Tuning custom exhaust- whats needed to get it to pop/bang

[Fiatpuntomk2b]

I had a cat back system custom made and fitted on saturday, which sounds awesome but I want it to pop when I lift off.

I get the occasional pop when changing gear but want it more frequently.

How do I do this ?

 

[fingers99]

There's no sensible way of doing it without damaging your engine. Forget it. Or invest in a harmless but silly fake blow off valve. PSSSHTT!

 

[Fiatpuntomk2b]

? ive read a straight through manifold could help, but wouldnt this sound excessively loud ?

 

[fingers99]

It shouldn't help or be excessively loud. There's not really any such thing as a straight through manifold, only tubular ones and the old Mk1 type.

The issue with either is that you'll have to either run without a cat (which is an instant MOT fail or a likely VOSA impound) or mount one downstream of the manifold (so your exhaust will need modification.

If you think about, to pop you need fuel in the exhaust, a little oxygen, and a heat source. These will upset (and ultimately kill) your lambda and your cat.

You might like to try an older car -- Minis were spectacularly good at banging on the over-run -- a mixture, probably, of dodgy exhaust valves and haphazard carburettors.

 

[s and b]

http://www.jegs.com/p/JEGS-Performance-Products/JEGS-Electric-Exhaust-Cutouts/1231909/10002/-1

then you will also need a wolf whistle too

http://www.ebay.co.uk/itm/WOLF-HORN...624?pt=LH_DefaultDomain_0&hash=item3388e4bf30


eeee them wert days when you could have these

 

[olimortimer]

If you think about, to pop you need fuel in the exhaust, a little oxygen, and a heat source. These will upset (and ultimately kill) your lambda and your cat.

Not exactly. The new MINIs purposefully run rich, which gives them the pops on over-run.

Running a decat will also increase pops, but this is obviously not road legal...

 

[fingers99]

I've never heard a new Mini pop, and I've driven a 200bhp one!

 

[olimortimer]

I've never heard a new Mini pop, and I've driven a 200bhp one!

You've never heard a MINI pop? A BMW MINI? Wow. They all pop. The facelift models more than the pre-facelift, but they all pop.

 

[fingers99]

Nope. Cooper S Works. And it's not as though you don't drive those fat little buggers on full throttle and over-run. All I can suggest is that the Works ones use the fuel for something more adult than popping.

 

[olimortimer]

Nope. Cooper S Works. And it's not as though you don't drive those fat little buggers on full throttle and over-run. All I can suggest is that the Works ones use the fuel for something more adult than popping.

Works are all show and not much more go - I run 240+bhp on my track MINI, with fairly simple mods, and have owned it for over 7 years now. The MINIs use the extra fuel to run the engine cooler, due to the extra heat produced by the supercharger...the pops are a by-product, as you will...on all MINIs, including the Works.

 

[dave]

my panda 750 used to pop when there was air leak in the joint between middle and back box

 

[fingers99]

Works are all show and not much more go - I run 240+bhp on my track MINI, with fairly simple mods, and have owned it for over 7 years now. The MINIs use the extra fuel to run the engine cooler, due to the extra heat produced by the supercharger...the pops are a by-product, as you will...on all MINIs, including the Works.

Why should the supercharger produce more heat? Not only is it the wrong side of the exhaust, but there's a socking great intercooler between it and the cylinder head. It's excruciatingly difficult to make anything run appreciably rich, run a cat and get through the MOT. Indeed, cats are pretty much the biggest problem faced by tuners (unless they choose to ignore them).

The works cars got within 10bhp of the BBR cars, which are probably at the limit of what someone who has to offer a guarantee of some description would want to go to.

Even my MR2 turbo (which can run obscenely rich, it doesn't have to pass modern emissions regulations -- it's a 1990 car -- and has big black stains on the rear bumper, not just the tailpipe) doesn't pop and bang. Probably would if I had a hole in the exhaust, but what would be the point?

And isn't a popping and banging 1.2 Punto just going to be the butt of police attention and jokes?

 

[Ziggy122]

Simple - Dont

Bang and pop = bad!

Why do bad?

Ziggy

 

[s and b]

Works are all show and not much more go - I run 240+bhp on my track MINI, with fairly simple mods, and have owned it for over 7 years now. The MINIs use the extra fuel to run the engine cooler, due to the extra heat produced by the supercharger...the pops are a by-product, as you will...on all MINIs, including the Works.

sorry but my calendar says todays date is 4th february 2014
april 1st is ages off
uses extra fuel to cool the jimmy
if it was a santapod hemi i might buy it for a 12 second pass of course

 

[olimortimer]

Wow, people really do have their blinkers on on this forum

 

[Brendan W]

You could try some or all of the following.
Make a leak in the exhaust
Remove the cat
Loosen off the inlet manifold so it runs lean
Set the valve timing wrong
Fit high lift cams
Remap to run lean or rich
Break the ht lead cores so it misfires a lot
Open the plug gaps right out
Search for a 'help my exhaust is popping, I'm way down on power and guzzling petrol' thread and undo all the suggestions to fix it

I know it's a bit of fun but in my experience sudden noises can frighten and panic some road users into doing what you least expect - especially cyclists, children and the elderly.

 

[portland_bill]

Wow, people really do have their blinkers on on this forum

Hazard warning lights - broken down Fiat.

 

[homeward]

Hazard warning lights - broken down Fiat.

Surely almost unheard of...?! :devil:

 

[s and b]

ive just been reminded how we used to get our cars to pop
we turned the ignition off
put pedal to the metal
turned ignition back on
only problem was we once blew a back box open like a sardine can when the fuel ignited

this wont work on a modern car though that has floor panels and such

 

[fingers99]

Wow, people really do have their blinkers on on this forum

Well, you can use extra fuel to cool a turbo engine down, for anti-lag or to improve the woeful seals on prehistoric supercharger designs and make them pump better. But you're not going to get a Euro 4 car through the MOT with any of those strategies implemented.

The era of easy tuning is long gone