warmmilk

well there's plenty of track days. you can easily go to more 1-2 track days a week if you want during the good weather season. there are 4 tracks within 4 hours of me (I live just north of Tacoma), 1 of them is 15 mins from my house. couple more if you wanna drive to canada just north of the border. but there aren't any time attack events. import modified scene is pretty small at track days. most cars are stock or almost stock (I shouldn't be talking, my car is pretty mild). I typically just end up comparing times to a friend of mine with a BRZ. S2k's are relatively common though, usually a group at most track days I go to.

in case you're wondering, here's the list of the tracks

Pacific Raceways
Ridge Motorsport Park
Portland International Raceway
Oregon Raceway Park (haven't been, but a buddy of mine that goes says its awesome. they don't run sessions, its just open track all day. its kinda in the middle of nowhere so they usually don't have big groups of people)

pm me if you have more questions so we don't derail the thread more. just fyi, I'm not exactly a veteran, just been doing 5-7 track days a year for about 3 years now

DavidNJ

The graphs at the end used different criteria: force applied from the damper obtained from the sensor (Izze Engineering sells the amp to CAN bus adapter, $150), and damper velocity and length from a linear potentiometer). The shocks a force dependent on velocity compared to a spring whose force is based on displacement. An anti-roll bar couples left and right dependent on relative displacement.

This data can be used to help in shock valving/tuning. on an adjustable shock, it would be possible to see what the changes did on the track. These often vary depending on the dynamics of the chassis. For the past 15 years, the dynamic nature of shocks has been a key part of chassis setup from soft spring/big bar (high rebound on the inside front kept weight on the inside rear on corner exit) to the current bump spring setups (which use pull down shocks to keep the car on the bump springs).

The dynamic tire temps are probably the biggest help and easiest to use. Taking tire core temps with a probe has been the norm for over 40 years. But that averages turns, braking, and changes in the time it takes to get where the temps are measured and from what is encountered getting there. These tire temp sensors ($300 each) let you see the whole picture and see what happens when adjustments are made to shocks, springs, bars, tire pressures, ride height, camber, toe, etc. They let you analyze each corner separately.

To get vertical load he mounted a strain gage on the barrel of the shock. From the video it seems to work but I'm curious about its accuracy. It seem to work and lets you see how weight is transferring the corner. By working with the different settings on a shock (and a rebuildable shock gives virtual full control, with Penske, Bilstein, etc. providing known shim stacks). It is not that unheard of for an oval track car to be setup to rebuilt shocks in the trailer, it isn't that complicated.

A lot of this depends on what your crew is like. If this is a Formula SAE team with engineering students hanging from the rafters, there are lots of people to do the setup. If you are going to the track solo, the data may be something you deal with after getting back to the shop.

For reference, AIM's evangelist's son ran in Spec Miata about a dozen years ago and had extensive data acquisition. He won the first SCCA Spec Miata national championship.

This was answered in the YouTube comments:

Unbr3akable

This is a track test; teams and companies do track tests at HPDE's all the time... It's not a race and the car is being driven within it's limits...

The alignment is fine, it's a combination of hot air and VIR is notoriously hard on the LR and LF.
Tire temperature will vary from corner to corner. Quite a few IMSA teams at VIR in August were running a different compound PER corner. Measuring tire temperature is a must if you want to exploit the full potential of modern "slicks".

These sensors are mostly aimed towards professionals and manufactures, but these videos help visualize the data.

Caleb

freq

Speaking of DE Champs, my wife calls me the King of DE.

What do I do? I'm not changing chassis and all I keep hearing is how horrible the S2000 is in any TT class. I'm in no position to go W2W either, tons of $$$ and not sure the skills are there anyway.

Maybe I'll do TT anyway and get participation trophies because of weak entry lists? Maybe win a tire here or there.

DavidNJ

For the record, Caleb is Izze Engineering...all those clever sensors are his doing. A very, very smart and very, very clever guy.

Question: were you using a linear pot with the shock shaft strain gauge?

Question: Are the measurements on the barrel of the shock accurate? Doesn't the fitting for the reservoir or the valve assemblies on an Ohlins TTX affect the linearity?

Question: What software is available to create the overlays used in your videos?

IMHO, in a competitive racing situation, the tire temp and dynamic load data could be priceless. My experience, more oval and road racing in another era, is that track time at an event is limited. Each race event is expensive, more so with the amortized cost of annual maintenance (e.g. engine/transmission/diff rebuilds) and crash repairs. That data would seem to help get the car dialed in much faster, assuming it can be quickly accessed in a meaning full way.

1tuffbb6

In for Caleb's response! -Jon

Unbr3akable

SakeBomb Garage

Very cool setup, do you have math channels to account for the anti-roll bar's effect on the wheel loads? It looks like you have the lower damper mount force calibrated to read in actual tire Fz, but that alone wont account for the ARBs. Since you have linear pots you should be able to account for the ARB with the delta damper length and a stiffness to find the delta load between the left and right wheel.

DavidNJ

I searched the GCR and NASA ST rules and couldn't find a reference to infrared sensors or tire temp sensors.

Doesn't the Autosport Labs data recorders and app work with your sensors? They show this video:

AlpineFD

great to have a real race engineer amid us =)

I'm very curios about the wheel load sensor, how would this get installed on a car like the S2000?
I"m abit confused on how some thing like that can be mounted on the shock.

What is the cost like for wheel load sensor? specifically i'm asking because i'm very curious to experiment with various aero components.
I do have AIM MXL2 dash for datalogging.

On another note, when you guys test with the shock velocity meter, do you find you always endup within a certain critical damping ratio range on the optimal setup?
assuming a street car based race car with low downforce, say a total DF of about 400LB at 100mph.
I have a theory that optimal shock damping ratio is always within a certain range (exception to high downforce cars).