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Tamiya mini cooper

Old 06-27-2013, 11:31 AM
  #19111  
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Originally Posted by Granpa
If you weren't the nether regions of a horse, you'd understand that.
Thank you for reinforcing my point.

I saw nothing wrong with the way he asked for help.
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Old 06-27-2013, 01:05 PM
  #19112  
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Ok guys in my post I hadn't thought about how it would have been taken. The issue was hammered out. Grandpa although a bit rough at times is a great source for info. As are the rest of you that have chimed in and pm'ed me. I am grateful for all help given.

Now on to what has happened since my post. I went out and attempted to locate some shims and ended up with a new ball diff for the mini. The LHS did not have any shims so I sprung for the ball diff as I have been wanting to make the upgrade anyhow. As a side note realized after I put the gear diff back together to put it in the spare parts box that it wasn't worn like I thought. Apparently the screws had backed out allowing the nasty slop I heard when I shook it. Lesson learned but wanted upgrade acquired anyhow.

Now back to the mini and the reset.

Jason
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Old 06-27-2013, 01:55 PM
  #19113  
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I leave you guys alone fr a few days and look what happens!

That 2oz of lead in the back of your car may be making things worse. It can create a pendulum effect. It took engineers at Porsche almost 50 years to get that one sorted. You seem to be going in the right direction. A firmer diff will cause the car to lose a little steering. I think we're all tuning on the edge now - we create a car that will have massive front grip and attempt to attenuate that front grip through various tricks. Fun!
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Old 06-27-2013, 03:18 PM
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Ok a short report after assembly and quick test run in front of the house. The ball diff solved a few other issues that I thought were secondary and would have been worked on later. But apparently did play a bit of a part in my end swapping issues as suggested.

1. Ditched the Mito body in Favor of the Cooper body I found why digging around in the hobby room.

2. I switched the shocks as Grandpa suggested. Front to back and back to front. Fronts now have Black/Red 35wt and Rear Black/Blue 40wt.

3. Sway Bars on order.

4. Diff swapped to Ball Diff. (Huge difference)

5. Have yet to rebuild shocks but may do later today after I take the car to the track to test it there.

6. Current ride height Front-4.5 Rear-5.0

So I have noticed I am now pushing rather much on the street. But know a prepped track will have more traction and may not have this tendency. But my question is if it does still push more than I like what quick change could I make to help? Harder springs on front? Softer on rear?

Jason
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Old 06-27-2013, 03:32 PM
  #19115  
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A rear sway bar seems to be an effective way of getting the car to rotate more, without negative effect. I've gone to pretty much the same setup as you and have added the hardest rear sway bar. Works pretty well. It also seems to help keep the opposite (diagonal) front wheel planted a bit more when I get on it in a corner.
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Old 06-27-2013, 04:05 PM
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Default Glue your tires - it may help

Have you CA glued the outer sidewall of your front tires?

75% of handling comes from the tires. Everyone tunes their tires whether it be compound, sauce, diameter, inserts, or whatever. You show me a surface race where guys aren't tuning their tires, and I'll show you some out of control vehicles.

It's a lot cheaper and, in my experience, a lot more effective than buying a bunch of hop up parts and muddying the waters even more.
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Old 06-27-2013, 04:40 PM
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Monkey, As soon as the bars get here I will do just as you suggested.

SMcD, I know tires are an integral part of ANY onroad and even offroad vehicle. But for purposes of future TCS racing am trying to tune the car in for Spec TCS tires. Not to mention continue to try and get a handle on what does what to the mini. It seems I am starting to get a handle on the TC's I run and how to tune them. But like I said before the Mini just keeps stumping me as what works in TC's does not always translate to Mini's well if at all.

Jason
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Old 06-27-2013, 05:35 PM
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Originally Posted by fresnojay
Monkey, As soon as the bars get here I will do just as you suggested.

SMcD, I know tires are an integral part of ANY onroad and even offroad vehicle. But for purposes of future TCS racing am trying to tune the car in for Spec TCS tires. Not to mention continue to try and get a handle on what does what to the mini. It seems I am starting to get a handle on the TC's I run and how to tune them. But like I said before the Mini just keeps stumping me as what works in TC's does not always translate to Mini's well if at all.

Jason
Glad you're getting some help now and have learned Rule #1 about tuning Minis. Forget the TC stuff cause a lot doesn't transfer over.

Some of the push you're now getting is from the Type As you have up front. For now though, I'd suggest leaving them there while you're developing your basic set up. You can switch to S grips on all four corners later when you've got something you can live with. Almost all the TCS racers use them on all 4 corners.

Now this is just my opinion and may not be widely held. Roll bars on a Mini are useful on the rear. What they do is to keep the front tire on the outside of the corner from "dumping" and digging in by controlling the amount of roll. This is also why putting the stiffer springs and shocks on the rear, helps plant it. Sometimes.

Tim K had a long post on traction roll. It had a lot of good info and is worth going back, finding it and committing it to memory.

Good luck and glad we got our differences worked out.
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Old 06-27-2013, 07:59 PM
  #19119  
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Looks like I should be having an M06R coming in soon. Can't wait to install the speed gears I got from monkeyracing so I can finally keep up on the straights.

Anyone try the 3racing or Tech racing suspension arms? The Tamiya stock arms were too soft and got horribly sloppy pretty quick. And no, my car doesn't have to be TCS legal.
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Old 06-27-2013, 09:39 PM
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Grandpa, After a run at the track it pushed less but it still pushed more than I like. But at this point I attribute a good portion of it to the unprepped track and untreated A's on the front. I think these 2 things should allow the car to straighten itself out. I shall know more tomorrow at the races. At this point its looking like it should be a huge improvement.

I will look up that post and check it out.

Jason
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Old 06-28-2013, 05:14 AM
  #19121  
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Hi Jason,

If you're happy with your tires and diff set up then there are a few things you can try to stop it from pushing in the corners.
-Harder springs rear, softer on the front. If you want to see if this is going to work for you then go to the extreme ends of the spring spectrum and then dial back from there. For example, run red or fluro red soft springs on the front, and then ultra hard purples on the rear. If the back starts to step out then you've gone too far, so you can go back to a blue spring on the rear and see if that gives you the balance you're looking for.
- rear toe in blocks. Tamiya make alloy rear uprights in 1, 1.5 and 2 degree. If you use the rear M05 alloy plate for SWB it will add another 1 degree toe in so that 3 degree toe in overall is possible (but only on the SWB). The more rear toe in, the more stable the car will be. If you go to a 1 degree rear toe block you're taking away rear grip and giving back more steering. You can even try a zero degree plastic rear upright, they can be found on the TL01 B-parts tree (part no.50736), these came with the first generation of M03 & M03L kits.
-inserts. If you have to use a control tyre front and rear, then you can try using a harder insert in the rear and softer in the front.
- front uprights ball stud/steering link position. If you look at the mini from overhead (plan view) you will see that there are 3 holes on the front upright 54177 (if you're using this one). Move the ball stud to the forward most hole if you need more steering.

Hopefully one of these suggestions will help.
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Old 06-29-2013, 10:06 AM
  #19122  
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Tim,
I think it's a misconception to think that moving the ball stud to the forward hole gives more steering. It does do two things:
1) Changes the Ackerman = makes the inner tire turn a little bit more in relation to outer tire = makes the steering more reactive at slower speed, when the wheels are rolling, but scrubs speed at higher speed when the wheels are sliding more.
2) Shortens the link = makes the wheels turn more in relation to how much the steering wheel is turned. So it may feel faster, but to me this just makes the car feel more reactive = "twitchy", just like using a too-fast servo for controlled driving. Hi-end radios have a servo speed adjustment feature to deal with this. Most good drivers use this tuning aid, especially in twitchy F-1 cars. My old Spektrum doesn't do servo speed, but steering expo can also help here, although this alters the curve, whereas steering speed is linear.
Happy Tuning...
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Old 06-29-2013, 12:21 PM
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Ok gave the mini a thorough racing last night. Results were a much faster car. Shaved on average 1.2 seconds a lap. It will still get loose but not swap ends, sway bars should handle this. No push on prepped track. It did start traction rolling though. So I need to track down that post on traction rolling and study it.

Thanks again to all that helped me get this car sorted out. It was again fun to run mini. Wish i could say the same for TC last night .

Jason
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Old 06-30-2013, 03:35 AM
  #19124  
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not the cleanest paintjob....as I was too excited to see how the shell performs. Anyway, love the handling Durability not the best though...
Attached Thumbnails Tamiya mini cooper-20130623_115212-small-.jpg   Tamiya mini cooper-img-20130617-wa0014.jpg   Tamiya mini cooper-img-20130616-wa0083.jpg   Tamiya mini cooper-img-20130616-wa0085.jpg  
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Old 07-01-2013, 10:07 AM
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Originally Posted by Laguna Bozo
Tim,
I think it's a misconception to think that moving the ball stud to the forward hole gives more steering. It does do two things:
1) Changes the Ackerman = makes the inner tire turn a little bit more in relation to outer tire = makes the steering more reactive at slower speed, when the wheels are rolling, but scrubs speed at higher speed when the wheels are sliding more.
2) Shortens the link = makes the wheels turn more in relation to how much the steering wheel is turned. So it may feel faster, but to me this just makes the car feel more reactive = "twitchy", just like using a too-fast servo for controlled driving. Hi-end radios have a servo speed adjustment feature to deal with this. Most good drivers use this tuning aid, especially in twitchy F-1 cars. My old Spektrum doesn't do servo speed, but steering expo can also help here, although this alters the curve, whereas steering speed is linear.
Happy Tuning...
Ackerman----interesting subject, largely ignored, probably due to a lack of understanding of how it affects steering. It seems to me that it's the inner hole mounting position that affects Ackerman more than the forward or rear hole. Also, whether you run the forward or rear hole, the Ackerman will change if you're using toe out or toe in to start.

From my perspective and observations made with my Minis at the Tamiya track, the LWB car liked the inner hole and the MWB car seemed better with the rearmost hole. Your experience may differ from mine and I'll not dispute it.

M05 owners can ignore this stuff, cause the steering link is too short to use the inner hole.

Anyone want to take on the subject of "bump steer"?????

Last edited by Granpa; 07-01-2013 at 10:29 AM. Reason: addition
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