I want a Kerker

roy-b-boy-b wrote:

I'll be tuned in !! :laugh:

Here is my old kerker and Mac. I actually slipped the Kerker over the Mac. Roy

You have the rest of that Kerker Roy?

It's on my bike. Roy

ROy,

Can I get you to take some measurements of the MAC pipe when you get a chance..... Similar to these measurements...

Bet from exhaust port down to 4-1 collector, ~ 34"

Thanks....

OMR

I'll do that tomorrow. Roy

TerryK wrote:

I also have a very slight 3-4k burble that I just cant jet out, but when I put a Kerker on it was gone.

Are you running a baffle? If so, what size?

Since you are getting all in to make your own exhaust I just want to help out with some fun facts...


Keep the header pipe ID around 1.16x exhaust valve open area (valve circumference x lift x number of exhaust valves). This will keep your exhaust gasses moving along as a reasonable speed without being restrictive. <--- (as recommended by Mr. Cameron)


4-2-1 will work well to keep you from having a flat spot or drop in torque at mid-range rpm's. They will not produce as much top end torque as a well designed 4-1, but you will show a much smoother torque curve if designed correctly.


I have found 3 or 4 differing formulas used to determine "optimal" performance. These formulas all revolve around the length of header BEFORE A JUNCTION to give maximum "boost" from the negative wave created by the junction... any length you chose will however create a positive wave at some other RPM, which will cause a drop in torque.

You could use an actuator off of a sport bike and open a secondary chamber at varying rpm's, this will insure you are always making use of the negative wave and avoiding the positive.


Exhaust tuning is fascinating stuff, glad to see you stepping forward into the 21st century!

Well! After coming back to see what else has been written here on this thread and reading how others are in the midst of compiling the formulas for different exhausts, I feel a bit foolish saying what I did about trying to copy what I had.:blush: I suppose I should shut the heck up and just lurk and see what comes about , rather than reinvent the wheel here. but I will ask the question as to whether the "patching job" would get me by till I can obtain a new or newer pipe.

Here's an interesting earlier thread about dent removal and some collector ideas.

Click here > Out, Damn'ed Dent!

Good Luck!

roy-b-boy-b wrote:

Macs are hard to find!!

night hawk!

click the 5 minute mark...not a kerker but wow




(youtube)

Leather. I have cut dents out of headers on the down tubes and welded/brazed a patch. on. Patch on. Roy

Leather..."I feel a bit foolish saying what I did about trying to copy what I had. I suppose I should shut the heck up and just lurk "....

Naw KZ brother, don't go there.... If you haven't figured us all out yet, we're somewhat opinionated here... :huh: :dry: :laugh:

As you mentioned, nothing wrong with fixing her up until the research or $$$ for what you want are there.

Me, I'm no way giving up my Kerker w/1.5" comp baffle..

The "design & fab my own pipe is for the next KZ build and to just see if I can do it effectively. Meaning place the desired power band where I want it following the lines of that beautiful curved Yoshi header... DROOL!

But from what I have come to realize, there's a hell of a lot more to a pipe deign than sound & looks & power & increases I just didn't fully understand.

Example, pending my engine build displacements and cam selection, I'd find a pipe with longer or shorter primaries & exhaust lengths to fit more closer to my engine build...

This is where the true power comes to life in our builds.
We can do all this, all that in the engine & head but if we choose the wrong exhaust, that power won't come through to desired expectations.

For most manufacturers out there, they're build their exhaust systems to an average cc displacement (903/1015) and cam selection (70BDC/30ADC)for the KZ series... Based on the exhaust measurements I've taken, they're all around this 7000 peak torque range...

In my cam selection, I'd want to shift the power band more towards the 6000-6500rpm range... Henceforth "Tuned Exhaust" for my build! Yeah baby!

Anyhoot, don't take us Neanderthals too serious for this is just how we are here....

OMR