dual exhaust or no?

[loosekannon]

If i bent up some dual exhaust for my 400ex when i get it would it hurt or better the performance. (keep in mind that we are a custom headers shop so we have knowledge on how to.)

[ryanh250ex]

i'd say keep the single. it might help on a big bore bike, but with stock internals like i guess you have, the gain would be minimal over a quality made single system...


custom header shop eh.... feel like giving me a quote on a 4.7 Grand cherokee ? :devil:

[underpowered]

duals would be unique. as for power, probably not much difference than a single, but the sound would be where its at. a good dual system just has a great sound, like LTE. i say go for i if you have the means.

[sixer3]

i think with a worked motor duals would start to show more power increases...really really worked motor though...definately a good idea if you want to squezze that extra hp out of it, as for a stock motor it wont hurt performance, and since you work at the place might as well, since the price for good pipes these days is ridiculous...more expensive than for my off-road truck was

DO IT! that would be so cool!

[400exstud]

Originally posted by sixer3
i think with a worked motor duals would start to show more power increases...really really worked motor though...definately a good idea if you want to squezze that extra hp out of it, as for a stock motor it wont hurt performance, and since you work at the place might as well, since the price for good pipes these days is ridiculous...more expensive than for my off-road truck was

That may not be completely true. The stock 400ex pipe isn't the worst thing in the world. You actually don't gain too much with a good aftermarket exhaust. It would be easy to lose power.

[sixer3]

whats your theory behind losing power with an aftermarket exhaust, i'd just like to hear it...not flaming

[nakomis0]

He was refering to lossing power in a custom made exhaust.

Bad design can cause a lose of Hp. A couple of reasons why.. is a loss of velocity, or not tuned good where its not creating a good vacuum to help draw the exhaust out.

Or you put the hp in an rpm range thats not as practical or usable.

[loosekannon]

We are a pretty big shop im sure the custom guys can handle it.

[NacsMXer]

Originally posted by nakomis0
He was refering to lossing power in a custom made exhaust.

Bad design can cause a lose of Hp. A couple of reasons why.. is a loss of velocity, or not tuned good where its not creating a good vacuum to help draw the exhaust out.

Or you put the hp in an rpm range thats not as practical or usable.

This is true. Look at the Curtis Sparks X4 and X6 exhausts. One is geared for a stock to mild motor and the other is meant for high performance applications. Put the X6 pipe on a stock quad and you won't see the kind of gains you would with the proper X4 pipe.

I had to do the same when I upgraded from a mild 10:1 440 to the current engine setup in my sig. I used to run a CT midrange exhaust which has smaller headpipes and is designed for low-mid gains. When I had my motor rebuilt by GT Thunder, that same pipe wasn't going to cut it so I switched to the CT high-output exhaust which has larger sequentially-stepped header pipes to match the application. These motors aren't as sensitive as a 2 stroke to pipe design, but there is still some science behind it all ;)

Here's a pic of my CT header. The stepped design along with the reverse megaphone helps to keep the backpressure where it needs to be.
http://www.imagestation.com/picture/sraid174/p78235a2d3a20aa59a62cca50bb3571a4/f38ff99e.jpg

[boricua]

looks pretty cool! what do you mean reverse megaphone? do you mean that it starts bigger (closer to engine) and gets smaller towards the silencer?

[NacsMXer]

Originally posted by boricua
looks pretty cool! what do you mean reverse megaphone? do you mean that it starts bigger (closer to engine) and gets smaller towards the silencer?

Thanks, it's the opposite. Where the header connects to the silencer it isn't just a regular round pipe that attaches to it. It is a welded cone that hooks up to the silencer and momentarily allows the exhaust gases to expand before entering the silencer core. The TC shorty exhaust shares this same design.

You can sort of make it out in this pic if my description was kinda confusing
http://www.imagestation.com/picture/sraid152/p84892a994f524f546504b6e258c154d4/f5af1069.jpg

Don't mean to hijack the thread :scary:

[boricua]

yeah i get it now. how does that pipe compare to the HMF?