Cobra Pipes add Power???
Posted on the GWRRA BBS for Valkyrie by J.Orr. on March 27, 1998 at 12:29:42:
I've got the results from Factory Pro. First off if you have a 6 into 6 exhaust with unequal length pipes like the Cobra drag pipes you are starting at a loss. The pipes on the dyno compared to the stock pipes started off with approximately 3 less hp. So what that means is they sound great but don't quite go as good as they sound. Talking with Marc he says that there might be some different baffles to increase the performance. But you're stuck with the unequal length problem. Setting that aside here goes.
After approximately 20 runs on the dyno and all the changes. The improvements were best from idle to about 2700 rpm and 5600 rpm to the rev limiter. In those areas there is an an approximately 5 hp increase over stock. Also in the same areas there is an increase in torque to coincide. The area between 2700 and 5600 rpm is 1 hp. Remember this is over stock numbers. Compared to the Cobra 6 into 6 base line add approximately another 3 hp to every thing and actually more in some areas. The cobra exhaust is not a high performance system. The results should be better with one that truly is a high performance system. If it sounds that I'm unhappy with the Cobra pipes you're right. I paid a good chunck of change to sound good and lose hp. The term drag pipes must refer to dragging an anchor around.
The modifications are as follow;
-Cobra 6 into 6 drag pipes
-K&N filter (w/o prefilter)
-Air box modification ( remove the cover and turn it over, remove the plastic wielded baffle
near the intake and replace the cover)
-#38 pilot jet
-3.5 turns on the fuel screw or as needed
- Front needles set on the #3 position
-Mid & rear needles set on the #2 position
-#115 main jets in all carbs
Marc came up with a change for those of you with high performance exhaust systems;
-The main jet size is changed to #118 -#120 ( you just have to experiment, but at least you have a range to work from.)
-Everything else is as above.
-The air box mod was noticeable on the dyno results.
Good luck! I hope this helps. All said and done there is a noticeable difference with my bike. Now I have to hold on even harder and try to keep my front tire on the ground and my rear from spinning.:-)
Check out the sound bit www.factorypro.com go to dyno sounds h78a.wa . I hope it sounds as good as my bike. For some reason I can't play it ?
DISCLAIMER; I don't work for Factory Pro. But they are a good group and want the best product out there. And as soon as I can get a high perfprmance exhaust I'm going back to them.
Thanks Bob G for the tip.