Sacrificial ride height indicator on track or mechanism

[steve everard]

Any ideas for checking actual ride height on track with some kind of sacrificial block ???? Using the floor is a tad too late

[EricP]

Firm foam insulation affixed to the bottom was suggested to me.

[2BWise]

Shock pots?

[problemchild]

It is not exactly what you are asking, but once you get close, painting strategic spots on the underneath with a paint marker, will tell you when you are perfect. Better gauge than most drivers

[BeerBudgetRacing]

The problem I see with any of this is whatever you attach is probably going to come off in pits as you make your way to the track.

That said, I'd attach something like these near each corner. Long ways.
https://www.amazon.com/gp/product/B0...OHY40SSM&psc=1

At first I was think just a bend 1" strip of alum, but that will end up sharp.

Something like this might be even easier:
https://www.mcmaster.com/70535k75

Stick and go.

[EricP]

The problem I see with any of this is whatever you attach is probably going to come off in pits as you make your way to the track.

That said, I'd attach something like these near each corner. Long ways.
https://www.amazon.com/gp/product/B0...OHY40SSM&psc=1

At first I was think just a bend 1" strip of alum, but that will end up sharp.

Something like this might be even easier:
https://www.mcmaster.com/70535k75

Stick and go.

The amazon item could be a good option. I have those McMaster thingys and I’d bet they’ll rub the ground but bend and not be clear as to how close you were.

My plan is to affix the insulating foam in the pits because yes, the paddock drive would take it off.

[Purple Frog]

This is going to sound crazy to some.
And please consider this is related to SEDIV tracks that are for the most part smooth without frost heaves.
(Sebring being a HUGE exception)

I'd go out with cold tires and on the out lap expect to hear the rub strips talking to me, especially in the hard braking zones.
By lap 3 if they were still barking, I knew I needed to lift the chassis a hair or two.

If on the out lap on cold tires, the rub strips didn't talk to me... I knew we were too high.

I believe you should always have rub strips that can be easily replaced. (The Tatuus had neat little brass pucks) And, very important, the leading edges of the floor pan should be protected so that it can't catch on something and be peeled off. ouch. (it's a bit bothersome when the whole cockpit fills up with sod from below.)

[Beartrax]

I'd go out with cold tires and on the out lap expect to hear the rub strips talking to me, especially in the hard braking zones.
By lap 3 if they were still barking, I knew I needed to lift the chassis a hair or two.

Just curious: How much do you figure the tires "grow" between cold & hot? Or how much clearance do you gain between cold & hot?

[DaveW]

Just curious: How much do you figure the tires "grow" between cold & hot? Or how much clearance do you gain between cold & hot?

I don't think radials grow much, but the tire pressure and, thus, spring rate increases significantly, raising the effective ride height.

For the F2000 radials, the spring rate for Hoosiers increases about 45 lb/in for each psi pressure increase. So it will definitely change the ride height and reduce rubbing as they warm up (usually ~3-4 psi from cold to hot, so 135 to 180 lb/in change).

For bias tires, they will grow a bit as temperature & pressure increase, so it's a different calculation, but the same effect.

[sathorp]

Allstar Performance ALL10725 Ground Clearance Indicator

https://www.amazon.com/Allstar-Perfo.../dp/B003TPM6SC

Allstar Performance ALL10726 Wear Rods (4/Pack)

https://www.amazon.com/Allstar-Perfo.../dp/B003TPKVWA

[BeerBudgetRacing]

Allstar Performance ALL10725 Ground Clearance Indicator

https://www.amazon.com/Allstar-Perfo.../dp/B003TPM6SC

Allstar Performance ALL10726 Wear Rods (4/Pack)

https://www.amazon.com/Allstar-Perfo.../dp/B003TPKVWA

Neat, but....

From the description it appears the bracket is 4" wide. I was already having trouble thinking of where to mount something like this - before I read that.

[sathorp]

Neat, but....

From the description it appears the bracket is 4" wide. I was already having trouble thinking of where to mount something like this - before I read that.

Bracket is 2" wide x 1/2" tall. Wear Rods are ~1/2" Dia x 4" Long. Here's a Photo!

[JLind]

Go fancy with a laser
https://www.kasensors.com/en/product...-height-sensor


Sent from my iPhone using Tapatalk

[DaveW]

Bracket is 2" wide x 1/2" tall. Wear Rods are ~1/2" Dia x 4" Long...

I'd think any Nylon, Acetyl, or other plastic rod 1/2" diameter would do the same job.

I'd just mount it with a couple of 1/2" ID EMT clamps one above the other fastened to anything convenient.

Having said that - I use Frog's method - just touching when the tires are cold.

[sathorp]

I'd think any Nylon, Acetyl, or other plastic rod 1/2" diameter would do the same job.

I'd just mount it with a couple of 1/2" ID EMT clamps one above the other fastened to anything convenient.

Having said that - I use Frog's method - just touching when the tires are cold.

That would work too as long as you can adjust and clamp the rod. I picked the Alstar Performance Mounts I have up at a Swap Meet. I have 4 of mounts I think I paid $5/ea and the extra pack of Wear Rods was another $7.

[Purple Frog]

Dave,

I wonder who i learned that method from.

Between crewing for you and attending not one but two seminars by Pare/Lathrop... some of it stuck.

[BLS]

Those wear rods look a lot like hot glue sticks.

Just sayin...

[DaveW]

Those wear rods look a lot like hot glue sticks.

Just sayin...

It's some type of plastic rod from Quadrant Engineering Plastics - it says that on the rod...

[Charles Warner]

1" Delrin rod fixed to the corners of the car with a recessed -10 flat head bolt. Pick your thickness. Cheap and easy to change.

[BorkRacing]

I run at Mosport and the entry to Moss Corners causes a lot of compression. If the car will bottom out it will be there.
Was told stand on front cross rail of car and jump up and down. If it just barely touches its good.

Always did that and then Steve Lathrop told me to use just enough bump rubber to keep the car off the ground without springs on.

Same result. Same idea as Purple Frog. YMMV

Robby

[EricP]

This is going to sound crazy to some.
And please consider this is related to SEDIV tracks that are for the most part smooth without frost heaves.
(Sebring being a HUGE exception)

I'd go out with cold tires and on the out lap expect to hear the rub strips talking to me, especially in the hard braking zones.
By lap 3 if they were still barking, I knew I needed to lift the chassis a hair or two.

If on the out lap on cold tires, the rub strips didn't talk to me... I knew we were too high.

I believe you should always have rub strips that can be easily replaced. (The Tatuus had neat little brass pucks) And, very important, the leading edges of the floor pan should be protected so that it can't catch on something and be peeled off. ouch. (it's a bit bothersome when the whole cockpit fills up with sod from below.)

How about magnesium pucks to throw sparks!? (joking)

[Jayeff]

How about magnesium pucks to throw sparks!?

Oh I can't WAIT to see that one!

[romoman]

You're standard plastic bolts from the hardware store work great too. You just have to screw them down more after each session.

[Fred Michael]

How about magnesium pucks to throw sparks!? (joking)

Titanium!