9 replies to this topic

[Danksy123]

Hi, I have a twin Fletcher exhaust with stainless steel link pipe on my classic 998 Mini city. The engine was recently reconditioned.
I was wondering if there is any way to get it popping occasionally. Overall the car runs a tad rich but very sweet and very smooth with pretty good compression.
I know popping can be caused by a badly set up engine which I don't want.. But that occasionally noise when changing gear or when going down a steep hill is what I'm frantically looking for 😉

I'd like to here your ideas!

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Edited by Danksy123, 23 November 2015 - 12:50 AM.

[KernowCooper]

Unless you can bleed air into the system its a non starter, not something I like to hear as you pointed out if I hear a car coming popping and banging I just think bad setup/exhaust issues, usually those twin big bore exhausts rob you of power but its your view not mine that counts

[dklawson]

You "want" it to pop?

[jaydee]

Mine will occasionally pop on the over-run only when revving the nuts off, and thats with the two box' RC40 and the correct timing/fuelling

I think its a combo of cam overlap and su carbs that richen the mixture at the gear changes due to their design

Anyway one of those big single box stainless exhuasts like a fletcher will occasionally pop on the over run even when set up correctly

 

If you want it to pop..apart from drilling a hole in the silencer....theres a way to make it pop but i will not post it for now since it may damage the engine if abused.

[Danksy123]

Ok, thanks for your guys input

Edited by Danksy123, 23 November 2015 - 12:46 PM.

[cal844]

My 1275 pops a lot on over run, its running rich (sooty spark plugs) and the Ypiece is leaking very slightly.

 

Exhaust system is:

1.75 inch maniflow LCB manifold

1.75 to 2.25 inch Y piece

2.25 to 3 inch link pipe

3 inch piped back box

[carbon]

Dansky - here's how to make an exhaust go 'pop'...

 

My dad used to get Morris Minors from work as pool car, and with these the best sound result was when going down a long steep hill

- first put car in in fairly low gear

- then turn off the ignition

- when you get close to the bottom of the hill turn the ignition back on

 

And you would get an almightly pop!

 

Not to be tried if you have column ignition/steering lock...

[Danksy123]

Thanks, it's just my brother has a single fletcher exhaust which Pops like crazy, and runs so sweet!! I am some what jealous

[Danksy123]

Dklawson


Yes, just on the Over run really

Edited by Danksy123, 26 November 2015 - 12:54 AM.

[dklawson]

I don't understand why you would want to make your car sound like it is in poor fit and running condition but to each his own.  Others have told you things they have found when their cars backfired.  

 

Generally, backfires on deceleration are the result of a rich mixture in the exhaust combined with an exhaust leak letting air in.  If you "want" to make a backfire, find some way to introduce a controlled air leak into the exhaust and set your mixture up to be a bit rich on idle.  Be advised that this can also do a wonderful job ruining mufflers.