Gents,
See here:
www.volusiariders.com/viewtopic.php?p=301378#301378
The thunder intake install was pretty straight froward. Take off the old, "alien head" air intake. Unscrew the sensor (one screw) from the back of the old intake. Remove chrome cover from left side of bike (as you sit on it). Remove the 5/8" rubber tubing that goes from the vac pump (the left side that you just removed cover from) thru the V-Twins to the right side. This is the 5/8" tube that used to be attached to the stock air intake. Use the rubber plug off the bottom of the stock air intake to "cap" the phlange on the vac pump (the left side of bike that you just took the rectangular chrome cover off of).
Remove the two curved braces that are mounted to the V-Twin cylinders; you won't be needing them or the 5/8" tube any more!
Install the probe you took off the stock air intakeo onto the new adaptor. It's obvious where it goes. Make sure you get the upper air intake housing securely and evenly placed on top of the adaptor and use the stock clamp to tighten it on. Mount the adaptor to the V-Twin cylinders using new screws from Thunder.
Mount the air filter plate to the adaptor. Mount the emblem to the outside of the air filter plate, and you're done! Viola!
When you fire it up, you will hear a faint sucking sound. Yep, that's your new air intake sucking BIG air, not a vac leak! Now your engine's breathing like it should! :wink:
Hope this clarifies the install enough; should make it a breeze and only take you 1/2hr - 1 hour max. Maybe less, depending on how good of tools you have available to you. Pretty simple install, so don't panic over it! You'll see what I mean...
Best,
Daryl