Getting it to "fire" on the upshift

[blackiepaul]

Being a bit of a kid I love the way the car bangs and pops especially now I have Quickys Decats.

Every now and then I seem to get it just right and the noise that happens on the up shift is fantastic, it really is like gun fire.

Now being a immature person I want to know how to do this on purpose rather than by fluke.

Tips please!

[T40ORA]

Get it nice and hot, and change at around 3k revs.

Never fails on mine....

[blackiepaul]

mine seems to happen higher up in the rev range but does not happen often. The sound really is so different to normal.

[Hilti]

It's unbunt fuel igniting in the hot exhaust manifold. Usually happens when you get sudden throttle responses and fuel passes through the engine unburnt and hits the hot manifold.

J

[blackiepaul]

Hilti said:

It's unbunt fuel igniting in the hot exhaust manifold. Usually happens when you get sudden throttle responses and fuel passes through the engine unburnt and hits the hot manifold.

J

J Thanks for the response, how do I get it to happen on purpose?

[Don1]

Lift off around 3k, and it will tend to happen.... either that, or lift off, and then gently press the accelerator a tiny bit, to get the fuel flowing again. Works in the Chim every time!

[bing]

Hilti said:

It's unbunt fuel igniting in the hot exhaust manifold. Usually happens when you get sudden throttle responses and fuel passes through the engine unburnt and hits the hot manifold.

J

Exactly what he ^^^^ said, I usually get it in the Lotus when changing very high up the rev range usually smack on the change light!!!!

I'm nit sure if it bad for the car but it sounds the lovely!!!!

[blackiepaul]

bing said:

Hilti said:

It's unbunt fuel igniting in the hot exhaust manifold. Usually happens when you get sudden throttle responses and fuel passes through the engine unburnt and hits the hot manifold.

J

Exactly what he ^^^^ said, I usually get it in the Lotus when changing very high up the rev range usually smack on the change light!!!!

I'm nit sure if it bad for the car but it sounds the lovely!!!!

Now thats where I think I get mine - not around 3K revs but way up there around 7K revs, the sound is so very different to your normal banging and popping

[bing]

blackiepaul said:

bing said:

Hilti said:

It's unbunt fuel igniting in the hot exhaust manifold. Usually happens when you get sudden throttle responses and fuel passes through the engine unburnt and hits the hot manifold.

J

Exactly what he ^^^^ said, I usually get it in the Lotus when changing very high up the rev range usually smack on the change light!!!!

I'm nit sure if it bad for the car but it sounds the lovely!!!!

It's lovely!!!!!




Now thats where I think I get mine - not around 3K revs but way up there around 7K revs, the sound is so very different to your normal banging and popping

[Zippee]

blackiepaul said:

bing said:

Hilti said:

It's unbunt fuel igniting in the hot exhaust manifold. Usually happens when you get sudden throttle responses and fuel passes through the engine unburnt and hits the hot manifold.

J

Exactly what he ^^^^ said, I usually get it in the Lotus when changing very high up the rev range usually smack on the change light!!!!

I'm nit sure if it bad for the car but it sounds the lovely!!!!

Now thats where I think I get mine - not around 3K revs but way up there around 7K revs, the sound is so very different to your normal banging and popping

Same here. My T350 has a JP backbox but still has the CAT. On a shift change at high revs I'll get quite a cool bark from the pipes, sounds very different to the crackles on the over-run that occur when the revs drop below 3k.

[blackiepaul]

Tony,

I need to work out what can be done to get this to happen at will. I think it is at the over run at high rev just before you change meaning the fuel is going through the system but not sure.

Paul.......

Zippee said:

blackiepaul said:

bing said:

Hilti said:

It's unbunt fuel igniting in the hot exhaust manifold. Usually happens when you get sudden throttle responses and fuel passes through the engine unburnt and hits the hot manifold.

J

Exactly what he ^^^^ said, I usually get it in the Lotus when changing very high up the rev range usually smack on the change light!!!!

I'm nit sure if it bad for the car but it sounds the lovely!!!!

Now thats where I think I get mine - not around 3K revs but way up there around 7K revs, the sound is so very different to your normal banging and popping

Same here. My T350 has a JP backbox but still has the CAT. On a shift change at high revs I'll get quite a cool bark from the pipes, sounds very different to the crackles on the over-run that occur when the revs drop below 3k.

[bing]

Indeed on overrun - also can happen if your very high up the rev range and suddenly lift off for a sec, don't do this mid way round a speedy bend otherwise there may be another type of pop-bang!!!

[T40ORA]

I can definitely get WWIII under my car at motorway speeds in 4th and 5th on lift off, but maybe the fuelling/injectors are diffferent in my car so more fuel is getting through. Does happen when it's nice and hot though.

[blackiepaul]

So I think the process is.

Way up in the rev range with the loud peddle pressed down.
Press the clutch and leave the loud peddle just for a second for some extra fuel?
Let go of the loud peddle
Should then get the noise?
Then shift into next gear with smile on face

[BatleyBoy]

Piece of cake to be honest. Get the engine hot and revs up, and then bang it down through the gears and it goes off on one....unbelievable amount of pops and bangs!
NTELS decats + JP back box fitted.

[blackiepaul]

BatleyBoy said:

Piece of cake to be honest. Get the engine hot and revs up, and then bang it down through the gears and it goes off on one....unbelievable amount of pops and bangs!
NTELS decats + JP back box fitted.

Hi there, we are talking about something very different to the normal pops and bangs. It is on the up shift not on changing down.

[VARLEYHYD]

blackiepaul said:

we are talking about something very different to the normal pops and bangs. It is on the up shift not on changing down.

7000+rpm upchange to next gear and BANG!

Thats the one, regular when hot, but only seems to be the Sags & Tuscan S's that do it mostly, as the seem to be overfulled at max throttle?

G

[hollowpockets]

What a thread!

[dvs_dave]

VARLEYHYD said:

blackiepaul said:

we are talking about something very different to the normal pops and bangs. It is on the up shift not on changing down.

7000+rpm upchange to next gear and BANG!

Thats the one, regular when hot, but only seems to be the Sags & Tuscan S's that do it mostly, as the seem to be overfulled at max throttle?

G

Wot he said. My Tuscan S does a nice big double barrel shotgun blast on on a 2/3+ throttle up shift. With a full decat and CCC's it's good and loud too!!

[T40ORA]

VARLEYHYD said:

blackiepaul said:

we are talking about something very different to the normal pops and bangs. It is on the up shift not on changing down.

7000+rpm upchange to next gear and BANG!

Thats the one, regular when hot, but only seems to be the Sags & Tuscan S's that do it mostly, as the seem to be overfulled at max throttle?

G

I think I mean the same thing; normal pops and bangs in mine are loud, but when it's really hot even when I'm only at about the 3k mark there is a proper explosion from the underside. Sounds just like a gun at close quarters But definitely at lower revs, and on lift off - so change up too.

The RG FFF 4.0l engine has different fueling (definitely bigger injectors) and must be overfueled the same as the Sags and Tuscan S's. I know that the increase in fuel consumption was a bit more than I expected from the 3.6