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 2003.01.16, 11:58 PM   #1
Adult_driver
Mini-Z Novice
 
Join Date: Dec 2002
Location: Seattle
Posts: 13
Modena, Finally Drives

Finally, I got the suspension and steering tuned so that this car drives controllably on hardwood (a severe test of man and machine). What a lot I went through to get here. It is amazing how subtle the handling influences are.

First upgrades were a Kyosho Ball Diff and MZR bearings. The MZR bearings are so free rolling that the slight unevenness in the rubber of the tire causes the heavy part of the tire to settle to the bottom. That helped, but it only encouraged me to drive faster and then I was out of control again.

Next I made a "square" rear plate. It is amazing how precisely you must drill the holes. If the pairs of holes on each end of the plate aren't exactly parallel and exactly square to the long axis of the car, you can't ever get it to steer. Finally, through careful work I finally got an accurate plate. But, I think it was too stiff and I think the front end suspension would bind on the king pins.

Next came a 3 degree toe-in (Square) and 2 degree camber knees. These are very precisely made and the front suspension compresses and rebounds with no resistance, except the spring. I went to the stiffest springs. Boy, the car ran straight but would not turn, except at very low speeds. Somewhere along the way I tightened the differential. That also helped going straight at speed.

I went down to 2 degree toe-in. Now the car could turn. But one of two things would happen--at speed in a straight away, the reaction to a steering correction would be delayed, I would over-react and turn too much, and then the front wheels would bite and it was all over (so to speak). Or, when I aimed correctly down the straight away and slowed down to turn, the oversteer was severe.

Now I start analyzing this, reading a lot in the forums, and doing my homework. The stiff back-end and stiff front end were about the worst combination I could have chosen. First, I softened my "square" plate and turned it into an 'O' plate by removing the center. This made the back-end more compliant vertically, but still allows almost no sideways twist. So, I get the benefit of no roll, but with a rear-end just moderately more stiff than stock. I think with the Modena's long wheelbase position, the stock H plate is too soft (in the med. wheelbase position it is just about right, though still too twisty). I also use the ear plug trick as a dampener, though I need slightly softer ear plugs.

At the same time, I switched the front end from the yellow hard springs to the stock springs. Now the softer front end could result in too much oversteer. But, my problem was initiating any turn at all. Softing the front end compensates for the understeer of the toe-in (I will try 1 degree next. Three degrees was too harsh. Two is drive-able.) And the simultaneous softening of the back-end gives the back-end enough additional traction to keep the rear tires on the driving surface enough to prevent the front softening from causing spinouts or excess oversteer.

Now, I am happy. The Modena is much easier to drive and I can reach higher speeds in the straight aways and still turn into the curves without slowing down too much. It really works noticeably better. I had to assemble a reasonable repertoire of different parts before I could try a good range of alternatives. It amazing how significant the effect is of such apparently (at least to our big bodies) subtle changes.

So, my theory on why the Modena, despite being one of the longest, widest stance Z's can be so hard to drive is this. Because of the huge added offset in the front wheel to increase width--easily 3/16"--the general slop of the z steering works with a very large radius so that with zero or negative toe-in, the front wheels wiggle through a very large arc at the ends of the axles. Narrower cars have the same slop, but the absolutely arc of "wiggle" is less. So, the toe-in corrects the slop, then you need to balance the toe-in to still be able to turn. I think it would be even better to elimate the slop because excess toe-in is harsh medicine that requires a lot of subsequent compensation.

So, the final setup is:

rear suspension: custom moderately stiff 'O'plate with ear plug dampener
front suspension: stock springs (moderately soft)
front steering: 2 degrees toe-in, one degree camber

The final experiment with this setup will be the adjustable front roll bar. With the Square toe-in and knuckles the suspension movement is so smooth (a good thing) that the anti-roll bar does almost nothing. I think the front wheels will stay in better contact with the driving surface with less roll in the curves. This is the final adjustment to compensate for the increased roll of the softer front springs.

There you have it.
Adult_driver is offline   Reply With Quote
Old 2003.01.17, 11:08 PM   #2
Skylineboy
ZoomZoom
 
Skylineboy's Avatar
 
Join Date: Jul 2002
Location: Australia, Vic
Posts: 206
Adult_driver,

Are you still running on stock tires?

They are not very good in terms of grip (on wooden floor)and it will be worth while to invest in some softer compound tires.

You'll be surprise by how well your car can be glued to the ground just by having softer compound tires.

My Z is pretty much stock (with the exception of springs, rear shock, tires and H-plate which I've changed), I've got the to the stage where oversteer does not occur at all.

If you do a search on your "tires", I'm sure you'll find a lot of info.

Have fun with your Z.

Skylineboy
Attached Images
File Type: jpg z-chassis.jpg (70.0 KB, 51 views)
Skylineboy is offline   Reply With Quote
Old 2003.01.17, 11:41 PM   #3
mini-zfuel
F1 Perfectionist
 
Join Date: Dec 2002
Location: The Woodlands, TX
Posts: 616
my setup...:)

great post adult... my modena has:

red soft kyosho front springs...( are the stocks any softer do you or anyone know???)

powerline rear spring shock with blue spring

powerline roll shock set with yellow springs

powerline t-bar (medium one) (still considering mzr.com o plate)

stock tires on square 360 modena gt cup aluminum wheels

so far so good she runs great!!!

anyone got any ideas???
mini-zfuel is offline   Reply With Quote
Old 2003.01.17, 11:42 PM   #4
mini-zfuel
F1 Perfectionist
 
Join Date: Dec 2002
Location: The Woodlands, TX
Posts: 616
oops...

forgot to add I run on a flat concrete garage track, and maybe moving up to an ozite layed garage track soon but right now shes running ok
mini-zfuel is offline   Reply With Quote
Old 2003.01.18, 07:12 AM   #5
Skylineboy
ZoomZoom
 
Skylineboy's Avatar
 
Join Date: Jul 2002
Location: Australia, Vic
Posts: 206
Re: my setup...:)

Quote:
Originally posted by mini-zfuel

red soft kyosho front springs...( are the stocks any softer do you or anyone know???)

miniz-fuel,

From memory, the stock springs are slightly stiffer than the red ones.

Skylineboy
Skylineboy is offline   Reply With Quote
Old 2003.01.18, 09:38 AM   #6
mini-zfuel
F1 Perfectionist
 
Join Date: Dec 2002
Location: The Woodlands, TX
Posts: 616
thanks skyline... anyone else verify this???
mini-zfuel is offline   Reply With Quote
Old 2003.01.18, 12:30 PM   #7
Adult_driver
Mini-Z Novice
 
Join Date: Dec 2002
Location: Seattle
Posts: 13
Tires on Modena

I tried the 30 tires and they were slicker than the 50s. Maybe because I had broken in the 50s on concrete. But, I took sandpaper to the 30s and they were still slippery. I think the 30s are sticky enough that they picked up so much dust so quickly that they became slippery. Anyway, I sort of came up with the notion that hard surfaces require hard tires and soft surfaces require soft tires.

Should I give the 30s another try?

I also discovered that I need to get the ball diff. as tight as is usable for good straightline tracking.
Adult_driver is offline   Reply With Quote
Old 2003.01.18, 12:37 PM   #8
wrcracer
Offroad Specialist
 
wrcracer's Avatar
 
Join Date: Nov 2001
Location: Wilmington NC USA
Posts: 1,647
Send a message via AIM to wrcracer
you got it backwards: soft tires for hard, slick surfaces, and hard tires for, grippy surfaces.
__________________
My truck is like my fat girlfriend. All it does is f*** me and take my money.
AIM - TheBigGreenGMC
'Wheelin is Life.
WRCRacer's Gallery
wrcracer is offline   Reply With Quote
Old 2003.01.18, 12:45 PM   #9
mini-zfuel
F1 Perfectionist
 
Join Date: Dec 2002
Location: The Woodlands, TX
Posts: 616
so what are the stock kyosho modena tires??? 50 all around???
thanks
mini-zfuel is offline   Reply With Quote
Old 2003.01.18, 12:52 PM   #10
wrcracer
Offroad Specialist
 
wrcracer's Avatar
 
Join Date: Nov 2001
Location: Wilmington NC USA
Posts: 1,647
Send a message via AIM to wrcracer
i think so
__________________
My truck is like my fat girlfriend. All it does is f*** me and take my money.
AIM - TheBigGreenGMC
'Wheelin is Life.
WRCRacer's Gallery
wrcracer is offline   Reply With Quote
Old 2003.01.18, 01:24 PM   #11
ChaserRC
Registered User
 
Join Date: Dec 2002
Location: Hong Kong
Posts: 214
if it's running on hardwood surface, it's better to use foam tires..
__________________
http://www.ChaserRC.com
Online Store - High Performance Motors and Parts
Mini RC Forum - News, Product Reviews and Discussion
ChaserRC 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
WTS: 2.4GHZ Kyosho Ferrari 360 Modena MR02 with free Dnano marc Mini-Z Marketplace 8 2008.10.09 09:50 AM
modena on AWD: body clips michvin Mini-Z AWD MA-010, MA-015 1 2006.04.28 01:23 PM
Drives worse after hop-ups??? Dempy Parts and Hop-ups 22 2003.03.11 09:53 PM
360 Modena ?? NT2 Beginner Questions 23 2002.12.29 05:08 PM
I Finally Got It!!!!! Asmenoth Parts and Hop-ups 1 2002.03.20 07:41 PM


All times are GMT -5. The time now is 08:24 PM.


Powered by vBulletin® Version 3.8.3
Copyright ©2000 - 2024, 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