T40 question

[mad-driver]

I'm about to put Twin 40s on my SR, just wondering what this was though, the black cable on the right hand side of the image, does anybody know?

http://img.photobucket.com/albums/v300/tvrman123/carbcable.jpg

Sam

[Adam]

Is it connected to the carb, or did you just get it with them?

[supanova1400]

could be a vacume pipe, is it a cable or a pipe?

[mad-driver]

looks like a pipe, and Ad they were already on the carbs. I have seen a Nova in total vauxhall before that has the same pipe but blanked off so maybe it is not needed?

Also i thought you didnt use the vacuum on twin carbs

[mikey14sr]

Proper origional sport dcoe's did have the vacum take-off for the dizzy, though theres nothing to stop you blanking it off should you choose to run without vacum advance.

[mad-driver]

What advantage/disadvantage do you have from not using the vacuum advance?

[Adam]

I dont think anyone uses the vacuum advance.

[mikey14sr]

I think the vac advance is only for starting, just to get the spark to kick a bit earlier, but just about every nova I've ever seen thats been on some rollers has had it disconnected.

[mad-driver]

I know, i too have never seen it connected, but just wondered what it did

[CP]

Mikey is right. The std dizzy on an SR has 2 sorts of advance/retard mechanisms. The main 1 for all types of running is a centrifugal weight device which alters the advance with engine speed. There is also a small diaphragm ( the round thing stuck on the side of the dizzy) which when connected upto the suction from the inlet manifold delivers more advance at low engine speeds. Its mainly an economy/emissions thing and therefore by definition a waste of time when using twin 40'slol