I know enough to be dangerous, but pipes are a pet peeve of mine. To me the whole purpose of changing the pipe is for performance. So that's where I'm am. Included in that is ground clearance, at least for the pseudo ricky racers among us. (no ref to member of same name)
I'm working from memory here. Back in the day, there were several "shootouts", tests performed by magazines, about the CB750 pipes. Drag strip times and Dyno Runs. That's what we're lacking now. Several manufacturers had their pet designs. Few of which stood up to scrutiny.
The original 4-1 were pretty good. They could easily be made better by withdrawing the long baffle on the early pipes, and rejetting. Good for a couple of HP, at the expense of more noise. The later pipes had the short baffle, so pulling it didn't make as much difference. Ground clearance was pretty good but limited on both sides.
The real drawback to the stock pipes was weight. Double walled headers and 4 mufflers. A 4-1 could knock 20+ lbs off IIRC. Unlimited clearance on the left, about the same on the right +/-. The rt side exit was chosen to appease dragsters, usually lower bikes that always turn left, and to keep the chain goo off the pipe.
The RC Eng pipe was likely the most popular thanks to Russ Collins and his high performance profile. His claim was that the 4 pipes entered the collector in the order of firing, 1,2,4,3 circular making a swirl. His pipe was always #1 or tied for #1 in the tests. The Jardine 4-1 was always the competition. Not nearly as pretty, had a weird sound, didn't have the swirl design, they just entered 1,2,3,4. Made the same HP, IIRC. Kerker was always in the hunt. They eventually bought out Jardine.
All the rest were after. The Triple AAA hung its hat on equal length headers, hence the wiggly. This was a car guy fad. I'm pretty sire it died out. At least it didn't help Triple AAA any.
A few of the 2-1 set ups would match the pairs: 1-4 and 2-3. This was expensive to do, over the 1-2 and 3-4 pairs. But overall 2-1 set ups were the poorest performers, (worse than stock IIRC) and poor ground clearance. So matching the pairs never proved out either. They did allow the use of saddlebags.
The Yosh pipes were seldom included in the tests as they weren't even pretending to be street legal, way too loud. Probably the best performer though. Still, "Where's Beel?" dynorun?
I see now that CycleX has the 4-2-1 where he matches the pairs, and he has equal length headers. But, no dyno runs. I would LOVE it if he would. He's got the situation, where he could just take one of his motors, and put his pipe on it, run it, then put someone else's pipe (the Yosh, though without a baffle its not apples to apples) on that same motor, run it and let the results speak. But that sort of disclosure opens one up for the "wars", my s--t is better than your s--t, and everyone should know no two dynos are alike. It would take more guts than its worth. His pipe tells a good story though.
My Marshall DT has squiggly pipes, but I've never seen them advertise that equal length was a selling point. In fact, visually the squigglies are not equal length. OCICBW Also, the pipes are not paired in any fashion. They just run into the collector in numerical order. If they go to the effort of making the squigglies (gotta be hard) why not equal length and firing order? Anyway, they have a massive catalog and many of their pipes have dynoruns. But not the CB750. All were equal to or better than stock. Usually EU legal, though they must be louder than stock. It might be the DeepTone which holds the db down.
My choice was Kerker or Marshall, I wanted a new shiny pipe. The Kerker interferes with luggage. So it was the Marshall for me as the Meg has a low exit. It may suffer on clearance though. I'm taking a chance that it doesn't DETRACT from performance.
Maybe this should be a new thread? If anyone has those old Pipe tests (Hinomaru) I'd love to see them.
