Page 3 of 3
Posted: Mon Nov 30, 2009 3:33 pm
by kiwicar
Hi Tom
I think Ians suggestion sounds pretty good, all the real steel ones are some sort of off set or spirel baffel set up, so will have no advantage over the vauxhall one, I would go with whatever is cheeper (and will fit).
Mike
Posted: Mon Nov 30, 2009 8:57 pm
by topcatcustom
Fancy that! Vauxhall Cavalier mufflers being the supercars choice
Ian I dont suppose you know the size of the inlet?
Posted: Mon Nov 30, 2009 9:59 pm
by Ian Anderson
TC
Sorry but I don't
Ian
Posted: Tue Dec 01, 2009 6:54 pm
by JP.
Running mine on the standard cast iron SD1 manifolds (4-2-1).
Cause can't fit tubular ones cause they are made for rhd and my steering collumn is on the other side.
According to the book Tuning Rover V8 Engines ( David Hardcastle) they ( the SD1's) perform well and more than some so called performance tubular/extractor designs. ( picture on page 30, upper pic and quote on page 28 )
I run them cause they where cheap, are small as I havent much room and still have no horsepower issues that I know of.
Offcourse there may be some horsepower improvement for me by choosing the right model of headers & design but at the moment I have more than plenty horsepower so I don't miss what I don't know....
Posted: Thu Dec 03, 2009 2:28 pm
by topcatcustom
JP I have ported my heads maybe a bit too much and the ports are slightly larger than standard now so cast manifolds will not go on without being opened up themselves.
One of my steel suppliers has got back to me and can supply the tube I want, not cheap but goes through the books so no VAT, I am getting 1 5/8" for modifying the primaries I already have (6m length might be a bit overkill!!!), 2" for the secondaries and more 2 1/2" for the remainder.
Before I order- thickness wise am I best going for 1.2mm for the 1 5/8" and 2" and 1.5mm for the 2 1/2"? Actually its a bit of a bugger as I only need about 2m of each, wouldn't normally care but the 2 1/2" stuff is nearly £50 a length, the 2 smaller sizes average about £24 each...
Posted: Thu Dec 03, 2009 2:45 pm
by kiwicar
the choice of wall thickness is really down to how many bends you have to put in it and how long you want it to last, if you can run 2 1/2 but if budget is limited then go 2" (you could always run 4 pipes as the other chap with one of these has.
Mike
Posted: Thu Dec 03, 2009 4:41 pm
by topcatcustom
Yea I suppose 0.15mm extra wall thickness wont make too much difference! I'm definitely running 2 1/2" main, just wasn't sure if the pipe was about the right or at least the normal thickness!