So often racers just guess what's best based on friends recommendations, write ups in magazines or heaven forbid ad copy!
dunecj2a over on TT wrote up the following test of pipes on his YZ250. It's an excellent write up. But more than that he did it on his own without sponsorship or advertising to "color" his testing.
OK I did the Pipe "Shootout" this Saturday. This is how they stacked up for me.
Bike = 06 YZ250. V-Force3 reeds. Stock Gearing.
Jetting = Stock pilot. Stock needle and clip pos. 180 main, (1 up from stock). Stock air screw set 1.5 out.
**Note: 180 main on all tests. 178 looked a little lean but performed same as 180**
Fuel = straight VP C12. 30:1 mix (Yamalube...always!)
Temp = 80 ish, sunny, dry
Riding area = Open Desert. Deep sand, Hardpack area''s, MX type track with DEEEEP sand whoops, lots of berms with jumps right out of them. Hardpack and Sand berms.
Rider = 165 lbs. Stupid old man who thinks he's 16.
1. Stock pipe with PC R304 shorty and FMF Shorty. I included these 2 together because both silencers performed almost identically. Fit and finish on both cans are a 10. FMF shorty is just a little louder. The silencers make the motor snap and really clean up throttle response. Right away you can notice the difference on the bottom and thru the mid. Bottom end gains are really noticable, especially pullin out of turns with deep sand. The mid pulls harder and crisper with no overrev loss. Without a Dyno there is no noticable loss on top end overrev either. What I liked most with this combo was how the different silencers gave the bike a "lighter" feel. It produced more snap and made the motor crisper so hitting big jumps was easier. Thats what made the bike have a "lighter" feel. Power comes on sooner and hits hard, it really wakes up the charecteristics of a 2 stroke. Great combo if you are a 2 stroke die hard and love the crisp snap and hard hit of the power band.
2. FMF SST with FMF Shorty silencer. Fit and finish is awsome, top notch. Bolts on with eez, installation is a peice of cake. Stock pilot and needle are perfect. Stock main is also good, but I went up one because my plug looked a little lean with a 178. The first thing I noticed with this combo was how much more torque it gave my bike. Throttle response was perfect and immediate. It was noticable right from the bottom to the top. It made my 250 feel like a 4 stroke. I was able to shift way sooner in the deep sand and turns. Wheel spin was reduced comming out of hardpack turns since the motor didn't want to rev out high and quickly. Some of the 2 stroke snap was gone with this combo and moved to produce more torque. I noticed that I lost overrev in the middle and top, but traded it for more trackable torque. This pipe combo produced the most 4 stroke like power, it smoothed out the powerband hit and took away the snap when you crack the throttle. In exchange you get more trackable torque with less wheel spin all across the range. I could definately have run a 49 tooth rear and maybe a 48 with the power it produced in the mid and top. I could pull 3rd gear starts and grab 4th quickly.
2. Pro Circuit Works with R304 Shorty. Just like FMF for fit and finish, top notch. Throttle response was crisp and immedeate also. On the bottom I noticed it pulled a little longer and harder than the other combo's. In the middle it gained some overrev and pulled long with plenty of power. It was very similar to the Stock/304 & Shorty combo. The Works pipe had a little more torque up top but signed off quicker than the Stock combo. It sacrificed top end overrev for torque. This combo was really good in tight sections and deep sand, it also revved higher and longer than the SST combo. The PC combo didn't smooth out the hit and powerband like the SST did. It produced 2 stroke like power and was very similar to the Stock combo. I did notice a loss in Top end overrev especially in wide open sections compared to stock combo. This was a great set up in tight situations when you need a little extra on the bottom and mid and aren't needing to use top end power alot.
Well my favorite combo was the Stocker and either the PC or FMF shorty. I love the Top end overrev and how hard the motor hits with this set up. All I noticed were gains across the power band with switching out the silencers. Anyways just what I came up with, but just between these three different set ups there are a considerable amount of differences....Go Ride
What do you think about tests like this?
