92B+ to 93B pipe conversion

[matt glascock]

The Torque Engineering "Competition Only" on my 93B Super Rat has apparently lost its charm. Its not, shall we say, stealthy. I have ordered the parts from SH to complete a stock 92B+ pipe. Has anyone converted a 92B+ pipe for 93B application or are they simply not the same pipe. I'm aware that I'd need to mod the header from threaded nut to slip-fit and add some mounting tabs. Thanks all!

[Al Harpster]

I don't think you'll have any problem.

I haven't done it, but I did swap out my B+ pipe for a super rat pipe as offered by hodaka-parts.com.

The B+ pipe will thread right up to your rat cylinder. Keep that slip type manifold, they seem to be kinda rare.

I wouldn't call the B+ pipe quiet. Not sure if quiet is what you're after.

The U bolt mount to the frame and the pipe nut to the exhaust should do it. There is an additional bracket by the flame thrower outlet you may want. Not sure it's really necessary.

[matt glascock]

Hi Otilladillon. Thanks for your reply. I have the bike so dialed in with the Torque pipe that I really hate the thought of swapping it, but there is no spark trap and it is insanely loud. That's all ok for MX, but I'd like to campaign it on a couple hare scrambles this fall and as is, it won't pass tech without a spark trap. Is there any concern with mounting the pipe with the threaded nut? All my other race bikes have a slip-fit mount held in place with springs. It seems I recall this set-up being more durable and safe for high-performance applications due to engine vibration at high RPM. Thanks again!

[viclioce]

Matt. Can't you add a removable spark arrestor to the end of the pipe? Just wondering. Victor

[Al Harpster]

The exhaust nut mount is solid.

That and the U bolt should do it for you.

The brace at the end of the B+ pipe may not be needed and may not hook up to the rat. Seems I recall that end brace bolts to the luggage rack on the B+.

[viclioce]

My B+ does not have an end brace which bolts to the luggage rack. The pipe it too low to connect to it and there's no attachment point on the pipe. Victor

[matt glascock]

Hey Fellas, I might try removing the (totally useless) silencer and checking ID/OD to see if there's an available prefabbed silencer or one which could be made to fit with a simple mod. I'd need to weld on a couple spring anchors to the pipe which could easily be removed to restore the pipe to stock. Hmm...

[Al Harpster]

Not sure what you're after here, but the B+ exhaust has 3 primary parts.

The pipe, the spark arrestor part with the swirl chamber in it, and the little short baffle that's held into the spark arrestor with 1 screw.

You could leave the little short baffle out and still have the spark arrestor.

This might give you less back pressure & maybe a bit more performance.

The B+ pipe is shaped like a modest expansion chamber and was considered a performance enhancement over the Ace 100 all chrome plated exhaust.

If you've gone to the trouble of obtaining a B+ pipe complete with all parts I'd encourage you to try it.

[matt glascock]

Will do, Otilladillon. Do you think there will be any issues with the threaded attachment nut vs. the slip fit spring mount? I'm also wondering what jetting changes will be required.

[viclioce]

Matt. If you're going to remove the silencer, I have a spot for it!!! Victor

[matt glascock]

The "silencer" is an insert on the Torque Engineering pipe. It takes the pipe note from 160 decibels to 159 decibels.

[Al Harpster]

Only concern with the slip fit exhaust adapter is getting it to unscrew. The exhaust nuts on the iron cylinder always give me trouble.

Perhaps someone on the forum can offer a better tool than channel locks.

I believe there's an exhaust nut tool shown in the original Hodaka 90 workshop manual.

If so, I'd like to buy one.

Jetting?.... you're probably close. Might want to lower the clip on the jet needle a notch or two. That will pull it up higher making it run richer.

Or if you have extra main jets around put in a big one and work back.

[matt glascock]

Thanks Otilladillon. Yep, I use Channel Locks with the each jaw wrapped in about a quarter inch of vinyl electrical tape. Works like a charm. I'm going to try and mount the pipe tonight. Fingers crossed.

[matt glascock]

Well, here's a kick in the backside. Apparently, the pipe has been modified. From what I can tell, it looks like the pipe was cut at the end of the header where it joins the divergent section and the entire aft end of of the pipe from the divergent section onward was rotated 90 degrees to the left and rewelded. Its almost like it was modded to be some sort of down-pipe affair. Fixable, but hmmm...why? Has anyone seen this modification before?

[Al Harpster]

No idea on the modification.

If you're ever in Columbus Ohio I've got a VERY nice, complete B+ pipe hanging in my basement.

I'm sure we could reach an accord.

[matt glascock]

I do get back to Pittsburgh from time to time. Columbus is on the way. That would be great. Thanks Otilladillon!