Author Topic: Rotax 793 engine in to pilot  (Read 24391 times)

ludedude

  • Hero Member
  • *****
  • Posts: 1478
  • Karma: 0
    • View Profile
Rotax 793 engine in to pilot
« Reply #45 on: March 05, 2007, 07:16:48 PM »
Quote from: "Lee1969GB"
ludedude, I could do with doing something with the throttle but need to be careful that it shuts off, with the cvt drive you can not put the clutch in and I dont think the brakes would overide the engine. It does seem to be getting better but thumb ache will start to set in after 10 mins. Maybee lighter springs in the carbs will help me.


That's what the kill switch is for ;)  :P   Plus I have upgraded my fronts to disc ;)

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #46 on: March 06, 2007, 02:44:30 PM »
Yes A big red kill switch you can not miss :D
I will be fitting discs also. I had it out again today for a short time trying to work out what the diff is doing, I put one rear wheel in a puddle and the other on dry ashfelt/ tarmac and accelerated as hard as possible, boyh tyres spun so the limited slip diff is locking to an extent. on dry ashfelt/ tarmac driving along at about 30 mph then give it full throttle and the rear tyres spin, with road tyres it might wheelie. Turning on ashfelt/ tarmac there is no understeer at all with my standard pilot it would understeer bad.

FL670R

  • Global Moderator
  • Full Member
  • *****
  • Posts: 180
  • Karma: 1
    • View Profile
Rotax 793 engine in to pilot
« Reply #47 on: March 06, 2007, 03:32:42 PM »
If you've ever broken a CV or axle (I as have) you will find out that the pilot  will barely be able to move itself with 1 wheel drive...

It will however make great circles or dig a nice hole in sand....

Can you make a 360 circle with your pilot and tell us what the new turn radius is ?

Progress looks great - Keep us posted...

Dennis

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #48 on: March 06, 2007, 04:48:40 PM »
Fl670R, Yes I will try that, I will compare it with one of my standard pilots without sliding, with the same tyres on it.
Ozpilot, Sorry I only just saw your post (last one on previous page) Yes that makes sence, probably a good race set up but more fun to slide it a bit, with a bit of time I am sure I will find a way to get it to slide.
I am geting those vented discs and I will try them as fiddle brakes also, That will give me even more options.
The wedge shaped bit with slotted holes on the secondry clutch (can be seen in the photo in the thread about the belt) What does that adjust, Is it the helix or something? I want a wheelie out of this thing :lol:

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #49 on: March 07, 2007, 04:03:15 PM »
I had another drive today, I compared the turning circle of a one of my standard pilots and my pilot with rotax engine and limited slip diff, they both have the same tyres on. The standard pilot did it in 40 foot radius inside to inside, the one with a diff only needed 16 foot inside to inside. that was driving very steady and no sliding.
It turns fine with no throttle or holding a steady speed but if you try to turn while hard on the gas there is some understeer, I was not sure if this was because of the diff locking under hard acceleration or because the front tyres were barely in contact with the ground. I got my 12 year old son to drive so I could see what was happening , under hard acceleration the front suspension was unloaded and the front tyres were skimming across the ground. :shock:  when he pulled up he said I am not driving that again its a beast!
The combination of a short light buggy with 140 hp was always going to want to wheelie, If I fit some brake discs on to the inner cv cups for rear brakes I can also use them as fiddle brakes that should cut out the understeer.

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #50 on: March 08, 2007, 01:54:30 PM »
removed

Ozpilot

  • Jr. Member
  • **
  • Posts: 92
  • Karma: 0
    • View Profile
Rotax 793 engine in to pilot
« Reply #51 on: March 08, 2007, 06:29:18 PM »
Looks great in the video.  Isn't it amazing how much time you have to spend OFF the power.  
I'd be a little wary of the idea of fiddle brakes.  With the diff being limited slip each time you dramatically slow an inside wheel the friction material in the diff (I'm not sure whether it is a cone or plate type) will be fighting and wearing away.  If the diff is set reasonably tight then the fiddle brakes may also not work all that well (the diff may try to slow the outside wheel when you apply the inside brake).
Just a few thoughts...  If you're putting on dual discs anyhow then you might as well try them as fiddle brakes but if it's a lot of effort it may be effort that is better spent elsewhere.

But, I've gotta say again ... the machine is looking great!!

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #52 on: March 09, 2007, 03:17:55 AM »
It seems everyone can view the video but me, when I click on the arrow it just goes off, what am I doing wrong?
I am told the lsd is a plate type so it will ware. The understeer is mainly a problem on fast sweeping bends so I am not after a big difference in inner and outer wheel speed.
Quaife do a torque biasing diff to fit in this subaru casing with no parts to ware but it is ?550 thats about $1000 us.
Thanks for the comments.

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #53 on: March 09, 2007, 02:03:18 PM »
What I am now thinking of doing is fitting 2 discs to the inner cv cups with 2 master cylinders on to 2 peddles, so my left foot works the brakes on the rear left wheel, my right foot works the brakes on the rear right wheel.
I have some ex 400 discs and calipers I will fit to the front wheels and use the right side brake lever (on steering wheel) for the right front wheel and use the left side brake lever for the left front wheel.
This way I have fiddle brakes, a sort of ABS (if one wheel locks probably a front release some pressure to that wheel) and with all of these individual brakes I should be able to make it dance.

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #54 on: March 12, 2007, 06:40:19 PM »
I got my rear brakes today, they are kelgate brakes from a 250 gearbox (shifter) kart.
I will mount the discs on the inner cv cups and have 2 pedals 1 for each rear brake so I can use them as fiddle brakes.

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #55 on: March 18, 2007, 04:07:09 PM »
I got my vented discs mounted on a spare subaru diff today, I welded lugs on to the inner cv cup to hold the discs.

lee1969gb

  • Jr. Member
  • **
  • Posts: 54
  • Karma: 2
    • View Profile
Rotax 793 engine in to pilot
« Reply #56 on: April 18, 2007, 12:57:59 PM »
I tried out my pilot again yesterday with the fiddle brakes fitted, one pedal for each rear wheel, It certainly helps it turn when on the power :D
I got it to turn A bit to tight at one point and it almost went over :shock:  but I turned in to it and it went back down with a thud, when I looked down the front wheel was hanging off, the bottom ball joint had pulled out of the a arm, It had been fixed previously but not very well so I ground all of the old weld off and re welded it.
I have managed to get a good sized wheelie out of it, it seems to just spin the tyres on most ashfelt but on one more grippy part it grips enough to wheelie, I will try lower tyre pressures or grass tyres to see if that helps.