1981 GPZ1100 Kerker exhaust question

I guess V&H should know, but it's hard to see any real restriction in the shape of the road exhaust. It probably depends how highly tuned your motor is as to whether it makes any real world difference and I would also suspect the difference is at the highest of rpms.

With the system I bought the two other baffles for it. Those baffles fit both style exhaust systems. I suspect is has to do with the length of the pipe after the collector. Back pressure/scavenging? I've noticed modern systems have longer runs and smaller mufflers.
Steve

Found this.
Steve
kzrider.com/forum/14-vendor-forum/593247...25-00#s5_scrolltotop

Thanks everyone for all the input. I'm gonna go with the Kerker 127-61004 exhaust.

Now...I have another delema.

I'd like to install the largest baffle available. I believe it should be the 2.5" competition baffle. SuperTrapp lists the part number as 100-6356.

Doing a google search of that part number shows 2 baffle sizes. Some web sites list that part number as the medium 2.0" baffle, some list it as the 2.5". From what I see, the SuperTrapp catalog may be incorrect. But I can't say for sure. Its confusing.

Does anyone know which is the correct SuperTrapp part number for the large competition baffle? Depending on the google search it could be either 100-6356 or 100-6357.

Thx

Way expensive. Too big a baffle and you will lose ponies.
Steve

I called SuperTrapp, spoke with a customer service agent and explained their website lists different part numbers for the same baffle(s). The customer service guy was as confused as I was. Long story short, the 100-6357 is the large 2.5" inlet with 2.5" outlet baffle and the 100-6356 is the medium 2.5" inlet with 2.0" outlet. SuperTrapp will update their catalog to reflect the part number mistakes.

Can you explain a little more? The motor won't be stock. It's being built and will be pretty healthy. Going from the medium 2.0" baffle to the large 2.5" baffle isn't a big step. Or at least I didn't think so.

That's a 25% increase.

It depends on how it's going to be used. What works in the 1/4 mile won't do well on the street. With stock carbs the street baffle worked but the competition was better. Add the larger carbs the street baffle was like putting a cork in it. I tried the race baffle and my top end dropped off. GONE If it's a new exhaust, I'd try the middle one for a while, then get the bigger one if need be.
Steve

Wonder if he should run his mods by Larry C and see what he thinks ...... at 180 bucks a baffle you could buy a complete V and Hines or a Delkevic for the price of 2.

TexasKZ wrote: That's a 25% increase.

Well it's actually area that matters, not just the diameter, so it's proportional to the radius squared, so it's actually a 56% increase in area, which is quite a lot, but while I can do the maths, I don't know what actual real world difference that makes