Track speed gearing and clutching debate.

WyoBoy1000 · Jan 19, 2011

It seems like track speed really doesn't mean much, but I'm still curious to know what others are seeing. What I would like to know is,

1 elevation 9-10000ft
2 lbs of boost 6lbs
3 what sled 09 HCR
4 who's kit Twisted

Speed around 42mph

I know there are more factors too.

At 9-10000ft from a died stop going WOT in deep snow before I really gained speed but the sled built power I was getting about 42mph TS and holding around there. Twisted rg 09 HCR on 6lbs of boost and holding 12.5ish on the A/F and 81-8200rpm, to me it seems really low but was still pulling like a turbo. I know there have been times I have seen 47mph on my m1000 at the same elevation but he hcr will fly past the m1000. So just wondering what you guys are seeing. Remember this doesn't really mean much so don't over analyze it, just board and curious.

powder pounder · Jan 19, 2011

I found the sme thing Track speed does not make sence sometimes. In 07 hade a m8 and m1000 both getting same track speed. m8 lighter should be going faster and higher. No m1000 was dominating both sleds riden by me. does not make sence??? I had a pump gas m8 that ran hard and only got 45mph track speed at times at 6000 ft. It destroyed stock sleds that said they were getting 50mph track speed.

Coxy · Jan 19, 2011

Same thing here, 43 or so on my cpc pump gas at just under 6psi, 153 claw at 6-7000 feet with pretty heavy snow.

WyoBoy1000 · Jan 19, 2011

Its almost comical, So I must be doing pretty decent at 9000+ft to be getting 42-43mph. I noticed last year my buddies BD pg M1000 was only pulling around 45-51mph on 5lbs and my piped m1000 was pulling 47mph and I was turning out about 70% of the way up and his pulled a wheelie over the top. Me riding both. :noidea:

ray: anyone else notice this, this smilie is supposed to be pray, but it looks like its got balls hangin off its chin.:focus:

Catman 42 · Jan 19, 2011

60+ mph track speed

The way I measure track speed is on a steep climb with deep enough snow that I may not make it to the top. When the ground speed is down to about 10 mph I check the speed. I usually see at least 60.
06 M7 bored to 8 Garrett 2871
13lbs on avgas
162 powerclaw
6500'

WyoBoy1000 · Jan 19, 2011

Thats about How I checked it also. your basically running the same thing I am (m8 with a 2871) other than a 162, at that elevation and boost it seems to be on the same scale. My piped 07 m1000 at 6k would turn 55-60mph, stock challenger track.

If some of you that read this don't know what your turning would you look next time and post it.

mynewuseddoo · Jan 20, 2011

Excelent thread! I have been wondering the same from other turbo riders also.

7000 feet
9 psi boost
CPC stage 2
50/50 av/premium
2009 M8 162
powerclaw
gearing 57/63 (stock).....for now

8000 RPM
12.3-12.5 AFR
CPC secondary w/green spring set at 5
Primary, CPC gold spring and 80-90 gram turbo mags at 86 grams.

In a fresh, steep and deep climb 46-50 mph. Climbing the same grade in a harder packed snow I can see as high as 55-57 mph.

Thank you for the honesty from everybody. Before I bought the turbo I would always hear stuff like "a solid 60 mph in a deep climb", from guys running pump gas kits at lower boost than I am running. With seeing my track speeds in the deep snow climbs only hitting 46-50 mph and running higher boost than them had me thinking something might be wrong or my clutching was off.

I am lowering my gearing to 54/66 to hopefully gain a little more from the really deep heavy snow climbs and pick up the track speed into the mid 50's. I'd like to see 55 mph in a deep climb at 9 psi boost.

Or I could just turn the boost up I suppose

I will report back after I get to ride the new gear set and see the difference.(Mid February)

WyoBoy1000 · Jan 20, 2011

I would not gear down. just me but I think its going backward. If you run the usual setup, gearing down will put you into a higher helix angle and you will have to compress the spring father to get the same speeds, I thought it was always a good idea but after hearing some stories and looking at it from all angles I don't think gearing down is a good thing. Some think that because the new sleds have lower gears its better but its because they rap higher rpm and will have the same top end, not really to give them more power. I also think most people think it helps because it makes the clutches work better, when all it is is a band-aid for bad clutching.

mynewuseddoo · Jan 20, 2011

The stock gears will top out around 90-100 mph if a guy could go that fast. The lower gear set will top out around 75-80 mph. Just looking for a better mechanical advantage to spin the 162 in the snow a little more efficiently and hopefuly get a few more MPH out of her in the process. At the very least it is easier on the belt and I can take a marker, draw a line on the sheaves and play with the tortional secondary to dial it back in on the mountain. In the spring time when the snow is set up, I will most likely go back to my stock gearing.

WyoBoy1000 · Jan 20, 2011

Lower gears in a cvt system is a fallacy, The whole purpose of the clutching is to go from 0 gear ratio to 1:1, and these I think go to a 8:1 after that in the last 1/4" of the sheave. The only positive effect you "might" have is getting the belt closer to a 1:1 ratio. It has far more to do with geometry and the physics of the clutching then it does the gearing. The key is to apply as much upshift as possible as fast as possible, then once it gets to the final shift for the power, you want the clutching in a stage to keep it there, ie the weights, springs and helix pulling it as hard as possible in that gear.
If you ever got to a 1:1 once you go past its a loss in a hurry, and anywhere up to a 1:1 the only factor is to keep the belt from slipping and if you can do that there is no point for lower gears. But lower gears will most likely help maintain speeds because there is less shift to be made while higher gear will see the higher track speeds but could bounce around more. Or maybe I have no idea. Back to topic

mynewuseddoo · Jan 20, 2011

I've been talking with someone on here. He was explaining to me about the 1:1 ratio you are mentioning and he figures with this gear set that this has him in the 1:1 ratio and maximum efficiency. His sled seems to work better than the same set up with stock gearing so I'll give it a whirl and see what the result is. Thanks for the input though, I'm not a clutching guru by any means and am always open to suggestion.

Basically the way I see it, if the secondary is dominant over the primary then lower gearing will help with keeping the secondary in a higher gear, more stable speed, and cooler clutches with less torque needed overall and possibly more speed in heavy snow conditions as a result. I'm sure there is a point where you don't want to drop the gearing too low and also you don't want to go too high but where is the happiest medium? 57/63, 60/60, 54/66?

I think of it like riding a bicycle going up hill in a higher gear. My legs are working their hardest to maintain a lower speed. Take me off the hill on a flat surface in the same gear and my speed goes up. If I shift into a lower gear on the same hill I can maintain a higher speed or even accelerate, to a point as my legs will only go so fast. I know that is quite a simplistic reference and that other stuff is going on, but just my basic starting point to go off of and work from. Does my 57/63 gearing while riding in very deep snow keep the secondary sheaves closed due to torque and not allow me to achieve the 1:1 target? I don't know but if the new gearing works better then it works better.

WyoBoy1000 · Jan 20, 2011

Your looking at it from the wrong points, if the secondary is over powering all you need is more force in the primary.

The bike is a good example. But look at it this way.
If you look at a bike you have to look at the gears as the clutching system, both front and rear gears changing to get speed. So if you can only pull a hill at say 10mph in the optimum gear. Now gear it down, but you can't the change gears (ie clutches) So to gear down you would put a smaller tire on it, which in turn would gear it down. Now you will be able to run a higher gear, but the higher gear with smaller tires turns into the same output gear ratio and most likely the same speed. Like I said gearing is a band-aid for clutching IMO.

backcountryislife · Jan 20, 2011

lowering gears only makes sense to me if you are underpowered & need more grunt on the bottom. I can see how you could think that it would help, but it'll cost you in the long run.

Low gears is a fun fad... but nowhere near the gains that people think, if they were clutched properly in the first place they wouldn't gain anything.
My 09 RIIIIIPPED until I lower gears by 3 points... then it fell on it's face in a climb.

WyoBoy1000 · Jan 20, 2011

So what your track speed.

SSWIM · Jan 20, 2011

Great thread. Nice to hear "honest" track speeds. I check mine similar to the above posts. Steep pull, deep snow. Track speeds for my sleds.
Elevation-10k-13k'

OVS TM1200-3076\Fastlane tunnel-162 PC-Timbersled Suspension 13-15Lbs.Boost----85-90MPH

TAPEX-Midmount 2871\LCC tunnel-174CE-20-22 lbs boost----75-80MPH

OVS TM8-RG\153" 15-17 Lbs. Boost----55-60MPH

Almost all of our riding is above 11K'. It is amazing how elevation once you get over 10k' effects the sleds performance. Even with BIG turbos. It is exponential and at 13K, they really "suck". HAHAHA:face-icon-small-ton

These are average speeds. Sometimes a little higher, sometimes lower.

Sam

matt159 · Jan 20, 2011

2008 m8 153"
stock gearing
EGT's 1225-1275
08 Boondocker RG w/ large intercooler & fan
100% 100LL
Watching playback on helmet cam, I could see track speed well.

10.5psi at 10,000 feet 7800-7900rpm (I know.. not enough rpm)
Starts at 53-55mph & holds 45mph at side-hill/turn-out velocity.

Spun the boost-Tee to 12.5psi & hit it again 8100-8200rpm
Starts at 60-62mph & holds 50-52mph at side-hill/turn-out velocity.

The above hill is about 400 vertical feet (7-fools) & track speed was surprisingly consistent on multiple pulls.

Over at Sugarloaf at 10.5psi on snow that you can stay on top of (crusty), it starts at 80mph & pulls down to 70mph, but pulls right back to 80mph as you wheelie over the top. :face-icon-small-hap

twsandrew · Jan 21, 2011

All around 9-10k ft

Twisted RG M1k 174
13 - 18lbs. Mid 70s to low 90s. Was a full 10mph faster with the 162 PC track but the land speed is obviously faster in deep snow and slightly slower in hard pack with the CE 174.

Impulse Race Apex 174 with gobs of motor work and an HTA 3071
92-115mph 17 - 25 lbs
Not bragging just sayin...

matt159 · Jan 21, 2011

twsandrew said:
All around 9-10k ft

Twisted RG M1k 174
13 - 18lbs. Mid 70s to low 90s. Was a full 10mph faster with the 162 PC track but the land speed is obviously faster in deep snow and slightly slower in hard pack with the CE 174.

Impulse Race Apex 174 with gobs of motor work and an HTA 3071
92-115mph 17 - 25 lbs
Not bragging just sayin...

:face-icon-small-sho I figured a 174" track would come apart turning 100+ mph. Wow.

WyoBoy1000 · Jan 21, 2011

twsandrew said:
All around 9-10k ft

Twisted RG M1k 174
13 - 18lbs. Mid 70s to low 90s. Was a full 10mph faster with the 162 PC track but the land speed is obviously faster in deep snow and slightly slower in hard pack with the CE 174.

Impulse Race Apex 174 with gobs of motor work and an HTA 3071
92-115mph 17 - 25 lbs
Not bragging just sayin...

dam, hows it do against the m1000, is the m1000 have the X-kit

cpatts2000 · Jan 21, 2011

twisted m1000 race gas
7-8 lbs 4-6k feet
Geared down 1 ratio for belt heat(dont really know if it helped much) and it holds a steady 65-70 mph in bottomless light snow,

09 dragon pgt 7-8lbs,
never saw over 55mph.

My 1000 absolutely stomps the 8 into the ground, not even comparable

Track speed gearing and clutching debate.

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