Dual Exhaust on Hawk DLX

[JasonOnTheRez]

Ive seen dual exhaust setups for other model China bikes, but has anyone seen one out yet, or have experience with, a dual exhaust setup for a Hawk DLX?

[aaw611]

It only has one cylinder.

[JasonOnTheRez]

Obviously, and yet...

http://www.2040-parts.com/racing-dua...-bike-i122883/

[RedCrowRides]

I am not aware of one, but i do know that a lot of people use the single exhaust for a Honda CRF230 F on the Hawk, or at least they did on the original Hawk, I assume the DLX has the same frame but not being a Hawk Owner myself you may know more about that than me- So, what I'm getting at is see if you can find a dual exhaust set up for the CRF230F., and if you can then i guess it's your call on if you want to try and make it work .

[Wild Dog]

On these engines is pretty much pointless, it will just add dead weight.

[Falkon45]

Not so much. Apparently there is gain to be had. It's the same with the rc390. There are dual muffler setups for it also, that make more power than most of the single pipe setups.

[Wild Dog]

Originally Posted by Falkon45

Not so much. Apparently there is gain to be had. It's the same with the rc390. There are dual muffler setups for it also, that make more power than most of the single pipe setups.

They are way too different. One is a Dohc engine water cooled with 4 valves. The other, Ohv with 2 valves.
The only thing in common they have, is that both have a single cylinder..

[Deckard_Cain]

Originally Posted by Falkon45

Not so much. Apparently there is gain to be had. It's the same with the rc390. There are dual muffler setups for it also, that make more power than most of the single pipe setups.

Engine dynamics and airflow characteristics would be totally different though. Whereas the RC390 may benefit from it, likely because of improved soundwave flow and backpressure changes, the CG pretty much wont.

I mean, anyone can feel free to try it, either for looks or to see if there is an improvement... but it won't be me.

[franque]

I'd be willing to bet that 99% of the dual exhaust is cosmetics (though some of it might all work together), like in the case of KTM, to match the bigger bikes, though potentially also to make things quieter/smaller mufflers vs. 1 humongous muffler to meet Euro V standards.

I would imagine that when one of the big 4 first came out with the dual exhausts for MX bikes, the engineers calculated certain exhaust scavenging advantages, but those calculations (having to do with frequency of resonance, pipe restriction/length, intake diameter, specific engine, jetting, and many other changeable factors etc.) would only apply if nothing was changed, like a camshaft, throttle body, porting of the head, piston, or air filter.

If you're an engineer, or really good at Helmholtz calculations, you could probably get some benefits from a dual exhaust, but only if you did 100s of hours of calculation. Think a bit like designing an expansion chamber from scratch, but those figures/numbers for calculation are much easier to find.

For the average person, and for anything that bolts on, unless the motor is setup perfectly for the exhaust system (which like stated, would take 100s if not 1000s of hours to do properly), unless everything is idealized to work with the exhaust system, a dual would effectively net less than a single, mostly due to the weigh.

A little too much flow on an exhaust system can be worse than slightly too little, as too little restriction kills the torque output. Honda used very small exhaust exits for the 250/450R motors, because they were almost definitely working with tuned pulse frequency, and also because they know that too much flow wouldn't give any torque.

The link above proves nearly nothing, only that P.T. Barnum was right.

[RedCrowRides]

I personally dont think you will ever get enough additional power increase out of a dual exhaust set up for a Hawk even assuming there is one to effectively offset the weight increase ,but that said if you want it for aesthetics and dont mind forking over the cash and living with no power increase then that's good with me ., Lord knows i have certainly put plenty of things on motorcycles over the years for no real reason other than it looked better imo.

[Bruces]

It appears the system being looked at it is basically a “t”with two more 90@ elbows going into two chineese “race tuned “ mufflers ,I cant see how basically adding 4 90@ bends on the end of a well tuned race bike like a hawk is going to help a thing other than the speed increase because of your lightened wallet (please pay for it with your change ),and it probably will run worse than it does now .That being said I say go for it !nothing to hurt

[Deckard_Cain]

For the $125 it costs, money that is better spent to have a ported and polished head installed. You're more than halfway there if you have someone do the machine work for you.

That is a guaranteed power increase, especially with the usual aftermarket exhaust already fitted.