STM Tunnel Protector Install

[finnpowersports]

Ordered a set of these full length protectors for my '23 SRX. For those who have installed them, can you do it without removing the rear suspension? Can you just remove the rear bolts, and drop the back of the suspension with sled on lift and get them in? I did a search and didn't really see a definite answer.

Thanks!

 

[21GT]

I did mine by Lowering just the back of the suspension but it's a pain in the #*$&@. And your working right on top of the track. Mine kept sliding forward on the rails into the front heat exchanger probably from the track hitting it. Stm said to leave them butted up against the front heat exchanger so that's what I did.

 

[NYTurbo]

Yes , you can . The left side is a cake walk, the right side is a bit of a PITA because the fasteners are facing the side of the tunnel. Patience is key. Lol

 

[Turboflash]

I'm not saying anyone is wrong. My opinion of tunnel protectors is:

A. Why are they needed? My riding group has a mixture of '17 thru '20 TCats - all with big tunes, lots of long studs, etc. Some use 1.575 Woodys Megabites on 1.25" Ripsaw2 tracks, some use 1.625" StudBoy Lake Racers on 1.25" Ripsaw2 tracks. Exactly none have had any issue with studs hitting anywhere IF the track is tensioned correctly. None have tunnel protectors. (From TD's website - - Make sure you have a tight track (must not hang at all when lifted off ground, must be hard to push off the front bogey wheel). ( It is highly preferable to have a 4 wheel kit upgrade to maintain reliable track tension especially when running high power and or fast speed. Running a loose track will rob lots of top speed (as track balloons from centrifugal forces). Also loose track can cause ratcheting of track drivers which will damage them and or the track. Radar running require a VERY tight track as high speed cause expansion.). (https://turbodynamics.mybigcommerce.com/td-performance-guide-for-998-turbo-snowmobiles/).
B. All those covers over the heat exchangers inhibit cooling since snow does not contact the exchangers, only the covers. This might cause coolant temps to be higher. Covers prevent snow from contacting the heat exchangers.
C. IF you run the track at the right tension, even studs that are .50" higher than grouser bars on track will not hit anything. This is proven by our group of tuned TCats over 25,000 total miles. Absolutely no sign of studs hitting anything IF track is kept tensioner as per what TD states in their performance manual.

 

[NYTurbo]

I have full length STMs and never had cooling issues when other sleds in the group didn’t. Your right but I like the extra protection especially at very high speeds . Also they protect the coolant hoses and eliminates the need for those aluminum ones that are prone to break off.

Nice thing about the STM is their easily removable and put on another sled.

 

[dmarriner60]

I was looking hard at the STMs but I have always wondered with tunnel protectors it they didn't add to the building of ice build up being an insulator. Then this year I see the OEM putting out aluminum short protectors makes me think they are trying to keep the transfer up with the cooler. I am going to give them a try and see if there is difference in icing at least

 

[finnpowersports]

All good points! Thanks for everyone's input.

I have both the Full STMs and the factory aluminum ones for the rear, so I have a choice right now on which ones I use.

I'm going to be running 1.575" Triggers down the middle, track will be tight (like TD says) and sled will be stock with no tune. The longer length studs made me think I needed the STMs, but now I'm leaning towards the factory aluminum ones in the rear, as I do not want cooling and ice build up issues. hmmmm.

 

[1nc 2000]

I am running the aluminum ones on the rear cooler but not the center one. Leave that one off.
Studs could hit it if track is too loose.
Also have the stm plastic protectors installed and trimmed on the fwd end with BOP hose protectors on the fwd end.
1.5" lug with 1.86 studs.
Not much room up front with a 1.5 lug track and stm protectors. Maybe 1/8".
I ran my track using Precision EFI recommended method of 1/2" sage of track and studs hit my tunnel before tunnel protectors.
After that track has been run with no sag and no issues.

 

[finnpowersports]

I'm probably leaning towards just putting the factory aluminum 2 in at the rear, keeping the track tight and keeping an eye on things. If I feel I need to add the STM front ones, I will add them later.