used Spec ii ID. Are they for RD or RZ?

[smokah]

Last year I bought a set of used pipes that were supposed to be for my RD. Upon trying to fit them, the rear mounting tabs don't line up with my hanger points and the cans hit the rear axle bolt. I can manipulate the tabs to get them to work and to clear the crown nut, but if they're for the RZ the powerband will be too high. Any stampings or clues that I can use to tell the difference?

[m in sc]

the mounting points will be wayyyy off for an rz, so if it super obviously off like 3-4 inches, then yeah, probably rz. I dont know of any particular stampings that id them.

[pdxjim]

350, 400, Daytona and RZ are all different.

Spec2 made waay more aircooled pipes than RZ pipes, so like Mark said, unless the mounts are waay of they are prob for one of the aircooled variants and close enough.

Pics would help.

[Dvsrd]

The way I read it, Smokah is more concerned about powerband/rpm than the mounts themselves.
Considering the fairly large differences in exhaust port duration between R5/ RD350/RD400/Daytona, I believe that for example pipes for a stock Daytona won't necessarily work that great on a RD350, or vice versa. Or am I totally wrong?

[smokah]

The mounts aren't off by more than an inch. That's an easy fix. If they are that close then I guess they're prolly for my bike or close to mine. Next question. I have a set of DG's that are coming off to fit these. I was told to measure the cones and headpipes and compare the lengths to the DG for powerband comparison. For every inch longer = 1000 rpm higher powerband. Does that sound correct?

[m in sc]

thats about the difference between 250/350 pipes and 400 pipes. just fyi.  do you have the flanges? 400 wider, 250/350 narrower except for lc. (wider)

[smokah]

I do have the flanges and just put new o-rings on them. They look killer. I need a photobucket account so I can post pics again.

[SoCal250]

I need a photobucket account so I can post pics again.

Just resize the pics and attach to your message. No account needed.
Note the restrictions listed below the Attach button

[Jspooner]

There's an app called "Image Size" load that on your phone and use that to resize your pics. It's simple. I use 680 x 480

[smokah]

Here are the pipes for comparison

[Evans Ward]

There's an app called "Image Size" load that on your phone and use that to resize your pics. It's simple. I use 680 x 480

Love the Image Size app! I have it on my iPad and it is so easy to use.

[Dvsrd]

The mounts aren't off by more than an inch. That's an easy fix. If they are that close then I guess they're prolly for my bike or close to mine. Next question. I have a set of DG's that are coming off to fit these. I was told to measure the cones and headpipes and compare the lengths to the DG for powerband comparison. For every inch longer = 1000 rpm higher powerband. Does that sound correct?

Rather the opposite, shorter pipes have a higher resonant frequency, so work better at higher rpm. The angle of the baffle cone (the reverse cone just before the stinger/silencer) will strong influence on the useful powerband width. A gentle taper will make it wider, a sharper taper will make it narrower. Of course the porting is another main factor, and a longer exhaust duration will require a longer "tuned length" for the same target rpm. Some gocart pipes have been made with a slip fit center (belly) section, to be able to adjust powerband for different tracks. The easiest way to modify street bike pipes would be to make longer manifolds, if lower rpm target is desirable. Other than that, you can also experiment with stinger pipe diameter and length. If drastic changes are needed, other pipes or cutting&welding is required. For "tailor made" pipes, TSA (Two Stroke Addicts) in the UK seems like a good source.

[Jspooner]

Here are the pipes for comparison

Look at the angle and radius of the head pipe. I don't think those are for an RD. The rear hanger does not look the same as it does on Spec II RD pipes either.

[SUPERTUNE]

Even though DG's are crap for power, those Spec II pipes have a very long headpipe...don't look like RD or RZ to me.
Chuck

[teazer]

Agreed.  They look superficially like the set on the RZ that I bought in 91, but are actually very different in length and hanger placement.