So what exactly causes this phenomenon? I would think that a very good suspension set up should not be showing this much lift. Is it the combination of stiff springs and blown rear shocks? Too stiff of a swaybar? Bad driver? Theories?


Matt

 

a proplery tuned suspension should see only a slight bit of light under a hard corner...

I don't see why a car should be getting up on 3 wheels on every turn and with so much ground clearance....I'd rather have 4 wheels planted

 

Yes, a well tuned suspension should not show much lift... but of the car just isn't using that unloaded tire, why not? In a turn, it would really do nothing. In theory, you want optimum grip in the tires that need them... a) the outside tires in the turn b) the tires that power c) the tires that turn. Other than that... lifting an unweighted tire's not a big deal.

Just like RWD cars would lift their inside FRONT tire. (Look at sportscar magazine CM Champion Alien Daddio's pic of Tysons Car for an example).

The unweighted tire away from the drive wheels really isn't being used.... so it's not a big problem. If it's a drive wheel... you better have some kind of limited slip on it.

--kC

 

I would say the front end is too soft considering the differential in ground clearance between the right front and left front. In fact the entire car could be too soft as it appears to be leaning excessively.

 

front springs are 600lb, rears are 800lb.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by speedracer33 &raquo;</TD></TR><TR><TD CLASS="quote">

so what exactly causes this phenomenon? </TD></TR></TABLE>

A great driver making the most of his braking . Who is this anyway? Are they here to comment?

As to WHY it happens: with most of our weight on our front wheels under braking, the rear springs are extend (duh). Once the small load on the outside wheel is distributed though the sawy bar, our rear suspension system will reach an equilibruim. all we have left is the rotational force, and the car just rotates with response from the suspenion. Try it at home with a jack on the rocker panel. Aplly a rotation al force by the rear wheel. Both rears will slowly unload but the near one will unload first. You could also simulate a string rotational force by driving in to the dirt and flipping, but I don't reccomend it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gotocrx &raquo;</TD></TR><TR><TD CLASS="quote">A great driver making the most of his braking . Who is this anyway? Are they here to comment?</TD></TR></TABLE>

It's me. It's not under braking though, that is a fourth gear turn, and I'm full throttle at the time the pic was taken.


Matt

 

A big rear swaybar causes that to happen. The outside suspension is getting compressed (because the car is rolling that way). The sway bar gets twisted and tries to force the inside wheel up as well. As far as I know, the "peeing dog" is one of those handling compromises - maximize outside drive wheel traction at the cost of the inside non-drive.

 

https://honda-tech.com/zerothread?id=224837

The basic deal is that it happens because all or almost all the weight is being transferred off of that wheel. In your case much of that weight is going to the driver's side front, which is bad. And of course your overall grip is down (but just a little) because there's one less tire on the ground. It seems though from the other thread that the disadvantages are outweighed by the benefits of setting up the suspension w/ stiff rear springs, big rear swaybars, etc.

 

...are you shure that was not before the apex, and that you might not be 100% full throttle just yet? That seems like alot of air under the tire for an accelerating car, but what do I know.

I guess with a very low car (short travel in the rear), and a stiff rear sway bar, lifting a tire up is very EZ. I know my car does it also, I just never thought it was doing it under acceleration.


Modified by 57STS at 4:37 PM 11/3/2003

 

The roll center is too high and the suspension is too soft. Just based on the picture. My Integra did a pretty good lift in the kink at CMP due to the fat rear bar, but your whole car is pitched over like a top heavy tug boat. Not good. Its OK to lift the inside rear some because it isn't doing anything anyway, but sloshed over that much means you are lifting the inside front too much and just plain beating the **** out of the outside front.

Possibilities...
- Rear bar too small (yes, this helps keep the fronts planted)
- Blown shocks causing lack of spring control
- Too much rebound in the shocks
- Not enough spring
- Too high
- Turning in too early and planting the entire car on the outside front tire
- Some sort of combination of the above

A little tinkle is OK, but that picture reminds me of watching showroom stock VWs with high roll centers and stock shocks/springs.

 

Think about it.

From the moment the inside rear is unloaded, the amount of lift depends on how much more body roll there's going to be. Which depends on the front roll stiffness.

If you want to reduce the pissing dog effect you just have to increase front roll stiffness using either springs or bars.

If you do that then you might want to increase rear roll stiffness too or else you'll change the dynamic cornerweighting curve and transitional corner phases will be more prone to understeer.

Take two fwd cars like the one in the picture, identically set up, but one has more front weight bias. That car will lift the inside rear higher.

Get it?

Scott, who thinks it's funny to be explaining over and over things that warm beer drinking englishmen racing minis knew back in the days of the druids...

 

Scott, you might be onto something with the height contributing to it. With those 225/50/16 Toyos, and the corresponding changes I had to make to the coil overs to keep from rubbing, the car is sitting about an inch and a half higher than it used to. That, along with the shocks/swaybar, is probably why it is so dramatic. Thanks.

Matt

 

You and Dudek seem to 3 wheel more then most, but Dudek runs no front bar and a 26mm rear bar. What size bars are you running? My guess would be that your higher then average ride height might have something to do with it.

 

front and rear are both ITR bars, 22mm.

 

Front ITR bars are 26mm so I doubt you will need more bar than that. I'm not sure about the spec tire thing for 04 but, I'd try and get some smaller tires and lower your ride height. If that isn't enough, up the spring rates. Are your shocks revalved for your spring rates?

 

The only part of the ride height theory that's correct/applicable is that if you've got the car jacked up by some amount, then you've got that much less droop travel (leaving aside the motion ratio).

The roll centers move up and down approx 1:1 - so the roll moment doesn't change. It's not rolling more because it's running higher.

The lateral weight transfer is higher because the CG is higher. The developable lateral loading is decreased.

Stiffen it up, and run a bit less static negative camber.

Scott, who says that car is too softly sprung, and the bars are too small...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by solo-x &raquo;</TD></TR><TR><TD CLASS="quote">i'd guess you aren't using a front swaybar at all? </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">front and rear are both ITR bars, 22mm</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 57STS &raquo;</TD></TR><TR><TD CLASS="quote">...are you shure that was not before the apex, and that you might not be 100% full throttle just yet?


Modified by 57STS at 4:37 PM 11/3/2003</TD></TR></TABLE>

Yeah really. If you aren't on the brakes there why is the tire not moving? With no brakes the tire should spin for awhile, especially from if it has to spin down from the speed of a 4th gear turn as you say. You gotta be touching the brakes a little.

But who realyl needs that tire?

F of Friction &lt;= F Normal * Coef
or
the force need to overcome an instance of static friction much exceed the normal for(in this case car weight) multiplied by the Coefficient of Friction between the rubber and the road(or the "stickiness" ).

By this we know that the mount of cornering force we get form a tire is proportinal to the amount of weight we have on it at any one point, and by that we know that at the point right before the tire comes off the ground, the weight on it is 0 so it was offereing no cornering force. so we didn't need it anyway. Conversely, all three of the other wheels have picked up the wieght that the lifted wheel has left. And since the normal force on those is now higher, they can hold higher loads. Of course this breaks down as soon as the force achieved by weight exceeds the structural integrity of the tire, which then leads to a smaller Coef of Friction, and a sliding situation.

So in theory the suspension is never to blame. always the tire

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 89civicdx &raquo;</TD></TR><TR><TD CLASS="quote">front and rear are both ITR bars, 22mm

</TD></TR></TABLE>
ja, i saw dat after i made my post. slow typing 0wn3z m3!

nate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by gotocrx &raquo;</TD></TR><TR><TD CLASS="quote">

Yeah really. If you aren't on the brakes there why is the tire not moving? With no brakes the tire should spin for awhile, especially from if it has to spin down from the speed of a 4th gear turn as you say. You gotta be touching the brakes a little.
</TD></TR></TABLE>

Would think most photographs do not distinguish the difference between a still tire and one moving 10-20 mph.

 

Check to see if your front sway bar doesn't have any play. How does the car feel at turn in? If the car feels wishy washy at turn in, but has good mid corner grip, it would be a sign that the front sway isn't all the way connected and would result in your car pitching over like that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phat-S &raquo;</TD></TR><TR><TD CLASS="quote">

Would think most photographs do not distinguish the difference between a still tire and one moving 10-20 mph.</TD></TR></TABLE>

Actually when I took the pic, I recall the rear tire not moving or just barely moving (though not 10-20mph), and I was using a relatively slow shutter speed (1/100) to capture as much motion in the photograph as possible. I'll scrounge up some other cars that I snapped in relatively the same spot for comparison sake

Brian

 

Matt, that's the same front rate as I run and my car doesn't lean over near that bad. And I'm a few hundred pounds heavier than you. I think the guys talking about roll center are onto something.

I think the 16" wheels need to go.

 

Stock suspension (not sure of tires though)





*Corey is a little further into the turn, but past the braking area


*Phil is a little further into the turn, but past the braking area


*John is a little further into the turn, but past the braking area













Hopefully the pics can help shed some light. My guess is (as far as the rear not moving) you were still on the brakes some when you turned in and lifted the rear wheel. It did stay up there for quite a while

Brian