RPM-VS- EXHAUST BAFFLES

[Big dog papa]

When I bought my bike it had Vance & Hines shot gun exhaust with no baffles. First thing I noticed riding it home was how loud it was and the louder back off sound it had. Hitting red line rpm was no problem but it was too loud for me. I installed 4 inch long baffles and that took care of the loudness but when I got to 4 grand the rev limiter kicked in. NOT GOOD! I started cutting the baffles down. When I got to 2" long I could get 5.5 grand with no loud back off sound. So that's where I left it. 5.5 grand is plenty for me and the sound is just right for me. Lessons learned for me is this motor doesn't like baffles with these pipes. Ride safe.

 

[1 B.M.F.]

In my opinion your bike was probably jetted for exhaust without baffles. So when you added the baffles you should have had your carburetor re-jetted. I think the popping your hearing when you let off the throttle is the unburned fuel.

 

[Big dog papa]

In my opinion your bike was probably jetted for exhaust without baffles. So when you added the baffles you should have had your carburetor re-jetted. I think the popping your hearing when you let off the throttle is the unburned fuel.

Thx for your post.....so do I go bigger or smaller with the Jets?

 

[Mikeinjersey]

Thx for your post.....so do I go bigger or smaller with the Jets?

No formula that I know of. Trial and Error or probably the best but obviously not the cheapest is to get it Dyno Tuned. That way you will be able to see where your power is. Remember you probably spend most of your riding time between 2k and 4.5k so consider that when selecting your jets. FYI ,Big City Thunder has some worthy baffles to choose from.

 

[Big dog papa]

No formula that I know of. Trial and Error or probably the best but obviously not the cheapest is to get it Dyno Tuned. That way you will be able to see where your power is. Remember you probably spend most of your riding time between 2k and 4.5k so consider that when selecting your jets. FYI ,Big City Thunder has some worthy baffles to choose from.

Thx for the info

 

[Olde Man]

It has been a while for me but if my memory serves me right if it lays down and pops on full throttle at the RPM you describe I think your high speed jet is small and it is going lean. Make sure the air bleeds are not plugged. I really don't like running them hard and lean at the same time. It is all in the attached S&S info.

 

[Big dog papa]

It has been a while for me but if my memory serves me right if it lays down and pops on full throttle at the RPM you describe I think your high speed jet is small and it is going lean. Make sure the air bleeds are not plugged. I really don't like running them hard and lean at the same time. It is all in the attached S&S info.

Thanks for that info Olde Man.