So, Car Tripoding

[CaptainSquirts]

So I noticed some cars go into tripod mode during autocross and always wondered.. Is it a good thing, A bad thing, or doesn't matter kind of thing?

[Loren]

It's generally not a horrible thing. Mostly just "a thing" as long at the shocks are good and the whole process doesn't disturb the driver. (on the FASTiva, one of our early suspension setups had LOTS of rear swaybar and front springs that were too soft... that was disturbing)

Mostly happens with FWD cars. A FWD car often has an open diff, and you're asking the front tires to turn and accelerate at the same time. So, there is benefit to transferring any weight you can to the front when powering out of a turn. There's only about 40% weight on the rear, so the rear's not doing much. You never even notice when the rear wheel comes up! (if you're not smooth, you may feel it when it comes down)

In theory, weight transfers diagonally, so when you take all the weight off of the inside rear, that weight should go to the outside front. In practice, some of that weight is redistributed across the other tires, as well. That weight transfer can reduce the inside front wheelspin coming out of a turn. This is why a bigger rear swaybar helps on a FWD (and sometimes AWD) car.

It can also happen with the front of a RWD car, usually when the front end has a REALLY stiff swaybar. And, again, you don't really notice it because when it happens, you're coming out of a turn and HARD on the throttle. (if you got on the gas too early, you'd understeer) All the weight that's come off of the inside front is mostly redistributed to the rear and keeps the back end planted. This is why a RWD car likes a larger front swaybar.

[Amphoteric88]

As an example of when it isn't too helpful:
On my car, with the passenger side rear shock blown, any sort of quick direction change would have to be carefully executed; else that rear spring would preload fully, and then on the change in direction, would almost hop the car. There were times when I'd be exiting the turn around going to the left, then make a hard right. Since I was exiting (therefore accelerating) and turning right, the weight transferred to the undampened wheel. As soon as I would swing left, the weight would leave that side violently, overburdening the front tires and cause a jolt of understeer.

[Jamie]

For some cars -- typically short wheelbase, and stiffer in the back than in the front -- it's inevitable. Stock Rabbit/Golfs are famous for it because of the soft front springs, and it's one of the reasons why running a massive front bar on VWs (and some other front drivers) actually reduces understeer. When I was running a '79 Rabbit, I used to go around freeway cloverleafs on three wheels. It's not desirable -- you're taking one wheel's worth of grip out of play, and the dynamic wheel camber goes to hell -- but unless you stiffen the front end, there's not much to do about it.

[Native]

Daniel, your car is fine. In fact, it's terrific.
If you stiffen the front to get the back wheel down, you'll likely bring back some of the understeer you just got rid of.
If you soften the back to get the wheel down, well, now the back will stick more, and same effect.
If you do make any changes, do so gradually, but, your setup right now is really quite good.

[Loren]

I haven't driven your car, but I'll side with Steve. You've made MAJOR improvements to your suspension. It's obviously very good. Give yourself some time to adapt to it before you think about making more changes. Then do so with data. Subjective data, like "what does it feel like", but also get some photos/video not just of wheel lift (not a big deal as long as there are no side-effects), but of your tire contact patch on the loaded corners. That's where the action is.

Now, one thing some of us might not be thinking about is AWD. Rear wheel lift in an AWD could have a problem that FWD doesn't have. On FWD, that wheel is fully independent to spin or stop or whatever without issue. No axle, no diff, no limited slip diff. Just a stub axle with some bearings spinning away. It can lift or not lift, doesn't really matter. AWD has an axle attached to that wheel, attached to a diff, possibly an LSD. Add some TORQUE to that equation... there is potential for breakage there. Sort of like if you put super-grippy tires on it and a super-grabby clutch, cranked up the boost and launched hard... wheel hop would hammer your axles and possibly break something.

You'd do best to inquire of people who have experience autocrossing YOUR car in a modified form to learn whether this is something you need to think about or not.

If you want/need to tame that wheel lift, you can start by making the front shocks stiffer (if they are adjustable). Next would be stiffer front springs. You'll be trying to balance the suspension so that you get as much of that weight transfer off of the rear as you can... just short of lifting the wheel and losing traction. May or may not be necessary to do that. I can't say for sure.

[CaptainSquirts]

I'm pretty darn happy with my current setup. Only thing bothering me is my front driver side tire is rolling onto the triangle roll indicator. Was hoping the roll center adjustment kit and added negative camber would fix that but didn't. I believe it's only happening on the turn around since last 2 events I went to had a right hand turn around. Psi was set to 34 before the first run, still rolled over after 3rd run(rechalked). I've seen some other peoples tires get destroyed on the outer edge, don't really want the same to happen to me. So at this point more pressure is needed but also I'm thinking about a front sway bar so it could help with the front roll. But like Steve said, it might cause some understeer issues(i think) which would be no fun.

Wasn't really creating this tread about my current issues, just curious if tripodding was something I should worry about(looks like I shouldn't) and peoples thoughts about it.
I myself saw pictures of my vehicle having rear inside tire lifting mostly during the initial turn into the box. I didn't notice/feel anything negative when going into it so I'll ignore it.

I guess back to my own roll over issue.. If I only have the tire rolling over on turn arounds, should I not worry about it? Should I add more pressure? Should I be thinking of something to help with the body roll so the tire doesn't roll over?

[Loren]

More pressure, more negative camber.

[aw614]

For some cars -- typically short wheelbase, and stiffer in the back than in the front -- it's inevitable. Stock Rabbit/Golfs are famous for it because of the soft front springs, and it's one of the reasons why running a massive front bar on VWs (and some other front drivers) actually reduces understeer. When I was running a '79 Rabbit, I used to go around freeway cloverleafs on three wheels. It's not desirable -- you're taking one wheel's worth of grip out of play, and the dynamic wheel camber goes to hell -- but unless you stiffen the front end, there's not much to do about it.

I've been wondering about the big front bar setup on the MK1 and MK2 VWs and really want to drive one. The setup seems completely opposite to the big rear bar setup. I'd be interested to see it applied to more modern cars that also use the same style suspension setup of the macstrut with rear beam in the back (i.e. Honda Fit)

How does that big front bar deal work with wheel spin out of corners with an open diff? It can't be that bad with a sub 100hp car can it?

Still makes me want to find a mk1 scirocco as a project.

I never notice the wheel lifting in the air on my cars when im driving, but I don't think it lifts it as high as that gti vr6 shown in the pic..

[Solar]

More pressure, more negative camber.

Yup, when I had my Civic Si I was running Azenis on it, and my front tire pressures were around 38 - 42 psi. Never had an issue with edge wear, and that car didn't have much negative camber either.

[twistedwankel]

'suote="aw614"]Still makes me want to find a mk1 scirocco as a project.I never notice the wheel lifting in the air on my cars when im driving, but I don't think it lifts it as high as that gti vr6 shown in the pic..[/quote]

A racing acquaintance on an off camber turn with R tires (similar to modern 200q) put his pristine Scirocco on it's roof at Topeka. The battery + touched the hood and the car kept running until the oil stopped it. His take away from that is to always cover the + post with a non conductor. The car was totaled but didn't burn. Also in 90's at a Prosolo in Toledo watched a Shelby Dodge GLH on R tires on an off camber turn around do a complete roll over. Also at Topeka in 90's(?) saw one of Loren's favorite Saturn S2(?) go up on two wheels like a Hell Driver at the county fair until he finally turned the wheel and sat it back down. That same car broke a new rear wheel bearing assy completely off the car a few months later at a local event.

My take away from all this is you better know what you are doing when you mess with a FWD suspension and add gummy tires to the mix. Then hope nothing breaks.

[Solar]

Heres a old pic of my Civic Si when I had it set up pretty well, running on Azenis with adjustable D-Spec suspension, and a big ass rear swaybar.

[twistedwankel]

Brian is back?

[Solar]

I wish I still had that car back. I'm looking at attending a couple this summer, getting to damn hot to ride the bike.

[twistedwankel]

I wish I still had that car back. I'm looking at attending a couple this summer, getting to damn hot to ride the bike.

Brian is back. Life is Good.