S
I'm sick of digging through old threads regarding clutching info and not finding what I'm looking for. I present the following trial and error info regarding high elevation clutching on a Proclimb M8 with turbo.
162 x 3" track. 20/49 gearing.
I have the Rapid Response primary and Team Tied secondary, which were set up by RacinStation for an N/A sled.
Primary using MDS weights at 78 grams with white spring. I believe it is a Team 120-310.
The Tied has helix: 71-55-.36---71-57-.36 ER TIED HELIX (AC960049), and I'm not sure what spring is in it.
I rode the sled for a week with this clutching, and it held a consistent 8280 RPMs. Snappy engagement and nice warm, but not remotely hot clutches. I was more than happy with the setup.
Then... I got an inclination to put a Boondocker PG turbo on the sled. Base kit, and I had it set to run 7 psi boost on a 30% Racegas/91 mix.
I put the Lime Green spring from Boondocker in the primary, and their best guess was to run 80 grams in the primary, so I added 2 grams to the heel of my MDS weights. I'm not 100% certain which spring comes in the BD kit, but I have reason to believe it's a Team 150-340 primary spring.
I did not make any changes to the secondary, because there isn't **** for useful info on the Tied secondary with a turbo at 10k+ elevation. Boondocker said they had no testing with that setup.
Test ride was conducted in perfect turbo sled conditions. Over the hood fresh/falling powder at Rabbit Ears. I did not expect everything to be perfect, and I found the following:
Engagement is harsh as sh*t, IMO. I could rarely see my gauges because of snow coming over the hood right away, but it seems to engage between 4500-5000 RPMs, and when it does, it causes an immediate track spin that I only dig out of because turbo.
Max RPM is 8500 RPMs... about 300 more than I would prefer.
I cleaned the clutches up before the test ride, and it looks like the bottom half of the clutch sheaves have belt slip marks. Not black or excessive, but not clean like they used to run.
Clutches do not get hot.
This was a relatively new, but broken in belt. There seems to be wear on face of the belt cogs, maybe pulling too much into the secondary?
Backshift seemed to be pretty good, but I felt like it was revving slowly on the bottom end, and the bottom end has no "snap" to it. It actually kinda sucks. Edit* By "snap" I mean the throttle response. It has lots of "snap" on engagement. It's stupid.
Sled pulled hard on the top end, but I didn't want to get too crazy since it was over-revving. It's completely ride-able, but not nearly optimal.
Max boost shown on the BD box was 5.8 psi and I don't really understand why, since I had it set for 7. New to turbos.
I did the BD install myself. I was greatly impressed with the quality and fitment. The only "bug" I had with the turbo was the TPS sensor bogging me out. This was due to the throttle cable being overly tight. Loosened the throttle cable and the issue was 100% resolved. I ran the base BD #'s and found them to be suitable. No throttle dead spots or bogginess once I cured the throttle cable issue.
I cracked my TCL after about 20 miles of riding. The dudes at VOHK didn't have one in stock, but one of the techs had a spare at his house. Reps to those guys for helping a guy out.
Long post, but maybe will help guys out who are just setting up a turbo sled for elevation and I can tell you that this particular setup works, but it's a little bit sh*tty. Would not recommend it.
I'm going to call RacinStation tomorrow and see what they have to say, and hopefully some guys can chime in with a setup that works better.
What RPMs are guys shooting for with a turbo setup? It seems like with a turbo and the elevation, it would be better to rev a little higher than HP peak, which people claim to be 8000-8100 RPMs.
Thanks in advance.
162 x 3" track. 20/49 gearing.
I have the Rapid Response primary and Team Tied secondary, which were set up by RacinStation for an N/A sled.
Primary using MDS weights at 78 grams with white spring. I believe it is a Team 120-310.
The Tied has helix: 71-55-.36---71-57-.36 ER TIED HELIX (AC960049), and I'm not sure what spring is in it.
I rode the sled for a week with this clutching, and it held a consistent 8280 RPMs. Snappy engagement and nice warm, but not remotely hot clutches. I was more than happy with the setup.
Then... I got an inclination to put a Boondocker PG turbo on the sled. Base kit, and I had it set to run 7 psi boost on a 30% Racegas/91 mix.
I put the Lime Green spring from Boondocker in the primary, and their best guess was to run 80 grams in the primary, so I added 2 grams to the heel of my MDS weights. I'm not 100% certain which spring comes in the BD kit, but I have reason to believe it's a Team 150-340 primary spring.
I did not make any changes to the secondary, because there isn't **** for useful info on the Tied secondary with a turbo at 10k+ elevation. Boondocker said they had no testing with that setup.
Test ride was conducted in perfect turbo sled conditions. Over the hood fresh/falling powder at Rabbit Ears. I did not expect everything to be perfect, and I found the following:
Engagement is harsh as sh*t, IMO. I could rarely see my gauges because of snow coming over the hood right away, but it seems to engage between 4500-5000 RPMs, and when it does, it causes an immediate track spin that I only dig out of because turbo.
Max RPM is 8500 RPMs... about 300 more than I would prefer.
I cleaned the clutches up before the test ride, and it looks like the bottom half of the clutch sheaves have belt slip marks. Not black or excessive, but not clean like they used to run.
Clutches do not get hot.
This was a relatively new, but broken in belt. There seems to be wear on face of the belt cogs, maybe pulling too much into the secondary?
Backshift seemed to be pretty good, but I felt like it was revving slowly on the bottom end, and the bottom end has no "snap" to it. It actually kinda sucks. Edit* By "snap" I mean the throttle response. It has lots of "snap" on engagement. It's stupid.
Sled pulled hard on the top end, but I didn't want to get too crazy since it was over-revving. It's completely ride-able, but not nearly optimal.
Max boost shown on the BD box was 5.8 psi and I don't really understand why, since I had it set for 7. New to turbos.
I did the BD install myself. I was greatly impressed with the quality and fitment. The only "bug" I had with the turbo was the TPS sensor bogging me out. This was due to the throttle cable being overly tight. Loosened the throttle cable and the issue was 100% resolved. I ran the base BD #'s and found them to be suitable. No throttle dead spots or bogginess once I cured the throttle cable issue.
I cracked my TCL after about 20 miles of riding. The dudes at VOHK didn't have one in stock, but one of the techs had a spare at his house. Reps to those guys for helping a guy out.
Long post, but maybe will help guys out who are just setting up a turbo sled for elevation and I can tell you that this particular setup works, but it's a little bit sh*tty. Would not recommend it.
I'm going to call RacinStation tomorrow and see what they have to say, and hopefully some guys can chime in with a setup that works better.
What RPMs are guys shooting for with a turbo setup? It seems like with a turbo and the elevation, it would be better to rev a little higher than HP peak, which people claim to be 8000-8100 RPMs.
Thanks in advance.
Last edited: