Tamiya mini cooper
Joined: Sep 2010
Posts: 2,313
From: Chicagoland
First, I do appreciate your replies.
So tell me about tires. I'm asking because these tires feel like they're pretty sticky. Am I seeking harder tires? Softer tires? How about sauceing the tires I have?
This answer again? Hah. I'm going to need to do something about this. About TCS, I'd like to keep my changes ~in line~ with TCS, so I could potentially pony up the $150 and do a quick conversion to TCS legal. But, that may just be a pipe dream.
What are proper springs? With the stock springs, the car doesn't droop much, or at all, really, harder springs are just going to make that situation a little worse. I ended up preloading the front springs as that seemed to produce a little more push, and avoid the rollovers.
I'll get the thing weighed, and corner weighted tonight. I wonder what surprises we'll find.
Black CRC Carpet, it always seems really sticky to me. It's common to see VTA cars bicycling on it.
Yes, I'm using the kit gear diff. It's wide open at this point, with just a little tamiya grease in it. With the access problems in the M05, i'm not sure a ball diff is a good idea. Though, I will say, I got pretty good at getting in there over my bench sessions this weekend.
The 3Racing diff is something I could.. emulate... with the factory diff, but it would be a maintenance hog. Got it, get the sealed gear diff, or seal the diff I have. ;-) Any reason I should avoid the YeahRacing version?
So I'm feeling a bit... confused. "not enough rear traction" but "kit tires are ok in back". So.. are they sticky, or not? I feel like with the same tires front and rear, I should be able to solve this problem with springs or other suspension settings. And I'm still feeling a little weird about the differential situation. A LSD in a real car, never made the car want to snap around like that for me...
Well.. I have a 150 meg zip file to download and read.... and condense... and repost...
So tell me about tires. I'm asking because these tires feel like they're pretty sticky. Am I seeking harder tires? Softer tires? How about sauceing the tires I have?
read everything....
If you're using the stock long silver springs, get some proper springs so you can get a decent ride height without preloading the springs. Do you have any spacers/orings in your shocks to reduce the droop?
How heavy is the car, and how is the weight distributed?
How heavy is the car, and how is the weight distributed?
I'll get the thing weighed, and corner weighted tonight. I wonder what surprises we'll find.
Yes, I'm using the kit gear diff. It's wide open at this point, with just a little tamiya grease in it. With the access problems in the M05, i'm not sure a ball diff is a good idea. Though, I will say, I got pretty good at getting in there over my bench sessions this weekend.
The 3Racing diff is something I could.. emulate... with the factory diff, but it would be a maintenance hog. Got it, get the sealed gear diff, or seal the diff I have. ;-) Any reason I should avoid the YeahRacing version?
So I'm feeling a bit... confused. "not enough rear traction" but "kit tires are ok in back". So.. are they sticky, or not? I feel like with the same tires front and rear, I should be able to solve this problem with springs or other suspension settings. And I'm still feeling a little weird about the differential situation. A LSD in a real car, never made the car want to snap around like that for me...
Well.. I have a 150 meg zip file to download and read.... and condense... and repost...
Joined: Feb 2011
Posts: 8,406
Two degrees of front toe out will cause alot of sudden entry steering with a big push in the middle&exit of the corner... Your static toe out is also less than the dynamic toe out in the front wheel drive m05: so you might have over four degrees dynamic toe out if you factor in the suspension play, making the problem worse... I would reduce the front toe to one degree or a little less...
Also, I would reduce droop as much as possible, with CA glue on the front tire sidewalls+1mm ca on the threads...
For the front diffing out, you will need to put stiff springs in the rear, contrary to popular belief, and softer front springs, and drive slightly on power around the turns(do not lift off completely)....
Also, I would reduce droop as much as possible, with CA glue on the front tire sidewalls+1mm ca on the threads...
For the front diffing out, you will need to put stiff springs in the rear, contrary to popular belief, and softer front springs, and drive slightly on power around the turns(do not lift off completely)....
Joined: Sep 2010
Posts: 2,313
From: Chicagoland
I've done a lot of work to suck out the play in the steering. I've got two tricks left in my book, and I will be doing that tonight.
As it stands, I've shimmed the bellcrank to sit against the top of the supports. Any force on it would push it to the top of it's posts and change the toe in. So.. I pushed it to where it naturally wanted to be. That took a solid half degree of play out of the steering. By shimming the knuckles, I lost another degree (the knuckle can't move up and down, and introduce steering angle now..) I should also put 2mm of spacers under the bellcrank, to reduce bump steer... At leas thats what I've seen on setup sheets.
I'll try getting rid of all the toe out.
So.. what spring set should I buy? I've got the ultra mini CVAs. The setup you're suggesting is what you do for a real FWD car.
My most consistent laps have been with driving with some power on in turns. Before I glued the sidewalls, it was diffing out that maintained corner speed without tipping over.
As it stands, I've shimmed the bellcrank to sit against the top of the supports. Any force on it would push it to the top of it's posts and change the toe in. So.. I pushed it to where it naturally wanted to be. That took a solid half degree of play out of the steering. By shimming the knuckles, I lost another degree (the knuckle can't move up and down, and introduce steering angle now..) I should also put 2mm of spacers under the bellcrank, to reduce bump steer... At leas thats what I've seen on setup sheets.
I'll try getting rid of all the toe out.
So.. what spring set should I buy? I've got the ultra mini CVAs. The setup you're suggesting is what you do for a real FWD car.
My most consistent laps have been with driving with some power on in turns. Before I glued the sidewalls, it was diffing out that maintained corner speed without tipping over.
Joined: Feb 2011
Posts: 8,406
Good work ! I would put the blue or white springs in the rear, and yellow springs in the front to start... If yellow fronts get to be too soft, then try blue, but ca on the threads is very important with a low profile tamiya body slammed down all the way....
What are proper springs? With the stock springs, the car doesn't droop much, or at all, really, harder springs are just going to make that situation a little worse. I ended up preloading the front springs as that seemed to produce a little more push, and avoid the rollovers.
I'll get the thing weighed, and corner weighted tonight. I wonder what surprises we'll find.
Black CRC Carpet, it always seems really sticky to me. It's common to see VTA cars bicycling on it.
Yes, I'm using the kit gear diff. It's wide open at this point, with just a little tamiya grease in it. With the access problems in the M05, i'm not sure a ball diff is a good idea. Though, I will say, I got pretty good at getting in there over my bench sessions this weekend.
The 3Racing diff is something I could.. emulate... with the factory diff, but it would be a maintenance hog. Got it, get the sealed gear diff, or seal the diff I have. ;-) Any reason I should avoid the YeahRacing version?
Black CRC Carpet, it always seems really sticky to me. It's common to see VTA cars bicycling on it.
Yes, I'm using the kit gear diff. It's wide open at this point, with just a little tamiya grease in it. With the access problems in the M05, i'm not sure a ball diff is a good idea. Though, I will say, I got pretty good at getting in there over my bench sessions this weekend.
The 3Racing diff is something I could.. emulate... with the factory diff, but it would be a maintenance hog. Got it, get the sealed gear diff, or seal the diff I have. ;-) Any reason I should avoid the YeahRacing version?
So I'm feeling a bit... confused. "not enough rear traction" but "kit tires are ok in back". So.. are they sticky, or not? I feel like with the same tires front and rear, I should be able to solve this problem with springs or other suspension settings. And I'm still feeling a little weird about the differential situation. A LSD in a real car, never made the car want to snap around like that for me...
Well.. I have a 150 meg zip file to download and read.... and condense... and repost...
Well.. I have a 150 meg zip file to download and read.... and condense... and repost...
We switched to the new carpet for the second half of our race season. I fought with my car, as did everyone else, but solutions were found. Here it is (my setup) in a nutshell.
- Yellow springs all around. I ran the black ones, but the whites are about the same. 40wt oil. Ride height as low as possible and level. Shocks, end to end, are about 55mm.
- Rear toe in is a bit vague, are there's so much slop, but I've got the parts on for 2.5°. Front is a few degrees out. Camber is about stock out of the box.
- Diff - 3Racing with 1 million or heavier is our local go to. I've had good success with the stock diff, with 2 extra shims PER SIDE and a LITTLE antiwear grease. You can use the case screws to adjust tension. A very small hole drilled into the chassis will allow access for adjustment.
- I had good luck with M Grips on the front, with glued sidewalls and first trad block. Rears are some 3 year old S Grips, or kit tires. I like the S Grips as you can make hem more or less grippy as needed.
I've got one of the Yeah Racing diffs on the way to mess with and compare to my 3Racing diffs. This is just great timing, of course, since the next car has been announced and it uses a totally different unit and everyone knows I can't resist a new mini. Tamiya, you ruthless, brilliant bastards!
- Yellow springs all around. I ran the black ones, but the whites are about the same. 40wt oil. Ride height as low as possible and level. Shocks, end to end, are about 55mm.
- Rear toe in is a bit vague, are there's so much slop, but I've got the parts on for 2.5°. Front is a few degrees out. Camber is about stock out of the box.
- Diff - 3Racing with 1 million or heavier is our local go to. I've had good success with the stock diff, with 2 extra shims PER SIDE and a LITTLE antiwear grease. You can use the case screws to adjust tension. A very small hole drilled into the chassis will allow access for adjustment.
- I had good luck with M Grips on the front, with glued sidewalls and first trad block. Rears are some 3 year old S Grips, or kit tires. I like the S Grips as you can make hem more or less grippy as needed.
I've got one of the Yeah Racing diffs on the way to mess with and compare to my 3Racing diffs. This is just great timing, of course, since the next car has been announced and it uses a totally different unit and everyone knows I can't resist a new mini. Tamiya, you ruthless, brilliant bastards!
- Diff - 3Racing with 1 million or heavier is our local go to. I've had good success with the stock diff, with 2 extra shims PER SIDE and a LITTLE antiwear grease. You can use the case screws to adjust tension. A very small hole drilled into the chassis will allow access for adjustment.
I've got one of the Yeah Racing diffs on the way to mess with and compare to my 3Racing diffs. This is just great timing, of course, since the next car has been announced and it uses a totally different unit and everyone knows I can't resist a new mini. Tamiya, you ruthless, brilliant bastards!
Joined: Sep 2010
Posts: 2,313
From: Chicagoland
Well, the spring set has been ordered. As have some proper shims for the steering rack. And it just struck me I should have ordered two sets of springs. YEY!
Getting slop out of the rear end, is possible. Most of my efforts haven't been that effective. I still have a few degrees of "vague" back there. Solving it would be a matter of using the setscrews in the aluminum uprights, taking the contact points from the sides of the upright, to the ends of the lower pivot pin... (that's what they do on touring cars) Is it worth the effort? Is it TCS legal? :-)
Getting slop out of the rear end, is possible. Most of my efforts haven't been that effective. I still have a few degrees of "vague" back there. Solving it would be a matter of using the setscrews in the aluminum uprights, taking the contact points from the sides of the upright, to the ends of the lower pivot pin... (that's what they do on touring cars) Is it worth the effort? Is it TCS legal? :-)
They fit in no problem and even cranked down, the diff will still turn. It takes a Few minutes of breaking in, but it works. I just chuck it up into my cordless drill and spin it a little. The problem with running only one extra shim per side is the diff gets notchy. For some reason the extra shim I use smoothes it out quite a bit.
Joined: Sep 2010
Posts: 2,313
From: Chicagoland
I went to the track tonight, with "just" the M05 to run on the roadcourse.
I'm down to half a degree of camber in the rear wheels. I am down to a degree of toe on the front. And.. . I can drive it. it still diffs out, and as traction comes up during a run, it starts to get tippy again. I think I need to re-glue the tires.
For tire glue maintenance, do you strip the existing glue? or do you just glue overtop?
Springs and sealed diff are in the mail.
On the ride height question, the ultra mini shocks have the ride height very, very low as it stands. somewhere in the ballpark of legality. When the carbon arms come in, I'll get the droop setscrews in them, and see how much further I can go.
I'm down to half a degree of camber in the rear wheels. I am down to a degree of toe on the front. And.. . I can drive it. it still diffs out, and as traction comes up during a run, it starts to get tippy again. I think I need to re-glue the tires.
For tire glue maintenance, do you strip the existing glue? or do you just glue overtop?
Springs and sealed diff are in the mail.
On the ride height question, the ultra mini shocks have the ride height very, very low as it stands. somewhere in the ballpark of legality. When the carbon arms come in, I'll get the droop setscrews in them, and see how much further I can go.
Joined: Jun 2002
Posts: 3,549
From: Melbourne, Australia. Home of rc-mini.net
How close to real 1/10th are Tamiya cars? Find out...
https://www.facebook.com/pg/rcmini.n...06292446285627
https://www.facebook.com/pg/rcmini.n...06292446285627
Probably Tamiyas artsy-fartsy way of sending the message that this 'started from a clean sheet of paper'...
Looks like they took their CAD rendering and ran it through a sketch filter in Photoshop or something.



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