I do not think you are getting more air flow with the snorkel since the direct mount puts out more HP past the 6,000 RPM mark with the TM carb.

It has to do with vacuum signal. Usually the freer the air flow the larger the main you need to make up for the loss of vacuum.. Yet with the direct mount you run a smaller main, which shows more restriction yet it puts out more top end HP.

When I was at Looney on the dyno one time the running it guy said that every time they add a pipe they need to richen up, but sometimes when they open up the airbox they have to lean it out a bit even though its putting out more power. Maybe THEBOM, Hr HP or OMR can fill int the blanks.

On my build the snorkel has a better curve below 6,000 and the direct above. I have spent a lot of time tuning at the dunes and on the dyno and have found for me the direct mount has proven better.

I do not ride in water or mud with my DS, I have a 4X4 Polaris for that. I only ride dry so I do not need an airbox. If I come to a creek I just have to slow down

Vic, I was riding today and I think this new spark arrestor from RW is about as loud as when I was running 12 discs in my end cap, but like I said it cost no power loss over an open end cap for me. If you want to try it let me know and I will send it your way after my trip to Sand Mt next week. It will bolt right on the base of the ODP endcap I sold you in place of the SuperTrapp stuff.

 

Thanks for the clarification. Way to throw a monkey wrench into my train of thought. lol

I guess the best thing to do it get a bunch of plugs and some jets that are bigger and smaller than the 155 and do some field testing. Is there a recommended way to properly run the bike to get a good reliable result? I have heard a few ways to do it but it sounds like you have way more tuning experience that the guys I've talked to.

Thanks Again!

 

Look under the sticky at the top of this board titles Hightower, OMR and other how to's. I posted the TM45 factory manual and I have found the roll off works very good to get the jetting very close and its pretty easy to do.

 

Cool. Thanks!