I was trying to understand what Makofoto was posting in a previous thread about swaybars and would like input about the wheel lift in autocross situations. Is it always bad? It feels faster and helps with rotation when I have that sway cranked up in the back. My times are better too. I posted a picture that was taken of me "in the act"

http://img.photobucket.com/albums/v716/aacera/AX53005P1.jpg

I am running as an underdog in STX because I HAD to do some power mods first an' make it more entertaining on the street. I wanted to be somewhat competitive so I thought it would be a good idea to pick up sways to help.

Daily driven
Cobb (bare-minimum) Stg2 93oct. / STX 2 Engine Mgmt
Up and Shorty Down pipes rest of exhaust is stock incl. 3rd cat
16" Azenis
Carbotech Bobcat pads in Front
Aligned to max front camber for stock
rear has camber bolt
Front say is Whiteline 22/24 adj. w/ Noltec Endlinks set at 24
Rear sway is Whiteline 20/22/24 adj. set at 24 (untill it gets too cold on course)
Tire Pressure is typically 40 PSI fr and 36 PSI back
No aftermarket springs/shocks/camber plates

It's not bad per se... however it would be better to have 4 wheels on the ground tho. It's better than having everything stock.

--kC

Like all of our cars, it's a work in process.

More spring, less bar.

It's also a matter of having a stiff chassis.
http://image.mypicgallery.com/evodesignz2/corner-cropped_large.jpg

At the last event I got a bit sideways and as I was gathering it back up someone told me my wheel was close to 8-12" off the ground. I'm also in a FWD so it tends to tri-pod more frequently.

It's a subie thing.... ;)

http://www.rallydecals.com/kccar/photogallery/kc_rs5.jpg

--kC

You put a stiffer rear swaybar on a front nose heavy McStrut car with a stiff chassis and it's hard to not lift one of the rear tires. EVOs are the same way regarding rear wheel lift when you throw a bigger swaybar on it. The only real way to combat it is use less bar and more spring, but then you compromise the daily drivability of the car.

You put a stiffer rear swaybar on a front nose heavy McStrut car with a stiff chassis and it's hard to not lift one of the rear tires. EVOs are the same way regarding rear wheel lift when you throw a bigger swaybar on it. The only real way to combat it is use less bar and more spring, but then you compromise the daily drivability of the car.
Exactly. Personally I never let the big bar and less spring thing slow me down.

Unless the car feels upset and is having issues with traction when coming back down (i.e. a pissed off diff) then worry not and drive on. :)

-Biggly

...EVOs are the same way regarding rear wheel lift when you throw a bigger swaybar on it.

this is one of our local buddies driving his stock EVO
http://homepage.mac.com/alandahl/.Pictures/Photo%20Album%20Pictures/2005-02-15%2009.39.35%20-0800/Image-E33154CA7F7411D9.jpg

Lean!!!!

I have seen alot of stock cars with sticky tires three wheel sti included.

also drove a newer tiburon that had some pretty heavy suspension mods and got it to three wheel also. fwd i think it is going to be pretty common and not an issue when it comes down.

can't post links yet otherwise i would have some good pics for you.

http://warpthree.com/images/warp3/72sm-1.jpg

Join the club! :D

Hmmm...more spring and less bar...I may have to consider that. Especially since I'm at the max setting on my adjustable rear bar, so the "less bar" part is a free mod. :lol:

Shane -- SM 729

I have a wrx rear sway bar (upgrading in a few weekends) but other than that i'm on a worn out stock impreza RS suspension in STS. I like my tricycle :p


http://filebox.vt.edu/users/tknoll/f337e1e0.jpg

wheel lift = bad 99% of the time

more spring, less bar? might as well just paint the car yellow for all the good that'll do ya. :huh:

nate

Not an autoX, but even us track guys can do it. Stock sway bars, DMS 50s, 325lb rear springs
http://img.photobucket.com/albums/v80/horo1/26-DSC_9389XX.jpg

wheel lift = bad 99% of the time

more spring, less bar? might as well just paint the car yellow for all the good that'll do ya. :huh:

nate

i'm not following...

more spring, less bar sounds like the obvious way to keep the wheel from lifting?


whether that's faster then more spring, more bar i suppose is a different story. :p


- andrew

This has nothing to do with anything, but if you are running a Quaife then both wheels MUST be on the ground.

I had this problem quite a bit. I have 600 lb springs, no rear bar. It works rather well and rotates fine. I think I'm going to put a stock bar with stock (longer) endlinks and try it out.

Back when I was tripoding, I could feel when the car got all four back on the ground b/c it would "hook up" and take off. I think this was costing me some time.

This has nothing to do with anything, but if you are running a Quaife then both wheels MUST be on the ground.

Funny you should mention that...one of my plans for my car for quite a while has been a Quaiffe ATB for the rear (since the 99RS has that wonderful open rear diff :rolleyes: ). Then one day I was looking at that pic I posted above and suddenly it hit me...I can't run a helical diff in the rear with the wheel lifting like that! D'oh :o

Shane -- SM 729

My car is set up exactly the same, but I have Helix sways and minus the rear camber bolts. I haven't had an issue in the three events(all first places) I've been STX modded, from DS previously. The rear sway is the best mod IMO for a lightly modded car, I wish I did it sooner.

http://www.wideopenwest.com/~onyschuk/6-19-05-1.jpg

http://zzyzxmotorsports.com/images/intro/flsh2.jpg

http://zzyzxmotorsports.com/images/intro/flsh2.jpg
Showoff. When you going to join the rest of the DSP folk and flare the fenders? :D

Showoff. When you going to join the rest of the DSP folk and flare the fenders? :D

LOL!!!!!!
I was just thing of that pic Steve.
KC, he's got some else in mind.


Well this is all I got right now. Close only counts in hourse shoes and hand gernades.
http://members.cox.net/izoomtoo/neoklans/display/30.jpg

http://zzyzxmotorsports.com/images/intro/flsh2.jpg

I've seen this pic before. Is this following a bump?
How in the H*ll does one get BOTH tires off?

How in the H*ll does one get BOTH tires off?
In a word: Grip!

I've got pictures of the S2000 with just the tiniest bit of rubber on the ground on the inside tires. And pictures with both front and rear tires lifted (at different times). With a little more grip, I could easily have both inside tires in the air.

Andy H.

http://redirx.com/?3cqg

That's at Oscoda, I had real bad problems with rear wheelspin up until that event, where I had a Kaaz rear LSD installed. I never really developed the suspension enough to take care of the wheel lift.

http://gallery.onalimbracing.com/albums/album02/IMG_8463.jpg

Oh, waitaminute... :lol:

http://www.trunkmonkey.com/pics/lil.gif (http://www.trunkmonkey.com/) NESIC Web Site (http://www.clutchdrop.com/) | Trunkmonkey FAQ (http://www.trunkmonkey.com/) | Trunkmonkey Racing (http://www.trunkmonkeyracing.com/) | Trunkmonkeys in Action (http://www.trunkmonkey.com/gallery/Trunkmonkeys/)

i'm not following...

more spring, less bar sounds like the obvious way to keep the wheel from lifting?


whether that's faster then more spring, more bar i suppose is a different story. :p


- andrew

it's not a matter of what is faster. more spring, less bar will generally have zero effect on wheel lift provided roll stiffness distribution remains unchanged. remember that a spring is displacement sensitive. as the rate goes up there is a smaller change in displacement of the spring as load changes. ie, a stiffer spring won't extend as far once you unload it as a softer spring does.

if you want to bring that inside rear down (and you should if you want to go fast) you need to be looking at stiffening the front of the car. helper springs on the rear of the car might help some too, but most of the pics posted here show excessive body roll being the number one reason behind the lift.

nate

it's not a matter of what is faster. more spring, less bar will generally have zero effect on wheel lift provided roll stiffness distribution remains unchanged. remember that a spring is displacement sensitive. as the rate goes up there is a smaller change in displacement of the spring as load changes. ie, a stiffer spring won't extend as far once you unload it as a softer spring does.

if you want to bring that inside rear down (and you should if you want to go fast) you need to be looking at stiffening the front of the car. helper springs on the rear of the car might help some too, but most of the pics posted here show excessive body roll being the number one reason behind the lift.

nate

For a fact, I know that you are incorrect on your first statement. I had prodrive springs on stock struts with a big ass cusco bar on teh back. Rear wheel lifted all the time.

I put some 600 lb springs back there, with NO bar, and the wheel stays on the ground. If that's not an example of more spring and less bar, I don't know what is.

A friend of mine put some stiffer springs on, still has the cusco bar on, but at it's softest setting. He will BARELY lift a wheel, but it happens sometime.

It sounds like you are trying to say that a spring will not fully decompress, even if the wheel comes off the ground. If the wheel comes off the ground the spring will be at it uncompressed length. Spring length has nothing to do with this problem.

:lol: :lol: :lol:

Go ahead Nate... I'll bite my tounge.

I've seen this pic before. Is this following a bump?
How in the H*ll does one get BOTH tires off?

http://e30.us/video/2wheels-wmv.wmv

or if that doesn't work scroll down here http://www.e30.us/

a classic:
http://members.aol.com/turbojohn/Videos/JohnReamerUpOn2Wheels.wmv

save target, rename from JohnReamerUpOn2Wheels.wmv.htm to JohnReamerUpOn2Wheels.wmv
---

Tripods are fun. Believe it or not, this thing (http://www.bellsouthpwp.net/j/o/jordanad/escort/liftleg_0.jpg) was a blast to drive.

When I spin the inside rear wheel of my RS though.. it's not nearly as much fun. Open rear diffs suck on subies.

BOth of those videos are crazy ... that's some serious grip.

When I spin the inside rear wheel of my RS though.. it's not nearly as much fun. Open rear diffs suck on subies.

Mine will spin the inside rear, alot. But is course dependent.

I remember pics of that wagon, what did you do with it?

Mine will spin the inside rear, alot. But is course dependent.

I remember pics of that wagon, what did you do with it?
I've returned it to stock and am in the process of cleaning it up to sell. The RSB was too strong for the fragile little mazda suspension (equipped with H&R/Tokico), so after breaking both rear control arms and ripping a chunk out of the rear subframe I gave up and bought an RS. :D I've got a lot more respect for FWD thanks to that little car.

tripod rear wheel action is not cool when you don't have a REAR LSD .. i gotta find one

Funny you should mention that...one of my plans for my car for quite a while has been a Quaiffe ATB for the rear (since the 99RS has that wonderful open rear diff :rolleyes: ). Then one day I was looking at that pic I posted above and suddenly it hit me...I can't run a helical diff in the rear with the wheel lifting like that! D'oh :o

Shane -- SM 729
Forgive me if this is a stupid question, but why can't you?

us BMW drivers face a similar problem.

todays race tires have insane grip, and at the track width and center of gravity we have to work with on our sedan shaped cares, wheels are going to get pulled off the ground.

you can fight it with various tricks, but they may have more downside than they are worth.

basically, under stock, or street prepared rules, lifting a wheel here and there may be less than ideal, but it might be the best you can do under the rules.

I can keep my BMWs rear wheel on the ground by deleting the rear swaybar entirely, but then to still handle well requires really stiff springs. Which have all sorts of new tradeoffs, like less stability on non smoothe surfaces, needing tender springs to keep some rebound travel (or else you pick up a wheel again!) etc etc

Forgive me if this is a stupid question, but why can't you?
Gear type LSD's can apply a multiple of the torque of the wheel with less grip to the wheel with more grip. I couldn't find values for the factor with a quick search, but I seem to remember that something like 5 is typical. So at most it can apply 5 times as much torque to the outside wheel as to the inside wheel. If the inside wheel is in the air, you can apply 0 torque to it. So the outside wheel gets 5 * 0 = 0.

Gear type LSD's can apply a multiple of the torque of the wheel with less grip to the wheel with more grip. I couldn't find values for the factor with a quick search, but I seem to remember that something like 5 is typical. So at most it can apply 5 times as much torque to the outside wheel as to the inside wheel. If the inside wheel is in the air, you can apply 0 torque to it. So the outside wheel gets 5 * 0 = 0.
Ahhh, thanks. That's is exactly what this link says: http://auto.howstuffworks.com/differential10.htm

In the case of a subaru tripod, a clutch-type LSD with some preload is probably the best to have, correct? The viscous LSDs that come stock on Subies require some wheelspin in order to work.. wouldn't a preloaded clutch help to avoid that?

I put some 600 lb springs back there, with NO bar, and the wheel stays on the ground. If that's not an example of more spring and less bar, I don't know what is.

Yes... that was my point exactly... I just didn't want to come out and say "no bar, more spring" as few are willing to consider this concept valid.

In the rear especially any swaybar reduces the amount of travel you have and thus causes the 3wheel action.

Although I don't think 3 wheel action is good, it isn't really going to hurt you a ton as long as it's during corner entry or lifting... but if at any point your on the throttle with a tire in the air, you're not going as fast as you could.

Jon

In a word: Grip!Don't forget about some pretty freakin' stiff spring rates too!

Although I don't think 3 wheel action is good, it isn't really going to hurt you a ton as long as it's during corner entry or lifting... but if at any point your on the throttle with a tire in the air, you're not going as fast as you could.

Jon

Fred Puhn (I love saying that name) does a good job early on in his book, How to Make a Car Handle, explaining why it is always better to have 4 wheels on the ground - relating to slip angles, centrifugal forces, and vertical loads. I won't even try to recite it from memory but the thing I took away from it was that 4 tires is always better than 3.

Edit: page 44 through 46 convinced me that 4 wheels is better than 3.

Also, most of the cars in the pics and videos above are on three wheels much longer than the transition from gas to brake. I suck and I still don't take that long to move my foot from the gas to the brake pedal.

Craig

http://images9.fotki.com/v176/photos/4/43793/2140986/Karl2Wheeling-vi.jpg

Karl Asseily, lots of tire grip ... not enough spring ... problem now solved.

Stock Evo ... lots of R Tire grip in A Stock, not enough spring (allowed):

http://images6.fotki.com/v1/photos/4/43793/2140986/JustNotFun-vi.jpg

My car ... very stiff chassis, 550/550 springs ... Hotchkis bars full stiff, lots of front suspension travel, 245 Kuhmo 710's, -2.1 camber in the rear, -3.5 in front +6 caster. Added more negative front camber, -3.9 ... softened the rear sway bar ... testing this weekend:

http://images10.fotki.com/v206/photos/4/43793/2462668/P7231295_mako12-vi.jpg

btw. the new Cross Member goes in soon ... to fix the bent front right A Arm mounting point. Putting in the new wider Sedan A Arms and even stiffer front bushings unmasked a bent, 5 mm narrower wagon A Arm that I've apparently had before I even started AX'ing ... and partly explains my chamber challenged-ness that I've always been (not correctly) dealing with! The front A arm mounting point is bent FORWARD ... I've been told this can happen falling off of a service lift. So far this is the only explanation for what must have been a memoriable and odd impact !? I've certainly never clotted anything remotely hard enough ... and my car isn't a loaner.

My Evo has 560 lb springs all around with stock sway bars. I still lift the inside rear, not nearly as dramatically as a stock Evo though.

Here's one where I come close to lifting both inside tires:

http://www.brennen.net/images/evo_two.jpg

And here's a good photo showing the inside rear coming up just a bit:

http://www.brennen.net/images/pic041705_2.jpg

Personally, I'm not trying to keep that tire on the ground. With as much negative camber as I've got, the tire would be seriously camber challenged if it were on the ground. I figure that having all of the rear weight on the outside rear tire -- which is almost perfectly perpendicular to the ground -- is better than transferring that weight onto the inner inch of the inside rear tire. That's not something that I can back up with actual facts, but it makes sense in an intuitive way.

that's some crazy cornering power!

My car has been a progression as far as the suspension goes. For a while I was lifting the inside rear tire. After I changed some parts I started lifting the inside front tire (not much just 1-2").

The idea is pretty simple. Tires give you more grip per pound of downforce the less downforce there is

So you get more grip from 4 tires with 500lbs of force on them each than you do from 2 tires with 1000lbs of downforce on them each.

Fred Puhn (I love saying that name) does a good job early on in his book, How to Make a Car Handle, explaining why it is always better to have 4 wheels on the ground - relating to slip angles, centrifugal forces, and vertical loads. I won't even try to recite it from memory but the thing I took away from it was that 4 tires is always better than 3.


Craig

corey, am i to understand that you are lifting the inside rear on your car intentionally? or were you wanting me to speak more about bar vs. spring? at any rate, i'm biting my tongue too. i've hashed and re-hashed this subject to death on this and other forums. i'm bored. time to focus my attention on determining if a droop limited front suspension will help the Reynard i'll likely be driving next year.

nate

you can rehash it all you want, you would still be wrong to suggest that changing sway stiffness won't effect whether a wheel gets lifted even if front/rear roll stiffness ratios remain constant.

sways resist roll by 'pulling up' on the inside wheel, springs don't. This is why less rebound stiffness in your shocks can help stop lift as well.



corey, am i to understand that you are lifting the inside rear on your car intentionally? or were you wanting me to speak more about bar vs. spring? at any rate, i'm biting my tongue too. i've hashed and re-hashed this subject to death on this and other forums. i'm bored. time to focus my attention on determining if a droop limited front suspension will help the Reynard i'll likely be driving next year.

nate

Nate,

Nothing to do with my car, I don't lift wheels that often. I was in fact referring to this remark.

For a fact, I know that you are incorrect on your first statement. I had prodrive springs on stock struts with a big ass cusco bar on teh back. Rear wheel lifted all the time.

I put some 600 lb springs back there, with NO bar, and the wheel stays on the ground. If that's not an example of more spring and less bar, I don't know what is.

To which I would ask this person if they are running 600 lb springs in the back and still running the Prodrive springs on the front. IF NOT, and they increased the front spring rate also, then Nate already addressed that in this statement:

if you want to bring that inside rear down (and you should if you want to go fast) you need to be looking at stiffening the front of the car.

But I didn't want to quote all that before.

Corey #89 STS

Nate,

To which I would ask this person if they are running 600 lb springs in the back and still running the Prodrive springs on the front. IF NOT, and they increased the front spring rate also, then Nate already addressed that in this statement:


Corey #89 STS

I put stiffer suspension all the way around - 500lb front and 600 rear. When I still had the swaybar on the car, it lifted the wheel worse than with the softer prodrives (same swaybar, btw)

He is correct, you can stiffen the front of the car considerably. But if you do that on the WRX, you're probably going to lose a lot of rotation.

A swaybar will make the suspension less independent, specially in teh rear.....which is why it lifts the rear inside. Put on a smaller bar that isn't as strong, and it will bend more, allowing the wheel to stay on the tarmac.

so does all this answer the overall question...
what is better the big sway with the inside tire lifting
or no sway and having inside tire on the tarmac?

so does all this answer the overall question...
what is better the big sway with the inside tire lifting
or no sway and having inside tire on the tarmac?

It is car dependant.

Depends on how well your car rotates and how much power you have.

If the car is stock, the sway bar lifting the wheel and getting the car to rotate is going to be better than piggin' it through the turns. A front swaybar is also an option to reduce the understeer and will allow the wheel to stay on the ground.....If you're running stock class a rear sway bar is not allowed.

If you have a lot of power, you have to get it to the ground, IMHO. Make sure the wheels are on the ground.

My car ... very stiff chassis, 550/550 springs ... Hotchkis bars full stiff, lots of front suspension travel, 245 Kuhmo 710's, -2.1 camber in the rear, -3.5 in front +6 caster. Added more negative front camber, -3.9 ... softened the rear sway bar ... testing this weekend:


now thats some camber settings!

depends!

if your differential is up to the job lifting a wheel is only a minor problem.

even if you get it on the ground it may only have 10lbs of force on it so it isn't like things have changed much from a tire-weight distribution point.

so does all this answer the overall question...
what is better the big sway with the inside tire lifting
or no sway and having inside tire on the tarmac?

depends!

if your differential is up to the job lifting a wheel is only a minor problem.

even if you get it on the ground it may only have 10lbs of force on it so it isn't like things have changed much from a tire-weight distribution point.

very true,
in my case i have a lot of power to get to the ground i am just in the process of choosing my suspension compontents and i want to be sure to go the right way !