oOple.com Forums

oOple.com Forums (http://www.oople.com/forums/index.php)
-   Tamiya (http://www.oople.com/forums/forumdisplay.php?f=22)
-   -   Traction Roll Issue (http://www.oople.com/forums/showthread.php?t=11874)

501X Driver 24-06-2008 03:03 PM

Traction Roll Issue
 
I run on a hard packed dirt surface that stays moist. Little dust.
It has a lot of small holes requiring us to run a soft setup.
So I am running #4 and 32 wt oil in front and #3 and 27 wt oil in the rear.
I am running the largest Kit sway bar in the front and a custom .063 bar in the rear. I think the factory large bar is .056 So I am running a lot of bar I think.
But it still traction rolls if I don't reduce my speed below what I think would be normal. I run Taper Pins up front and Square Fuzzies in the front. If I use a tire with with good traction I roll at a slow speed.

Do I need to run more sway bar?
Do I need to go to a Larger Piston and Heavier Oil?
Smaller Piston and Lighter Oil?
:eh?::eh?::eh?::eh?:
I Don't Have a Lot of Practice Time to Try Different Setups.
So if anyone knows what direction I should start it would be very helpful.:)
Other wise I am going to just change and test durning the race.

sosidge 24-06-2008 03:16 PM

The thick bars are working against your soft setup, they will make the car worse over the bumps, is it possible the bumps are flipping the car not the traction?

chrispattinson 24-06-2008 03:21 PM

My advice would be to raise your roll centre, bringing it closer to the CoG, reducing roll. This is accomplished by lowering the camber braces.

Try running a lower ride height aswell, or using some limiters in the shocks to prevent huge amounts of droop, unless there are big jumps to deal with.

jimmy 24-06-2008 03:30 PM

Laying the shocks down on the tower will soften them but allow them to absorb the roll rather than throw the car over - worth a try. It's usually my first step when I'm getting a lot of grip roll.

millzy 24-06-2008 03:35 PM

I do what Jimmy says and then also check how much camber gain your getting at the wheel under load

Richard Lowe 24-06-2008 04:16 PM

I'd be looking to loose some grip at the tyre, that will make it better on bumps too.

werner1619 24-06-2008 05:43 PM

I think millzy hit the nail on the head, you need more camber all round. The thin oil results in quick weight transfere, resulting in quick camber change. So when you are cornering with the little bumps and ruts you travel to min camber and then experience traction roll.
A lower roll centre as mentioned above would also aid in your current situation.
Also, tires have a big impact, so try tire with a very round shoulder profile.
:)

501X Driver 24-06-2008 07:40 PM

Good Feed back so far- I have tried alot of these-
sosidge- Correct, I don't want to go any larger and would like to get rid of them. The 2 corners that I need to carry the speed in are 95% smooth. The rest of the track and a lot of the straight leading to the first corner has most of the bumps.

chrispattenson- I do not have any spacers under the inner camber blocks. They are short in the rear and long in the front. The rear has 3mm spacer on the outside to raise that end. There aren't any big jumps, it is setup where you can easly land on the down side. The limiters will be a good test. But I need to not shorten to much because of the bumps.

jimmy- I will try laying the shocks down some. I have been moving the bottoms out and in to see what that did but didn't seem to do much.
I will try this before putting any spacers inside the shock.

richard- the tapers pins up front have the least amount of traction and the square fuzzie normally doen't work on this dirt, no one runs them and I have the hardest ProLine foam (dark grey). If I run the Double D's, Evil Twins, Holeshots I have to use brake to really slow down in the corners.


A lot of the 4wd and some mod buggies are having this problem.
We are guessing that the track just has alot of traction, but there has to be some way to use it and not waste it.

Thanks for the ideas so far, don't stop I need more.
Thanks again.

PS- this Team Azarashi body is the bomb. It seems to make the car handle better and feels like it has much more down force

sport10 24-06-2008 08:23 PM

I was dealing with this problem at one of the tracks I run at. I run an X-5 but these changes should work on any 4wd buggy. The changes that made a difference for me were using a heavier spring up front, lowering the ride height, and adjusting the camber. You can take out some of the camber to dial out traction in the corners. I usually start with 0 degrees camber in the front on a high traction track. The heavier front springs help with ruts and bumps in the corners too from what I have seen. I also swapped in a front one way to gain back plus some the low speed steering I lost too. With these small changes my setup was dialed and I was able to carelessly go thru the corners I previously would traction roll in without upsetting how the buggy handled on the rest of the track.

stefke 24-06-2008 10:32 PM

Most effective measure against traction rolls are internal shock limiters. On astro tracks like the upcoming belgium GP, I run 5mm at the back and 3mm at the front. I don't like swar bars on offroad cars.
that's why you have downstops on most onroad cars.

Richard Lowe 25-06-2008 08:35 AM

Quote:

Originally Posted by 501X Driver (Post 136678)
richard- the tapers pins up front have the least amount of traction and the square fuzzie normally doen't work on this dirt

If the worst dirt tyres are still giving too much grip, don't use dirt tyres :p

Try some GRP, Schumacher or BB tyres!

Are you sure it's traction/grip roll the car is suffering from, not just randomly flipping on bumps?

millzy 25-06-2008 09:04 AM

Quote:

Originally Posted by werner1619 (Post 136628)
I think millzy hit the nail on the head, you need more camber all round. The thin oil results in quick weight transfere, resulting in quick camber change. So when you are cornering with the little bumps and ruts you travel to min camber and then experience traction roll.
A lower roll centre as mentioned above would also aid in your current situation.
Also, tires have a big impact, so try tire with a very round shoulder profile.
:)

I wouldnt add camber.
I would check the chamber change from unloaded to loaded at the wheel and then shorten the camber link and rase it to reduse the amount of camber gain at the wheel under load.


the lower the camber link in bored the more aggressive the wheel will go from unloaded set camber to loaded camber angle - by slowing this down you gain more forword traction but lose side bite, leaving you with a loser rear into the bend and a more stable rear on power

start at the rear first

501X Driver 25-06-2008 02:15 PM

Quote:

Originally Posted by Richard Lowe (Post 136805)
If the worst dirt tyres are still giving too much grip, don't use dirt tyres :p

Try some GRP, Schumacher or BB tyres!

Are you sure it's traction/grip roll the car is suffering from, not just randomly flipping on bumps?


It rolls at 3 points on the track (+/- 3ft) . It is a 23 second lap with 11 turns.
Our Shops don't keep thaose tires around. I have thought about playing in the street to wear down some tires to try.

I have taken pictures of other cars on the track and some have carried enough speed that the tire has rolled under so much that the rim is biting into the dirt.
Below are some pictures of others in the main corner.

http://i244.photobucket.com/albums/g...g/DSC_0902.jpg

http://i244.photobucket.com/albums/g...g/DSC_0915.jpg

http://i244.photobucket.com/albums/g...g/DSC_0824.jpg


Again thanks for all the ideas to try.

Lee 25-06-2008 02:20 PM

If the tyre is folding under load then you need a stiffer insert.

sparrow.2 25-06-2008 02:36 PM

How about slowing down where you always tip over and have the car work well on the other 9 corners of the track. ;)

Looking at the pictures though your inserts might be a little soft. Try some truck inserts instead of the buggy ones and see how it goes :)

501X Driver 25-06-2008 07:52 PM

I am using a Grey Proline insert that is very firm. Probably the firmest I have seen.

And who wants to run full throttle 100 feet, brake to 1/2 speed for 10 feet and then back to full speed for 40 feet. If it won't roll over this is a second or more quicker. Right now I do slow down.

PaulRotheram 25-06-2008 08:23 PM

You shouldnt be using full throttle everywhere, i think you need to try smooth your driving style down, unless it is quite an open track i'd try slowing down abit. Then afterward if you're still having issues start looking more in to the car.

slower is faster :)

frogger 25-06-2008 09:36 PM

We do it on the smaller cars and it works equally well on the 10th scale off roaders - super glue the side walls of the front tyres. Some people I have seen super glue them from the rim all the way to where the pins start (usually also cut the first row or 2 of pins off). It sounds like its worth a try in your case. :)

sport10 27-06-2008 03:08 AM

Maybe the problem lies with your selection of tires. Try some different tires in the rear instead of square fuzzies. Like Tapers or BK Bars in the rear. The idea is to get a tire with less side bite.

steveproracing 30-06-2008 02:54 PM

a proven set up to try
 
shocks
fr blue ae spring 5 hole piston 35wt 3mm droop spacers 3out on tower middle on wbone
rr ae silver spring5 hole piston 30wt 0.5mm droop spacers 2out on tower middle on wbone

car on longest wheelbase setting

camber links
front
hub kit with 2mm spacer inner middle no spacer under camber link brace
rear
middle hub 2mm spacer mid inner no spacer under brace
1 deg anti squat
37t pulleys all round car will be easier to drive with diff
no roll bars!!!!!!!!!!!!
take some of your steering travel off on tranny
use neg expo on tranny
ride height as low as poss ie 18mm fr 20mm rr if track allows

if running alloy steering link mid hole no washers


this car is ultra stable on any high grip surface!!
why?
because low pack in shocks allows susp to work on bumps better
no roll bars allow susp to work independantly
c of g changed to control roll stiffness
front shock more upright to help fr end from colapsing mid corner


this set up is track proven and is grounded in theory

it will help you

i dont post often because i dont like to get into stupid debates but i like to help with factual solutions if i can
i am sure some of the ne racers will vouch for my experiance in this area esp with the 501x

any qs
dont hesitate to ask

steve


All times are GMT. The time now is 07:21 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
oOple.com