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I was giving the sled a royal cleaning today under the hood and noticed somthing about my helix. You can clearly see the marks that the nylon rollers make on it and they didn't go all the way to the bottom. The marks from the rollers only go about 3/4 of the way onto the helix so it looks like i'm not getting my full shift out. The sled is 2006 F6 EFI, it isn't a sno-pro but has the 1 3/8 track. I currently max out at 96 MPH but I KNOW it has more in it. Any suggestions?
 

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Don't worry about those marks just worry about the ones on the back roller. I hate to think how much hunting the secondary is doing when it is not using ether roller.

I will say this again.

The secondary has such a wide ratio that full shift is 1.375"s of travel. Now if you take the spring out of your secondary put the roller back where the roller starts..... mark the outter most face of the outter sheave on the helix with a scratch owles. Move the secondary all out to the farthest mark. Make another scratch. Measure the distance from one mark to the next. I bet it is in at 1.125"s Hmmm .25" short of full shift right! So how do you fix this? Well remember the old secodary how it floated at the most .060 Ya. Well the DDrive cann't float and should never float or you will loose gears and bearings. You can for speed runs but that is it.
Now setting up the alignment for a given belt and given compound you should set it the free float way. Get the bar for center to center checked and the stager in the primary set then free float for the alignment. Sled on a track stand or rear up in the air with it pointed to an open field. Take the belt, secondary, and all the shims out from behind the secondary off. Put the secondary back on. Put the belt back on. Set the deflection to where at idle the track just wants to creep ahead. NOw run the sled up to speed and you will see the secondary move in then back. About 20-25mph. This is why the old secondary floated. The alignment needs to change if you have alot of shift travel or you will loose belt grip down in the secondary. So back to the test do it a few times and measure off the motor plate to the secondary and remember this number.

Take the secondary off and put in enuff shims to get it set to the numbers you meaused. With the stock 10" or 10.4" you will need to run the stock belt and run it tight even if it is chirping a bit. Why? Tighter belt needs less off set to run right. This will keep your off set right deeper into the secondary at full shift. The off set is very poor at full shift or over 1.125" of shift in the secondary then the belt twists and lose of grip. You see this with the bigger track because of how much torque feed back your putting on the drive shaft more pull against the belt. I seen this with my M6 141X2.25"er but still could pull it to 105 with my 600 with more off set and stock belt nice and tight.

SOoooooooooooo some will find that you cann't get nuff shims out from behind the secondary to get it set right before the bolt bottems. Few guys are putting in washers.... that works others just running a harder belt nice and tight. You need to watch and see how far and what is hitting what with the secondary in that far. So you give up correct off set on the outter most part of the secondary for correct off set down deep in the secondary. Holding the belt running out more on the top end. I feel this is the way to set up because the larger outter part of the secondary will hold the belt better with more belt to sheave and you will not see as much belt slip with poor off set.

Now AC has gone from a 10" to a 10.4" and I for see and even bigger one and longer belt. If you do run a bigger secondary and longer belt your shift will not need to shift all the way to 1.375" to get higher mph. Why? Your 1-1 is higher in the primary and secondary thus getting into the shift farther with less lateral shift letting you pull more over drive with the correct off set and with more belt to sheave. Then you do not need as much off set on the top end to keep the belt stuck like glue and track size will not effect mph as much. Lets face it much over 100mph track hight makes a differece from windage.

Ok so you put on the biggest secondary you can find and fit in to said space. Get a nice big 8.5" primary and longer belt. Now the F7 is not over geared nerely as bad to the point you may need to gear up.

http://www.ddracing.com/03-TechBoard.asp

Hmm what is this?

This bad boy on the 07 runs a 47.625" belt and the max lateral shift is 1.06" with the 8.5" primary. Your MPH is 90.5mph belt to sheave or 7.838"s at 1-1 compared to 73.25mph with the 10" and 7" belt to sheave at 1-1. The wide ratio 10" is not the only problem.

So in conclusion, The wide 10" ratio with the latral delta distance traveled is to great for the off set alowed on the DDrive. The 10.4" is poor all be it better than the 10". YOu will find you need to get to a lateral shift around 1.125" to bolt the secondary down solid with out loosing grip down in the secondary. I feel a 11" secondary will give the firecat what it needs and a 46.625" belt........just make it fit. Milling .045 off each sheave to make the 10" into a 10.4" stands to give a 10.4" milled off .080 each sould yeld a 11" secondary. Going back small is easy just put on a shorter belt and set the deflection for it.

Don.
 

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WOW! That is a lot of numbers for me to take in. I have been trying to get my secondary set up because it is way off. I have 06 F7 with the big track and it is a dog on the top. ONLY CAN GET 100MPH but with the little track 105mph. My question is can you run NO washers behind the secondary? It seems that while on a stand and you smack throttle and hold they seem to be aligned with no washers, but if I leave all 4 washers the secondary at WOT on stand, the belt is on angle. I do not have an alignment bar but heard they dont work any way. I would love to see 110mph with big track like my 03 F7 would run.
 

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WOW! That is a lot of numbers for me to take in. I have been trying to get my secondary set up because it is way off. I have 06 F7 with the big track and it is a dog on the top. ONLY CAN GET 100MPH but with the little track 105mph. My question is can you run NO washers behind the secondary? It seems that while on a stand and you smack throttle and hold they seem to be aligned with no washers, but if I leave all 4 washers the secondary at WOT on stand, the belt is on angle. I do not have an alignment bar but heard they dont work any way. I would love to see 110mph with big track like my 03 F7 would run.[/b]

You want the belt on and angle. This angle keeps the belt flat under load. The belt twists when pulled on and you want to counter act this with off set......hence off set. You are off setting the twist. IT is keeping the off set durning the shift.

http://amber.sharebigfile.com/...NGM0I=&captcha=353631

Check this out. Me and another guy built this for the DDrive sleds. Look at the delta distance and the last sheet. The ploter I and a few guys feel the only way to make it fly is to go with a bigger secondary and longer belt. Before I took into account the off set I was sure the 10" would run out better yet it will but you cann't hold the belt consistantly down deep.
 

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I have 05 F6 EXT bougth as a carry over in 06. Last year was able to ride about 1200 miles and did not have any belt issues. this year only riding in my dreams. But after reading all the posts over the last year in regards to belt off set & deflection I decided that I would look at my set up. I have zero clutch experience so was a little concerned about messing with things as last year I did not have any belt concerns.

Inital reading from the frame to inside secondary sheave was slightly over 1 1/2". Pulled all the shims and ran on the stand. The reading without any shims was 1 3/16". Pulled the three thick shims, leaving only the thin shim and the distance is at a little over 1 1/4". This leads me to believe that without any shims the secondary wants to run up tight against the DD and with the thin shim the offset is still a little more than desired.

Question: Can the secondary be run without any shims?

Thanks,
 

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I have 05 F6 EXT bougth as a carry over in 06. Last year was able to ride about 1200 miles and did not have any belt issues. this year only riding in my dreams. But after reading all the posts over the last year in regards to belt off set & deflection I decided that I would look at my set up. I have zero clutch experience so was a little concerned about messing with things as last year I did not have any belt concerns.

Inital reading from the frame to inside secondary sheave was slightly over 1 1/2". Pulled all the shims and ran on the stand. The reading without any shims was 1 3/16". Pulled the three thick shims, leaving only the thin shim and the distance is at a little over 1 1/4". This leads me to believe that without any shims the secondary wants to run up tight against the DD and with the thin shim the offset is still a little more than desired.

Question: Can the secondary be run without any shims?

Thanks,[/b]

Most of us have measured to the inside of the outer sheave....and land at roughly 3 1/8". The outer sheave is the stationary sheave and measurements to the outer sheave will NOT be impacted by how your defelction is set.
 

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ok I have question on this to I justgot a shift ast from D&D i Havent put it on yet ( need spring tool yet ) To day i pulled the secondary and try to float it this is what I did pulled all the shimms ran the sled up to 45 and let it coast to a stop put a dial indactor on the secondary and it was .128 from the back side so did the test 2 more times and got .100 and.112 so i figuared i need about .114 for shims does this seam right ? that putsthe inner side of my secondary at 3.095 of the frame so if i make a .014 shimm will this be ok or not ( i've got the 044 belt if that makes a diff or not )
 

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I have an 03 F7 and I have always wondered why the secondary is held tight. Wouldn't it be better to take some of the front shims out and let it float?[/b]
I think you could set it up to let it float more, not 100% sure. But it does float somewhat as the rubber o rings at front and back of clutch give it some movement.
 

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I have an 03 F7 and I have always wondered why the secondary is held tight. Wouldn't it be better to take some of the front shims out and let it float?[/b]

There was a type error in the service man. YOu should never let the DDrive secondary float it will take out the top inner bearing and if your lucky not dink the gears.
As long as the secondary is tight you can run it in as far as you want. On the reverce modles I think you need to keep a .010 shim in there or the secondary will hit the DDrive case at full shift.

So keep her tight. Running the blet tight will help if you need more off set. This will help keep the belt from twisting under load as well. This fixed secondary is was it killing the top end.

Here is a picture for you. Depending on how tight you have your belt will depend how much diferent yours is than another guys. in the pic see where it reads 3.25"s this is where you want 3.125"s Move the secondary in making the belt laying in there look like this.

Don.
 
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