle speed. It is also necessary that the exhaust system have rather open mufflers.

Why This (normally) Happens:

1) When the throttle valve is in the idle position, fuel does not flow out of the main system (needle, needle jet, main jet). Fuel is only delivered to the engine by the pilot (idle) system.
2) The combined effect of the closed throttle and elevated engine rpm is to create a fairly strong vacuum in the intake manifold. This vacuum, in turn, causes a high air flow rate through the small gap formed by the throttle valve and carburetor throat.
3) Under these conditions the pilot (idle) system cannot deliver enough fuel to create a normal, combustible air/fuel ratio. The mixture becomes too lean to burn reliably in the combustion chamber. It gets sent into the exhaust system unburned and collects there.
4) When the odd firing of the lean mixture does occur, it is sent, still burning, into the exhaust system where it sometimes ignites the raw mixture that has collected ---- the exhaust then pops or backfires.
5) Completely stock Harleys do not do this until open-end mufflers, such as the popular Screamin' Eagle slip-ons, are installed. The exhaust must be both free-flowing and have an open exit for the popping to occur.

[1Bad454]

Also:

Other possible causes:

Air Leaks:

Any source of fresh air into the exhaust system can create or worsen the conditions that bring about exhaust backfiring. The most common entry point is the junction of the header pipes and mufflers. Even a small air leak can dramatically increase the intensity or likelihood of exhaust system backfiring.

A high temperature silicone sealant, as can be found in many auto parts stores, may be used to seal the pipe/muffler junction.

Lean Carburetion:

While exhaust system popping may be considered normal, it is certainly made worse by an overly lean idle circuit.

Be sure that your carburetor's pilot jet is the correct size and that the idle air mixture screw is correctly adjusted before looking for other causes of popping. The procedure for adjusting the pilot circuit is covered in the Tuning Manual.

Ignition:

If exhaust system popping is very loud, irregular and accompanied by loss of power, then you should suspect that the ignition system is not performing as it should. If, for some reason, the ignition sometimes fires at the wrong time, then exhaust popping can become very energetic (loud). Look for failing high tension leads (plug wires), failing ignition coil(s) and especially switches or connectors as possible causes.

[The DoN]

Hmph, thanks for the info.

[onlydrive4WD]

It also helps if you have a manual, and you can just downshift and get all the crackle you want. Makes me miss my Jeep...

[gray_silverado]

word onlydrive...i had a pathfinder for like 6 months and i cut the cat off and everything behind it i loved downshifting to 2nd at like 40 it was loud as heII