Internal Exhaust Coating & Exhaust upgrade?

[jetmechmarty]

Who here has used these? Which one is preferred? What quantity is required for a new Mac 4 into 2? Thanks.

I spend a lot of time on the XS650 and that bike has a lot more performance parts available. Supposedly, aftermarket pipes have shortcomings where they meet the head. This has been addressed on the 650. What about our XS11?



Read about it.

They say imitation is the sincerest form of flattery. Having been so fortunate as to have learned from the Anti-Reversion Master himself, Jim Fueling, I have been working with this concept over 30 years, so it's not surprising I am able to offer a superior product.
Now an improved CNC version, including stock pipe replacement rings, with enhanced exhaust port flow, less heat radiation into the head, less reversion. Billet assembly, suitable for 1 1/2" to 1 3/4" head pipes. Bolt in.

www.650central.com
Mike's XS Part #07-0769
OMAR'S

[CaptonZap]

Who here has used these? Which one is preferred? What quantity is required for a new Mac 4 into 2? Thanks.

I spend a lot of time on the XS650 and that bike has a lot more performance parts available. Supposedly, aftermarket pipes have shortcomings where they meet the head. This has been addressed on the 650. What about our XS11?



Read about it.

www.650central.com
Mike's XS Part #07-0769
OMAR'S

Howdy Marty,

Not to rain on your parade, but some research shows mostly con opinions as to the benefit of the anti reversion cones. This is from motorcycles as well as aircraft sites.
And secondly, looking at the cut away, I don't think that the cones would fit in an OEM exhaust, due to the reduction in diameter of the inner pipe, just inside the flange area. Those folks with aftermarket pipes might not have a fitment (as our English brethren might say ) problem, but if one were to consider buying two sets (they seem to be marketed for two cylinder machines) to install on an XS, it might be prudent to get a return authorization from the seller before purchase, in case they did not fit.
Below are two URL's, found with a Bing search for "anti reversion cones" and "exhaust reversion". They seem to be typical in opinion.

http://www.nrhsperformance.com/tech_arcones.shtml

http://www.badweatherbikers.com/buel...tml?1125948543

What I find interesting is that the crossover CHAMBER of the Standard models is said, by exhaust pros, to increase the mid range torque. (Hbonser, are you listening?)
Interesting stuff, though.

CZ

[jetmechmarty]

CZ,

This is what I read on one of your links:

My guess is they'd be more effective on a system where the pipe was oversized for the motor size and target rpm.

This is the problem. The MAC pipe does not fit like OEM. That's why I think our bike might benefit from torque inserts at the head. The MAC pipe is larger diameter than the OEM exhaust. This item is completely useless on our bikes equipped with the OEM headpipes.

Please do not order the tq inserts listed in my post. They will not fit the XS1100. The XS650 has larger exhaust ports than the XS1100. I believe they would have to be custom made for our application.

It's a common comment that aftermarket exhausts move the XS11 torque curve to a higher RPM, and that the OEM exhaust works best.

[crazy steve]

'Torque cones' are a popular 'crutch' used by the V-twin guys to help with low-speed performance if running open i.e 'straight' pipes. In these specific cases, they help restore some low-speed torque. If your system has mufflers with any backpressure, they'll hurt rather than help performance...

[jetmechmarty]

Those cones are used on the XS650 to take up the void left by the stock headpipes once they are removed. Also, big pipes are common on the XS650 and the bike doesn't get enough RPM to make use of it. The cones and optimizers are used to bring the torque curve to a usable RPM. In that case, it works. I don't know anything about the V-twin use. I was thinking we could use it because the MAC pipes are so much bigger than stock. That's where my question is.

Also, what about the internal pipe coating? Who's using them. I have a new exhaust on the shelf.

[crazy steve]

Marty, I doubt if you would see any noticable power increase with the cones. The original design incorporated pipes that 'flared' out at the exhaust flange so that even with the cones installed, the cross-sectional area that the motor saw remained the same i.e. the cone diameter was the same as the tubing except the tubing got bigger at the flange. The major limit as to how much 'flare' was used was generally the location of the flange bolts. Then some bright boy figured out by reducing the cone diameter, you could get a partial benefit when installed in non-tapered straight tubing if running open exhaust.

Because of the flange design on the XS, you can't enlarge the tubing so you're just installing an additional restriction.

While I haven't used either of the exhaust products on my personal bikes, I've heard the CycleShack stuff is a tiny bit better and I believe cheaper....

[skids]

I used chrome guard. There is a warning about reverse aspiration (back fire?) or something like that. Bake the head pipes in the oven prior to use. I can't say that it was effective, because I don't really have any way to compare it. My head pipes on the Jardines did turn somewhat goldish and that is OK for me.