Mini-Z, Kyosho Mini-Z Racer, MR-03, MR-02, MA-010, Forums, News, Pictures, Parts, and Shop - Mini-ZRacer.com
Forums, Mini-Z, MiniZ, Kyosho Mini-Z, Kyosho MiniZ, Kyosho Mini-Z Racer
Mini-Z Hop-Ups, Mini-Z Parts, MiniZ Hop-Ups, MiniZ Parts, Kyosho Mini-Z Hop-Ups, Kyosho Mini-Z Parts, Kyosho MiniZ Hop-Ups, Kyosho MiniZ Parts, Kyosho Mini-Z Racer Hop-Ups, Racer Kyosho Mini-Z Parts
Old 2007.10.01, 01:53 AM   #1
michvin
Registered User
 
michvin's Avatar
 
Join Date: Dec 2003
Location: Brooklyn. Got a problem with that?
Posts: 1,498
Car balance

I figured Iíll share what I learned, since many of us are struggling with the setup. If youíre an experienced racer, donít waste your time reading this. Itís pretty basic. It just came to me as revelation. A little of a background, so youíll have an idea of what I can know about mini-z (not much, but Iím learning). Been racing on regular basis for the last two years. Track is huge (never saw anything bigger) RCP, rough side up. Until recently, I was running all available classes (but NASCAR), which includes MR02 stock, MR015 Speck, F1 and AWD. None of the cars handled well ever.
Recently I become tired of this situation and decided to make at least one car handle. MR02 was chosen for this purpose. Disassembled it, rebuilt taking all regular precautions to avoid binding and to assure free movement in every part of the car. After some pretty sporadic tire changes combination that worked more or less was found. Result Ė 25-27 laps (Iím going to use this as a standard). Further tire changes yield no improvement and I was curios what else should be done to improve the car. The most annoying problem was that it understeered a little under acceleration and oversteered off-power. I went to look at the car and noticed that that if you push on the front of the car (with the body on) with the finger Ė the rear lifted in the air. In contrast, the rear was very soft. To make the car somewhat drivable I had to make the front very stiff to take away steering. That felt wrong: I never saw a real 1:1 car with such a difference.
Thatís when I first start thinking about front-to-rear balance. Fix took some time and involved changing front springs, front suspension travel limiters and rear shock adjustment. Finger test showed that front and rear reacted equally to pressure and that when I push on one side, the other stayed planted. Some obvious improvement (after tire selection, more below) was achieved (27 laps, consistent). The problem was cured almost completely, but the car felt edgy and I had to drive it carefuly. I started observing otherís cars and noticed that at least 70% of the cars have this problem (understeered under acceleration and oversteered off-power). Thatís why I decided to write this.
As I said, the car didnít feel well, especially when changing direction. Every steering wheel movement unsettled its balance and the car was quite difficult to drive. And the ultimate goal was stable and predictable car.
That make me think about right-left balance. Using finger as a testing tool again I pushed on the side of the carís body downwards. It was interesting to see how the front wheel opposite the pressure point was lifted in the air. It felt wrong, and it was wrong. I noticed that rear was soft compared to front in left-right direction. Changing the T-plate to hardest and making front a little softer gave the desired result Ė when pushed on one side the wheels were planted, only the body moved.
I always thought that the correct tire is 90% of the setup. I still think it is true, but apparently it was a mistake I made to try to fix the flaws of the suspension with tires.
So now as the suspension is fixed, to the tire selection. I hate this process. To make our life hard different manufacturers use completely arbitrary degrees of their own, so that PN 8 is harder than Kyosho 20. To make things even more interesting, thereís no consistency within the brand (PN/Kenon). Why in the world 15 front slicks provide WAY less traction than 25 radials from the same brand? I donít get it.
The only way to choose the right tire combination in a proper manner is to get all possible tires and to try all possible combinations.. Expensive, time consuming, boring. I started thinking about systematization of this process. And hereís how I did it. It worked for me, might not work for you.
There are slow and fast tires on each particular surface. I started with finding fastest rear tires; after all they transmit the power to the track. For this purpose I put hardest tire possible on the front and I didnít care about the steering Ė only straight speed. After finding best tire from what was available at the store, finding the front that will give the grip I want was easy Ė took only an hour (final setup below).
The car now is fast, predictable and I can put it where I want it to be on the track and it is easy to drive. Oh, since I started with laps as a measuring unit for the setup, hereís the number: with this car I did 30 laps in 2 heats out of 3 (I used different car for the third heat). Track record for this layout is 31.
Bottom line: if the car doesnít work Ė check the suspension operation.

Setup:
MR02 with 3010 board, Mclaren body with appropriate offset plastic wheels. PN speedy 07 motor with 8T pinion
Front:
15o PN slicks
1o knuckles, Alu, Kyosho.
Shortest travel limiters (most suspension travel)
Stock tie-rod.
Red Kyosho springs

Rear:
PN Alu multi length mount
Hard T-plate
PN Disk damper with softest springs
Stock Gear diff
20o Kyosho wide slicks

Hope you found it usefull
__________________
And now my Scale Models too!

Last edited by michvin; 2007.10.01 at 02:01 AM.
michvin is offline   Reply With Quote
Old 2007.10.01, 05:32 PM   #2
lfisminiz
MINI-Z BODY NUT
 
lfisminiz's Avatar
 
Join Date: Mar 2003
Location: pa.
Posts: 5,028
Excellent write up with good points. You hit the nail on the head with alot of your comments.
__________________
MINI-Z BODY NUT





DG DESIGNS - PN RACING - MANTISWORX
lfisminiz is offline   Reply With Quote
Old 2007.10.02, 12:25 AM   #3
michvin
Registered User
 
michvin's Avatar
 
Join Date: Dec 2003
Location: Brooklyn. Got a problem with that?
Posts: 1,498
Quote:
Originally Posted by lfisminiz
Excellent write up with good points. You hit the nail on the head with alot of your comments.
what were the ones i missed? Really interested to know
__________________
And now my Scale Models too!
michvin is offline   Reply With Quote
Old 2007.10.02, 09:12 PM   #4
lfisminiz
MINI-Z BODY NUT
 
lfisminiz's Avatar
 
Join Date: Mar 2003
Location: pa.
Posts: 5,028
Thumbs down

No i mean you hit pretty much all the good points. Ive been dealing with the same things as you have and it was very interesting reading. Good job.
__________________
MINI-Z BODY NUT





DG DESIGNS - PN RACING - MANTISWORX
lfisminiz is offline   Reply With Quote
Old 2007.10.04, 01:44 AM   #5
Programmers
iTomCash
 
Join Date: Feb 2007
Posts: 1,706
Thanks for this, VERY useful. I've recently encountered problems with my HFAY car that this topic will probably help me solve. So I was wondering:

You say you used the shortest suspension limiters for most travel. Why not use none?

I'm curious, I use none at the moment but my car doesn't handle so well. I've yet to learn what's 'causing certain things in particular areas.
Programmers is offline   Reply With Quote
Old 2007.10.04, 07:37 AM   #6
bemoore
Rolling Chicane
 
Join Date: Dec 2005
Location: Madison, Alabama
Posts: 239
Quote:
Originally Posted by Programmers
You say you used the shortest suspension limiters for most travel. Why not use none?
I'm no expert at setting up a Mini Z, but in the 1:1 world of racing, you don't want the suspension to bottom out, and you don't want a tire hitting a fender. A suspension that bottoms out will cause handling problems. IMO, the proper suspension limiter would be the shortest one that keeps the tire from hitting the fender. And then, if you're bottoming out, you should use a stiffer spring. I have also heard of people putting shims in the front suspension to lower the car, but of course, this would reduce suspension travel, so you'd need to be racing on a very smooth surface.
__________________
Atlanta Mini Scale Racing
bemoore is offline   Reply With Quote
Old 2007.10.04, 10:43 AM   #7
michvin
Registered User
 
michvin's Avatar
 
Join Date: Dec 2003
Location: Brooklyn. Got a problem with that?
Posts: 1,498
Quote:
Originally Posted by bemoore
I'm no expert at setting up a Mini Z, but in the 1:1 world of racing, you don't want the suspension to bottom out, and you don't want a tire hitting a fender. A suspension that bottoms out will cause handling problems. IMO, the proper suspension limiter would be the shortest one that keeps the tire from hitting the fender. And then, if you're bottoming out, you should use a stiffer spring. I have also heard of people putting shims in the front suspension to lower the car, but of course, this would reduce suspension travel, so you'd need to be racing on a very smooth surface.
I'm not an expert either, but i'll agree. I never tried running without the limiters, but this IMO would have dual negative effect (assuming that body doesn't rub on the track when the front is compressed): You'll be in danger of rubbing the body with wheels and by allowing too much travel you provide too much traction to the front while braking by allowing more mass to be transfered. You can compensate for that by using tires with less grip, but that's exactly what you want to avoid - such a compensation. Another thing (that's a question, i don't know the answer): how the springs are kept centered on a kingpin without the limiter?
__________________
And now my Scale Models too!
michvin is offline   Reply With Quote
Old 2007.10.04, 01:42 PM   #8
Programmers
iTomCash
 
Join Date: Feb 2007
Posts: 1,706
Yeah, after my question I decided to have a close look at the cars front end. Without the limiters, the suspension has about a whole mm of vertical play!! It also doesn't keep central (as you mentioned). So I put the shortest shim in.

I also followed the initial guide and applied pressure in the same places, and balanced the back out with the front. Now all my wheels stay planted too!!

Very cool thread, thanks again.
Programmers is offline   Reply With Quote
Old 2007.10.04, 02:21 PM   #9
michvin
Registered User
 
michvin's Avatar
 
Join Date: Dec 2003
Location: Brooklyn. Got a problem with that?
Posts: 1,498
No prob, i'm happy i got something right and could help. The ultimate test however would be the track and lap times.
__________________
And now my Scale Models too!
michvin is offline   Reply With Quote
Old 2007.10.04, 03:28 PM   #10
Programmers
iTomCash
 
Join Date: Feb 2007
Posts: 1,706
Yeah, it'll be about no more than a week before I can test it on the RCP. It'll be an easy comparison. My car was very unstable out of corners before. Hopefully, it'll stay nice and flat now. My setup only slightly changed so if it causes me problems, I can change it back easy.

I'll also post any new findings or problems.
Programmers is offline   Reply With Quote
Old 2007.10.04, 10:31 PM   #11
byebye
Moderator
 
byebye's Avatar
 
Join Date: Dec 2003
Location: Stafford, Va
Posts: 6,063
One more thing to consider when adjusting the front suspension is how much compression is caused when the car is sitting flat? I mean is there a gap between the knuckle and the chassis? Let me take some pics to show what I mean.

Kris
byebye is offline   Reply With Quote
Old 2007.10.04, 10:35 PM   #12
michvin
Registered User
 
michvin's Avatar
 
Join Date: Dec 2003
Location: Brooklyn. Got a problem with that?
Posts: 1,498
Quote:
Originally Posted by byebye
One more thing to consider when adjusting the front suspension is how much compression is caused when the car is sitting flat? I mean is there a gap between the knuckle and the chassis? Let me take some pics to show what I mean.

Kris
you mean spring so soft that it compresses, knuckle go up and the gap is between lower suspension arm and the knuckle? Is that what you mean?
__________________
And now my Scale Models too!
michvin is offline   Reply With Quote
Old 2007.10.04, 10:38 PM   #13
byebye
Moderator
 
byebye's Avatar
 
Join Date: Dec 2003
Location: Stafford, Va
Posts: 6,063
Okay well never mind . I don't have any cars that do that. But basically the weight of the chassis and the softness and height of the spring can cause it to sit with a lot of play. This means that any bumps can cause it to unsetlle.

Good write up though. You can tell that you had to test and tune, test and tune until you found what was right for you.

Kris
byebye is offline   Reply With Quote
Old 2007.10.04, 10:41 PM   #14
byebye
Moderator
 
byebye's Avatar
 
Join Date: Dec 2003
Location: Stafford, Va
Posts: 6,063
Quote:
Originally Posted by michvin
you mean spring so soft that it compresses, knuckle go up and the gap is between lower suspension arm and the knuckle? Is that what you mean?
Yes! The only way to fix this is shims and or new springs that are not of the "lowering" type.

I personally take my suspension limiters and cut them as short as possible. They act more as spring holders than limiters. I'd rather control travel with a stiffer spring and allow it to travel as much as needed.

On my VDSII car I run stock springs. On my points car/modified(used to be) I run a hard spring. The wider rear end of the VDSII means more push so I like to have soft springs up front for more steering. With the Mclaren I run stiffer springs so I get more push but of course it's not as fast as the VDSII so I don't need as much steering.

Kris
byebye is offline   Reply With Quote
Old 2007.10.04, 10:42 PM   #15
michvin
Registered User
 
michvin's Avatar
 
Join Date: Dec 2003
Location: Brooklyn. Got a problem with that?
Posts: 1,498
Quote:
Originally Posted by byebye
Okay well never mind . I don't have any cars that do that. But basically the weight of the chassis and the softness and height of the spring can cause it to sit with a lot of play. This means that any bumps can cause it to unsetlle.

Good write up though. You can tell that you had to test and tune, test and tune until you found what was right for you.

Kris
Thanks!
I think i see what you mean. No, my car doesn't have droop in the front. Is it neccesary and i'm missing something? I don't know...
__________________
And now my Scale Models too!
michvin is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
FS: RTR Kyosho 1/10th rally car, Airtronics MXA ChattavegasSE Mini-Z Marketplace 9 2008.05.29 11:33 PM
My Season 6 HFAY Car... Programmers Stafford Mini Z Racers England 6 2008.05.06 03:44 PM
'Neutral car' and newbie learning Aurora Mini-Z AWD MA-010, MA-015 5 2007.02.18 08:54 PM
Motor only runs when Car is off! denvajim Mini-Z Racer MR-02 6 2005.03.07 03:10 PM


All times are GMT -5. The time now is 10:07 AM.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright ©2011 Mini-ZRacer.com
Mini Inferno Sale - Up to $85 Instant Savings!
Micro-T Hop-Ups
RC18R, M18, Micro RS4, Mini-LST, TamTech-Gear, Minizilla, RC18T, RC18B, RC18MT
shop.tinyrc.com Products

more»
Tiny RC Community News
[03/22/17] MZR was on vacation, didn't... : All kidding aside, the host experienced a bit of a server meltdown last week and efforts to restore the site to a new server took longer than anticipated. The current server is temporary until - more»
[11/25/15] Did You Hear? Our Black... : Hey Racers,
We're getting started a bit early with our Black Friday sale this year.  Generally we're not supporters of retailers opening early on Thanksgiving, but in our case, we're - more»
[06/30/15] shop.tinyrc.com: Have You... : Hey All! Just a quick reminder to everyone that we post all of our shop.tinyrc.com Newletters here on the MZR Forum. If for some reason you miss them in your email inbox, you can always see the - more»
Mini-Z, Mini-Z Racer, MR-02, MA-010
M18, M18T, RC18T, Mini-LST, Mini-T, Micro RS4, XRay, 1/18, 18th scale
XMODS, XMOD, Micro Flight, ZipZaps, ZipZaps SE, Bit Char-G, MicroSizers, TTTT, Plantraco Desktop Rover, SuperSlicks, Digi Q
Mini Inferno, Mini Inferno ST, half EIGHT, 1/16, 16th scale
Epoch, Indoor Racer, 1/43, 43rd scale
E-Savage, eSavage, eZilla, e-Zilla, HPI
Robots, Bots, Bipeds, Wheeled, Manoi, Roomba, NXT, Lego, Hacking
Crawling, Crawlers, Micro, RC, Losi Mini-Rock Crawler, Duratrax Cliff Climber
Kyosho Minium, Caliber 120, Minium Forums
Mini-Z Hop-Ups, Mini-Z Parts, Mini Inferno Hop-Ups, Mini Inferno Parts, M18 Hop-Ups, M18 Parts