I hope to get these on the dyno at some point...
They are 1.5" diameter flex couplers for my Rage. The exhaust port is 1.5" in diameter, so it makes sense that at least the first part of the primary header tube should match the outlet size of the port in order to obtain maximum flow. These taper to a 1 7/16" primary. The stock coupler and primary measure about 1 5/16", which is the same diameter as the 4 cylinder RX-1 and Apex, which of course breaths through 4 of them.
It really looks like Yamaha corked up the 3 cylinder engine. One can actually see the mismatch in the factor cut-away photo...
They are 1.5" diameter flex couplers for my Rage. The exhaust port is 1.5" in diameter, so it makes sense that at least the first part of the primary header tube should match the outlet size of the port in order to obtain maximum flow. These taper to a 1 7/16" primary. The stock coupler and primary measure about 1 5/16", which is the same diameter as the 4 cylinder RX-1 and Apex, which of course breaths through 4 of them.
It really looks like Yamaha corked up the 3 cylinder engine. One can actually see the mismatch in the factor cut-away photo...
Here the diameter differenence can be seen between the couplers.
The header with my first merge collector... I may buy the collector next time, they are difficult to fabricate.
My bet is there are some good gains here, the small RX1 couplers Yamaha uses on the 3 cylinder engine are a likely bottle neck.
The header with my first merge collector... I may buy the collector next time, they are difficult to fabricate.
My bet is there are some good gains here, the small RX1 couplers Yamaha uses on the 3 cylinder engine are a likely bottle neck.
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superchuck
Newbie
high flow header
Excell motorsports has a highflow header for the triples. It made big hp. Check out his web sight for the dyno results. looks like you have some time into your project. looked good from the pictures. check out excell motorsports.com
Excell motorsports has a highflow header for the triples. It made big hp. Check out his web sight for the dyno results. looks like you have some time into your project. looked good from the pictures. check out excell motorsports.com
Oak Hill
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Be careful not to go to big on the pipe. You will lose torq! That is why Yamaha used the smaller pipe. Excell's pipe made more power on the top end and sacrificed low and mid range torq (look at the dyno chart on thier site). Torq is key to a great trail sled engine and drag racing. Top end HP is great for lake racing (long distance). You are on the right track and will see gains from making the pipe the same as the port. Keep up the good work. 
I did consider Excell's unit, looks nice and high quality to boot. Fabbing one myself was more fun, though, and cost less.
The great thing about headers is if they don't give the desired results, one can change em' out. Time will tell if this design works well.... I do have hopes that the flex couplings will prove to be the magic bean on this engine.... maybe even with the stock header.... might be wrong, wouldn't be the first time.
Thanks!
The great thing about headers is if they don't give the desired results, one can change em' out. Time will tell if this design works well.... I do have hopes that the flex couplings will prove to be the magic bean on this engine.... maybe even with the stock header.... might be wrong, wouldn't be the first time.
Thanks!
superchuck
Newbie
I don't know what chart Oak Hill is looking at but from 7500 and up it is all gains. I watched my tach last night at trail speeds it hardly ever is below 7000. When decked your sled should be at max rpm, right? How am I loosing mid? My vector with Excell full kit is very strong from bottom to top. I don't know it all but I lost nothing but wieght with this exhaust.
If you look at the dyno chart provided by Excell, below 6k rpm there are 5hp losses. Probably acceptable since the low and mid range is quite fat.
Superchuck did you have to make any jetting changes with you new exhaust?
I see you bypass the donuts.....
good with the coffee, bad for my sled..
I like this. Did you had to make the frame opening bigger. Let us know the outcome... more so if you go serial.
good with the coffee, bad for my sled..
I like this. Did you had to make the frame opening bigger. Let us know the outcome... more so if you go serial.
Dubblerage
Veteran
AGREED! Looks great.........I'd like to get my hands on one!
I used to have an Excell header on my 05 Rage, I really liked it, woke up my sled pretty good. I didn't notice anything lost on low or midrange. You can't notice a lost 'range' when you're not in it! Just put a zip tie on your throttle, it'll keep you thumb from getting sore!!!!
Bjowett, great work, let us know if they become available!
I used to have an Excell header on my 05 Rage, I really liked it, woke up my sled pretty good. I didn't notice anything lost on low or midrange. You can't notice a lost 'range' when you're not in it! Just put a zip tie on your throttle, it'll keep you thumb from getting sore!!!!
Bjowett, great work, let us know if they become available!
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