Those X-pipes

Ya know, I'd really like to see some independent info on those X-pipes, and I'm really tired of seeing the listings on Ebay that are full of absolute nonsense. It seems the X-pipe could, in-fact, be a good design. Logically, it would be able to perform as well as a 4:1, even with quieter baffles. What gets me is the big list of utter crap that these Ebay listings use to hype the product:

The "urban-legend of scavenging"?! Give me a break, guys. Yes, with high-overlap cam-profiles and lots of scavenging, you can waste a lot of fuel. However, this does not hurt performance in the least, and can help the engine run cooler. And the X-pipe absolutely does use scavanging to gain power. Why they decided to claim it does something else is completely beyond me. "Four-into-one's ALWAYS lose power on the bottom-end to only gain 1% on top"?! Again, pure BS. Brock Davidson's 4:1 for the ZX-14 gained power EVERYWHERE. The article from the late-70s that used to be linked from KZR compared several 4:1s available at that time for the KZ1000, and they ALL gained in the low-and mid-range and actually lost a little on top (except perhaps the Yoshimura pipe. I don't recall for sure). Effectively, a 4:1:2 X-pipe is nothing but a 4:1 with a really large muffler, split into two for better fit. As far as the business of jet-change requirements go: if you set your fuel-mixture based on what won't turn your pipes blue, you are wasting fuel and hurting your performance. Up to the point of detonation, leaner and hotter= better performance. Jetting requirements are for the most-part greatly exagerated, but anything that significantly changes airflow through the engine can very-well change fueling requirements. If a pipe makes no significant change in airflow through the engine, it will make no significant change in power. Again, you still may not need to rejet. With older bikes, many are too rich from the factory for best performance. Others are too lean. It just depends.

Just aggravates me that people who probably have a pretty-good product to sell feel the need to spew a bunch of hooey to promote that product.

I am thinking about buying one based on looks alone.

I sgree, would really like to see some dyno testing and on the road results. Anybody here who buys a set NEEDS to report and possibly make a video for all of us! Interesting concept though...

There's already a vid on Youtube.com of a KZ650 with an x-pipe.
It sure sounds nice, but the poster of the vid doesn't offer any details on how it performs.
KZ650 with X-pipe

Judging from his Youtube name, it looks like he's here in CA. If he's in So Cal, maybe we can coax him into joining up with our merry band of So Cal lunatics on our next KZr group ride.

Funny thing is, I could swear I've seen that pic posted here before. Maybe he's already a KZr member?:huh:

i promise as soon as i buy a digital camcorder, i will post a video of one on a 1260 and then the one i have for the 650.
as for running, it does seem to have a better torque curve between 4000 and 8000 but it could all be in the jetting of a perfectly tuned set of 29's.
( btw, wide open is just so much better but will give you a headache after an hour or so )

the one i have for the 650 is a campell which is not as good as a murry.
dennis murry made the best one's and will not make any more unless we can convince him we have a sizeable order we can pre pay for.
i bug him every couple months.

so if anyone runs across an orginal murry x-pipe in a auction or in someone's garage, please let me know.

Subjective impressions are nice, but the real answer comes from back to back dyno tests.

And I'm not buying what they say without independent third party dyno charts.

For high rpm power increase i'd prefer the collecter be closer to the exhaust ports on any 4-1 pipe. Take a look at some custom piping for dragbikes..... they do the same for cars. What's sense in great scavenging at 4500 when peak power is made at 9000? ? ? HUH!

so many variables here such as primary tube diameter tube length overall length.each has its own ups and downs smaller primary tubes make more low end torque as do longer primary tubes big diameter tubes are better on top end.the old( Tri Y ) or 4 into 2 into 1 has killer torque on the bottom and mid range but falls off on the top where a kerker does much better on top end while losing on the bottom.carbs cams and timing will also come into play what works good with one exhaust setup doesnt mean it will work with another.but i would still buy a X pipe just cause it looks cool.

I think the bike in the video belongs to ZeeEuro who is a member here. Here is his bike in the project forum.

ZeeEuro's Bike

I sent him a PM. Hopefully, he'll respond.

I think last time i checked you couldnt change the oil without taking the whole xpipe off.

steell wrote:

Subjective impressions are nice, but the real answer comes from back to back dyno tests.

And I'm not buying what they say without independent third party dyno charts.

Amen.