Omega Owners Forum

Chat Area => General Car Chat => Topic started by: BazaJT on 27 April 2014, 09:37:45

Title: The point is?
Post by: BazaJT on 27 April 2014, 09:37:45
Saw a small hatchback yesterday-didn't catch what make/model,you know the kind of thing massively lowered,big tailpipe and bigger wheels,fair enough it's each to their own and there are plenty of similar about.But this one was making noises like it was backfiring every second or so,this it seems is the latest thing,but what is the point exactly?How is it done?Obviously it's an age thing but I just don't get it,if my cars backfired I was on the case to make it stop doing so,now they're deliberately making them do it!
Title: Re: The point is?
Post by: ted_one on 27 April 2014, 09:59:56
Think it's some sort of statement that's probably a 'I've got a bigger willy than you thing' Erm! don't really care as I know that my 3.2 will eat that sorry pile of shite once that sowing machine engine starts to red line to the point of destruction ::)
Title: Re: The point is?
Post by: YZ250 on 27 April 2014, 11:01:57
Many years ago, one of the guys I work with had a Cavalier GSI that was deliberately mapped to backfire and spit flames. He spent a fortune having the engine fully rebuilt by a race engine company and this was an additional show-off extra.
As said, can't see the point myself, as a backfire was usually the sign of an ignition fault.  :-\
Title: Re: The point is?
Post by: jonny2112 on 27 April 2014, 12:54:14
There's obviously some sort of device you can get that also imitates the 'whistle' of a turbo dump valve.
Bloomin' annoying if you ask me!
Title: Re: The point is?
Post by: the alarming man on 27 April 2014, 13:05:03
my V8 pisses all over the little boys in their lowered 1000 cc corsa....prefer to hear to hear a V8 any day :y
Title: Re: The point is?
Post by: Stemo on 27 April 2014, 17:35:03
Unless I'm going mad, I'm sure I read somewhere that new noise regs are coming in soon. Cars will have to be quieter than a cats fart.
Title: Re: The point is?
Post by: the alarming man on 27 April 2014, 17:48:59
that may be so STEMO but I guess it will be new cars :y
Title: Re: The point is?
Post by: Sir Tigger KC on 27 April 2014, 18:05:26
Think it's some sort of statement that's probably a 'I've got a bigger willy than you thing'

Innit!  ;D
Title: Re: The point is?
Post by: 05omegav6 on 27 April 2014, 18:07:58
Aaayyee :D
Title: Re: The point is?
Post by: Andy H on 27 April 2014, 18:15:51
A few years ago the turbo rally cars were set up to keep the turbo spinning when the driver lifted off the throttle, don't know how it was done but the side effect was a series of impressive backfires.

Last week I followed a similar unidentifiable micro car with wide wheels for a while on my way home from work. Nothing special until we got into the Saltash tunnel where he proceeded to irritate the car in front of him by repeatedly accelerating to within a few inches of its bumper and then lifting off and making a noise like random gunfire.

Once through the tunnel he cut inside the leading car and shot off up the hill. The sound effects were irritating but the acceleration was actually quite impressive
Title: Re: The point is?
Post by: omega3000 on 27 April 2014, 18:28:16
Followed an orange Ford Focus RS yesterday tailgating a micra  ::) RS was popping and banging everytime he throttled off , old bloke in the micra was s#itting himself  :(
Title: Re: The point is?
Post by: Stemo on 27 April 2014, 19:31:27
that may be so STEMO but I guess it will be new cars :y
Just got this from the web:

Exhausts:

The vast majority of large or big bore exhausts are illegal for use on public roads. The fact they may have passed an MOT test is irrelevant as this only checks for exhaust gasses and emission legislation compliance.
Big bore and sports exhaust systems are usually fitted to increase the sound emitted and this contravenes the Type Approval of the vehicle, which is an offence. There is no requirement for police to measure the sound level from the exhaust system, it only requires an opinion that the system is not standard and that it is noisier than a normal vehicle of the same specification.
It is not an offence to sell these exhaust systems, but it is an offence to fit one to your vehicle and drive it on a public road. Motorists who do so would be reported to court and may face a fine and court costs.
Title: Re: The point is?
Post by: 05omegav6 on 27 April 2014, 19:35:23
I know someone who got points for having a noisy scooter exhaust ;D felt a little sorry for him, for about a minute iirc ::), as he had only bought said exhaust as a cheap replacement for the original one which had fallen off...
Title: Re: The point is?
Post by: dad1uk on 27 April 2014, 23:02:54
I wonder how many have told the insurance they have these exhausts on, my son bought a car with one fitted,thought no more until he was rear ended, the assessor saw the car and next thing was insurance declining to pay because they were not informed of the modification even though he bought the car as it stood.....
Title: Re: The point is?
Post by: Vamps on 27 April 2014, 23:09:56
I wonder how many have told the insurance they have these exhausts on, my son bought a car with one fitted,thought no more until he was rear ended, the assessor saw the car and next thing was insurance declining to pay because they were not informed of the modification even though he bought the car as it stood.....

That's a hard lesson to learn, just for an exhaust.......... :(
Title: Re: The point is?
Post by: YZ250 on 28 April 2014, 08:56:45
I wonder how many have told the insurance they have these exhausts on, my son bought a car with one fitted,thought no more until he was rear ended, the assessor saw the car and next thing was insurance declining to pay because they were not informed of the modification even though he bought the car as it stood.....

Ooh, that's not good.  :'(  Some people genuinely wouldn't know what was standard and what isn't but if it gives the insurers a way out they'll go for it. 
My exhaust isn't noisy but it is stainless so I notified my insurers and they added it under the 'modifications header' on the certificate. Better safe than sorry.  :y

Title: Re: The point is?
Post by: Gaffers on 28 April 2014, 09:27:18
my V8 pisses all over the little boys in their lowered 1000 cc corsa....prefer to hear to hear a V8 any day :y

So does my milk float.  I had a full charge coming back from London last night and some barry boy was trying to get away from me at the lights to cut ahead of me through the roadworks.  He floored it after it went green and then, when seeing that he couldn't keep up, he backed off as if to say 'Ar, I werent trying, honest' 

Oh how I laughed ;D ;D
Title: Re: The point is?
Post by: aaronjb on 28 April 2014, 11:26:28
A few years ago the turbo rally cars were set up to keep the turbo spinning when the driver lifted off the throttle, don't know how it was done but the side effect was a series of impressive backfires.

Easy peasy - when the throttle is shut add air to the cylinders via a bypass mechanism and continue to inject fuel, but trigger the spark plug so late in the cycle that the resulting combustion goes straight out of the open exhaust port keeping the turbo spinning.

Valves, seats, exhausts and turbos don't last long doing that but that's just fine on a rally car that gets rebuilt every stage/rally..

I've seen some aftermarket systems that dump fuel, air & spark straight into the exhaust runners so at least all you need is a turbo rebuild rather than an engine rebuild.

http://www.rallycars.com/Cars/bangbang.html


Backfiring when lifting off in a road-tuned turbo car is usually the engine pegging rich as a vent-to-air dumpvalve opens on a MAF based engine management system (engine goes rich and then the vapour will combust either on the hot exit of the CAT or in the silencer with no CAT).  RX8s (naturally aspirated) tend to do it when decatted as they run pig-rich all the time and if you lift off at the redline a little unburnt mixture goes bang in the hot exhaust.
Title: Re: The point is?
Post by: omega3000 on 28 April 2014, 12:46:26
When i had my Aprilia rsv 1000 you could easily make it backfire by over revving the v twin and flicking the engine on/off button  ::)
Title: Re: The point is?
Post by: Stemo on 28 April 2014, 13:06:57
My mate had an orange ford anglia with tinted windows and liked nothing better than to sneak up on a bus queue of old ladies and turn the ignition off as we passed. Woke most of them up, probably killed a few, we never hung around to find out. :D