How to reduce lean?

[Dev]

Hey henrich... When we hook up you can take a spin in my car...

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TEAM FOCALJET: NorCal
ZX3ford/Rainforest Green/Pioneer DEHP7200/Punch 150a2/Punch 200a4/Injen CAI Ractive filter/Superchip/ProgressSprings/Progress rear Swaybar/Esslinger pulley/Badge's removed/Limo Tint on rear 3 windows/custom exhaust/painted bezels & trim/B&M Shifter/carbon fiber look eyelids and tailcovers/Kent Cam gears/indiglo gauges

[squiggee2000]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by henrich:
But what does each of those items do?
<HR></BLOCKQUOTE>

Strut tower bars or tie bars are used to strengthen the body flex of the car. It is possible on some cars to have 4 tie bars - Upper and Lower Fronts and Upper and Lower Rears. Normally without them your cars body would be like this in a resting position: | | When your car is moving and comes into a turn, the body isn't very rigid and will flex some making it do this: \\ or // Strut Tower or Tie Bars will reduce this reaction giving you a quicker turning response because now not as much energy is being sucked up through the body shift.

Sway bars do just what they sound like they do. They reduce the side to side sway of the car. They do this by being attached to the A-arm or some part of the suspention. They react in a way to reduce body roll.

My brain is now hurting so I hope this has cleared some of it up a little better that just a list.

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Team FocalJet: MidAtlantic
2001 Twilight Blue Clearcoat Metallic ZX3
Mods: 30% Tint, Drop-In K&N Air Filter, Wrapped Front Markers, Eyelids

The Ron Jeremy of FocalJet
IM at squiggee2000

[henrich]

So in practice does sway bars actually make
a noticeable difference to the handling of the vehicle? How noticeable? Im looking at this group buy for springs/bars and the price looks right!

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2k1 Yellow ZX3
18x7.5 ASA JS5's
215/35ZR18 Parada's
Ice-Man Intake
Vibrant Exhaust

[vavenom]

deffinatly a yes, they helped alot for body roll as well as just all around tightening of suspension.

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01 silver ZX3, Intrax 3 inch drop springs, Koni shocks, Vibrant cat back with dual DTM tip, FS flex pipe, B&M shifter w/carbon fiber knob, clear corner lites, platinum window tint, eibach sway bars, poly bushings, FS 8mm plugwires

[focusownerskid]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by zx3ford:
Hey henrich... When we hook up you can take a spin in my car...

<HR></BLOCKQUOTE>

Same here.....Eibach Race Springs...Hell ya!!!!!!


Next G2G!!!!!


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FocaljetTEAM:NorCal/CD Silver ZX3/5 Speed/KKM Intake/Esslinger Underdrive Pulley/Ground-Control Coilovers/Focal Center Caps/50% Tint,14% Mirror/Euro Grilles/Custom Exhaust/B&M Shifter
Best ET-15.97@88 MPH
'98 SVT Contour,Fully Loaded
It's not mine,it's Y2K's
Focaljet Stands Alone!!!!!

[henrich]

Okay folks, what needs to be done to remove
the heavy lean/roll when cornering fast and tight in the ZX3? Springs? Shocks? Both? Either? Any and all information is greatly appreciated, thanks!

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2k1 Yellow ZX3
18x7.5 ASA JS5's
215/35ZR18 Parada's
Ice-Man Intake
Vibrant Exhaust

[sit'n'on_chrome]

strut tower bars front and rear sway bars good shocks and performance lowering springs.
did i leave anything out ?

[henrich]

But what does each of those items do? Im new to this auto-tuning gig, (having left it all up to the dealer before , and dont really have a solid grasp of what adding sway bars will do, or if I just alter the springs for example. Thanks for the info!

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2k1 Yellow ZX3
18x7.5 ASA JS5's
215/35ZR18 Parada's
Ice-Man Intake
Vibrant Exhaust

[sit'n'on_chrome]

the strut tower prevent the the bay from twisting the front end of the car causing it to be stiffer the same for the front and rear sway bars . there added stiffness reduces the swaying of the car on tight turns helping limit bodyroll throughout the car .
hope this helps a bit .

[lacox]

Just like Chrome stated:

Sway bars are designed to reduce body roll, sport springs help out too + they have the benefit of lowering the car's gravity center.

Finally, dampers are used to control the spring's movement.

.02

[This message has been edited by lacox (edited 01-25-2001).]

[Shmee]

You will get the best results out of swaybars if you already have a good set of springs and shocks/coilovers.

The affectiveness of the Strut-bar I explained here...
http://www.teamfocaljet.com/ubb/Forum3/HTML/000293.html

As for the lower tie bars, the focus doesn't really need them.
the lower control arms on a focus don't sit as low as they do in a Honda so we don't really need a bar coneting them.

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We must regulate our means in which we do battle. Prepare for the wrath of my Foci!

www.club-focus.net

[P-51]

Nobody in this discussion has any racing experience, that I know of. Shmee has a good grasp of the concepts from listening to the right people.

I probably have the most handling experience of anybody on this board (5 years autocross experience, 4 track days). This is not to brag, just stating my credentials so you can decide who you listen to.

There are two answers to your question since it wasn't specific enough.

Do you want to reduce your steady state body lean (ie: going around a long corner), or your transient body lean (ie: through a slalom or going around tight corners really quickly)?

The best way to reduce your steady state lean will be with the Eibach anti-sway bar kit. Period.

The best way to reduce your lean through a slalom or quick sharp corners is actually better *shock absorbers*. The Focus has very weak shocks. This leads to a huge pendulum effect when you make quick direction changes.

Springs can help steady state lean, but most of the springs out there are not stiff enough to have much of an effect. They sacrifice performance for comfort. To compound the matter, lowering the car more than 1-1.5" inches by using some of the available springs can actually increase your lean because the roll center is lowered too much (complicated suspension geometry term).

A strut tower bar, or stress bars with have *absolutely zero*, ZILCH, nada, NOTHING , no effect on body lean. Nothing. It's not physically possible. It would break every law of physics and engineering for a "stress bar" to decrease the amount of lean a car experiences.

To add to what Shmee said about stress bars not being necessary for the Focus because the shell is quite stiff already. I throw out this challenge:

I will bet you $500 that you can't *really* feel any difference with a stress bar on this car.

I'll set up a handling course in a parking lot. You'll be blind folded while I either remove or reinstall your bar. Then you run the course. Come back, and tell me if you think the bar is either on or off the car. I bet $500 dollar that you won't be right more than 70% of the time. (remember: you have a 50% chance of being right to start with just out of chance)

Any takers?

I'm not saying they don't do *anything*. I'm saying they don't do enough on this car that your average person is actually capable of feeling it. You're kidding yourself if do.

Until you can run an autocross course consistently with .2 seconds, you don't have a good enough feel of your car.

[This message has been edited by P-51 (edited 01-26-2001).]

[sit'n'on_chrome]

good info there p-51 . no resenentment taken .

[Dev]

P-51 does it again!!! Damn man I need to copy these.

[JohnsZX2SR]

When a car leans the suspension on one-side is in a different position than the other side. Anti-sway bars tie the sides together (think of them as a spring, torsion bar actually) that connects the two sides and resists this differential. Anti-sway bars therefore resist lean (or sway) without stiffening up the car with respect to bumps. Springs connect each suspension corner to the frame of the car.

The polyurethane bushings in the anti-sway system also have compliance. So if you want to reduce sway, go to both a stiffer sway bar and bushings. You will have to decide how much front/rear to change.

Another thing you can do is reduce the center of mass. Lowering the Focus 1-2" with properly designed springs helps. If you get good, progressive, shorter (Eibach) springs that are not too much stiffer than stock, don't expect very much degradation of ride. make sure you align the wheels after lowering the car.

Shocks are tricky, they only act when the shock is actually moving. Too stiff shocks can make the car stiff to short transients and very uncomfortable. I suggest getting adjustable (Tokico) shocks slightly stiffer than stock and go from there.

Finally tires. Tires can and do roll under. A lower profile (45, 50 etc.) will roll under less than a 60 profile which is better than a 70 profile. Also consider high pressure tires. Increase the pressure and increase the stiffness. With a small car you can safely run big 50 series, high pressure tires below max. inflation pressure safely. I run the Goodyear Eagle F1's (205/55VR15) on my ZX2 S/R at 30-32 psi when I want a comfortable ride and 40-42 psi for autocross, time trials, etc. It makes a difference.

Try stiffer bars (+2 to +4 mm), stiffer bushings, lower the car 1 to 1.5" with progressive springs, stock shocks and 215/50VR-16 or -17 tires. I think you will like the results and the ride would not be too harsh.

By the way, on a light car like the Focus (or my ZX2S/R) tires larger than 16" usually do not help handling. The improved dynamics of a larger diameter wheel/tire will be offset by the increase of unspring weight. On a light car the % increase of unsprung weight is enough to affect handling adversely. A few months back Sport Compact Car evaluated 15-19" tires on small cars and reported this effect. If you are looking for handling rather than looks I would stay with 16" or 17" max. diameter tires.

Have Fun!!

[This message has been edited by JohnsZX2SR (edited 01-26-2001).]

[PhocusZX3]

You guys forgot the cheapest and easiest way to get rid of body roll. Just tell your passengers to lean into the turn...hey...it worked in Speed.

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2000 ZX3:
FocusSport Race Header w/flex-pipe
Borla cat-back w/2.5inch Aerospeed muffler
Generic K&N conical
Apex Springs
Euro Grills
AndersenTek front lights w/PIAA bulbs

Coming Soon: Eibach sway bars, H&R Cup Kit, Engergy bushings, forced induction

"Hike up your skirt a little more and show your world to me." ~Dave Matthews

[This message has been edited by PhocusZX3 (edited 01-26-2001).]

[P-51]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Anti-sway bars therefore resist lean (or sway) without stiffening up the car with respect to bumps.<HR></BLOCKQUOTE>

This is not entirely true. Sway bars have no effect if both left and right tires hit the bump simultaneously, like a speed bump, you can't feel them.

But if you have a bump that hits only one side, like a pot hole or frost heave or something, then you will feel a stiffer bar as being rougher. When one wheel travels up, and the other stays down, the bar exerts a force on the body.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Another thing you can do is reduce the center of mass. Lowering the Focus 1-2" with properly designed springs helps.<HR></BLOCKQUOTE>

You seem like you know most of the fundamentals about suspension. You should learn the next step, get a good suspension book and start learning about the geometry of the suspension itself. Learn about "negative roll camber coefficient" and "roll center". Then you'll know why MacPhearson strut cars should not not be lowered more than 1-1.5".

This is not an insult, just a suggestion to take it to the next level so you don't give bad advice.

The Focus has very soft shocks. Most people would quite enjoy the feeling of a good sport shock. Ride in a Contour SE with the touring package, or a Contour SVT. Stiff, but not harsh. That's what most of these people want. And stiffer shocks will do more for transient body roll than any other thing will.

[JohnsZX2SR]

P-51 thanks for the input.

I have built a few cars that I ran in various SCCA events, mostly time trials and autocross. Suspension layouts are anything but simple. Unless you have a workstation with something like Pro-E or Adams it is hard to visualize how everything is going to move under load.

I agree with you that a MacPherson strut setup should not be lowered without serious mods to the suspension geometry. That is why I recommended lowering the Focus 1-1.5" without going into details. Tokico makes a set of struts that are intended for use with the Eibach springs, however, at some point you are going to have to modify the lower control arm length or axis of rotation or both if you want to do some serious lowering. The geometry is too complex to discuss here. Not worth it on the street.

You are right about the asymmetrical bump, since one side of the car is moving relative to the other. The example I was trying to present is how you can stiffen the car significantly against roll while increasing the spring rate only slightly. Too many people try to combat roll with very stiff springs, when they could have the same effect with a balanced set of roll bars with a much smaller effect on ride quality.

(On a '72 Opel GT I actually went to less stiff than stock springs and big fat anti-roll bars to get good anti-roll while trying to improve suspension travel and compliance. The GT used a transverse single leaf spring with a double-A arm suspension. It was a pain fining a spring shop that could make the spring I needed!)

[This message has been edited by JohnsZX2SR (edited 01-26-2001).]

[henrich]

So to overly simplify the information above, would it be correct to say that adding the Eibach anti-sway bars, lowering springs, and a stiffer shock (such as Koni when available) would have an excellent effect on reducing the lean on cornering, and indeed just going to something like the Koni&Springs would have a very positive effect?

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2k1 Yellow ZX3
18x7.5 ASA JS5's
215/35ZR18 Parada's
Ice-Man Intake
Vibrant Exhaust

[teamDFL]

Sorry Rob, 7 years autocross and approx. 20 track days. Of course, that shows ZERO about my suspension knowledge, just that I like to drive fast. The fact that I have corrected rear roll geometry in my BMW by designing a way to raise the suspension into the body 1.5" is probably more telling.

But back on topic, Rob's comment on how only the best drivers can truly tell the difference between setups is the most important. If you are not totally hard-core, just buy products based on price and recommendation from people you trust. If you only think you are hardcore, just spend the most money you can afford. If you are truly hardcore, you are debating the finer points of design differences between JRZs, Penske Blue Knobs and Ohlins dampers and really don't give a crap what I have to say.

And yes, Koni's a mild Eibach spring kit and some bars will dramatically transform your car's behavior. With a lot of experience, you will of course find faults, but a simple upgrade such as this has significant merits for MOST people.

Rich
teamDFL
2001 ZX3...deer whistles added
1984 BMW 318i track car...no deer whistles, will be installed before going to Summit Point

[henrich]

Hey Thanks for the Info P-51, in my case Im really only concerned about lean in tight short cornering &lt;1 second. Im not looking for racing, only improving real-world driving, and I dont find the lean all that pesky in normal cornering. Thanks again!

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2k1 Yellow ZX3
18x7.5 ASA JS5's
215/35ZR18 Parada's
Ice-Man Intake
Vibrant Exhaust

[P-51]

Ok Rich, but I hadn't heard from you for a while, didn't know you were around! ;D

What teamDFL did to his BMW, was exactly what I was talking about the geometry. I just don't want to get into it becuase it's *way* beyond the scope of this forum.

Yes, a balanced spring, damper, and anti-rollbar package will be excellent. I am going to be a big supporter of the full Eibach setup. It will be perfect for you guys. A mild drop, stiff bars that balance the handling out, and shocks that will be firm, but not hard. You guys might find Konis too stiff for your preferences, they tend to be more hard core.

[swooshUSN]

P-51, you wanna right book on suspension for us? Please? PREACH ON!!

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TEAM Focaljet: MidAtlantic Co-Leader/Moderator
2001Sangria Red ZX3;5-speed;all power;moonroof;B&M Short Throw(awaiting install);Pioneer DEH-P7200 and TSA6865 3way 6x8's;MTX 6000 12;MTX Thunder152(139Db on 8-26-00);K&N Drop-in FilterCharger;Zetec Inside Logos from ZetecInside.com;all new tint coming soon;Piaa Platinum Super Whites;Catz Hyper White Fog bulbs;Custom Sub Box;more to come...
Come visit my zing album
IM me @ swooshzx3

[ChemicleX]

Actually Rob if you could get a little deeper into the geometry of it I think most would like to read it. This thread has been extreamily interesting... smore info couldnt hurt.

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ChemicleX .-=(ToxiC)=-.
Some Times Team: SoCal
Some Times Team: NorCal

2000 ZX3 Malibu Blue w/ White trim

Coming:
Eibach springs and anti-sway bars
^^Putting Bday money to good use!

[teamDFL]

Konis shouldn't be too hardcore for most people. Since they are adjustable, you can somewhat tailor the ride comfort. Also, after a while, we should be able to get both Reds (softer) and yellows (firmer) so you can pick where you want to be on the ride/handling scale.

It is unlikely that I will champion the Eibach dampers. I love their springs, but the shocks are new. I would go with a more proven brand, and let the rich boys find out if they are good or not. This is not to say that the Eibach dampers will be poor, but most of the current crop of big names are big because they produce a quality product and have done so for years.

Rob, yes, just been lurking for a while. Watching can be fun too

Rich
teamDFL
2001 ZX3...underdamped because it is stock
1984 BMW 318i track car...underdamped because I am poor