Schumacher Corner
11-24-2004, 02:48 PM
#8177
For stock racing the grey belts front and rear are highly beneficial...also you can do away with all but the lower tensioner for the front belt, Including the power roller for the layshaft pulley....(dependent on each belts natural length, as ive found no 2 belts are identicle...
For modified, the standard black rear belt is the only belt I would recommend, have had durability problems with the narrow rear belt on high bite and Low turn mod, also you can replace the Kit included front grey belt with the R12 nitro belt...More durable and less prone to stretching over time.
Other tweaks I have made to my drivetrain are, replace the pullies with the CNC delrin items, and also remove the narrow belt guide on the right side of the front pulley, this can be replaced with the thinner one which comes with the cnc pullies or be left off altogether....also the belt divider on the rear pully can be replaced with the thinner version, or sanded down so that it doesnt actually pinch the belts at all....(noticable improvement)
The Mi2 out of the box is the free'est (SP?) belt driven car I have ever seen, with a few tweaks, can be made uber free!
For modified, the standard black rear belt is the only belt I would recommend, have had durability problems with the narrow rear belt on high bite and Low turn mod, also you can replace the Kit included front grey belt with the R12 nitro belt...More durable and less prone to stretching over time.
Other tweaks I have made to my drivetrain are, replace the pullies with the CNC delrin items, and also remove the narrow belt guide on the right side of the front pulley, this can be replaced with the thinner one which comes with the cnc pullies or be left off altogether....also the belt divider on the rear pully can be replaced with the thinner version, or sanded down so that it doesnt actually pinch the belts at all....(noticable improvement)
The Mi2 out of the box is the free'est (SP?) belt driven car I have ever seen, with a few tweaks, can be made uber free!
11-24-2004, 02:51 PM
#8178
We have found a noticable increase in acceleration by running the rear belt tensioner and running the front belt a little tighter then we used to. The car is just as free as before but it feels more snappy and it is certianly faster according to the lap times...go figure!
11-24-2004, 02:59 PM
#8179
I did forget to clarify that I dont recommend the tensioners be removed for Mod...Belt skip can be a problem...
I generally have the layshaft power roller on the forward most (loose) setting, and the low tensioner around middle way up...
the last grey belt I received was uber loose...way too loose for mod, I had to run the tensioner fully up, and it was still a rather limp....never skipped, but I was pretty sure if it was that loose from new, it would only stretch and possibly become a problem....although could be good for stock?..
I generally have the layshaft power roller on the forward most (loose) setting, and the low tensioner around middle way up...
the last grey belt I received was uber loose...way too loose for mod, I had to run the tensioner fully up, and it was still a rather limp....never skipped, but I was pretty sure if it was that loose from new, it would only stretch and possibly become a problem....although could be good for stock?..
11-24-2004, 03:03 PM
#8181
Originally posted by Speedie
Schumacher sells a narrowed rear belt that helps pn. u2721. The machined diff pulleys make a big difference as well. Ft pulley u2746, rear u2745. My front belt came with every other tooth cut off and holds up well the narrowed rear belt did not last with them cut off tho. The belt will soften up more still if you soak it in WD40 for a week or 2. The machined ones are made of delrin or delrin like material and are slicker than stock ones are.
Schumacher sells a narrowed rear belt that helps pn. u2721. The machined diff pulleys make a big difference as well. Ft pulley u2746, rear u2745. My front belt came with every other tooth cut off and holds up well the narrowed rear belt did not last with them cut off tho. The belt will soften up more still if you soak it in WD40 for a week or 2. The machined ones are made of delrin or delrin like material and are slicker than stock ones are.
11-24-2004, 03:06 PM
#8182
ok heres a question for the guys (particularly the U.S drivers who were at the worlds) who run spools regularly on rubber tires outdoors...
what changes, do you find work best when changing from a oneway to a spool.
I have always reduced castor to 2 degree, softened the front bar slightly, and reduced front droop to around 1.5mm...also moving the front arm rearward helped, perhaps softening front oil slightly.
what other tweaks have you all found work, link position, ackerman changes?., lower arm mounting height etc....arm position etc...
we dont tend to run spools often at our track, but im wanting to get into testing it some more.
what changes, do you find work best when changing from a oneway to a spool.
I have always reduced castor to 2 degree, softened the front bar slightly, and reduced front droop to around 1.5mm...also moving the front arm rearward helped, perhaps softening front oil slightly.
what other tweaks have you all found work, link position, ackerman changes?., lower arm mounting height etc....arm position etc...
we dont tend to run spools often at our track, but im wanting to get into testing it some more.
11-24-2004, 03:09 PM
#8183
Thats sweet Dotman those pulleys really help alot.
11-24-2004, 03:16 PM
#8184
Tech Master
Careful thinking that the machined pullies are the same as the mission. They are different to the ones origionally released for the mission. The Mi2 ones will fit the mission, but not sure if the Mission ones will fit the Mi2. They kind of will, but i have a feeling you don't get the belts properly lined up.
Adrian, it's interesting that you say the car is faster with the belts tighter. It doens't actually surprise me, as i think you always have to take up the slack of a loose belt, if the belt is tight when you start then that won't be the case. I haven't tried it personally, i run my car with them as loose as possible!!! but it is something that is worth trying!!!
I am almost certain that there is a happy mid point, go too tight and you will start to get things very very hot.
Adrian, it's interesting that you say the car is faster with the belts tighter. It doens't actually surprise me, as i think you always have to take up the slack of a loose belt, if the belt is tight when you start then that won't be the case. I haven't tried it personally, i run my car with them as loose as possible!!! but it is something that is worth trying!!!
I am almost certain that there is a happy mid point, go too tight and you will start to get things very very hot.
11-24-2004, 03:16 PM
#8185
King-G - Its hard to say as most of us have never had a one way on our Mi2's. At the Worlds Warmup the car required almost no changes. The oneways were better on a cool track and overheated the tires in the heat and the Spools were faster in the heat and just as fast in the cool.
Generally you do things to make the car have more agressive steering with a spool but it is always pretty easy to drive.
One thing we learned at the Worlds is that we are probably too stiffly damped with 40wt oil. We will be testing oil as lisht as 30wt over the nest few weeks. Possibly softer springs too. It all depends on your traction and how flat your car needs to stay for the layout that you run.
PW will be trying some stuff soon but is taking a few weekends off after the Worlds and during the Holidays. Everyone else has moved on to carpet for the winter so we have to look to the FL and SoCal guys for the winter asphalt testing.
Stay Tuned....
Generally you do things to make the car have more agressive steering with a spool but it is always pretty easy to drive.
One thing we learned at the Worlds is that we are probably too stiffly damped with 40wt oil. We will be testing oil as lisht as 30wt over the nest few weeks. Possibly softer springs too. It all depends on your traction and how flat your car needs to stay for the layout that you run.
PW will be trying some stuff soon but is taking a few weekends off after the Worlds and during the Holidays. Everyone else has moved on to carpet for the winter so we have to look to the FL and SoCal guys for the winter asphalt testing.
Stay Tuned....
11-24-2004, 03:20 PM
#8186
Matt - Its funny...I remember talking to Paul Lemieux at a race and he said that if he runs his XXXS belts loose enough to be free the car looses acceleration. Tighten them up and the car goes faster. We forgot about that until a club race when PW's rear belt started to skip. Putting in the tensioner was easier then replacing the belt so he tried that and went faster.
11-24-2004, 03:24 PM
#8187
Tech Master
LOL, yeah these things happen like that. In fairness now i think about it, we used to run tighter belts on one of the older cars as we said it was better - can't remember but it might have been 99/axis, somewhere way back then. We found that by accident as well!!!
I guess i have to look for a tensioner then!! I had one, but got told to take it off and have no idea where it went.
Too tight is bad though, when i ran the early proto car that was too tight and cooked all my motors!
I guess i have to look for a tensioner then!! I had one, but got told to take it off and have no idea where it went.
Too tight is bad though, when i ran the early proto car that was too tight and cooked all my motors!
11-24-2004, 03:31 PM
#8188
I've noticed the same thing. I found my self tightening up the tension more and more and the car just pulls harder and harder out of a corner. But here's one for you...
I just noticed that my front belt is hitting the screws holding the spur on. I'm thinking I need to redo the shims on the diff pulleys to shim the belt outward more. Anyone?
I just noticed that my front belt is hitting the screws holding the spur on. I'm thinking I need to redo the shims on the diff pulleys to shim the belt outward more. Anyone?
11-24-2004, 05:20 PM
#8189
Hi Gary...I have had experience with this, especially using the spur adaptor with Kinborough spurs, which are a little wider....
after I once had a layshaft bearing seize (right side) and melt the conical plastic spacer I have since used .1mm shims to get my layshaft correctly spaced..some trial and error was required...assembling and dissasembling until I got it spaced correctly between the 2 uprights so the belt didnt rub on the spur, or on the layshaft pulley. Carefull not to put too many shims on, causing side loading on the bearings...
as a side note, I now use acer ceramic bearings on the layshaft, and havent had a layshaft bearing seize since....(the only bearing seizures occured on a tight track, where we tested using the 17tooth layshaft pulley, causing everything to rev harder for longer)....
Everyone pretty much uses the 20 tooth pulley everywhere now, so may not be an issue.
after I once had a layshaft bearing seize (right side) and melt the conical plastic spacer I have since used .1mm shims to get my layshaft correctly spaced..some trial and error was required...assembling and dissasembling until I got it spaced correctly between the 2 uprights so the belt didnt rub on the spur, or on the layshaft pulley. Carefull not to put too many shims on, causing side loading on the bearings...
as a side note, I now use acer ceramic bearings on the layshaft, and havent had a layshaft bearing seize since....(the only bearing seizures occured on a tight track, where we tested using the 17tooth layshaft pulley, causing everything to rev harder for longer)....
Everyone pretty much uses the 20 tooth pulley everywhere now, so may not be an issue.
11-24-2004, 05:29 PM
#8190
Interesting to hear your thoughts on oil and spring rates being too stiff, I have had this thought for some time now, running between 30 - 40 weight....I am also constantly searching for a little more turn in, front end grip off power..looking at something slightly softer than the Ae blues, silvers seem a little too soft for my liking in the front..front end kinda dumps over mid turn...
was it Tamiya Yellows on P.W and Teemus car at the worlds?..
or painted yellow=)?
our track is fairly low bite, I think softer oil and spring is definately the way to go..
was it Tamiya Yellows on P.W and Teemus car at the worlds?..
or painted yellow=)?
our track is fairly low bite, I think softer oil and spring is definately the way to go..