Backfiring?

[richardsneddon]

This May sound silly But how do you get a nova to backfire? mines is 1.2spi with cat :thumb:

[d_kline]

well you could use a flamer kit (which is stupid)

[richardsneddon]

Nah Im more after the Popping noise whilst decelarating i think its sound the danglies there has gota be a way to do it i saw it on a nove a t guildford on sunday

[Stuart]

erm how about dont bother lol

[d_kline]

well you need to have your engine tuned extremely hard (which is what im thinking)...and you need a fair amount of money to get more out of a 1.2 nova

[Stuart]

your spi will prevent over run fuelling so the poping wont occur on fuel injected engines..

[richardsneddon]

Was just curious thats all gota be an easy way to do it

[richardsneddon]

Ahh ok then cheers!!!

[mikey14sr]

your spi will prevent over run fuelling so the poping wont occur on fuel injected engines..

I believe the multec spi system cuts the signal to the injector when the engine is coasting down?

[richardsneddon]

so it cant be done on a car wit SPI?

[Philsutton]

it cant be done on any injection car, get a carb one an flick the ignition on an off while driving to get a nice big bang an flame propa chav style innit man

[richardsneddon]

I aint a chav lol Just thot it was different thats all

[Stuart]

its not different, tis more a sign of a badly setup engine..

[richardsneddon]

ok that would be why im a cab controller and not a mechanic lol Although i would love a go

[Philsutton]

i did have my 1.2i flaming but that was due to ****ed ht leads

[richardsneddon]

hows that then?

[Adam]

I believe the multec spi system cuts the signal to the injector when the engine is coasting down? All injection management systems cut the fuel on overun.
It shouldn't happen at all on a injection system because of the above.
But you should listen to my SPi engine :thumb:
4 branch, 2" bore system and de-cat. Pops/Flames all the time, even when i dont want it to.Lol

[Philsutton]

very very very bad miss firing lmao

[Adam]

Lol.
I've tried a few things to stop mine doing it.
New lambda, cts, leads, dizzy cap.

Still does it :D

[richardsneddon]

Does it have a adverse affect on performance

[Adam]

Nope.
It just scares a few people when they are waiting at traffic lights etc, and i change gear, Pop,Lol.

I dont know why it does it tho, as there is no fuel going into the engine on overun, so what explodes?

[richardsneddon]

??????????? must be somethin tho how much did your exhaust system cost you altogether?

[Adam]

I get everything for cheap cheap.
Full ashley was ?60
4branch was ?40

I also have a gte cam fitted which cost me ?15.
It never used to do it at all when i had a std exhaust and cat.
If it starts popping when you have a cat fitted, it will probably kill the CAT.
Must be with the ashley system being very free flowing.

[richardsneddon]

ok my next spend will be on exhaust is yours loud?

[Stuart]

its probably the cam thats doing it.. more overlap etc

[Adam]

ok my next spend will be on exhaust is yours loud?
Its loud enough, even on a 1.2.

Stu, could be ye.
My old car never used to do it with a std spi cam.

[SuperNova!]

My 1.2spi engine used to backfire and pop flames on deceleration if you just nipped the throttle it would pop, The exhaust I had was a standard exhaust with the middle box and cat removed and a magnex 4" freeflow backbox,

It was stupidly loud and is changed now though.

So they can do backfires

[Adam]

A air leak before the lambda sensor would also caused it to pop.
As it senses extra air, richens the mixture.
So not all the mixture is being fully burnt.
And then ignites in the exhaust.

[richardsneddon]

Alright im going to get it decatted that will be a start can i just get a pipe of an older nova?

[Adam]

Nope.
As the 1.2i has a different front pipe to an old carb nova.

If you take the car to a custom exhaust place, they should be able just make you a straight piece of pipe.

You might have problems at mot times tho, with emissions.

[richardsneddon]

just have to change it back?

[Adam]

Yeah.

[richardsneddon]

Cheers matey

[Adam]

Id also get some new nuts/bolts for the cat/decat pipe join to downpipe and system.
They rusty solid, and most of the time you cant undo them.
I ended up dropping the whole exhaust system off the car, and grinding the old bolts off.

[richardsneddon]

will bear it in mind, although would an oxycetelene heater work?

[Adam]

Probably ye, just watch the fuel lines lol lol

[richardsneddon]

Yep i suppose lol

[Stanley]

my 1.2i pops/flames all the time

i have a standard exhaust system off of a 1.2carb (kind of a cheapskate de-cat) and a powerflow backbox.

if i sit at semi-high revs and blip the throttle, it pops and a flame comes out.

does it all the time when decellerating.

think the timing may be out......

[Adam]

What are you using off a 1.2carb system?
The whole thing, or just one section?

[Stanley]

everything bar the manifold and backbox

totally standard engine except K&N. standard 1.2i manifold

[Adam]

So does the 1.2carb downpipe fit the 1.2i manifold fine?

Only problem then, is that you will have to swap the entire system for MOT.

[Stanley]

aye it all bolted up fine. no probs at all

changed the studs, springs and flame ring for piece of mind too

i wish i had the standard system to change onto lol

im sure itl pass :thumb: maybe lol

[Ste L]

my valver does it, and its really anoying..

im sure its over fueling like a bitch

[mikey14sr]

My mates gsi allways gave a little pop when changing from first to second, K+N, Powerflow exhaust and a squeezed down fuel pressure regulator were the only mod on it.

[2LBaz]

When I had 40's on my 1.4 it flamed and popped at times when being pushed hard, due to overfuelling. My XE over fuels when coming off the accelerator causing a big rumbling noise! sounds good, echoes under the station bridge! lol
&
Has alot to do with the powerflow twin oval exhaust sytem I think!

[Adam]

A t40 engine will do it, as carbs carry on throwing fuel into the engine.
Injection engines stop injecting fuel on overun.

Rich, you could find a 1.2 carb system, and bolt the whole lot to your 1.2i manifold.
I didn't know you could do that, but Stan says his fitted fine.

[valver500]

My valver pops when on over run with a full power flow aswell, sounds wicked! Wish it did turbo stylee though!

[d_kline]

My valver pops when on over run with a full power flow aswell, sounds wicked! Wish it did turbo stylee though!

you can get a dump valve for non turbo cars aswell...cant remember the link but it was around 160 quid when i last checked

[Ash]

exhaust pop pisses me off, and i dont no how to stop it...

[Stuart]

retard your ign slightly (lose a bit of power), or lean off the idle fuel circuit.

[valver500]

you can get a dump valve for non turbo cars aswell...cant remember the link but it was around 160 quid when i last checked

sorry but id rather poke my eyes out than buy an electric dump valve!

[d_kline]

sorry but id rather poke my eyes out than buy an electric dump valve!

i know but i didnt say it was good:) ...besides its not worth 160 quid, i would rather add "go faster stripes" because they are light weight, they're about 10 times cheaper and they add an apPEELing look to your carlol :p






ill get my coat:p

[Martin]

A t40 engine will do it, as carbs carry on throwing fuel into the engine.
Injection engines stop injecting fuel on overun.

Rich, you could find a 1.2 carb system, and bolt the whole lot to your 1.2i manifold.
I didn't know you could do that, but Stan says his fitted fine.


What else do youhave to swap? as i have a written of 1.2carb and a 1.2i as a project car and cant afford a bigger engine or insurance lol



Martin

[Give it some rev]

if you want it to pop then why dont you drill a hole in the front pipe???

[Adam]

Fit the 1.2 carb downpipe and full system.

[philgte1.6]

all u do is rev switch off the ignition an then switch bk on quickly an it goes pop.

[Stuart]

and thats REALLY KOOL INIT lol.

who cares if it pops or not.. its bad tune if it does pop (unless its a turbo vehicle with a good setup for anti slag)

[philgte1.6]

the poopin is just unignited petrol in ure exhaust system. dnt mater what engine or exhaust u have. ive seen it done on 1.0 corsas

[Stuart]

exactly, badly tuned/maintained ;)

[Stoo]

Badly tuned/maintained??

MY DC5 teg type R does it! pops between gearchanges and on overrun!!

Cars VERY well maintained and Very well set up!!

Mind u it is running toda manifold, spoon decat and back box! Pretty much stairght thru!!

Sounds awesome

[Jamied]

My old sr used to pop as i let of the accelerator but since i changed the engine it doesnt do it anymore which is a pitty as it used to sound sweet. You could always try turnin the engine of and on quickly while u sit above 4000 rpm lol

[Martin]

Fit the 1.2 carb downpipe and full system.

loli was talkin bout fittnt he carb 2 my spilol i shudda sed

[Adam]

Why would you want an old carb fitted to your reliable SPI engine ;)

[Give it some rev]

Why would you want an old carb fitted to your reliable SPI engine ;)

o yeah, what are you trying to say about carbs eh???? :D :p lol