Product Description

SUPERTRAPP IND USA EXHAUST 2-1 SAT XL 86-99 SUPERTRAPP IND USA 825-70883 825-70883

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Product Details

• Amazon Sales Rank: #507729 in Automotive
• Brand: Supertrapp
• Model: 825-70883
• Dimensions: 12.80 pounds

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Customer Reviews

Most helpful customer reviews

4 of 4 people found the following review helpful.
Excellent power without earsplitting noise level
By Ronald L. Russell
In August of 2008 I purchased a used 1991 883 Sportster on which the previous owner had installed some straight-through unbaffled "mufflers". It was so loud I was embarrassed to ride it through my neighborhood to my house. I felt that some kind of new mufflers or even a complete new exhaust system was in order, so began researching what was available.

According to the "Sportster Performance Handbook" by Buzz Buzzelli, the SuperTrapp 2 into 1 makes more horsepower than almost anything else you can put on a Sportster and still be legal. So I ordered the complete system, and in the meantime, removed the mufflers and exhaust pipes from the Sportster so it would be ready to install the new parts. A few days later a UPS truck showed up with a big box for me.

I unpacked the box and began installing the system, which took less than an hour. The entire system, including the clamps, is made of brushed stainless steel. The muffler itself bolts directly to the s tock muffler support bracket on the frame, and the header pipes bolt to the cylinder heads using the factory snap rings and flanges from the old pipes.

The system is tuned so that the length of the header pipe from each cylinder is the same, and saves some weight by using the same megaphone muffler for both cylinders. The user can adjust the amount of back pressure and sound level by adding or subtracting discs from the exhaust outlet. I found a dyno graph online which shows that a 1200 Sportster makes maximum horsepower with 23-25 discs, so I reasoned that an 883 should run well with about 2/3 as many discs.
My system came with 13 discs (I think it was supposed to only be 12, but there was an extra one included), and I added six more, for a total of 19.

Running, the machine still has the same V-twin beat, but the volume level is much reduced, even with 19 discs. Idling at traffic lights, individual power impulses can be heard, with a distinctive " vintage" sound which is hard to describe, but pleasant and not objectionable. Riding around town, these separate pulses flow together to make a deep ragged growl and on the highway, the sound is a muted "motorcycle-like" roar, not whisper quiet, but not loud enough to cause fatigue. When I rode to work, one of my fellow employees said "that's the quietest Harley Davidson I've ever heard" which I took as a compliment.

What back pressure there is doesn't seem to be significant. Although the torque of the bike is still there, it feels more free to rev if I want to, and get up into the power band without shattering windows or eardrums (mine or anyone elses).

The very first time I rode it, it began to discolor where the two header pipes join together just before entering the muffler
After running for more than a year now, heat from the exhaust has turned the entire system a light golden color, a characteristic often seen in stainless steel which has bee n heated to high temperature. I don't view this as a defect, it's just something it does.

I like this system very much because it actually has an appearance which is a product of it's function, rather than just an appearance intended to have a certain "look". Further, it is a little different from the traditional and excessively loud staggered dual pipes most people have on Sportsters.