9 replies to this topic

[johnnysti]

Right

I have an lcb manifold fitted and on inspection of the rest of the system have two boxes at the end instead of the one. I know its a C**p description but ive got the one at the end with the tail pipes sticking out the back and a couple of feet further up the pipe is another similar sized box. It has no cat on and is a 1290 with a single carb(dont know which one....a metro one i think!!)

Is it worth removing the other box so it goes straight through to the back box or is it there for a reason and not worth the hassle removing????

Thanks

Johnny

[NunoGT]

Hi there.

In terms of performance, that middle box you´ve got is probably stealing a couple of ponies and/or a bit of accelaration.
In theory, at least.

If you go to a straight through exhaust, you'll need a mixture adjust. and probably a new carb needle.
Not to mention more noise

[binge]

ive got a 1 branch downpipe onto a straight through exhaust.
It goes right back to a central exit 3" tail pipe. But it spits out black soot from a cold start up! :tongue:

VERY annoying. Spits black poo allover my boot lid and bumper.
(Not to mention the car parked behind me) :fear:

<|Ben|>

[NunoGT]

ive got a 1 branch downpipe onto a straight through exhaust.
It goes right back to a central exit 3" tail pipe. But it spits out black soot from a cold start up! :tongue:

VERY annoying. Spits black poo allover my boot lid and bumper.
(Not to mention the car parked behind me) :fear:

<|Ben|>

Hi Ben,

Maybe it´s time to tune that mixture, right?
Or probably worn spark plugs...

My Clubman 1000 had that problem ... whenever I went full-throttle it looked like I had a diesel engine or something like that

Changed spark plugs, coil and tuned the mixture....done!
Oh, I´m on stock intake/exhaust manifold with straight through exhaust.

[johnnysti]

Well im waiting for SRE in Amesbury to get back to me with a price for a session on their rolling road so i could get the exhaust done then take a trip down to them


Johnny

[Wil_h]

I'd leave the middle box where it is.

Assuming it's a n RC40 or similar performance system, removing it will make bugger all differance to power, you might lose a few here and there through the rev range but you're likely to gain some at other points too.

If you did remove it though, I doubt you'd need to change the fuelling.

The only reason I use a single box system is that they are lighter, cheaper, easier to fit and only marginally noisier. But I wouldn't change a twin-box system to a single if it was in perfect working order, it's just a waste of time and money.

Wil

[binge]

Hi Ben,

Maybe it´s time to tune that mixture, right?
Or probably worn spark plugs...

My Clubman 1000 had that problem ... whenever I went full-throttle it looked like I had a diesel engine or something like that

Changed spark plugs, coil and tuned the mixture....done!
Oh, I´m on stock intake/exhaust manifold with straight through exhaust.

Well mine only spits out black C**p when the engine is cold, Or when I put my foot to the floor.

Its a pain in the ass, where can I get it tuned?


<|Ben|>

[Don't Panic]

I get allot of black soot from mine too, straight through exhaust doesn't help, It was apparently tuned before i bought it, but im wondering if the garage didn't do bugger all i didn't take it myself, had the previous owner do it as part of the sale (no specialists near me)

[Brett]

:saywhat: also i get occasional flame/fireball when the throttle is snapped shut. makes that chav in his nova thats always on my bumper keep his distance :grin: (well if i had a bumper)

[miniboo]

leave the middle bx on if the system is in good nick.

if it aint broke dont fix it!!