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View Full Version : MR01-1.5 Front vs MR02 Front effect on steering


Draconious
2006.05.07, 02:40 PM
I have been driving a MR02 with a RM90mm body for the last 10 or so races, its always been a bit unstable... I always thought it was my transmitter or servo etc... well I recently changed bodies to a MM98mm mustang body, and boy does it handle way way better...

Comparing this with what I have read recently, while searching for data to setup my own AWD chassis... I came to the conclusion that its best for the MR01.5 to use the RM lengths, and the MR02 to use the MM lenghts... due to the ackerman effect on the wider front end on the MR02 and narrower front end of the MR01 and MR01.5 rear end. The wider kingping location pushes the ackerman point back further on the MR02 to the 98 and 102mm settings, and the narrower front brings it forward closer to the 94mm setting on the MR01 1.5's.

Just thought I would state the obvious... so everyone can keep it in mind when choosing a body. It had a larger effect than I thought it would. Having the wide front on a 90mm body was making it whip into corners to aggressivly and not being very stable on the straight, even with toe rods...

This makes me wish the MR02 and MR01.5 had the front end a seperate piece, so you could swap between the narrow/wider front ends... and still have the choice of battery bays flat or narrow.

HammerZ
2006.05.07, 04:45 PM
I think battery location has some effect as well. With the MR01 and MR01.5 the batteries are closer to the centerline of the chassis, allowing more roll and planting the outside tires for more bite. The flat layout on the MR02 gives me a dead feel.

For me running MM on both the MR02 and MR01.5, I have a very hard time telling the difference as both feel the same. When using the RM/RML setup it is more clear that the MR01.5 turns better for sure.

One last point to address is tires. Most like to use the softest tires that they can get. To me running 10 deg tires is very much like driving a real car with the tires aired down to 10 PSI. Sure it grips the corners well, but the tires flex too much. I have got some flak over my choice of 20-30deg tires. To me the harder tires are more stable in a turn.

I respond to this as you have covered some good points there.

arch2b
2006.05.07, 05:17 PM
[QUOTE=HammerZ]....One last point to address is tires. Most like to use the softest tires that they can get. To me running 10 deg tires is very much like driving a real car with the tires aired down to 10 PSI. Sure it grips the corners well, but the tires flex too much. I have got some flak over my choice of 20-30deg tires. To me the harder tires are more stable in a turn....QUOTE]
what do you care if someone gives you flak over your tire preferences? i sure as hell wouldn't give you any. whatver works for you obviously works for you, nothing more to it really. stick to your guns and run what you like :)

opinions on tires are like opinions on motors, very subjective and driver specific

HammerZ
2006.05.07, 07:31 PM
Just making a point, that going to the extreme would seldomly solve a handling problem.

hobbycar
2006.05.13, 09:27 AM
Drac, that new Mustang you were driving last AA GTG was awesome! Your car was fast before. Now it's fast and much more stable and easier to handle. You're going to be giving all of us a good run for top spot even more now (after Chuck/onrailz of course :D ).

Here's a link talking about Akerman point (http://www.auto-ware.com/setup/ack_rac.htm).

I've always thought 90mm was just to short a wheelbase for the HFAY Tracks we run on. It seems like you can turn on a dime but like you said it was to unstable and hard to control.

Longer wheelbase cars in general are more stable. Shorter wheelbase cars in general have tighter turn-in capability (tighter turning radius).

-hobbycar

arch2b
2006.05.13, 10:01 AM
what setup do you have for the mustang? i was running that body for awhile....

Draconious
2006.05.13, 11:28 AM
Yea it was handling much better then F40 :) who knows maybe my tires were rubbing on the F40 LOL...

Body: Mustang

Chassis: MR02 with stock MM motor pod

Rims: From Mustang Autoscale

Front Tires: Atomic 20 front slicks - these wear out very fast, barely last 2 events. PN Tape under front tires, worked for a few races... but stickum was eventualy lost and they started comming off again, RCP dust gets in there and sticks to the tape instead of the tire ;)

Rear Tires: Unkown, barrowed from Will, they look like GPM 10s? I wore those out too.

Bearings: MZR.com Dry Race - a some what new set.

Wheel Nuts: Bulk Surplus M2 Lock Nuts :)

Knuckles: Kyosho Alloy 0 degree (gray)

Front Springs: Kyosho Yellow (hard?)

Rear Springs: Nota Zipo...

Tie Rod: Stock :)

H-Plate: Stock Plastic (was working better than my carbon plates)

Differential: Kyosho MR02 - adjusted so it does not squeeze together and drag the rear chassis bearings. ;)

Motor: Stock (From a Japan Overland ReadySet), I put some electrical cleaner/lube on the com, but its a pain to get it in there lol, a syringe helps. Motor Bearing Oil - Lubit8 got it in surplus.

This is far from a perfect setup! I need rear dampening to eat up the hopping... its just far far better than my previous setup was...

Wish Kyosho sold the stock H plates in a package of like 10 for $5.00 or something

arch2b
2006.05.13, 12:47 PM
i had a similar setup on my stang excpet for a cf h plate and kyosho rear oil shock. the reasons i dropped mine were;
front tires peeled off easily due to wheels being very close to the outside edge of the body
it looked/felt like the body weight shifted more so than others in turns which took a bit more finese to control well and i am not the best driver to begin with.

i really liked the mustang though and found it to be better than the m3 oddly enough. it looks huge compared to some other bodies though which makes it stand out. the blue with white racing stripes certainly gives it that hot rod racing look :) more so than the silver/white. it should be an awsome body to do custom paint jobs with. there are literally hundreds of racing livery's, high end custom cars to replicate. this is all making me want to get another ;)

i was not at all impressed with the gt however. soyverde bought one, he's a very good driver, and it was not as nice a ride as other bodies he's tried. it certainly looks good though so i traded for his and it's a shelf queen.