carb needles for slight tuning

[AlmondGreen]

hi all,

I'm now about to change the breathing on a standard 1098. All I'm going to be doing at the moment is changin the carb to a 1 1/2inch SU, LCB exhaust system & a K&N.

What I need to know is which needle will be suitable as I need to get them on the car very soon & cant afford the time with trial & error at the moment.

Any suggestions for a suitable needle?

Thanks in advance, Daniel

[winger300]

you'll probably find the default needle in the 1.5" SU you get is an AAM, AAA, AAU or something, they are all pretty similar and will do the job.

Only way of getting it perfect is with a rolling road, but that money may be better spent on a new cylinder head or something.

[Cam]

I found the 'normal' default needle in a HS4 SU (from a Mini 1000) is a AAC which is too lean for what you need. But as Winger said a AAM is right for what you need.

I have used the AAM with the setup that you describe and had good results.

[AlmondGreen]

Thanks guys.

while we're on the subject of LCB exhausts does anyone know where LCB exhausts are available in mild steel as I've heard & seen that the stainless steel versions can be poor quality (quite often)?

[Cam]

Maniflow do Mild steel versions, and yes the stainless ones I have had have been nothing but trouble.

[winger300]

am i correct in thinking that an LCB only adds power to the upper rev ranges and reduces low end torque?

Is a marina cast iron manifold a better option along with a suitable downpipe?

At the moment i have the standard exhaust setup, and the low end is really good, plus the original minor exhaust note is retained. I'm pretty happy with it.

[Peetee]

am i correct in thinking that an LCB only adds power to the upper rev ranges and reduces low end torque

On a standard engine, yes.
And as you will appreciate without a suitable well flowing inlet and head a LCB will not be an advantage at all.