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bigusnickus View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote bigusnickus Quote  Post ReplyReply Direct Link To This Post Posted: Jul/16/2009 at 8:04am
To elaborate on Joe's post; Ohio State's 2005 car had a Comet CVT to a Honda 250 5 speed box. The box was pretty much stock except for 2 small things...The input and output shafts had to be friction welded to allow for proper coupling of the CVT and the gear for the sprocket. It definetly hauled from 2-4th gears. 1st was so low it was a joke and 5th was too tall for the engine. We saw about 44 MPH on ashpalt;enough to clear 38 feet of air in one of our parking lots.
 
It worked, but if you can manage the same from a 1-2 speed custom gearbox with CVT the 5 speed is a lot of work for little gain.
Nick Balzer Baja Buckeyes Alum 08'
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ehunt Quote  Post ReplyReply Direct Link To This Post Posted: Jul/16/2009 at 10:53pm
Originally posted by charles ulaval charles ulaval wrote:

We use the new CVTech like Sherbrooke and ETS and it's working pretty well. I guess the 3 of us were in the top 10-12 fastest cars... The ratio is nice, not too hard to adjust, lighter than the previous one. The only scary thing is the 3/4" shaft for the driven pulley.


We also used the new CVTech and had good success with it. 2nd in accel in Alabama and fifth in Wisconsin as well as 2nd in the sled pull in Wisconsin. We got about a day of tuning done prior to Alabama and were really happy with how it was running.

The CVTech is a really nice way to go, you pay about 120 dollars which covers shipping and the whole nine yards. You specify what length belt you want and get the tuning kit (I forget whether that is included in the 120 or not) and then you wait a little while for it to arrive. The wait is always a little nerve racking but they've always showed up with plenty of time. The CVTech also features an over drive final shift ratio with the ratios you can get from their website if you want. The packaging is smiliar to the gaged as far as I can tell. Both are a lot smaller then the polaris. The driven pulley being about the same size as the drive is a rear packaging dream, kinda. The 3/4'' output shaft is also nice as we don't need a huge 1'' shaft going out to the pulley. I held our input shaft before it went in the gearbox and I can agree with Charles that it was a little scary, but the analysis didn't fail us. It'd be nice if now the engine shaft could be splined and a lot smaller, keyways are a poor torque transfering method, not to mention that we always seem to lose the keys when we take the CVT off.

Service with CVTech can be a little spotty at best, you have to persistant and have a little luck.

We'll definitely be looking at the gaged, though we will most likely stick with the CVTech.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rjwoods77 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/17/2009 at 12:18am
Was your 2 speed gearbox a hi low for sled pull or was it a shiftable on the fly 2 speed for running out on the track? Also what was that horrendous noise you box was making? I know hat straight cut gears whine but it sounded like something got miffed up in there.  I didn't get a chance to see you car up close since you guys were working on it and I didnt want to get in the way but I was wondering how you actuated the rear steer. Is it a passive or active system.


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Post Options Post Options   Thanks (0) Thanks(0)   Quote eenei Quote  Post ReplyReply Direct Link To This Post Posted: Jul/21/2009 at 5:19pm
Like to know if u can add the last pages of this manual, just send until 72, i need 72-last page.

thank you
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jhu42 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/24/2009 at 2:02pm

Got it fixed.

 
It's a zip file now.  All 84 pages should work. See the File Depot
Adam Baumgartner
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MK17 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/30/2009 at 10:11pm
Would any mind posting the weight of their CVTs? I know Polaris gives there's in the FAQ but I want to know how the other CVT's compare, particularly the 700 series comets.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rjwoods77 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/30/2009 at 11:59pm
If my memory/notes serve me correct:

7.5" Gaged secondary = 2.7lbs
5.5" Gaged primary = 4.5 lbs
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Red_Beard Quote  Post ReplyReply Direct Link To This Post Posted: Jul/31/2009 at 11:38am
Originally posted by paasch paasch wrote:


I would not recommend the wireless barrel racer system that SDSMT used at the SD competition in 2007.  Those guys had nothing but trouble with those gates.




I agree that system isn't the best one out there, but for the $$$ it works dang good! 

Plus we had only used the system a couple times before the comp. so we hadn't had time to figure out its little quirks.  Now we've got them down to a science and out of say 100 runs maybe 5-6 will fail...  Not bad if you ask me.


Edited by Red_Beard - Aug/03/2009 at 11:21am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Aug/05/2009 at 1:10am
After reading all the responses on the thread I decided to get a gaged CVT with a 5.75" primary and a 8" secondary.  Probably start out with 26 degree and 28 degree helixes for the secondary.

Anyone know what ratios I should expect?  Does anyone have a CAD model I could use?

Thanks for the suggestion on the Aaen manual.  I don't what I did without it.
Andy

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Post Options Post Options   Thanks (0) Thanks(0)   Quote thompm1 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/05/2009 at 2:17am
I can probably post those files but i would suggest you have a newbie or anyone on your team that has little to cad experience do it.  Its a great learning tool for newbies and its not hard to get right
Michael

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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Aug/05/2009 at 2:37am
Originally posted by thompm1 thompm1 wrote:

I can probably post those files but i would suggest you have a newbie or anyone on your team that has little to cad experience do it.  Its a great learning tool for newbies and its not hard to get right


Don't worry.  I'll probably have some newbies model it (once we get it) along with creating some nicer models of our shocks and other miscellaneous parts.
Andy

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Post Options Post Options   Thanks (0) Thanks(0)   Quote MK17 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/06/2009 at 6:31pm
Originally posted by johnpate01 johnpate01 wrote:

We used a Comet 700 series and had mixed results out of it.  It was very reliable, though.  I don't think we could kill it if we tried.  

I agree with the Auburn guy, we couldn't get the ratio quite right.  We had to settle with "close enough."



What do you mean by not getting the ratio quite right? I wanted to ask again if any of you 700 series users know the weight of the setup.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dillon_b12 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/06/2009 at 6:48pm
We've got it written down at the shop.  I'll check next time I'm over there.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dillon_b12 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/11/2009 at 11:13pm

Comet 790 Primary: 5.8 lbs

Comet 790 Secondary: 8.2 lbs
 
These are stock out of the box weights.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MK17 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/13/2009 at 7:47pm
This is the info that I got from QDS

All drive units weigh 6 lbs. 
The 790 driven unit: 7 lbs. 
The 780 driven unit: 8.5 lbs. 
The 770 driven unit: 9.5 lbs. 


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Post Options Post Options   Thanks (0) Thanks(0)   Quote dillon_b12 Quote  Post ReplyReply Direct Link To This Post Posted: Aug/17/2009 at 12:13pm
Hmm.  The primary weight I pulled off a spreadsheet where we weighed every piece of the car as we tore it down last year.

I weighed the secondary.  I'm 99% sure we have a 790.



Edited by dillon_b12 - Aug/18/2009 at 1:21pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MK17 Quote  Post ReplyReply Direct Link To This Post Posted: Sep/07/2009 at 7:17pm
Dillon, did you ever get a chance to verify if it was a 790 secondary? The 790 has the .54:1 OD ratio. It would be nice to know if all the secondaries are 1.3 lbs or so heavier.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dillon_b12 Quote  Post ReplyReply Direct Link To This Post Posted: Sep/07/2009 at 8:27pm
Our driveline guys confirmed that it is a 790. We don't have another stock one to compare with but the one I weighed hasn't been touched.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MK17 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/03/2009 at 12:33pm
Thanks for the info dillion.

Last weekend or so I weighed the Polaris p-90 primary secondary. I don't have the numbers on me right now but I remember that the total weight came out to exactly 16.18 lbs like Polaris says, only the Primary was heavier and the secondary was lighter. This was with weights and springs installed.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Oct/12/2009 at 7:18pm
Ohio State just became a proud owner of a new gaged cvt last week.  I gotta say it's a pretty nice looking piece of kit.  It's a lot smaller and also seems like it'll be a lot easier to tune than the P-90.  We also received an extra belt tagged with a label that says "Test Enduro."  I'm guessing this is the new belt compound I heard about.
 
Haven't weighed anything yet but the gaged secondary is substantially lighter than polaris's.
 
For anyone with the gaged setup, what's with the internal threads on the post?  Does this serve any real purpose, is it a part of the barrel lock system?  Also does the barrel lock system provide any real benefit?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jhu42 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/12/2009 at 7:48pm
Oh Nice,
Thanks for the info,



Do you have an pictures? Wink

Also what did it cost you?

Thanks,
Adam


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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/12/2009 at 8:52pm
Originally posted by mu mu wrote:

Ohio State just became a proud owner of a new gaged cvt last week.  I gotta say it's a pretty nice looking piece of kit.  It's a lot smaller and also seems like it'll be a lot easier to tune than the P-90.  We also received an extra belt tagged with a label that says "Test Enduro."  I'm guessing this is the new belt compound I heard about.
 
Haven't weighed anything yet but the gaged secondary is substantially lighter than polaris's.
 
For anyone with the gaged setup, what's with the internal threads on the post?  Does this serve any real purpose, is it a part of the barrel lock system?  Also does the barrel lock system provide any real benefit?


Which post, I assume primary since you're asking if it's barrel lock, but yeah the threads at the end of the post belong to the barrel lock aka the big nut that holds the barrel on  The barrel lock is kinda nice, but can be a PITA when trying to get stuff apart.

The "test enduro" belt works great.  We put it through absolute hell in Louisville and it came out looking like new.  By hell I mean mud up to the centerline of the secondary and a primary that had so much mud in it that it wouldn't shift back and forth properly and was "clutching" belt at all times during about the last hour just to go forwards.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Oct/12/2009 at 8:54pm
grand total was ~$1100.  That included the CVT, 3 belts, 2 helixes for the secondary, 2 primary ramps, 3 primary springs, 2 secondary springs (I think), and shipping.
 
I'll try to remember to get pictures, weights and basic dimensions next time I'm at the shop.
Andy

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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Oct/12/2009 at 9:05pm
Originally posted by CLReedy21 CLReedy21 wrote:

Which post, I assume primary since you're asking if it's barrel lock, but yeah the threads at the end of the post belong to the barrel lock aka the big nut that holds the barrel on  The barrel lock is kinda nice, but can be a PITA when trying to get stuff apart.

The "test enduro" belt works great.  We put it through absolute hell in Louisville and it came out looking like new.  By hell I mean mud up to the centerline of the secondary and a primary that had so much mud in it that it wouldn't shift back and forth properly and was "clutching" belt at all times during about the last hour just to go forwards.
 
Yeah, i meant the primary.  There are exterior threads to which the barrel lock nut is fastened.  The threads I was talking about are the threads on the interior of the post up near the barrel lock.  They just don't seem necessary, maybe I'm missing something.
 
Glad to hear that belt worked out (maybe not since you beat us...).  Our P-90 with a polaris belt was definitely starting to slip even with a fairly clean CVT.  The belt didn't seem to be in that bad of shape when we finished though.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rjwoods77 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/12/2009 at 9:09pm
The internal thread on the primary post is so if the post gets suck on the engine shaft you can thread a bolt into it so a bolt has a reaction to push against the clutch. Glad you like the cvt. They have been working hard over there for the SAE series and it is only gunna get better. They will continue to work on things to make a better product for us. Ill be suprised to see if anyone isnt running their setup in a couple years. They took the Jr. Drag community by storm and will do so as well with Mini Baja. Customer service is king.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/12/2009 at 10:04pm
Well Andy you now have the tools to bring it for the next race.  Can't wait to go wheel to wheel with you guys again.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MK17 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/13/2009 at 12:18am
That's really not too terrible of a price. Do you know what the low and high ratios are for it?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MK17 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/13/2009 at 12:20am
Also, it is okay to run a CVT setup in any direction? Like having the secondary positioned farther forward than the primary?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/13/2009 at 1:11am
We did last year, secondary was below and in front of the primary.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote adrive7 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/13/2009 at 1:33am
It just a pulley. It doesn't care how it's oriented.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Oct/13/2009 at 10:51am
Originally posted by MK17 MK17 wrote:

That's really not too terrible of a price. Do you know what the low and high ratios are for it?
 
I don't know the high/low ratios since I've haven't been able to do anything with it yet.  I've been going off what TTU said in an earlier post.  You can try contacting gaged.  They're reallly helpful over there if you can get a hold of them.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/13/2009 at 3:41pm
Low ratio is about 4:1 with the 8" secondary.  Overdrive is about .83:1 with the 5.75" primary.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rjwoods77 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/13/2009 at 8:56pm
A 5.5" primary will give you more low end and less top end.
A 6" primary will give you less low end and more top end.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mu Quote  Post ReplyReply Direct Link To This Post Posted: Oct/14/2009 at 10:04pm
Here's some photos of the gaged CVT next to a P90.  The gaged is a little smaller and has a ~9" belt spacing.  As far as weights go:

Gaged
primary (no weights): 5.70 lbs
secondary: 4.26

P90
primary: 7.34
secondary: 8.88









Edited by mu - Oct/14/2009 at 10:09pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jhu42 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/14/2009 at 10:07pm
Sweet,

Man that machining on the Gaged is pretty cool.

Thanks Andy!!

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Post Options Post Options   Thanks (0) Thanks(0)   Quote tp Quote  Post ReplyReply Direct Link To This Post Posted: Oct/15/2009 at 6:28pm
Has anyone run a Team Industries secondary? I saw where they have this new "Tied" secondary, where both the plates rotate in the same direction when it shifts out. It seems pretty trick, but it made for something with 150-200 hp, not 10.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jeiB Quote  Post ReplyReply Direct Link To This Post Posted: Oct/16/2009 at 5:27pm
CVTech 08, i dont have pictures but i have the weights

primary: 8lbs
secondary:6lbs

I used crappy scales, probably +/-1lb
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DrewT Quote  Post ReplyReply Direct Link To This Post Posted: Oct/17/2009 at 2:13am
It seems like everyone who ever used it is moving away from the comet, but we've done well with it at WWU.  We were 4th in accel and 2nd in hillclimb at washougal this year (the only team to beat an oregon state car to the top of the hillclimb)with a basically stock Comet from QDS and a car that was much heavier than the others who placed similarly in those events.  The comet is nice because of its reletively small dimensions(even if it is heavy), and QDS has done significant testing for this application.  We tried a bunch of other setups for springs and weights and ramp angles with the Comet, then did a bunch of dyno runs and timed 150 ft runs and ended up confirming that the setup QDS sent us for the drive pulley was optimal, and for the driven was very very close.  At oregon I talked with one of the guys from QDS who approached us during tech to see if we'd changed anything; when I told him how we tested and then ended up with pretty much the original configuration, he smiled and said "good." and walked away.
 
The only real issue we have had with the Comet is that getting a belt to survive 4 hours is difficult, and if you splash it through water and mud the belt will die even faster.  We went through 4 belts at washougal due to the water pit and elevation change.  The polymer pads on the driven ramp angle melted it got so hot.  Both our cars required one belt change each during the endurance race at Illinois the year before, but a new belt at every driver change was a little insane this time and has us working on sealing up our cover from water and mud and getting it some better ventilation/airflow.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/17/2009 at 4:38am
We ran the comet for ~20 years before last year and Ive never heard of melting or wearing out a belt in a single race.  I have a report from a season in the 80s where they went through all the available weights and springs for the 790 system and settled on the best one, but we still just couldnt keep up with some of the other cars running CVTechs et al.  I know you guys were really fast last year at Illinois and I didnt see you much this year but those numbers dont lie.  Do you do any mods other that stock comet parts to the clutch?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DrewT Quote  Post ReplyReply Direct Link To This Post Posted: Oct/17/2009 at 6:05am
Nope, the drive pulley was used exactly as we received it from QDS, and we only went up or down one step on the spring in the 790 driven (I forget which direction now with out my notes), other than the driven spring, it was exactly as we got it from QDS.  They've done their homework, and I spent a bunch of time in 2007-8 preparing that car for Illinois to basically verify that.  Ironically, we filled out the tech sheet with the wrong weights listed for the driven (blue with gold side washers instead of blue with gold side cones) and got DQ'd after a 2nd place endurance finish and what probably would have otherwise been 2nd overall. 
 
Certainly there are more advanced options for CVT's that offer the possibility of better performance than the Comet is capable of (I know for sure that the TTU car you guys brought to Oregon was fast as heck off the line), but the Comet ain't bad.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote CLReedy21 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/17/2009 at 6:51am
Our '08 took 4th at Auburn running a comet so we don't discount it, we just like the Gaged since it's quite a bit lighter and we've got it figured out pretty well.

As far as the Illinois race goes that's a black mark on our history too.  We were in position to take 5th (6th counting you) for 3rd overall (4th counting you) over a stupid sprocket.

I'm excited to see you guys are coming to SC.  I was very impressed with your car in Illinois for several reasons including but not limited to being fast as sh*t, using mountain bike brakes, and beating the hell out of your car on the course.  We'll have to swap some stories over brews in the spring.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote DrewT Quote  Post ReplyReply Direct Link To This Post Posted: Oct/17/2009 at 8:12am
yeah I remember that, I felt as bad for you guys as I did about ours,  seems like there were quite a few teams it happened to that year.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jhu42 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2009 at 8:45pm
Quote from Mad Drivetrain Lab

"While the fallbrook cvt is neat I think its application in mini baja is limited. The middle of the range is a 1:1 so it get not that far into the low end and way too high on the high end. You would have to have some pretty huge gearing and why anybody in mini baja wants an overdrive cvt is beyond me. We are power limited so why go into overdrive and the typical overall range excuse isnt a good one. Give me a cvt that has about a 4.5:1 low and a 1:1 high that is light and small and you have a winner. Gaged pretty much offers that.
- rwoods77  "

Rob,

This statement makes no sense.  Having an overdrive on your CVT is necessary if you want to achieve a higher shift range.  Actually having a larger shift range gives you much more power because it keeps your engine on the CVT shift rpm.

An example of this difference.

We run the CV Tech CVT,  That has shift ratios of 3.0:1 , 0.43:1
Your hypothetical CVT has shift ratios of 4.5:1 , 1:1

Assume max engine RPM under load is 3500 RPM - what we have found in testing (bearing friction etc)

Now to acheive 35 mph with 22" tires with your CVT you need a reduction of 6.54:1

The CV Tech needs a reduction of 15.22 :1 , This is because of the overdrive

Now when we are going 35 mph our wheels will both be going the same speed and since we both tuned our CVTs to shift at the same RPM (in this example :) ) our engines are both producing the same power.  Recall that Power = Force * Velocity.  Well since the power is conserved from the Engine output to Wheels the power at 35 mph is the same for both CVTs.

But thats the boring side of things

Where things start to get really cool is when you look at the Low RPM case.

Now lets look at the speed your car needs to travel at before it reaches its CVT shifting speed.
Well, I've done the math and with your reduction and 4.5:1 CVT (low range)  the speed you will be at when your CVT engages is 7.79 mph.

But on the other hand the CV Tech will reach its shifting speed much faster, at 5.01 mph. 
This is because of the larger shift range of the CV Tech vs. your CVT (6.97, 4.5)

So!!
What does that mean?

Well, what it means is that my setup with the CV Tech will get to the shifting RPM quicker than your setup.  By getting to the Shifting RPM quicker you dramatically improve your car's performance.  This is how Michigan is able to run such fast acceleration times, really big shift ratios!!

Shifting RPM is ideal because if you look at the Power Curve for the Briggs engine the higher your RPM the more power the engine outputs.









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Post Options Post Options   Thanks (0) Thanks(0)   Quote jeiB Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2009 at 9:41pm
hey adam,

nice write up! anyway i wanted to ask all of the CVTech users a little clarification about the cvtech cvt specs.

Does anyone know if their specs (3:1 low, 0.43:1 high) are torque based or speed base?

Im probably going to call them next week but if anyone is SURE.....
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Unproductive Quote  Post ReplyReply Direct Link To This Post Posted: Oct/19/2009 at 3:38pm
Originally posted by jhu42 jhu42 wrote:

.........


Take a look at efficiency at higher shift ratio's, Aaen mentions it in his book(it's in the file depot here). He claims that at much past a 1:1 ratio, efficiency falls off relatively quickly.

Also, on the same note, does anyone have more reading about cvt efficiencies, maybe something with data?
-Bob
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jhu42 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/20/2009 at 12:39am
hmmmm,   I see what you are saying unproductive.

I know I posted it Wink

Well, all I can say is that we have tried both ways and the overdrive is working pretty well for us so far.  We are working on a sweet two channel data logger.  I will get back to you with some hard data when that is ready.

Adam
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BroncoBaja Quote  Post ReplyReply Direct Link To This Post Posted: Oct/23/2009 at 3:00am
Hey all, new to the competition and have a P90 from last year (team didn't build a car but got the drive/driven).  I've been trying to find information on the P90 high/low ratio's as well as the c-c limits (available belts?).  The first so I can calculate the final drive the second so I can start modeling it.  

The pictures and weight post above made me feel better about using the P90, not too bad for old tech vs new tech.   Now that I've read this thread I have questions about tuning, mod's, orientation, mounting......

The driven of the P90 is threaded right?  So I would need a threaded jackshaft or take one out of a salvage snowmachine?

If Gauged gets a package together we will definitely look into for next years competition.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote kenneth.mandeville Quote  Post ReplyReply Direct Link To This Post Posted: Oct/23/2009 at 9:41am
listed here - http://www.polarissuppliers.com/sae_team/faq.htm
"3.83:1 underdrive and will top out near a 0.76:1 overdrive"
"The center to center distance on our P90 clutch is 10” +/- 0.050”."
And here are some other P90 Info

Good luck with the P-90
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Post Options Post Options   Thanks (0) Thanks(0)   Quote adrive7 Quote  Post ReplyReply Direct Link To This Post Posted: Oct/23/2009 at 9:47am
The driven is splined. You will need to find somebody who can cut them. Also, the driver is tapered to match the polaris engine. You will need to figure out a way to mount it to the briggs. We bore out the taper and press in an insert. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BroncoBaja Quote  Post ReplyReply Direct Link To This Post Posted: Oct/23/2009 at 1:33pm
Thanks so much for the info! 

We were thinking of selling the P90 and getting a comet 44 but the comet only has 1.24 to 2.8 ratios.  I don't think we can get the numbers we want with those ratios.   We're not planning for a gearbox since we are new and have nothing to start with.  Just using a chain drive off the jackshaft.  I think the P90 will work to get a car rolling this year, next year may be different.
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