It was a pretty mean task as its all pretty tight clearance wise! £520 all inc. Almost a shame to use it and get it dirty!
http://web.ukonline.co.uk/grahamf/index.htm
Adam
Just a quick plug. Took the Locost up to them last saturday along with a silencer and basically said 'erm, this joined to that please'. A
week later this is what was waiting for us:
It was a pretty mean task as its all pretty tight clearance wise! £520 all inc. Almost a shame to use it and get it dirty!
http://web.ukonline.co.uk/grahamf/index.htm
Adam
neat 
graham made my manifold too, piece of art even if i do say so myself 
looks great but shouldn't (ports 4 and 1) and (ports 2 and 3) be siamesed in a 4-2-1?
the wave pulses will surely be out of phase so you won't get any scavenging.....or does this give you 2 lesser bands of scavenging?
tom
quote:
Originally posted by indykid
looks great but shouldn't (ports 4 and 1) and (ports 2 and 3) be siamesed in a 4-2-1?
the wave pulses will surely be out of phase so you won't get any scavenging.....or does this give you 2 lesser bands of scavenging?
tom
quote:Looks like a 4:2:1 from the photo
Originally posted by Mark Allanson
quote:
Originally posted by indykid
looks great but shouldn't (ports 4 and 1) and (ports 2 and 3) be siamesed in a 4-2-1?
the wave pulses will surely be out of phase so you won't get any scavenging.....or does this give you 2 lesser bands of scavenging?
tom
As far as I am aware, a 4:2:1 is good for torque at low end revs, and a 4:1 is good for power at higher revs. As Adam is using a starter motor from a Pinto, the 4:1 may be more appropriate
On a bike engine 4-2-1 will give the best power all over, Due to the extra rev's it doesn't quite work out the same as car exhaust
theory.... how many aftermarket performance superbike exhausts do you see that are 4-1?
None, all 4-2-1
Yes, but you can't just choose random cylinders to pair up in the 4:2 sections (as far as I'm aware) which is indykid's concern.
[Edited on 22/3/10 by iank]
quote:Not on my BEC!
Originally posted by franky
None, all 4-2-1
The picture also looks like a 4-2-1 to me
His question is not "is that a 4 into 2 into 1" but "haven't you joined the wrong pairs of cylinders together?"
I have no idea on exhaust design... could someone in the know advise?
quote:
Originally posted by iank
Yes, but you can't just choose random cylinders to pair up in the 4:2 sections (as far as I'm aware) which is indykid's concern.
Very nice and shinny.
Interestingly Graham also made my exhaust and paired them 1 with 4, and 2 with 3.
Mine is basically the same engine (water cooled rather than air cooled). It looks to me like you have longer primaries and secondaries than I have
but it could be an illusion.
It would be interesting to see the design documentation, given the name of his company I assume there is some ;-)
I don't have power figures on my engine so don't know whether mine is right or not, but it seems to go alright.
Matt
just had a look at mine and he did 1+4, 2+3
Mines a modified Ford part & is 1+4, 2+3
The firing order of the GSXR 1100 is 1-2-4-3 which would suggest 1&4 should be paired and 2&3 should be paired.
Phil
huzzah, we got there in the end.
as has been noted by some people, my concern is that 1 and 2 are siamesed, as are 3 and 4.
the theory behind 4-2-1 is driven by the echo of the pressure wave scavencing the other cylinder. if you think of it like a clock, 12 scavenges 6 and
vice versa, both 2 cycles away from each other
that manifold has 1 scavenging 2, (3 oclock scavenging 6 o clock) but 2 can't scavenege 1 at the same rpm because it's got to get back to
2's exhaust valves being open....which is 3 cycles away, not 1.
i hope they can either prove their theory or sort it out for you. seems like an expensive manifold to not be tuned
tom
quote:
Originally posted by indykid
huzzah, we got there in the end.
as has been noted by some people, my concern is that 1 and 2 are siamesed, as are 3 and 4.
the theory behind 4-2-1 is driven by the echo of the pressure wave scavencing the other cylinder. if you think of it like a clock, 12 scavenges 6 and vice versa, both 2 cycles away from each other
that manifold has 1 scavenging 2, (3 oclock scavenging 6 o clock) but 2 can't scavenege 1 at the same rpm because it's got to get back to 2's exhaust valves being open....which is 3 cycles away, not 1.
i hope they can either prove their theory or sort it out for you. seems like an expensive manifold to not be tuned
tom
Just been googling.
It looks like Yoshimura (who are recognised as being pretty good on this stuff), connect 1-3 and 2-4.
Obviously a bit of a black art.
Are you going to ask Graham why he connected them like he did? He can be a bit gruff!
also like this one (bandit, but same engine as gsxr1100 oil cooled).
Once more proving that I don't understand exhaust design!
Matt
p.s. I like the wheels (Pug rallye perhaps?)
quote:
Originally posted by matt_gsxr
Just been googling.
It looks like Yoshimura (who are recognised as being pretty good on this stuff), connect 1-3 and 2-4.