How many clutch discs go in.....

[G'ginna]

As well depending on the manufacturer and the application you can have carbon, dirt (yes I said dirt) sand, dust, from various parts of the world for friction modifiers, fibers of various man made and natural occuring, nomex, kevlar, steel, brass, aluminum, copper, lead, wood (yes wood), rubber, resin binders and other friction modifiers that will never be listed or revealed to the masses.

Oh not 'dirt" that's a 4-letter word... we're talkin' sol (soy-uhl to ya'll northerners.) Sol has many different chemical properties. Some sol makes clay, some sol makes fossils, some sol makes gold, some sol's even good fer gardens... ya'll get my drift?

 

[FuelFC]

Lee you are on with the batches. As well it depends on who is tuning and how they set up thier own deal. Some run 4 new and one used, some run 2 new and 3 used...

Last place I worked it was all working off of thickness, rockwall, condition, re-surfaced and known wear per run. Just depends on the money you have and the tuners wishes that day or event.

Yes Georginna the drift you speak could be the smell of some dirt that well...what it is 'afore itsol' If that stuff were good for friction material I'd be rich in 'sol' with the two head of house cattle spreading it round here. The hell with the gas lease.

 

[Nick Name]

I had understood that several years back when the fuel cars were having consistency problems, that they were using disc from Rayspestos, that were made for Caterpillar.

Jay

 

[toffer]

In F1, actually, the clutches are mounted to the gearbox, not the flywheel. It's all about minimizing inertia.

A modern F1 engine, when shut down, can go from 19,000 rpm to zero in .2 seconds. That's not a typo. Two tenths of a second.

 

[nick name]

I had understood that several years back when the fuel cars were having consistency problems, that they were using disc from Rayspestos, that were made for Caterpillar.

Jay

Years ago, Frank Carstensen with AFT told me that in the early days of slider clutches the R&D budget wasn't large enough to pay for special compounds. Raybestos provided the discs at that time and there were a couple of organic compounds used plus the dreaded sintered iron.

He said that one of the organic compounds (As I remember, there were the 9135 and the 5191) was originally used for a Dodge dump truck. It had the right amount of grip, heat rejection, and wear for a Pro Stock application. As for the other, I think you're correct about it being a Caterpillar compound.

Back in the mid to late 90's, only the very brave chose to run the very aggressive, very hair-trigger, but potentially very fast iron discs. When the correct coating materials came into use, things got a bit easier. However, it was always a thrill to throw out your previous year's clutch data since each year brought a reduction in the diameter of the clutch.

 

[clwill]

This is as much a scientific wild a** guess as anything else--but assuming the clutch attaches directly to the back of the crank like any normal car--and a F1 motor being dry sumpped and with a very short stroke, the outside diameter of the clutch may the the lowest hanging part of the drivetrain. If you have a tiny OD clutch, you can sit the motor that much lower. (look under any manual tranny american V8 for example-the flywheel + clutch are the lowest point.)

Wow, there's an echo in here...

 

[Todd]

I love a good technical thread.......

Thanks guys

 

[G'ginna]

Lee you are on with the batches. As well it depends on who is tuning and how they set up thier own deal. Some run 4 new and one used, some run 2 new and 3 used...

Last place I worked it was all working off of thickness, rockwall, condition, re-surfaced and known wear per run. Just depends on the money you have and the tuners wishes that day or event.

Yes Georginna the drift you speak could be the smell of some dirt that well...what it is 'afore itsol' If that stuff were good for friction material I'd be rich in 'sol' with the two head of house cattle spreading it round here. The hell with the gas lease.

Well Jim, that there 'afore itsol' Ah'm thinkin' is actually v.o.c.s also known as volatile organic compounds containin' ammonia and methane. Right po'ful stuff in it's own right. That there cow 'afore itsol' may not be so good for friction, looks a little gooey, but horse 'afore itsol' is a whole other story. It looks to be a bit more solid.

Seriously though, it makes better sense to have something made of different compounds and possibly "woven" into wear layers before hardening.

 

[Bad Rat]

Greeting Pat! I remember seeing you at the LODRS race a few years ago in Brainerd. I can't remember if you were there to get your license or if you were shaking down a new car, but it was cool.

Hey Nate! I got my License at the Brainerd Divisional in 2004 and in 05-06-07 We ran the Divisional in A/A Comp to do some testing and get some seat time. Brainerd is a good place to get some seat time but testing a Divisional is luck of the draw. But with every pass we pick something up.

Next time we are at BIR and you are there stop by and see us. Or if you get up to the White Bear Lake area you can usually find me behind my Computer designing something at Herold Precision Metals (heroldprecision.com). Give me a call and I can arrange a tour of the Manufacturing Plant and the Race Shop.

 

[Outlaw Eric]

We are currently running 3 disks and 2 floaters in the N/TF car, but can go to 4 and 3 when we want.

EDB

 

[Tom]

It appears that the N/TF folks all have their own clutch set up. As stated here, Rockwell of the disks is an important factor concerning consistancy and track applications.

Question: How do you determine the disk rockwell? Does the rockwell change during each run? Has anyone look into the possible changes?

 

[AAFA-Freak]

Tom
Tool called rockwell tester messures hardness of material.
usally after disk have been surfaced after run.

Most everyone has 4-8 packs aready to swap in and out then after races they can surface and check the disks and floater for flatness and hardness.

thick gloves and arm protection required after a pass.


AA/FA 3/2 we run the same clutch disks around 2-3 races before we need to change them.

 

[Tom]

What is the cost of the rockwell tester and who provides the standard?

 

[.]

What is the cost of the rockwell tester and who provides the standard?

Rockwell scale - Wikipedia, the free encyclopedia

rockwell hardness tester - Google Search

 

[Tom]

Brent

Thanks for the info concerning the testers. I wasn't very clear when I asked about a standard. There needs to be a standard that is used to set the tester prior to inspecting the disks. Where can a person purchase the standard? From the disk manufacture? Or from the company that provides the tester? What scale are the teams using and where are they getting the tooling/testers?

 

[Nick Name]

There are probably some kind of standard you can buy, but I don't know about setting the tester. We had to send ours in for calibration every year or so. I don't know if they can be adjusted by the user.

All heat treating companies have them. call one and ask them what they do about calibration.

This might be of interest;
Rockwell Hardness Calibration: Wilson Calibration Laboratory

Jay

 

[unclebob]

I wasn't very clear when I asked about a standard. There needs to be a standard that is used to set the tester prior to inspecting the disks. Where can a person purchase the standard? From the disk manufacture? Or from the company that provides the tester? What scale are the teams using and where are they getting the tooling/testers?

Tom; all of the above can supply basic info. Most teams develop their own numbers of when to throw a disc away.
Almost all blown racers use a baseline perimeter set of numbers taken from a Rockwell "B" scale useing a 1/2" diameter ball. Some discs may be as soft as 39-40 R/B,
while most average 63-68 R/B. Back when I was a functioning "clutch psychiatrist", I used to throw them away at 86 R/B, because I felt that no matter what I did, they would not respond, no matter how thick they still were. Many used ones were bought up by others, ground, and a few more runs put on them. They must have had different numbers than me.
BTW, I gave my moniker to Bob Molinari, maybe you've heard of Dr. Bob

 

[Tom]

Bob,

That is great info! I always thought the rockwell would increase during the runs. Most of the NTF folks can't aford the tester. It appears that fuel and disks are more important.

Yes, I have talked to he and his sons a number of times. Great folks!