Identifying handling issues - The Three W's
 

Another primer we published a while back. Hope this helps some of you get your cars dialed in.

The Three W's
Race car handling terminology

This is a brief primer on race car handling terminology. We often have drivers asking for help trouble shooting a handling deficiency but are unable to articulate what they feel into actionable information. Handling issues may have separate cause and effect or overlapping issues. This is why isolating each issue and using terms that a setup specialist can understand will help in determining a strategy to correct them.

The first step in setting up a race car and either fixing it yourself or communicating with the crew chief, engineer or tech who will make the changes is identify the three key components of the issue. What, Where and When, "The Three W's". All handling issues have these three components. Leaving one unidentified can make determining a strategy to correct it impossible. Always tune your competition setup on tires that are the same type and as fresh as you will race on. Setting up on worn out low grip tires will not yield good results for fresh high grip tires.

What
The sensation the driver feels.

• Loss of grip front (tight/understeer), rear (loose/oversteer) or both equally?
• Linear (predictable) or non-linear (unpredictable) breakaway?
• Upset when bottoming suspension?
• Upset when topping suspension?
• Continues to bounce over bumps or settles quickly?
• Front or rear brakes lock first in a straight line?

When
When symptoms are present. A car can behave just fine in one condition but not in another.

• Accelerating, coasting, maintenance throttle or braking?
• With engine braking or without?
• Transitioning left or right (wheel moving) or steady state turn (wheel not moving)?

Where
The portion of track or turn where the issue presents itself.

• Entry, middle or exiting turn?
• Straights only?
• Positive camber, level or off camber?
• Bumpy or smooth section?
• Fast, slow or all sections?

Example report
Issue 1: Car oversteers on fast right hand corner entries, no brakes. Fine everywhere else
Issue 2: Car is unstable in straight line braking, tail wanders, fronts lock before rears.
Issue 3: Car turns in neutral and fine, but is too sensitive to throttle mid turn, OK exiting turn.

If there are several overlapping issues, it is best to work on one at a time. A brand new build or one with many recent updates can take several sessions to achieve the handling behavior the driver wants. One key differentiator between drivers is the ability to learn what makes the car the most competitive, even if it requires a handling trait the driver feels objectionable. Train yourself to pay attention to the car and conditions to more effectively diagnose handling issues. In other words, learn what is fast and adapt accordingly. Do not make the mistake of forcing the car to behave a certain way regardless of tire wear or lap times.

If anyone has any questions on the subject of identifying handling issues, terminology etc.. fire away.

It is my hope that by sharing this stuff, more drivers on this forum can get their cars dialed in. The basic terminology used by pro race drivers to describe handling traits to their crew chiefs or race engineers is the same around the world. Some pro drivers have difficulty articulating what they are feeling. Other pro drivers are adept and understanding what's going on in the car and can articulate that to their engineer. This helps the engineer to quickly quantify the issue and determine what changes need to be made.

Learning how to isolate and precisely identify any set up issues means you get a better car, sooner and spend less money to do it.

Problem i see, that even such proper diagnosing what is wrong and what worth fixing, also needs consistency and experience from driver.
I know for one, that my lacking skills and imprecise "butt dyno" are inadequate to find problems at fine enough scale even to well report problems to others, so instead i rather choose route of finding generic "ballpark" setup/mods/choices/settings that are reported to work "good-enough" for many, and then just keep driving, more to accustomize myself to that one "generic" setup, instead of trying out miscellaneous different changes, possibly misreporting issues, misdialing setup in wrong direction, as for me changes evaluated by far by non-objective placebo feel or by luck/chance varying amount of mistakes in inconsistent driving, that sum up to change of way more then some moderate car setup change would bring. I can evaluate "big" changes, eg. in stock vs performance oriented alignment camber/toe wise, but subtle changes? Or changes in adjusting shock rebound/bump? Only in big enough lumps :). And by then it's better to find reasonable starting setting suggestions for specific uses by vendor / other twin owners and stick with those, working more with improving nut behind steering wheel :)

I actually had a problem with my car's setup earlier this season. It mainly steemed from several factors but the main problem that I faced, and probably many do as well at a grassroots level of motorsports, is being the driver and the engineer of your team and lacking experience in both departments.

When I had just resigned myself that I could not find what to do to make the car go quicker, I had the idea of putting another driver with more experience and familiar with the tracks and layout of the car behind the wheel to get his input on it. I learned a lot by doing this, was able to improve the car's setup a bunch and went from being several seconds offpace to winning.

One thing that I though understood well but I guess not afterall was how anti-roll bars (sway bars, or whatever name people prefer to use). Mainly, in my head, when you have already a stiffly spring car, adding stiffer bars to it will not help it if the car was already very peaky grip wise (not predictable in its brakeaway). I decided to do it, mainly to have adjustable ones and be able to play with the balance of the car, but it actually made the car feel a lot better than before.

A lot of the knowledge out there is mixed in a with a bunch of anecdotal data and biased opinions that may lead people down the wrong path. Its nice to see that you guys are open about the research you do on the car and your setup for it, Im sure a lot of people will benefit from it.

True to an extent, but any driver can improve both their driving and diagnostic skills by taking a deconstructive and methodical approach. Only the most talented learn how to play a piano on their own. The rest of us have to do exercises and scales, breaking it down to its fundamentals. That is what learning the 3 W's is. Isolating a very specific characteristic just by focusing on it. No different than a yoga instructor getting you to focus on your breathing for example.

Most drivers don't pay any attention to what the car is doing when on track. They instead focused on going as fast as possible, traffic, emotions. What helps is turning off the "go fast" part, forget traffic by pointing others by and not chasing anyone, turn off the emotional part (I suck!.. I'm great!) and just zero in on minute body motions and responses.

Example:
"OK when I release brakes on left turn entries, the car rotates freely. When I do the same on right turn entries, it understeers. Why would it turn left different than right. Mixed tires? Pressures way off? Corner weights messed up? Asymmetric shock settings?

Most drivers would not pay close enough attention to the left vs right thing and just report "It's unstable and unpredictable" when in fact its perfectly stable but only in right turns. This is what I mean by paying close attention. What it did (understeer/oversteer), where it did it (corner entry), when it did it (during brake release).

The point is, you and anyone else can teach yourself this skill. I wasn't born with it either. I taught myself.

VERY FEW cars, if any, will be perfect in every corner no mater what. Fixing things in one corner may screw up another one so it’s always about finding the balance.

Yup. That's where a little bit of data analysis comes in. Learning how a change affects the sector time and total lap time. If you do not have data or don't know how to use it yet, always focus on getting the car to work best in the fastest turns first. The turns with the lowest minimum speed are the last priority.

Another difference is whether you are optimizing for time trial, qualifying or wheel-to-wheel racing. In wheel to wheel racing lowest lap time does not always win. Sometimes you have to optimize to gain or protect track position at the cost of lap time.

Something I have not touched on yet but is sort of the advanced version of all this, is setting up the car asymmetrically. This done purposely, turning left harder than right, or focusing on one critical fast right hand turn and sacrifing every other turn on the lap for example.

What.
Loss of grip front

When.
Braking

Where
Corner Entry

So, I'm having a hard time turning in a corner. Feels like the front end gets washed out, and I trail brake on the way to mid and power over on exit. The mid sections of Auto Club Speedway turns 5,6 and 9 when there's no road camber to help out show it more obviously. A friend road a long with me last time at Chuckwalla and said I was going in the corners too fast, loosing cornering speed while trail braking and stressing(too much throttle) out and over-steering on exits. Talked to another friend that has the same cusco LSD, said he had the same issues, to he needed to have a slower corner entry to avoid it.


current alignment
Front camber -3.0
front toe's out +0.10
rear camber -2.0
rear toe'd in -0.10

245/40r17 GT radial champiro sx2
17x9 +42 apex wheels
cusco street zero-A sport edition
-spring rate F/R 8kg
-lowered F25mm R30mm
Cusco LSD 1.5way RS

Do you think I should take out the LSD and see how it turns in with same driving style or I should just adjust my driving style and try to adopt with my current set up? Sometime I just think I should have tracked it first bone stock.

Have you collected tire temps?
Sway bar sizes?
How is the balance in steady state turning, like in a long sweeper?

I don’t have pyrometer yet(I know I need Asap)
But I do run 35psi hot after each sessions.

OEM sway bars. Mine is a 2019, I guess 17 n up gets a fatter rear bar than 16 and below

I haven’t tried the coilovers on Buttonwillow yet. I have tho on SOW CW and chuckwalla CCW and ACS Roval.

I only have a quick video of my ACS Roval PB

https://youtu.be/ZYsnh3bMnVw

cough, circle track nascars vs the roadcourse variants

from a casual:

35 is way high, i lower my guys to about 28 before sessions.
17+ sway bars should be 18mm front and 16mm rear
16 prior was I believe 14mm rear?

https://www.facebook.com/10000027757...220068033/?d=n

This is a small clip of SoW CW i found on my
Phone. I was having a hard time uploading it to youtube, so heres an fb link.