OK I understand about what the pops and bangs are on a decatted exhaust, thats fair enough, but it seems that the only time I would ever get flames would be after a long/hard run and then at a stand still, revving the engine.

Now that can't do the engine any good

From what i have picked up, fitting a VTA will "greatly" increase the likleyhood of flames. How come? Is it because with the VTA on, Exhaust exit speed is greatly increased?

Would the exhaust still need to be really hot or would normal temps work?

I dunno !!!!

Please don't all have a go because i'm looking for flames, i just wanna try em out

Heard my car being driven through the empty streets of Nottingham at 4 am the other morning and it sounded like the city was falling down It just needs a few flames to accompany the noise.

Fill ya boots boys, let me know ya thoughts.

Mikey

 

AFAIK the vta dump valves cause most scoobs to run rich... therefore on the overrun unburnt fuel is sent down the exhaust, which during a hard run will be pretty hot, which in turn ignites the vapours causing flameouts (I think )

Cheers

 

Have you tried blipping the throttle on changing down? my my99 used to flame sometimes when doing this!
PS was forced to go for an mot check by miserable copper that watched it flaming coming up to a junction. Thought the car was being unfriendly to environment. The car was only 8 months old so sailed through with no cats on.

 

What causes the pops and bangs? I've had mine pop once or twice, just wondering the best technique for when I'm the the local tunnel

Scorpian DP, STi 5 Centre, B&C Backbox (full de-cat)

 

i travel under several tunnels into leeds and find best sound effect comes from a 2nd or 3rd gear full throttle to 5-6000 revs and lift off without changing gear and just let it overrun!!!

 

I've sussed the pops and bangs bit, I don't know what's really happening in there but what i do is when the car is over running, really lightly "tap" the throttle. It's almost as if a tiny amount of fuel is being squirted into the exhaust.

It's like fooling the ECU because as far as i see it, when no throttle input is evident, the ECU severly restricts fuel supply (Engine don't need it) by tapping the throttle, its almost like it springs into action (As if you were going to accelerate)and then quickly stops again.Just quick enough for a squirt

Now before all you mechanic people scream and tell me i'm wrong, like i pointed out, that is MY description of whats happening in my world

So popping and banging is easy, i want flames and wanted to understand how they are formed. The running rich theory is a good one but if you are having pops and bangs anyway, then overfuelling is in evidence?

What duya reckon?

Maybe it's a Fuel to Air mix thing? i.e the fuel is already there (Rich) and the VTA somehow allows a bit more air into the system allowing combustion to occour?

Hows that for a theory?

Anyways, keep the thoughts and experiences coming

Mikey

 

Mikey - your method works for me!

 

Pops & bangs must be the same thing as the flames - it just depends if they've come out of the exhaust or not I think it's where some backboxes are better than others. And the resonator - if you've got one - is where the fuel will ignite (rather than out the back) so you get the pop/bang but can't see the flame.
I think

 

P20SPD, Your UK Turbo pass an emissions test with no CATs?? Is the emissions test less strict for the roadside test then?

 

See how your gonna start a back box war

Backbox salesman: " Just look at the quality of that finish"
Scoob Owner : "Sod that, will it flame? "

Seriously though, the resonator thing could be the culprit that is stopping me flame getting out. Sounds feisable to me

Anyone know if the JPI system has got one?

So we have the following guesses as to what is required to get flames (Not neccesarily all of them together, but any combination)

No resonator
Hot Exhaust
Throttle Tapping
Throttle "Mashing" (High Revs and lift off)
VTA
Total Decat
Quality exhaust (Didn't know there were any bad ones )

Anymore experiences chaps, keep 'em coming

Mikey

 

Here's another thing to consider, for all i know, i'm flaming like a man possessed

Dunno.......can't see

I suppose cars not following up ya *** and people clapping is a bit of a give away

Mikey

 

I can't tell if i've ever had flames but I'm sure I heard what I though must have been a flame (does that make sense ) when I floored it in 1st and bounced of the limiter as I changed to 2nd I didn't get the usuall pop more of a woosh... hard to explain....

 

So does a STi 5 centre have a resonator? There's a "lumpy" bit on it (spot the zorst numptie )

 

my car pops when i'm slowing down and i change down gear,dont know if i get flames...full s/s exhaust itg filter ppp'd ecu

rich

 

ChrisB
I think the STi 5 centre section has a silenser but no cat, although if you look at it there is a bulge as well where the cat is on a uk car. Surely to get the best banging flamer you should replace this with a straight through pipe - or go to Burger King :

Perhaps part of the Extravaganza day at Donnington next week should be a 'flaming session' where we can all give marks out of 10 for the biggest flames on a drive past :

 

Mikey when I followed you from TSL to the Anchor pub a few weeks ago there was lots of popping and banging but no flames
Saying that it was day time so maybe there would have been some at night
Hmmm another theory.... maybe its the moon ..yeh its got to be the moon making the flames, that why you only see them at night ??


Andy

SORRY

 

Chris you do have a resonator, but no silencer.

 

Any more suggestions? There must be a flame guru out there somewhere

Attu, like i say, pops and bangs are easy, flames is where it's at this month

Mikey

 

I'm no expert, but don't you need unburnt fuel in the exhaust which the hot pipe ignites? In other words, you need to map some fuel into the engine on the over-run.

 

you get unburnt fuel with the VTA BOV - lift off, BOV dumps air 'out' rather than 'in' so MAF (which gets backwash) continues to add fuel when with a recirc it wouldn't. So fuel goes in on lift-off & pop's & flames should abound. As long as there's no cats & resonators to get in the way! Oh, and the exhaust is hot enough to ignite the unburnt fuel.

 

Okay, but aren't atmospheric BOVs bad for Scoobs because they mess up the induction? They effectively fool the system into dumping more fuel?

 

I'd love flames, and pops and bangs, but don't get any of em.

And this is with a forge VTA DV, BMP Twindump Downpipe and Blitz Nur Spec R (Center and backbox).

 

Can't see why they're bad. What's wrong with not dumping oil in the MAF? Err, nothing.
The extra fuel (tiddly amounts) would eventually screw up a cat, but that's about it. The turbo shouldn't be affected either, which is the only other worry that people seem to have.

I think another thing that comes into play with getting flames is how sharply the pressure is dumped - or that's my guess, anyway. If it's too slow there's no effect.

[Edited by nom - 6/27/2002 10:10:20 AM]

 

I get shed loads of flames Ask me missus and Scott W

Boot it down a dual carriageway in 4th, lift off - bang + pop out a flame

Car is MY99, Forge VTA, ITG, Magnex DP, mid - no resonator, and Scoobysport BB.

Has been known to flame after only been running a couple of minutes so the exhaust can't have been very hot......

Luvin' It Although fuel consump drops a bit

My forge is fitted with the blue spring - this is softer and lets the air out quicker giving the whoosh noise, against the standard red spring which is harder and thus opens more slowly giving the WRC stylee chatter. Only ever had 1 or 2 flames with the red spring, with the blue its on demand

l8rs!

 

A pal of mine has a Sti V5 type R . Having gone through 3 motors he eventually sent ot off to get done propper . The reason It Kept going bang ? To many flames !

 

 

So two schools of thought here aswell then.

1) Flames Rock
2) Flames bugger up ya car

is this like induction kits

1) ITG crap cos of the oil
2) ITG good because of filtration properties

I reckon flames rock cos sure some peoples cars will blow up but so do a percentage of totally standard scoobs. I reckon the chances of summat going bang because there is a bit of MAF and ECU fooling going on which results in a quick squirt of fuel has gotta be minimal

Any more thoughts or comments dudes?

Mikey

PS Got told today by a cossie owner at the lights that my car sounded the dogs made my day, maybe they ain't all bad

 

Mikey, sounds even better with PPP

ITG PANEL filter is generally accepted as being the only safe alternative to the standard item. It's full of sticky jelly, not oil.

Cheers,

Richard.

 

500 odd views, 27 comments

C'mon guys, gotta be a great post to vent your questions about flames and vta's

Mikey

 

I get flames and pop's bangs when I press the button marked "Anti-Lag" LOL