Need help installing Thundermonsters on Big Radius pipes

1406 Views 10 Replies 5 Participants Last post by Thunder90, Jan 24, 2006

Woody72

Discussion Starter · Jan 21, 2006

The instructions say to put them 4" to 6" into the pipe. Should I take the tips off before I measure that or leave the pipe on. Also is that 4" to 6" where I drill the hole or where the washer deal should be inside the pipe?

Save

1 - 11 of 11 Posts

Halehardy

· #2 · Jan 21, 2006

Take the heat shields off and measure 4"-6" from the end of the
pipe that holds the baffle, just don't drill where the clamps will
be on the pipe. Slide the monsters in.

Save

Jack-Jack

· #3 · Jan 21, 2006

Before you start!

If you have miles on the pipes SOAK the installed baffles in PB Blaster or something similar.

Makes them drop right out!

Save

Thunder90

· #4 · Jan 22, 2006

Woody-

I have the Big Radius pipes on my 05 Thunder Mountain Custom. I've installed the Thunder Monsters (in these pipes, and in my previous 99 Fatboy that had V&H Short Shots on it).

First, if you want, call Jim Maybeck at Big City Thunder (704) 366-8672. He will walk you through the installation process over the phone.

Essentially, you can go through all the trouble of drilling new holes if you want, but the existing hole that the screw goes in to mount the stock baffles that come with the Big Radius pipes is fine. It's far enough up the pipe to do the job.

Send me a PM if you want more guidance....but this is a piece of cake. 30 minutes max.

Save

George C

· #5 · Jan 22, 2006

Thunder90 said:
Woody-

I have the Big Radius pipes on my 05 Thunder Mountain Custom. I've installed the Thunder Monsters (in these pipes, and in my previous 99 Fatboy that had V&H Short Shots on it).

First, if you want, call Jim Maybeck at Big City Thunder (704) 366-8672. He will walk you through the installation process over the phone.

Essentially, you can go through all the trouble of drilling new holes if you want, but the existing hole that the screw goes in to mount the stock baffles that come with the Big Radius pipes is fine. It's far enough up the pipe to do the job.

Send me a PM if you want more guidance....but this is a piece of cake. 30 minutes max.

Says who????????

According to BCT, you gain absolutely NOTHING by installing their baffle in the stock V-H mounting hole.
They recommend a 4" minimun, and like to se at least a 5" mount from the end of thye BR pipe.

Save

Thunder90

· #6 · Jan 22, 2006

George-

I discussed it with Jim Maybeck (owns BCT) on the phone on BOTH sets of pipes that I've owned (V&H Big Radius and V&H Short Shots).

In both cases, the existing hole that holds the stock baffle into the inner pipe is at least 4 inches from the end of the pipe.....on my pipes that was the case.

Obviously measurement should be done, but if the existing hole is good enough, why put another hole in your $500 pipes......that's all.

Save

George C

· #7 · Jan 22, 2006

Thunder.
I believe you, but then the same man said two different things to two different customers.
He was adiment with me concerning the importance of not using the standard V-H hole, and to drill my own, and no less than 5" from the end.
In fact, he told me that if I did use the stock hole, that there would be a distinct performance and sound disadvantage.

Save

Woody72

Discussion Starter · #8 · Jan 23, 2006

Well, I took the tips off and drilled my holes 4" back. Holy crap do they sound good! Exactly the deap throaty sound I was looking for! Thanks for the help!

Save

Thunder90

· #9 · Jan 23, 2006

George-

That's interesting......I assume you ended up drilling your own holes farther up the pipe....did you ever experiment for yourself to see if there was a difference in seat of the pants?

If not, maybe I will. I have the pipes off the bike as we speak doing a performance upgrade....

Maybe inconclusive though, because I wouldn't know how much of the difference was from the upgrades I'm doing and how much is from moving the Thunder Monsters deeper in the pipes.

Save

George C

· #10 · Jan 23, 2006

Thunder90 said:
George-

That's interesting......I assume you ended up drilling your own holes farther up the pipe....did you ever experiment for yourself to see if there was a difference in seat of the pants?

If not, maybe I will. I have the pipes off the bike as we speak doing a performance upgrade....

Maybe inconclusive though, because I wouldn't know how much of the difference was from the upgrades I'm doing and how much is from moving the Thunder Monsters deeper in the pipes.

I haven't received my bike from the dealer yet.
When I was first enquiring about using the BCT's in the Big Radius pipes, Jim first discribed the sound difference, and then went on to elaborate on how the BCT's will help limit the reversion that the BR pipes seem to be suspect to. He told me that installing them in the stock holes will do absolutely nothing for performance, and will kill some of the deep sound.
Now, maybe this advice was for the Big Radius pipes only, and the rest of the applications are fine using the stock holes. Maybe this is just something they are just recently recommending..
If you can, or are willing, drill a new set of holes 5-5 1/2" up from the rear of the inner pipe and tell us if you feel a difference or notice a deepening of the sound. I got to believe you will..

See less See more

Save

Thunder90

· #11 · Jan 24, 2006

George-

I've had the Thundermonsters in my Big Radius pipes for over a year now, and I've not had the same experience that Jim described to you. I didn't lose any performance......and I certainly didn't lose any of the deep sound. In fact, installing them in the stock holes definitely improved the sound from the stock baffles. Reversion is non-existent.

It may be new recommendations that they're giving now, I don't know.

Since the pipes are off the bike for my performance upgrade, I'll go ahead and move them deeper up the pipe and see what happens. Can't hurt.....

Like I said, it will be near impossible to determine how much, if any, performance improvement will be attributed to doing this......as I'm increasing compression, doing extensive headwork, and changing cams at the same time.

If I moved the TMs up the pipe without doing anything else to the motor, I'd know for sure.

Either way, I'll let you know when the build is done.

See less See more

Save

1 - 11 of 11 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month