FIRE! Flaming awesome or burning out?

[Paul the 6th]

I've seen an audi s4 which was designed to significantly over fuel on the over run to cool the piston crowns - this caused 12" flames to fire out of the back of it.

Used to get banging on my pointy 650 (not sure about flames) but I think it's just down to unused fuel getting through the system and when there's the right balance of heat/unburnt fuel/air introduced, the conditions are right for the fuel to ignite? Sure someone like embee or YC will be along with some equations to explain how & why it happens but that's my guess

Mine only really does it at about 4.5k rpm in third gear

Originally Posted by Reeder

Mine only really does it at about 4.5k rpm in third gear

accelerating ? or just on overrun

if its at 4.5rpm is prob's over fuelling at that point in the rev range mine does it at 5k theres also a flat spot there when accelerating

Cheers for all the suggestions and comments.

It does seem to happen more around the 3-5k rpm mark and as mentioned above, there is a flat spot around there (or it just there is a power jump @ 6k rpm?).

It's a Beowulf exhaust - I'm afraid I have no idea on model as it was fitted by BlueWolf (previous owner).

Also I'm planning to borrow my mates gopro tomorrow to take a video for all who are interested

EDIT: Exhaust is actually a Remus!

Only on the over run, and it doesn't happen massively often. It's only a few times each ride.

Originally Posted by Jynx

Cheers for all the suggestions and comments.

It does seem to happen more around the 3-5k rpm mark and as mentioned above, there is a flat spot around there (or it just there is a power jump @ 6k rpm?).

It's a Beowulf exhaust - I'm afraid I have no idea on model as it was fitted by BlueWolf (previous owner).

Also I'm planning to borrow my mates gopro tomorrow to take a video for all who are interested

the 5k dip is for emitions and apparently its a fueling blip (about 10th hand info there )

Originally Posted by Reeder

Only on the over run, and it doesn't happen massively often. It's only a few times each ride.

yeh almost like the fuel builds up ignites then the fuel builds up again then ignites again

So if it's not doing it at any other time then perhaps my pair thing is blocked off or removed?

Originally Posted by barwel1992

the 5k dip is for emitions and apparently its a fueling blip (about 10th hand info there )

Is this the thing I could stop by removing the 2nd and 3rd gear wires? I *think* the problem still happens in 4th...

This isn't fair, my SV never pops and bangs like that. You'd think with a full system it'd do it more?

Originally Posted by Reeder

So if it's not doing it at any other time then perhaps my pair thing is blocked off or removed?

doubt it :/