any consensus re 2 into 1 exhaust setups?
 

have not seen too much info on the topic on the forum...

the headers are 2-1-2 already. i assume the junction is just a straight through pipe that splits again. seems like Honda would have run separate headers if they wanted to keep all pulses confined to individual cylinders.

If you removed the OEM header from the bike. an really looked at the design... It has some factors of an X-pipe (like on a car). And sadly, most of the high end aftermarket exhaust systems(Akrapovic, Sato, etc) Have the very similar designs/ and even the Akrapovic "Full" header,exhaust systems have a exhaust "BALANCE" tube, between the two runs of pipe.
But as a consensus, why take away the duals... Be like all the inline-4s... Sure go ahead..

I tried it on mine for a while. I used the stock header with the left pipe blocked off and using a Moriwaki Ti pipe. I rejetted the best I could for it and found that compared to a dual setup I gained a tad top end but lost more on the bottom, including torque. This was all seat of the pants and runs next to a buddy on another Superhawk with TBR pipes. Here's a pic or two:

comments thus far duly noted. i tossed the idea out there because i know some of you have already experimented with it, and i'm something of a minimalist. lighter, simpler usually= better...

i've not pulled the right side exhaust off yet but i think i recall seeing a pic here of the head pipe junction. if it's not just a simple Y then obviously there is some other tuning concept in play. my guess is that in order to get adequate backpressure for this motor you need the extra exhaust can length provided by duals. i've built a number of custom setups for project bikes and fab my own ultralight aluminum cans.

i'm still considering selling the mint Devil carbon highmounts but not until i get time to experiment. runs great as is.

(quote) but not until i get time to experiment. runs great as is.

Strange enough... I think you and my father -have been drinking the same water...
My father is convinced- that he can inprove performance of the S-hawk to a RC-51 standard -using a single -sided exhaust.
Now being that he is retired, from a long career of engineering, master tool and die machinist..Hell ! let him attempt it..

no- not trying to improve on it. it's PLENTY fast as is :-)

just considering fabbing up a substitute system to free up the Devils for $$.

also, i wouldn't mind something a tad louder. sensitive ears- so i always ride with earplugs to eliminate low frequency hearing damage and shut out wind noise around the helmet. those cans are so far out the back that unless i'm cracking the throttle or up on the tach a bit i can't always hear exactly what the motor is doing. i'd much rather just listen than look down at a gauge....

and louder pipes might have even scared off that f-ing deer i hit the other day.

I've been thinking about doing dual Shorties, but that end under the rear sets, like the TBR gsxr750 style.

yeah- that's probably the best alternative to my existing system. more important to keep the low and mid than extra top end...

heres my 2-1 exhaust
www.vtr1000.org • View topic - My 2 into 1 project now with dyno print out

lloydie- that is one hilarious avatar you've got there...

so you just cleaned up a few welds, had a 2" (approx 51mm) midpipe made, and picked up a couple HP without losing torque? those cans in my pics above are 2" OD for the core so that's right on the money.... maybe i'll order a mandrel bend section and start welding. only problem is it's relatively irreversible in terms of cutting up the header. jury is still out...

i just posted a thread asking about this. What if you went with a 2 1/2 inch or bigger single pipe after the merger?

i wouldn't step the OD up that abruptly for a midpipe. stay with 2", IMO.

i did take a look in the right side junction. very odd restrictive looking setup that doesn't even appear to be balanced with the left side in terms of area. it would be a simple project to build a midpipe for just one can... i'm surprised Honda didn't at least make the 2nd Y junction a lot cleaner.

Its that way for a reason. So mess with what you might think is a.sloppy job and.you loose power. This has been proven on the dyno.

8541- duly noted. still, it strikes me as counterintuitive...

Can't say how the S'Hawk will react, but I know going to a single can on an RC-51 will kill the top end. Proven on the track at Road America. I felt bad for the guy as he bought the 2-1 setup and it wasn't all that. I forget who made those? Yosh or Jardine-? It may have cost less than my full Akra setup but it was also way slower.

That said, customization of ones bike is part of what owning one is all about. Leave it stock or mod the hell out of it. It's YOURS! :D

here's my 2 into 1 setup. sealed TIG welded custom aluminum shorty can, mandrel bend midpipe, steel outlet nozzle. weighs about 3 1/2 lbs total- 8 or 9 less than the Devil highmounts and gives away nothing in terms of performance. also a tad louder and easier to hear since the outlet is farther forward.

Barncat, would it be possible to get you to take another pic including the entire bike? I'm curious about lines.

Here is my 2 into 1, but it was mainly driven by the sp2 swing arm set up.
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and mine
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From those dyno charts it looks like you picked up 31HP and over 3 ft/lbs of torque? Must've been a lot more done than a 2 into 1 pipe conversion. I've considered the idea of 2 into 1 conversion for the last 13 years but always reconsidered for fear of losing the impressive bottom and mid range stomp. I want to do it for a very different reason than others- improved chain cleaning and lubing access.

It read the blip at the end as peak. A good dyno guy would have cropped that off.

have put a few hundred miles on my modified system. if you instantly crack the throttle wide open on the bottom end of 2nd gear the carb slides take a split second to catch up. but a smoother roll on, particularly if you're already up a bit on the tach will really launch you, and the reduced restriction seems to give it more top end. it's hard to find a stretch of road around here where you can really wring this motor out though without the risk of losing your license...

i have not gone back into the carbs yet to experiment with perhaps shimming up the needles a bit. that hesitation would not be happening with direct lift slides. CV/airbox carbs are always more of a pain to dial in.

all i changed on mine was the slow jets 45s to 48s
and a 1/16th turn out on the mixture.
i was already running 190dj mains and 4th clip on the dj needle .
i have found that the carbs need to be synced very well as a little out will cause the hesitation on the throttle at low revs .
and also blocking the 3rd dj hole on the slides helps alot on throttle response.
it now pops the front wheel up very easy in 3rd gear on the throttle

hey lloydie- thanks much for the tips re your setup. my tuning is very close and was barely worth mentioning but it could be tweaked slightly. i have to confess i've not gotten into the carbs at all yet as they were well tuned for the Devil highmounts. will report back at some point when i check jetting...

I'm running a 22 inch mid pipe with mgp growler can and kn filter 50 slow what mains are u running 190s in front and rear?

yep 190 dj mains in both

+30 HP and increased torque with card mods and single pipe. If this can be replicated by others, you should be inducted into the Firestorm/SH hall of fame. VTR Viagra indeed! What do you got in that can, a supercharger?:shock::shock::shock:

the dyno had a spike when it hit the limiter thats why he put the markers on the graph
you can see that it gained 2 torque and 3 bhp at the top.
but it also moved the dip in power and torque up the rev range which makes it much better lower down and for road riding
i wish it had 136.78 bhp that would be fun to ride but it dont it has 108.61bhp

well this is certainly more plausible. Thanks for the nice pics. I want to go this route just to get rid of those heavy-ass OEM cans, and to have a few more ponies wouldn't piss me off either. Oh, and thanks for the carb notes which will likely be requisite.

I doubt that this could get me roll on the throttle easy third gear wheelies though, but I'll take your word for that. I have 15/44 gearing and mine doesn't, but i usually have my balls against the tank because it makes them feel useful. haha

i also have a lightened flywheel that helps to