Has anyone converted the original dual exhaust into one and how? Please comment on the effect.

I don't think anyone here has done it and I guess I wonder why someone would?

If you are trying to save weight I guess it could be done but the stock Honda header isn't nearly as efficeient as a good aftermarket header.

Weight and performance and cost. Would the flow be more restricted(by moding original) by going through one pipe verses two. If not what sort of gains are we tralking about? 5 hp on to end?... mid-range? torque?
I'm to understand from what others have done and there comments that the best mod for performance is to install a PC111 usb. It helps increase mid range performance and smooths out over all throttle response.

I could be wrong here, but modding the original header and taking off one pipe would restrict the the flow even more. If so you would loose HP not gain it.

Its not worth the time and effort modifying the stock pipe. For the price of a single aftermarket system with a PC The performance gains are ++++1.
Keep saving your money!!

In theory, the effect of a 4 into 1 header could be duplicated and possibly exceeded by using the original pipes into a collector that was efficient at bottlenecking the flow. The mid-pipe needs to be roughly one and a half times the diameter of a single downtube. Smooth transition here means a lot. Megaphones rather than canisters make more power generally, but obviously don't quite match the aesthetic qualities of the CBR. The massive change in pressure wave as it reaches the canister is critical. This is a large optimization area to play with... and a dyno or a personal dragstrip would be required.

A Power Commander obviously would be essential to getting the max out of any exhaust changes.


I doubt any of the fabrication and tuning would be worth the time and effort it would take to do it unless you just want to be able to say that you built your own exhaust. Good on ya if that is your goal! A new or used name brand 4into1 is cheap compared to that much work though.

Could you tell me where you are from wynne? I'm curious because of your user name.

I did inot convert. I just got a Two Bro's 4 - 1 Ti Oval and it really woke the bird up.