2007.01.08, 06:58 PM
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#1
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Registered User
Join Date: Nov 2006
Location: SoCal
Posts: 921
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car understeering questions.
hey guys,
I finally had the opportunity to run my mr02 on the rcp track last weekend at a local event, but I'm wondering if anyone can give me some opinions and ideas on how to setup the car to eliminate some of the understeer i'm experiencing with my setup right now. such as if I don't change the tire what can I do to make it less likely to understeer or if I don't change the front springs, etc. From the research I was under the impression that the firmer front and softer rear will make the car oversteer more? or did I got it the idea reversed?
my current suspension setup:
PN white springs up front
PN disc damper/red springs
PN cf t-plate/soft
kyosho 30degree directional front
kyosho 20degree directional rear
PN +0.5 toe bar
PN +0.5 camber knuckle
kyosho ball diff
thanks in advance
p.s. I'm running my C5-R with +1N/+3W. not sure if this would also contribute to the understeer or not.
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2007.01.08, 07:06 PM
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#2
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GSR #222
Join Date: Feb 2006
Location: Houston, TX
Posts: 295
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I think the larger part of your issue is caused by your tires. I don't know about there, but down in houston all of us pretty much use 8º in the rear and 18º-20º in the front.
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2007.01.08, 08:28 PM
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#3
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Registered User
Join Date: Feb 2005
Posts: 1,683
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Softer at either end gives more bite, so to say, you do have the idea backwards.
Calvin is right to a point about the optimal tire combo. 8deg rear and 18 treaded pn or gpm 20 deg fronts are about ideal tire combinations. The tires you are runing give less overall grip than the previous. I suggest running a narrower offset front along with a softer spring. 1 deg offset fronts on Mr02's causes a lot of scrub in the front end, which heavily decreases front steering on rear wheel drive cars.
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2007.01.08, 08:46 PM
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#4
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yes, it's a boxer
Join Date: Dec 2005
Location: Seaville, NJ
Posts: 929
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Quote:
Originally Posted by FrankW1029
hey guys,
I finally had the opportunity to run my mr02 on the rcp track last weekend at a local event, but I'm wondering if anyone can give me some opinions and ideas on how to setup the car to eliminate some of the understeer i'm experiencing with my setup right now. such as if I don't change the tire what can I do to make it less likely to understeer or if I don't change the front springs, etc. From the research I was under the impression that the firmer front and softer rear will make the car oversteer more? or did I got it the idea reversed?
my current suspension setup:
PN white springs up front
PN disc damper/red springs
PN cf t-plate/soft
kyosho 30degree directional front
kyosho 20degree directional rear
PN +0.5 toe bar
PN +0.5 camber knuckle
kyosho ball diff
thanks in advance
p.s. I'm running my C5-R with +1N/+3W. not sure if this would also contribute to the understeer or not.
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this is my setup and it seems to work well for my mini-96+expansion as well as the big a$s track in SINY, which typically has some long straights and some technical spots, requiring tight radius turning as well as high speed work.
I am running a different body than yours, with differnet offset wheels (Mclaren), so what Cristian has said about them might very well be accurate considering i've only used Mclarens, however, for what it's worth-
0 deg tierod
1 deg Kyosho alloy knuckles
PN red springs (softies)
lowered in front with 4 kyosho .02 shims per side
Atomic Ti plate damper and delrin disks w/ no lube but polished with Mothers billet polish (gives a consistent slide)
Atomic green top springs
Atomic periwinkle bottom springs
Atomic LCG mount with Kyosho ball diff set on lowest axle setting
Diff is set so when i hit it with fresh pack and holding rear wheels, it barely slips, then i go a HAIR tighter
Kenon 8 degree or Kyosho 20 fronts, depending on what i have around and where i'm running
Kenon 8 degree rears
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2007.01.08, 10:41 PM
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#5
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Registered User
Join Date: Nov 2001
Location: makati, philippines
Posts: 8,702
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all valid points...
try softer tires up front...
try wide rims up front... (sounded silly when i first heard it, but it worked)
try knuckes with more camber, i.e. 1* or 2*...
hope this helps...
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2007.01.08, 11:28 PM
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#6
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Registered User
Join Date: Nov 2006
Location: SoCal
Posts: 921
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thanks guys, great information. I'll try out different settings suggested. I only have a wal-mart style track at home, but gonna experience with more settings.
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2007.01.09, 12:34 AM
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#7
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Moderator
Join Date: Dec 2003
Location: Stafford, Va
Posts: 6,064
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My opinion is you are not running a grippy enough front tire. Try a running a 8-10 degree front tire when using the Kyosho 20 rears. Your concept is backwards but thats okay. You're on the right track. It's easier to tune from understeer to oversteer and better in most cases because understeer means you are getting the rear end grip you need.
The Kyosho 20 degree rears are very grippy for the RCP track. The Kyosho 30 fronts are fine with the Kyosho 20 rears on a stock car running 0 offset wheels all around. On anything faster than stock you exceed the grip of the front tires.
Since you are running a wider lower body the car will not roll as much. You're wheel offset in the rear is the widest Kyosho makes so you can count on that rear with the soft h-plate having very good grip. I don't know how hard the white springs are up front but running a medium spring would give a little more grip up front when using the kyosho 30 fronts. Any softer and I think your problem will get worse if you continue to use the Kyosho 30 fronts. If you run a grippier front tire (which I recommend first) with a softer spring the car will really turn in and you may get the oversteer you are looking for.
-Byebye
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2007.01.09, 01:09 AM
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#8
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Registered User
Join Date: Nov 2006
Location: SoCal
Posts: 921
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mine is only a stock class with the PN speedy05 motor.
I found this list on kenonhobby which is the PN springs I bought. I can't find my green ones, so I'll try out the purple ones as it's in the middle. currently these kyosho tires are the only ones i have around, so i'll need to visit kenon to get some PN tires to try them out.
Yellow - Preload lift 175g = Kyosho Yellow
White - Preload lift 140g
Purple - Preload lift 115g
Green - Preload lift 100g = Kyosho Green
Red - Preload lift 55g = Kyosho Green
another nood question I have is that how much difference is there between the treaded tires and slicks?
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2007.01.09, 02:33 AM
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#9
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Moderator
Join Date: Dec 2003
Location: Stafford, Va
Posts: 6,064
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Quote:
Originally Posted by FrankW1029
mine is only a stock class with the PN speedy05 motor.
I found this list on kenonhobby which is the PN springs I bought. I can't find my green ones, so I'll try out the purple ones as it's in the middle. currently these kyosho tires are the only ones i have around, so i'll need to visit kenon to get some PN tires to try them out.
Yellow - Preload lift 175g = Kyosho Yellow
White - Preload lift 140g
Purple - Preload lift 115g
Green - Preload lift 100g = Kyosho Green
Red - Preload lift 55g = Kyosho Green
another nood question I have is that how much difference is there between the treaded tires and slicks?
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I'm assuming that the higher preload means stiffer springs. Purple might be the ticket to a little more oversteer.
The PNspeedy is a quick motor so you're entrance speed to the corner is higher. I'd say for now your only option is to enter the corners slower or use a different line entering turns.
The difference between treaded and slicks for you can only be determined by you and the track you run on.
I prefer the slick Kyosho 20s but in Germany you had to use some sort of treaded or grooved tire.
- Byebye
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2007.01.09, 02:48 AM
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#10
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Registered User
Join Date: Nov 2006
Location: SoCal
Posts: 921
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thank you for the quick response byebye
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2007.01.09, 02:53 AM
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#11
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EMUracing
Join Date: Oct 2004
Location: NYC
Posts: 7,417
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The 30d Kyosho radials in the front with Kyosho 20d radials in the rear are a decent tire setup at the track that I race at. You could try some Kyosho 20d slicks in the front and see if that helps...
If you use softer rear tires like GPM 8d radials, the Kyosho 30d radials up front have too much push, and 20d radials are needed. My normal track requires front tires with less front grip compared to most other RCP tracks that I have run on.
We can tell you what our setups are, but unless we are running on your track, our setups probably wont work perfectly. Some will be better than others... some will be worse.
You could also try lowering the front end... if you have medium soft AWD low down springs, and use the shortest limiter, you can lower the front end without running a hard preload using a shim under the knuckle. If you want to raise the front end, you can use a shim under the spring (on top of the limiter). Of course you have to make sure that the wheel clears the body and wheelwell at its most compressed position...
On my C5R, I am running the same offset as you, with GPM 8d rear and the front tires are stock tires from the AWD. I dont have it lowered, since it doesnt have the clearance with a new set of tires... once the tires are half worn, it can be lowered about 1mm. I am using PN Green front springs, medium MM t-plate with PN ML motormount/damper (running in an MM configuration). If you are running in an RM setup, you will have to run softer front tires. As Byebye said, you may want to try GPM 8/10d, Kyosho 20d radials/slicks...
RM cars tend to understeer much more than MM cars due to the weight of the motor being behind the front axle. I usually run the same softness in the front as I do in the rear with them. With MM cars I will run a harder compound in the front than an RM car.
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EMUracing
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Last edited by EMU; 2007.01.09 at 02:57 AM.
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2007.01.09, 06:45 PM
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#12
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Registered User
Join Date: Nov 2006
Location: SoCal
Posts: 921
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thanks EMU,
mine is the MM multi length setup from PN.
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2007.01.29, 10:25 AM
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#13
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Registered User
Join Date: Nov 2006
Posts: 24
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Quote:
Originally Posted by CristianTabush
Softer at either end gives more bite, so to say, you do have the idea backwards.
Calvin is right to a point about the optimal tire combo. 8deg rear and 18 treaded pn or gpm 20 deg fronts are about ideal tire combinations. The tires you are runing give less overall grip than the previous. I suggest running a narrower offset front along with a softer spring. 1 deg offset fronts on Mr02's causes a lot of scrub in the front end, which heavily decreases front steering on rear wheel drive cars.
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Qestion on H plates, I'm use to running 1/12 cars they use T plates, normally you would use a stiffer plate to reduce rear end tracktion, for example when running on carper vs asphalt. My question is does the same holds true for Mini-z?
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2007.01.29, 10:34 AM
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#14
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Registered User
Join Date: Feb 2006
Location: Stone Mountain,GA
Posts: 1,301
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I thought with any suspension(springs, t-plate, DDS), stiffening something up would make that end of the car looser.
__________________
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2007.01.29, 12:06 PM
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#15
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Registered User
Join Date: Dec 2003
Location: Brooklyn. Got a problem with that?
Posts: 1,498
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My setup is identical to yours (apart from yellow kyosho springs up front). The car understeer slightly with 30 up front but nothing majir. I actually prefer it that way since the 3010 board in my hands doesn't like oversteer. What i would suggest is to replace the ball diff with the stock diff or experiment with the BD settings
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