For those of you looking to do TB mods here is what I learned from the 2 I have done.

One is set up with an RCR pipe and the other with a Hot Seat pipe. We never ran the 2 machines against each other stock as mine already had the RCR pipe installed when a friend bought his TB and asked me to modify it.

I recommended the Hot Seat pipe to him even though I was happy with the performance of the RCR I was not thrilled with the way it installs. The Hot Seat is the only pipe ( when talking AAEN, HPD, RCR, and Hot Seat) that uses the stock system. The install was clean and easy and did not leak.

DG’s pipe appears to use the stock mounts too. I know nothing about this pipe; I’ve only seen it in a picture in Ronnie’s mail order catalog. I understand Dyno Port and PSI make a pipe for the TB. I have no Knowledge of these pipes either.

The RCR pipe uses the first portion of the stock pipe. It comes with an aluminum silencer that mounts to the top muffler bracket. Besides the springs up front this single mount is all that keeps your pipe on. The silencer fits over the end of the pipe and a hose clamp is suppose to keep it tight. My pipe kept moving as the hose clamp couldn’t clamp it tight enough to keep it from moving. I bought a conduit clamp (for 1” conduit I think) and bent it around a 1.5” pipe to get the initial shape. Then I clamped it on with a stainless bolt. It hasn’t moved since. It is somewhat of a pain to position the pipe so it doesn’t leak. It took about five times for me to get it right. The RCR pipe comes with a 140 main jet. If you take your carb off and turn it over and remove the plug the main jet will be staring you right in the face. One of my SAE nut drivers fit it like a glove so I removed the 130 stock jet and screwed in the new.

The Hot Seat pipe requires you to remove the stock exhaust flange and use the one they supply. The pipe slips right on using the two stock mounts. It is a single unit. We had a very small exhaust leak that disappeared after the first ride. You have to purchase the 140 main jet from Hot Seat for this pipe. They recommended a 150 on the phone but their literature says 140. We went with a 140 (I’m near sea level here in Southern Virginia) and it worked fine.

We are both running Hot Seat 49.2 heavy hitter weights (comes in their kit for piped bikes). My primary spring is OEM orange and his is OEM brown. He has Hot Seats entire clutch kit in his; I’m using an HPD violet secondary spring purchased through RCR. His is the white Hot Seat supply’s, and he has their helix.

The Hot Seat pipe hits later and harder than the RCR. It also signs off earlier. We did our test running K&N filters with the snorkel removed and the tube that extends into the airbox cut back to about 1 inch. HPD claims our springs engage at the same time with his shifting out a little latter, Hot Seat and EPI show my orange spring engaging later. The orange does indeed engage at a slightly higher rpm.

How do they compare? Out of the hole I can pull him by a quad length then everything stays pretty even until we reach topend and I walk away from him. I estimate my top speed to be 2-3 mph more than his. If we just run alongside each other easy and get on the gas after we are both in the power band we hang pretty even and then as we reach topend I walk away. When we are running alongside each other coming on the gas slowly together his quad will jump ahead of mine when it hits by the length of the tires then I can reel him back in. I can even let him get on the throttle first and still jump ahead of him after he starts moving from a dead stop. There isn’t that big of a difference where our springs engage, he just doesn’t make much power down low.

These results were the same when I was using the stock weights. I didn’t notice a big difference going to the Hot Seat weights. Maybe a little smoother.

For my money I would buy the RCR pipe with jet (if you want simpler installation, go with the Hot Seat) an orange spring and the violet secondary. I would purchase a UNI filter ($18 through Chaparral vice $30 for K&N, stops dirt better too) and cut the tube extending down into the airbox back to about 1 inch. These items make the biggest difference for the money. Make sure you put your clutch together correctly, I didn’t keep the X’s aligned on my primary initially. This caused my clutch to make a loud thrumming sound on topend and set up like this I could beat the Hot Seat quad out of the hole but he was walking away from me on topend, faster than I do him now.
Scott.

 

Hmmm,
So it appears I made a good choice...
c-ya,

------------------
Andrew Thomas

'99 Scrambler 400 & '99 Trailblazer, both with RCR mods.

 

That makes two of us:
'99 Sport 400 --
RCR Midrange Kit
Bigger Carb(havent decided what size)38 or 39
Getting Head work done
Wiseco Piston
ITP Holeshots/rims

 

I would like to hear from anyone that has HPD or RCR mods on their ride I can't decied on which one

Any help will be appreciated