fish_antlers
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The Truth is Out There
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posted December 07, 2003 03:39 PM
 Edited By: fish_antlers on 7 Dec 2003 15:40
ZX-10R Exhaust Valve?
I noticed at the MC show that the 10R employed a cable activated exhaust valve that was remotely operated by a motor that looked to be near or under the set.... Dunno if this has been discussed hear, but I am wondering what this will do to the aft- mkt pipes etc? Slip on only? Retain the exhasut valve or what?
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frEEk
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ummm... yeah
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posted December 07, 2003 05:17 PM
yamaha has had this for ages. seems plenty of people still replace it with aftermarket. just like non-valved pipes, top end is usually still bette ron aftermarket, but u often lose lowend and midrange, torque in particular. at least in comparison to "traditional" exhaust systems. since they're making the stock exhaust outa TI now tho, there doesnt seem all that much advantage to going to aftermarket exhaust. tho im sure there's weight (and certainly aesthetic) improvements to be had with that cheap looking aluminium can.
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swft
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posted December 07, 2003 06:00 PM
Yep.
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extremelean
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posted December 08, 2003 11:51 AM
aluminum on the muffler is just a shell wrapped around Titanium.
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swft
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posted December 08, 2003 02:47 PM
Oh?
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redelk
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Please... speak to the hand.
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posted December 08, 2003 04:00 PM
All titanium exhaust system and oval section muffler with titanium internals and a 1mm thick aluminum cover, designed for light weight
from the Aussie MC News
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There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games.
-Ernest Hemingway
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12RPilot
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posted December 08, 2003 04:20 PM
For most tracks I go to (all except Road America) I'll need the low and midrange more than top end. I think I'll give the stock exhaust a chance.
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k bryant
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posted December 08, 2003 04:34 PM
One little known fact that most people miss out on when it comes to the valves in the exhaust; No matter what the design concept, whether it's Yamaha, Honda, Kawasaki, Buell, or whatever version, a primary reason is sound. The valve attenuates sounds levels substantially during EC/EPA testing procedures. In a big way, it allows for much more non-restrictive mufflers, because the valve actuation limits the flow. Henceforth, the sound level. We first found this back in the 80's when testing Japan spec FZR400's with the first version of the "EXUP" valves.
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redelk
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posted December 08, 2003 04:45 PM
Edited By: redelk on 9 Dec 2003 20:42
I was typing my dribble below while you were posting, KB. Are you implying that these valves really do not provide better low end and midrange performance, as we have been lead to believe from the manufacturers?
Now... back to my "regular" post...
I've heard both Suzuki and Yamaha owners switching to a aftermarket full system and the majority of them did say that there was a loss in the lower to mid range torque. How much and how significant of a loss depended on who you asked. Some said they rarely, if ever notice it versus others just say, "yeah... but the top end punch is so bad ass!". The majority of these folks also think it's sounds cool with no packing in their canisters, too.
IMHO, unless someone manufactures a system that either contains it's own valve system built into the header (probably rather costly) or there would be some way to transfer the OEM system into the new system (kinda doubtful), it seems that a slip on canister would be the only ECONOMICAL way to gain a few ponies. It would seem that weight will not be as much of an issue with the 10R's system as it was with the 12R. My Ti/CF Oval system took off 17 pounds. I'm figuring a slip on might take off 2~4 pounds at best. A full system (with a valve) might even be 7 pounds lighter, but not 17. Plus, if it does have a valve in it, I'd be hard pressed to see a quality system like that sell for less than $1600, if not over $2000. Way out of my price range. With out a valve, they may be even cheaper and lighter, but would likely sacrifice mid range performance and that's something I can not afford to lose just to get good dyno numbers.
Sure, you might get a system that has a valve built in, but wouldn't it be even more effective if you could alter when and at what rate it opens instead of just having the same valve doing the same function? The tuning of the canister seems to be where the gains, albeit small, will likely be found for the first year of the 10R. The same would likely go for weight lose. It too, will likely be small. With slip on prices ranging from $250 (stainless steel - no weight loss) to near $600 (Ti/CF oval), the gains will need to enough AND in the right places of the RPM band, to even warrant a consideration of changing the stock system.
I now realized, through the experience of having a PCIII, "big numbers" at the "big end" ain't everything. It's those pesky "dips" and "stumbles" that can be both inherent of the bike and even amplified with an aftermarket system (slip on or full), are the issues that will need to be addressed. The "superbike" market has learned that the days of a pipe, jet kit and a filter are long gone. Even the combination of a pipe and filters will not be enough to get the best performance. So, if one is wanting to lose any significant amount of weight and get additional power, without "dips" and "stumbles", they will need to get ready to shell out almost $600 for a slip on, another $340 for a PCIIIUSB and about $100+ for filter(s). Seeing as how that all adds up to about the same as the MSRP of my old full system on my 12R... that's the route I will likely go.
All the same, I'd rather get a damper and frame sliders first.
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There are only three sports: bullfighting, motor racing, and mountaineering; all the rest are merely games.
-Ernest Hemingway
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k bryant
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posted December 09, 2003 09:18 AM
redelk - No. Wasn't implying that. They definetly provide better low-end & mid-range power. It pretty much makes common sense. Big diameter pipes and/or free flowing mufflers can ruin power at low/mid rpm's. With an in-line valve closing off some of the flow at those rpm's, you gain the necessary back-pressure to make them perform well. At higher rpm, when the valves are open, you gain the full advantage of bigger tubes & non-restrictive mufflers.
As to the rest of your dribble (though excellent), you are pretty much spot on. Nice job!
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