11Likes1/8 onroad setup help
07-10-2017, 09:06 AM
#1
1/8 onroad setup help
can someone please explain a litte how the effects of rear track width and rear
toe work on a 1/8 onroad car seems very diffrent to a car with a rear diff and
front/rear tyres the same width.at the moment i have off power understeer
and runout of steering at full lock and on power oversteer. gone as far as i can
with roll centres/rollbars/shocks/springs and downstops.
thanks rick...
toe work on a 1/8 onroad car seems very diffrent to a car with a rear diff and
front/rear tyres the same width.at the moment i have off power understeer
and runout of steering at full lock and on power oversteer. gone as far as i can
with roll centres/rollbars/shocks/springs and downstops.
thanks rick...
07-10-2017, 12:19 PM
#2
So rear track width effects the lateral weight transfer and so if you narrow the rear track you reduce the amount of lateral rear traction you have. Therefore increasing steering generally but at a cost of stability. To be honest on the 977 Viper I don't really change the rear track width and run it consistently at 263mm. The Behaviour is no different to a car with a diff. A track width adjustment also changes the roll centre slightly but in 1/8 onroad I don't really change the rear track width very often.
Rear Toe-in. Basically the more static rear Toe-in you run then the car will have less steering generally. The reverse is true. The greater Toe-in also generates more lateral rear grip hence less steering and so as you reduce the toe in the lateral rear grip decreases so you get more steering but less stability and perhaps the car generating oversteer situations. I generally start with 3 degrees and then reduce it towards 2.5 degrees as the traction of the track increases.
Rear Toe-in. Basically the more static rear Toe-in you run then the car will have less steering generally. The reverse is true. The greater Toe-in also generates more lateral rear grip hence less steering and so as you reduce the toe in the lateral rear grip decreases so you get more steering but less stability and perhaps the car generating oversteer situations. I generally start with 3 degrees and then reduce it towards 2.5 degrees as the traction of the track increases.
Last edited by dan_vector; 07-10-2017 at 12:40 PM.
07-10-2017, 12:22 PM
#3
The rear with a solid axle has to steer like a kart, the car is driven by the outside wheel and the inside wheel is lifted.
With toe-in the rear wheels will give a stabel straigh forward line and in the corner the toe-in of the outside wheel will work as an anti break out of the car
With toe-in the rear wheels will give a stabel straigh forward line and in the corner the toe-in of the outside wheel will work as an anti break out of the car
07-10-2017, 05:53 PM
#4
Always good to have knowledgeable ppl like Dan and Roelof.
You may be scrubbing chassis, scrubbing front on brake and rear on acceleration. No? I would do either one of these:
Ask local experts or bring everything back to default set up. Default almost always works. Or upload your set up sheet here.
Think of solid axle in rear as diff with crazy high cst oil like 3 mil or over. If you already understand what different oils do in rear diff, you'd be able to imagine how solid rear axle will work.
You may be scrubbing chassis, scrubbing front on brake and rear on acceleration. No? I would do either one of these:
Ask local experts or bring everything back to default set up. Default almost always works. Or upload your set up sheet here.
Think of solid axle in rear as diff with crazy high cst oil like 3 mil or over. If you already understand what different oils do in rear diff, you'd be able to imagine how solid rear axle will work.
07-10-2017, 07:48 PM
#5
Tech Adept
So rear track width effects the lateral weight transfer and so if you narrow the rear track you reduce the amount of lateral rear traction you have. Therefore increasing steering generally but at a cost of stability. To be honest on the 977 Viper I don't really change the rear track width and run it consistently at 263mm. The Behaviour is no different to a car with a diff. A track width adjustment also changes the roll centre slightly but in 1/8 onroad I don't really change the rear track width very often.
Rear Toe-in. Basically the more static rear Toe-in you run then the car will have less steering generally. The reverse is true. The greater Toe-in also generates more lateral rear grip hence less steering and so as you reduce the toe in the lateral rear grip decreases so you get more steering but less stability and perhaps the car generating oversteer situations. I generally start with 3 degrees and then reduce it towards 2.5 degrees as the traction of the track increases.
Rear Toe-in. Basically the more static rear Toe-in you run then the car will have less steering generally. The reverse is true. The greater Toe-in also generates more lateral rear grip hence less steering and so as you reduce the toe in the lateral rear grip decreases so you get more steering but less stability and perhaps the car generating oversteer situations. I generally start with 3 degrees and then reduce it towards 2.5 degrees as the traction of the track increases.
07-11-2017, 06:06 AM
#6
Front track narrower (less front lateral grip) and Rear Track Wider (more rear lateral grip) - Less steering
Bear in mind that a wider track width raises the roll centre at that end of the car and vice versa.
To be honest I pretty much leave the track width set in 1/8 as per the kit or latest setup direction and rarely change it.
07-12-2017, 12:49 AM
#7
The rear with a solid axle has to steer like a kart, the car is driven by the outside wheel and the inside wheel is lifted.
With toe-in the rear wheels will give a stabel straigh forward line and in the corner the toe-in of the outside wheel will work as an anti break out of the car
With toe-in the rear wheels will give a stabel straigh forward line and in the corner the toe-in of the outside wheel will work as an anti break out of the car
07-12-2017, 01:34 AM
#8
07-12-2017, 01:37 AM
#9
you should try once making it with no lift the traction is insane!!
07-12-2017, 03:36 AM
#10
I did with a DAX suspension where also the wheels were put straight on the ground, the wear on the shafts is also insane.....
| + YouTube Video | |
| + YouTube Video | |
07-12-2017, 04:40 AM
#11
looks cool, I just make my mugen suspension flat but I don't get any crazy where on my shafts..
07-12-2017, 05:14 AM
#12
Tech Adept
07-12-2017, 05:18 AM
#13
Tech Adept
Front track wider (more front lateral grip) and Rear Track Narrower (less rear lateral grip) - More steering
Front track narrower (less front lateral grip) and Rear Track Wider (more rear lateral grip) - Less steering
Bear in mind that a wider track width raises the roll centre at that end of the car and vice versa.
To be honest I pretty much leave the track width set in 1/8 as per the kit or latest setup direction and rarely change it.
Front track narrower (less front lateral grip) and Rear Track Wider (more rear lateral grip) - Less steering
Bear in mind that a wider track width raises the roll centre at that end of the car and vice versa.
To be honest I pretty much leave the track width set in 1/8 as per the kit or latest setup direction and rarely change it.
07-12-2017, 01:29 PM
#15
I have a couple of ways I do it, first I put your car on the setup board tires on and make sure u did all your other setup steps first.
then from the front body post push down on the left post then the right or right then left don't matter and see which rear wheel lifts.
lets say the left rear wheel lifts well what I do is first the 2 collets that go throu the bearings that hold the rear sway bar in the bulkhead I leave alittle play in the sway bar so the sway bar can slide alittle side to side and trust me it wont effect anything if there is some play.so after u did that and adjust the sway bar arm extend it so that tire lifts just alittle off the ground, if u extend it too much the the other side will lift.
then the front left shock oh this is done with the car facing u, the spring collar the u tighten or loosen to adjust spring tension u tighten that alittle at a time till that wheel does not lift.
and that's really it make sure the other side is still flat as well and u are all set!!!
then from the front body post push down on the left post then the right or right then left don't matter and see which rear wheel lifts.
lets say the left rear wheel lifts well what I do is first the 2 collets that go throu the bearings that hold the rear sway bar in the bulkhead I leave alittle play in the sway bar so the sway bar can slide alittle side to side and trust me it wont effect anything if there is some play.so after u did that and adjust the sway bar arm extend it so that tire lifts just alittle off the ground, if u extend it too much the the other side will lift.
then the front left shock oh this is done with the car facing u, the spring collar the u tighten or loosen to adjust spring tension u tighten that alittle at a time till that wheel does not lift.
and that's really it make sure the other side is still flat as well and u are all set!!!