just wanted to know what ppl think...on a 4stroke will the header pipe really make a differance. my local dealer told me that a slip on will provide the same H.P. increase and that the after market header will just save you a few ounces thats about it.
what can anyone tell me about their experience with after market 4stroke exhaust systems.

THANKS.

 

I wouldn't get one unless it's ported.

 

Depends on the machine!

My old 300EX had an absolutely pathetic stock header, and if any machine needed an aftermarket one, that was it.

When you get an HRC kit for the Honda 450R, it comes with a header. So, I guess there they are telling you straight up that the stock one needs to be replaced.

 

certain quads adapt to them better than others. for example a Rath Racing header for the predator is a 2hp increase and a 3ft-lb torque increase

 

Yeah there is some truth in that.. But you got to think.. If your running a good air filter..that flows good..It will help...More air in more air out makes HP...But there are alot of things that come into play...A slip on will work just as good on a stock motor...But if you have a built motor you need a header pipe

 

You can take the filter and silencer completely out of the equation and you're still restricted at the carb, intake and exhaust ports as to how much air can get in and out of an engine. I have limited experience with race set-ups but they seem to try to match pretty close to the diameter of the exhaust port.

Now I have seen some crappy head pipes with a crease in them (It's been a while though). I'm sure a new header would help those engines breath.

For example Spyder, a tornado claims to add 5hp but I don't really believe it. Now unlike that particular gimmick, I don't see a head pipe hindering performance. But if you do see gains, they probably wouldn't be enough to feel. Just think you'd be better off spending your money elsewhere. Cost to benefit seems high to me for a stock machine.

That's my opinion, you're welcome to yours.

 

I would ask other owners of YOUR PARTICULAR MACHINE (A Bomb 650???), what their experience has been.

 

From what i have heard, the ds has a good stock header pipe. A aftermarket 1 is not exactly needed.

 

Isn't the header just a pipe?! I mean, what is the difference between aftermarket and stock?

 

i agree with your opinion, for optimal gains, however, the curves, length and diameter of a head pipe determines alot of power. for example, a smaller tube is made for torque and low end power, it forces the exhuast gases out at high speed and have a ammount of backpressure, although not having restricted flow. a wide tube, such on a race set up is for when they're is a high volume of exhuast, like at high RPM areas. the wide tube lets the high volume of exhuast gasses to get out in a hurry. as far as bends go, a steep bend gives more torque while a wider more gradual bend is more horsepower based.

now that we have the ranges of diameter pipes down and their effects, i'll go onto say that the Rath Racing header actually does give the 2 horsepower and 3ft-lb torque, adn thats with a stock set up, the effects are multiplied when head work is done along with intake and exhuast.

if you cant feel 2 horsepower and 3ft-lbs of torque difference on your ***-o-meter then investing in a turbo charger for your quad might be a more cost-butt effective mod