Are there any advantages to having an individual pipe per cylinder? Two strokes have a pipe and expansion chamber for each cylinder but would there be any advantage to do the same on a 4 stroke Take this 1200R, does the pipe join into one before the cans for a reason
I have those pipes on my monster, I imagine the main reason for going 2 into one into 2 is to keep the routing compact and only require one exhaust flapper valve, it’s also got more to do with fashion than anything else. Expansion chambers are not required on 4 strokes Would there be an advantage in having a 2 into 2 exhaust?, probably not for road use , it would likely be bulkier/heavier and most modern exhaust systems are well designed to achieve the required flow and back pressure, of course small gains can be made by using systems that are performance orientated but usually there’s a pay off, more noise, less torque, flat spots that sort of thing, I tend to think that most bikes now have so much power that trying to get another few bhp is a bit pointless unless your racing, especially when you consider the cost, the above silencers are the best part of 1k, I bought the bike with them already fitted, they’ve probably saved a bit of weight over the standard set up but have they added 1k’s worth of performance, I don’t think so!.
Thanks for the reply @Mark9 I've read a little bit over the last few days, seems like there are pro's and cons. I was thinking for the Aprilia, V-twin, track bike so spends plenty of its running time at the high end of the rev range. Tempted to put a 550 engine in place of the 450cc and wondered about piping up each cylinder, one under seat one out the side. While its in bits I'll powder coat the trellis and titanium nitride coat the fork stanchions.
There’s a lot more to exhaust design than routing and making them look good. On a 4 stroke, individual pipes rarely work well. Header length and size affect performance quite a bit if you’re getting down to the nitty gritty. On multiple cylinders, joint the headers and where you join them can play a huge roll in getting more out. If you get a few hours over the dark nights, look up scavenging and gas flows.....that’s before you get to silencing.
Nice one, thanks Nelly. I read a bit about scavenging on a guys blog. The write up was predominantly aimed at Harley’s. https://www.denniskirk.com/blog/2018/09/19/2-into-1-system-vs-true-dual-exhaust-a-comparison/ I remember my mate in Oz having custom made headers and full system on his V8 Ute, he said each pipe at the manifold was slightly different to sync with the firing order of each piston. Sounds like I may be better off sticking with what’s tried and tested. Just stepping up to the 550 motor will make a substantial difference to the bike, they were only ever set up as 450’s in RRV form.
When the v4 came out, much of Wolf’s FB posts was trying different pipes and mapping to see which worked best before they raced them. It was the same with the V2 as well. I suspect that part of the current horrible system they have is best trade off for performance and noise. That can only happen with trial & error and lots of cash!
Thanks @Sev @nelly @bradders @Mark9 Learnt a lot from reading all your posts Will definitely leave exhaust as is, I'll concentrate on 550 lump and getting to the bottom of the fork leak. Plenty to keep me busy over winter
