Improved Handling ( depending)

[mahout]

Today on the handling track we discovered that disconnecting the antisway bar (at the front) greatly reduced understeer of our Fit as expected. But how much u/s was reduced was unexpected. The force on the steering wheel was halved! For only those of you, like us, who are not enthused with gobs of u/s you may wish to investigate diconnecting the driver side link from shock to bar arm. Why the left side? Its the driver's side where loss of weight in beneficial. OK so its only half pound. Still half-pound is half-pound. Now to the race track to see what really happened to handling overall.
cheers.

[SD_MR_FIT]

hmmm... interesting.

[kenchan]

Originally Posted by mahout

Today on the handling track we discovered that disconnecting the antisway bar (at the front) greatly reduced understeer of our Fit as expected. But how much u/s was reduced was unexpected. The force on the steering wheel was halved! For only those of you, like us, who are not enthused with gobs of u/s you may wish to investigate diconnecting the driver side link from shock to bar arm. Why the left side? Its the driver's side where loss of weight in beneficial. OK so its only half pound. Still half-pound is half-pound. Now to the race track to see what really happened to handling overall.
cheers.

damn, i better not eat that quarter pound burger, cause a quarter of
a pound is a quarter of a pound! jk


running without the front swaybar is going to make the car
feel real sloppy, i think given that you're on stock springs,
stock dampers. i wouldn't recommend driving like that on
hwy speeds.

[mahout]

Originally Posted by kenchan

damn, i better not eat that quarter pound burger, cause a quarter of
a pound is a quarter of a pound! jk


running without the front swaybar is going to make the car
feel real sloppy, i think given that you're on stock springs,
stock dampers. i wouldn't recommend driving like that on
hwy speeds.

Out of curiosity, why do you think handling will be sloppy? Do you think suspension geometry changed? And what is 'sloppy' If you mean less precise taking a set in corners, there was no change, just less effort to do so.
How about track speeds up to 100 mph including several corners from tight to very wide. No problem. Quicker lap times at less work to do it. The reduced lap times could be due to the learning curve. Statistically, they were were significant.

You may find it interesting to know that in Europe where handling is much more valued than in the USA they use antisway bars sparingly.
Antisway bars transfer a portion of the inside spring compression force to the outside wheel but in doing so they lessen the load on the inside tire which reduces cornering force. It may be flatter but its slower. Race cars get the most performance from minimized antisway bars; those bars are used only to balance cornering at each end to try to achieve neutral handling.
But there's another reason to boost understeering; courts have held, thanks to the legal profession, that the 'average' driver is far safer with understeer than neutral, certainly, oversteering handling. Started with Ralph Nader's 'expose' of the Corvair.

[kenchan]

i think handling will be sloppy because ive had experience with
adjustable swaybars over the years and have experimented with
various cars, various settings, thats why.

sloppyness is defined as non-nimble, loose connectivity between
your steering input and car, also the overall response/dynamics, etc.

you may also find it interesting to know handling and driving
spirit is also highly valued in japan where these cars are made.

[mahout]

We have over 50 years experience with chassis engineering from production cars to race cars. And 10 years managing a chassis department staff.
Your definition of non-connection between steering and car direction is understandable but your results with adjustable swaybars doesn't work. Adjusting swaybars merely changes the amount of understeer or oversteer that results and they are very useful. If the understeer/oversteer is extensive, reduction by lengthening the arm helps. If its not enough, shortening the arm is desireable. One of the best things about adjustable swaybars is that you can make very close adjustments, which is not possible with fixed bars or bar diameters. When you are seeking to balance oversteer/understeer front vto rearfor a given driver very small changes are ohten required. And not always the same for each side of the axle. If you didn't approach adjustments in that manner you easikly could really screw things up.
In the case of Fits, we think the understeer is excessive and better lap times from reducing it proved the point. If its not measureable its not real.
Incidently, I've driven in Japan and there roads are so congested there handling really isn't an issue. Of course, Japanese Fits aren't suspended or braked as American versions. Honda and others do know why they spec them differently,. Ditto European Fits.

[kenchan]

well it surely did not take me 50yrs of chassis engineering experience
and managing 10yrs of chassis department to understand how a
swaybar works.

I dont see your point why experimenting with adjustable swaybars
is mutually exclusive to your experiment with the swaybar link
detached. vitually you're doing the same thing, playing with
swaybar setting.

also, you mentioned something about not changing geometry on
your earlier post. the car's suspension geometry is designed to
work within a given range. when you go outside that range you
are not running inside the suspension's programmed geometry.
detaching the link to the swaybar will take you outside of that
range quickly which usually results in unfavorable feedback.

a lot of folks like to run inside their own programmed setting
within the suspension geometry for optimum consistent performance.
less the movement, the easier to control given that the tires can
handle the extra load.

anyway, keep us posted on your experiements because it sounds
interesting even if you are going against Honda's design and my
idea of suspension tuning. i'd like to hear all experiments.

Originally Posted by mahout

We have over 50 years experience with chassis engineering from production cars to race cars. And 10 years managing a chassis department staff.
Your definition of non-connection between steering and car direction is understandable but your results with adjustable swaybars doesn't work. Adjusting swaybars merely changes the amount of understeer or oversteer that results and they are very useful. If the understeer/oversteer is extensive, reduction by lengthening the arm helps. If its not enough, shortening the arm is desireable. One of the best things about adjustable swaybars is that you can make very close adjustments, which is not possible with fixed bars or bar diameters. When you are seeking to balance oversteer/understeer front vto rearfor a given driver very small changes are ohten required. And not always the same for each side of the axle. If you didn't approach adjustments in that manner you easikly could really screw things up.
In the case of Fits, we think the understeer is excessive and better lap times from reducing it proved the point. If its not measureable its not real.
Incidently, I've driven in Japan and there roads are so congested there handling really isn't an issue. Of course, Japanese Fits aren't suspended or braked as American versions. Honda and others do know why they spec them differently,. Ditto European Fits.

[mahout]

Removing one side's swaybar link is the same as removing the antisway bar. Just less work - now and when resale is anticipated. Most adjustment you can do. When there is as much understeer as the Fit has it's not hard to improve handling.
Sorry, but all suspension geometry is set to operate thru the full range of motion allowed by the shock travel. Using the antisway bar to limit suspension travel is dangerous due to metal fatique and variance.
And 50 years of experience playing with suspension design and adjustments is why I'm correcting your idea that removing a swaybar results in sloppy handling. It depends on what you're starting with. In this case a very understeering vehicle. A lot of adjustment is not only tolerated but expected.
And yes, even after 50 years I'm still learning but it took only a few short projects with experienced engineers to learn that swaybars are meant to balance not control. Sloppy handling results from poor geometry, poor shocks, poor balance, and poor alignment. You can screw up balance with poor swaybar application but reducing understeer on a front-engined vehicle is not one of them. (installing a beefier front bar would be, for example) Adding a rear sway bar to add oversteer to match too much understeer is understandable but often it's overdone and overall cornering is reduced and the ride as well. If the only result you are looking for is flat cornering adding oversteer to match too much understeer is a half-way solution. That's one of the things 50 years experience with 'adjusting' sway bars teaches.
We do have one advantage the old days didn't: computer modeling. It sometimes took weeks on the drawing board to simulate wheel/tire motion that now is done in 30 seconds. And not as accurately. Sure is nice. And yes I modeled the Fit suspension before we disengaged the front bar. We just guessed from experience that no antisway bar would still have understeer but a lot less and that would merely make the Fit a better driver. Less effort as a result of less understeer means better precision And the track proved it. Daily driving has too. Like I said before, the heavy understeer of the Fit may be a result of legal imposing specs rather than chassis engineers.
That happens more than you want to know.
cheers.

[jsensk]

So what precisely do you suggest if your are running a (Progress) rear sway (with coilovers)? Or is the equation not solvable with only that little bit of information? Imean, is there an overall more balanced application per your findings with the front sway experiment?

[kenchan]

mahout-

you know wat, if my car was still stock i would just go to my garage,
remove the endlink and let you know my findings. much faster than
50yrs. you seem to have a fixation with 50yrs. you should change
your handle to mahout50yrs. jk


since you modeled the fit's suspension before removing the link, what
were the factory spring rates? what are the stock damper rates?

this info has yet to be found.

[Skimmer]

Mahout: Any chance yet to compare before/after lap times? I'm very curious what you learn since this may be an easy way to reduce understeer and wheelspin for us stock-class autocrossers!

[mahout]

On same tires and pressures the Fit was 3.2% faster; the +/- 3s variation on the original was 1.45% so we found the difference significant on a fairly open course.
The difference we attributed to how much easier it was to set and hold turn-ins and track-outs in corners to follow the desired 'line'. We run 205/40x17 tires but not dropped on standard springs.And yes we have found it a good way to reduce wheelspin as well as more neutral handling.
If you try it ( if memory serves you only need a 14 mm socket and 5 mm hex to do it) let me know how you find the results. cheers.

[mahout]

Originally Posted by kenchan

mahout-

you know wat, if my car was still stock i would just go to my garage,
remove the endlink and let you know my findings. much faster than
50yrs. you seem to have a fixation with 50yrs. you should change
your handle to mahout50yrs. jk


since you modeled the fit's suspension before removing the link, what
were the factory spring rates? what are the stock damper rates?

this info has yet to be found.

Sorry but I only modelled the travel of the position of the wheel and tire to see how much difference there was between actual and desired position ( desire tire tread to be parallel to the road surface, which of course it almost never is) for various degrees of turn from zero to 12 degrees either way and various body lean angles. We do have shock analysers and spring rate checking devices but we don't release that information. Old NASCAR habits are ingrained. And modern lawyers.
The rate of change in steering angle, body lean, tread distotion, and camber changes get hairy when you strart to computer model that to find the relationship between tread and road. That program would likely wipe out my laptop although manufacurers have them on big computers. No, a Cray is not needed..

[mahout]

Originally Posted by jsensk

So what precisely do you suggest if your are running a (Progress) rear sway (with coilovers)? Or is the equation not solvable with only that little bit of information? Imean, is there an overall more balanced application per your findings with the front sway experiment?

I presume you are lowered as well so your addition of a rear sway bar to increase rear oversteer to counter front generated understeer is the right approach. In your case I would not remove the front bar. by itself.
The coilovers are surely stiffer than stock so my first step would be to remove both front and rear antisway bars to see what the new handling base balance is. The second step would be to install only one bar at the end that needs balancing. If the base balance is some understeer then I would go with a single rear bar and check balance. If that generates lots of oversteer then I'd add the front bar. If the bars are adjustable by arm length make changes on the arm 'length' of that bar that is strongest (lengthen rear arm if o/s, lengthen front bar if u/s) or (shorten front bar arm if o/s or shorten rear bar arm if u/s). You may spend a few hours on the skidpad. Good luck.

[Skimmer]

How was the body lean in corners w/o the front bar? Was it ridiculous?

[kenchan]

Originally Posted by Skimmer

How was the body lean in corners w/o the front bar? Was it ridiculous?

if you're stock, give it a shot?... it only takes 4-5min to unlink one
endlink. "ridiculous" is all subjective, so hard to measure.

but do it at your own risk!

[mahout]

Originally Posted by Skimmer

How was the body lean in corners w/o the front bar? Was it ridiculous?

Honestly, I can't tell the difference.
There has to be some difference I just cuoldn't tell. And what I might not find you may find easily so you need to try it. Its so easy to try that its not a big deal. Just rember to raise both front wheels so you can take the link off easily. If you like it fine and f you don't its no big deal to re-install.

[eldaino]

Originally Posted by mahout

Sorry but I only modelled the travel of the position of the wheel and tire to see how much difference there was between actual and desired position ( desire tire tread to be parallel to the road surface, which of course it almost never is) for various degrees of turn from zero to 12 degrees either way and various body lean angles. We do have shock analysers and spring rate checking devices but we don't release that information. Old NASCAR habits are ingrained. And modern lawyers.
The rate of change in steering angle, body lean, tread distotion, and camber changes get hairy when you strart to computer model that to find the relationship between tread and road. That program would likely wipe out my laptop although manufacurers have them on big computers. No, a Cray is not needed..

you would be doing the fitfreak community a great service if you were to tell us what the factory spring rates and shock rates are. its a shame you wont, as most of us have no access to this kind of equipment.

[mahout]

Originally Posted by eldaino

you would be doing the fitfreak community a great service if you were to tell us what the factory spring rates and shock rates are. its a shame you wont, as most of us have no access to this kind of equipment.

We didn't measure the spring rates or shock jonce/rebound rates. Measuring the spring rates is certainly easy enough to do though. All you have to do is take a spring and stack weights (in the old days we used barbell weights) to compress the springs 3 inches measuring the change in weight between 1 and 3". Take the weight difference and divide by two to get the spring rate. Works well unless the spring is graduated, meaning the coils are not evenly wound.

Shock dynamics are a completely different story and the legal issues involved are such that we, as any other shock tester, are better off not divulging what we find. There's no way of telling who sees the data and misapplies it. Besides, most shock manufacturers might find such information proprietary, as we do for our custom shocks.

Needless to say of course care in fixturing needs to used for safety. I am curious why this information would be useful to FitFreakdom.