S&s Collector Exhaust
S&S Collector Exhaust
EVALUATION
Improving exhaust systems began to get difficult when the factories learned how to make the systems work well in stock form. Since then it's become harder still, as the federal and some state bodies laid down their own rules for noise and emissions levels.
S&S Headers is an established manufacturer of exhaust systems for motorcveles. cars and boats. Their cycle line naturallv has been designed to meet the new rules for road bikes, that is. no undue noise and no requirement to rejet or otherwise modify the engine. (For the record, note here that federal law forbids changes by paid mechanics. The owners, unless state or local laws conflict, are still free to make changes as thev see fit.)
S&S offers mufflers and collectors for most of the popular street machines, so we ordered a 2-into-l svstem for Yamaha's XS650.
Installation required about one hour, and had several problems. First, the system appears semi-universal, meaning that the muffler is designed to fit several models via a choice of hangers for the muffler. Our system came with the w rong strap, quickly replaced bv the factory. Even so. the holes were not properly located and another hole had to be drilled.
One headpipe leaked at the cylinder head flange, but that was cured w ith a dab of high-temperature silicon seal. The rest of the job went right.
The S&S system doesn't block the drain plug and fits with center and side stands in place. Because the hanger bolts on to the frame bracket used by the righthand passenger peg. the peg was removed, although the peg could be retained with a bit of rework and welding.
When in place, the system extends about two inches outboard of the stock righthand pipe. This means a loss of cornering clearance. although the pipe didn't touch dow n during brisk street riding. During maximum cornering, a stock XS650 will scrape the sidestand on the left and the peg and muffler bracket bolts on the right. The S&S collector means no change on the left, and a loss of several degrees on the right, but because the bike won't drag anything unless it's already at the limit of the tires, this will be a significant loss only for the most determined of road racers.
At the dragstrip. the bike's best times were 14.29 sec., with a trap speed of 92.87 mph with the collector and 14.01 sec. at 93.45 mph with stock exhaust. This wasn't what we expected. The 650 ran well, with the normal big Tw in punch at the normal speeds, and it didn't have the flat spots or stumbles one would expect if the exhaustchange had throw n the jetting off'. Best we can sav is that because the system was designed to work with everything else unchanged and with noise controlled, it offers the same performance as stock.
Nice sound, though. The Twin has always offered a pleasant tone and the S&S* collector makes it a bit smoother and nicer. The noise control was an unqualified sue■ cess. Our informal replica of the official SAE test gave average readings of 80 db( A) stock. 81 with the S&S. During the noise test session a passing Honda 750 with aftermarket pipes recorded 82 and a trash, truck hitting a pothole bumped the needle to 85.
In short, the S&S meets all the noise tests and cannot possibly offend passersbv.
Suggested retail price for the system, part number Y-651. is SI 14.40. S&S deals through the usual retail channels, although they also offer a 15 percent discount, the approximate shipping charge, for customers who come to the plant, 3565 Cadillac Ave.. Costa Mesa. Calif. 92626 El
