EVO Exhaust Shootout
by George Crim, 5/24/00

Here's my evaluation of Evo Sportster exhaust systems. My opinions are based on personal experience and an article in the June 1999 issue of Hot Rod Bikes. HRB did an exhaust shoot out on Bartels H-D dyno. One thing that is very noticeable is that ALL 2-1 pipes have a noticeable dip in the torque curve between 2500-3000 RPMs. Most dual style systems have a more smooth torque curve from 2000 RPM s on up. 2-1 pipes seem to produce more torque in the 4000 RPM range.

Exhaust Shootout Dyno Spreadsheets
TORQUE POWER

The second Exhaust Shootout Dyno Spreadsheets
TORQUE POWER

My Top Secret
Baffle Modification

	STOCK: Obviously very restrictive and poor performing. Some people have drilled the baffle to enhance power and sound. Anything would be an improvement.
	CYCLE SHACK SLIP ONS (ORIGINAL SE's): Best bang for the buck exhaust system on the market @ $100+/-. The torque curve on this system is very smooth and predictable. They pull nicely from 2000 RPMs all the way to 6000+. The slash cut style has a removable baffle that can be modified for more top end power and sound. Jim Snyder's 1200S went 140 MPH with a set of my modified Cycle Shacks. That was about 4 MPH faster that stock SE's. There's a picture of my baffle modification at the above link.
	BARTEL'S SINGLE STAGE 2-1: This is my favorite looking and sounding 2-1. It has a 60 degree slash opening and a small fiberglass wrapped baffle that provide a nice raspy growl. Mine did rub the top of the timing/cam cover, but I've looked at others t hat fit fine. The power on this pipe is the least impressive of all that I've tested. The torque dip at 2500-3000 was very evident.
	VANCE & HINES SS2-R: This pipe just looks fast. The big canister hanging off the back of the bike gives you an instant “business” look that is usually reserved for squid thrusters. The sound was sort of mellow and the torque dip from 2500-3000 was not as dramatic as the Bartel's pipe. Top end charge was not too good and this is not a passenger friendly or saddlebag friendly system.
	SUPPERTRAPP 2-1: The nicest thing about the S/T pipe is the adjustability. By adding or subtracting disks, you can tune the exhaust for your set up or riding style. There will always be a torque dip in the upper 2000's but at least you have a means to try and minimize it. The baffle in this pipe has got to be very restrictive. I ran 125+ with it in and 133.9 with the baffle removed. (These speeds were recorded by the East Coast Timing Association.) Of course with 20 disks and an open end cap, performance below 3000 RPMs is poor. I haven't tried it set up for bottom end as I feel it is useless to try for power below 3000 RPMs with a 2-1 pipe. One note: My system is not a real SuperTrapp pipe. It was bought used and has a larger than usual collector and different header pipe routing than any other 2-1 pipe I've seen. But it does use SuperTrapp a baffle and disks.
	SUPERTRAPP 2-2 RACE PIPES: I've never been so impressed with any other exhaust system. These pipes produce HUGE amounts of low end grunt from 2000 RPM all the way to 5500+. I doubt if they are much good over 6000 RPMs but then who rides up there for long anyway. I did have to add several disks to get the upper RPMs to pull, but when I got it right WOW! Of course you can't use saddlebags with these pipes and passenger comfort is lacking. Even the rider's leg comes very close to the head pipes. But for those of you with a need for incredible throttle response and low & midrange power, you can't beat these pipes. The smooth power application makes riding in tight corners much easier as you A) don't have to shift as often and B) the power comes on smoothly and predictably. Not the all of a sudden surge of a 2-1 system.

So when choosing an exhaust system, try and determine where you want the power to come on. Low RPM cruisers are better served by duals. Higher winding riders may want to choose a 2-1 system. And of course, drag pipes are horrible performers everywhere exept at the very upper RPM range.