Performance and/or decibel comparisons between exhausts

[fulcrum]

Hey,

Maybe someone can shed some light on this for me. I know its not so clear cut and includes many variables but its more for my own curiosity. What are the performance differences between a 4 to 2 and a 4 to 1? Will I see an increase in hp when going to a 4 to 1 from a 4 to 2 if proper jetting is done? Also, is a 4 to 1 louder or quieter than a 4 to 2? Or does that depend on materials found inside the canister/muffler?

Any input would be appreciated. If not we could just talk about the physics of exhaust! haha..

[2wheel]

Its going to depend on the manufacturer and model of the exhaust. Some pipes are made to be quieter but still add HP. A 4-1 is going to be lighter too.

Here is a quote from an ex-racer friend:

"Taking off weight is just like adding horsepower!"

[fulcrum]

its a Jardine 4 to 1...

I heard of story of this burning exhaust valves. Is this possible? (I assume this could be caused by an exhaust leak due to using the original exhaust gaskets) Id like to add a new exhaust but dont want to go down the Mac Exhaust road...

[ZooTech]

First off, nice bike! Had one identical to it.

Secondly, for the most part a 4-into-1 (or 2-into-1 for that matter) will add horsepower but at a cost down at the low end. Anything from the aftermarket should be louder than the factory pipes on the NightHawk 700SC (those suckers are Honda quiet). Personally, I prefer the look of the 4-into-2 on the NightHawk simply because I like the symmetry. However, if top-end power is your game (and you'd like to shed some weight in the process) the 4-into-1 will be your best bet.

[flynrider]

its a Jardine 4 to 1...

I heard of story of this burning exhaust valves. Is this possible? (I assume this could be caused by an exhaust leak due to using the original exhaust gaskets) Id like to add a new exhaust but dont want to go down the Mac Exhaust road...

The burning of exhaust valves is usually the result of someone installing a free-flowing aftermarket pipe without changing the carb jets to compensate for the resulting leaner mixture. Higher exhaust gas temperatures will eventually erode the valves if the engine is often run at high power outputs.

Zoo is right on the money. A pipe change can add a few hp at the top end, while robbing some power from the lower parts of the powerband. Unless you are a drag racer you'll probably end up with a louder bike, but a net loss of horsepower in the places you normally use it.

I used to run a dyno on the weekends and was never surprised to see bikes with aftermarket pipes putting out lower hp than stock. Unless care is given to match the carb jetting (or FI map) to the pipe, the result is usually a net loss of hp.

[fulcrum]

Zoo:
yes these are great bikes, there something about them, they have soul... Ive seen your bike on hondanighthawks.net (the corbin adds a nice touch to these bikes)

Zoo and flynrider:

So when we are talking high end were talking about 8000 rpm plus right?


ps. does anyone have any suggestions for exhaust painting? VHT seems the way to go

[flynrider]

Zoo and flynrider:

So when we are talking high end were talking about 8000 rpm plus right?

Yes. Exactly where depends on the particular bike and pipe combo, but on the dyno a well matched pipe would show an increase in peak hp, which is usually close to redline, with a flattening of the hp curve in the lower rpms.

[ZooTech]

Indeed. The 700SC doesn't come onto the cams until the tach is north of 8K, and that's where the power increase from the 4-into-1 will be felt.

[canuckerjay]

I have no opinion on your exhaust!!

But for once I agree with Brother Zoo -- Those things are great bikes. My bud had one for a while and I loved riding it. No matter what pipes you buy, enjoy, dude.