Rev happy Flywheel / clutch choices for street use.

[rejracer]

Hugh,

That's exactly what I was thinking only I was envisioning attaching the wires to the flywheel itself using a bolt with a washer welded on and inserted into the pressure plate bolt holes.

 

The good idea for making this out of plywood and making it large enough for wheels.

 

I have an extra sheet of 1/4 plywood in the garage that would work perfect for this. I think make the attachment points 13" from center as most of our Z tires come in at about 24" depending on the combo. I could not imagine using a combo 25" or larger.

 

If we are going to be sharing numbers it's best if we have the mass of the device as close as possible, so it's construction is important imo for moi.

 

-Robert.

[Tony D]

Tony D: Sure makes a hell of a lot of sense what you have experienced. The springs are just another failure point. Thanks ever so much for the explanation. Did not know about solid hubs but they make a LOT OF SENSE. Now I want a solid hub clutch disk!

 

Oh gawd, what have I started!

[Tony D]

Wouldn't a cone suspended from a central point be self-centering and have less 'noise' for hte calculations---and as long as your cone was big enough, anything with a hollow center could be hung on it and spun.

 

Like, maybe, eviscerating one of those Harbor Freight Bubble-Style tire balancing thingamabobs, and using it as the centered hub.

 

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91939

[rejracer]

Tony, I think it would work, but then the material that you hang it from becomes very important. The device that Hugh is talking about, I believe would be less important on the material used for the wire.

 

With a single wire/rope in the middle it's all about the diameter / strength of the material used, and it's also subject to fatigue and tempature, so getting accurate readings on the same item would be more difficult. Obviously I have no experience in this, but I as I understand it, those are the principles of the device.

 

With the three wire setup the winding motion with the wires further apart provides greater vertical movement, which increases the radial "spring" or rotational force. The three primary factors of this device that determine the amount of rotational force are the length of the wires, the distance they are mounted from the center point, and the total mass of the object(s) hung from them.

 

 

My plan for making this thing is to create a center mark and then draw a series if of concentric circles on the plywood to eyeball the object being measured to center. It's not perfect, but It will get us close.

 

Although....If the material used in the center wire setup were not stretched/twisted beyond it's yield (or is it tensile?) strength then I suppose it would be accurate over multiple tests, neglecting temperature of course.

 

The scientific way of doing this is to have a known and calculable rotational force. This device eliminates the importance of the materials used in the wire, and temperature as variables in the calculation.

 

 

Hugh,

I was thinking about making this thing out of guitar wire. Reason being is that both of us would have the same materials readily available to us. For example we could use the high E string of Ernie Ball electric guitar strings. That pretty much narrows it down to a tightly controlled diameter/composition of wire to eliminate that as a variable for mass.

 

...and once again, I've never seen one of these things operate, so if i've stated something that's not accurate, let me know. All my comments above are just my understanding of the real world. I won't guarantee my understanding is accurate.

[Tony D]

With a couple of Small Ball Bearings in the center of the hub, a piece of steel rod with small lever arm connected to a truck bungee or light spring of known tension could replicate this setup under a normal shop workbench thereby negating the requirement to put it in the middle of the room and have a long suspension setup...

Various springs of various known tensions could be used depending on the physical mass of the object being tested. This variable springrate (also possible by using multiple holes in the lever arm...) could allow for testing of quite heavy objects as even a single 1/4-20 all thread piece can suspend several hundred pounds!

 

The only drawback is the friction inhernet in my suggested device, but this could be compensated through by doing several tests of know differential and cancelling out through the calculations.

 

And then it's under the workbench (kitchen table...), where the wife doesn't complain about it...

 

A flywheel dangling in the middle of the family room with inscribed arcs on the wall and a laser pointer might upset even my wife if I was called away on the phone and she arrived home unexpectedly.

 

She already suspects the issues with the stove stem from curing HiTemp Paint and Exhaust Manifolds therein...

[hughdogz]

My plan for making this thing is to create a center mark and then draw a series if of concentric circles on the plywood to eyeball the object being measured to center. It's not perfect, but It will get us close.

 

I was thinking the exact same thing.

 

 

Hugh,

I was thinking about making this thing out of guitar wire. Reason being is that both of us would have the same materials readily available to us. For example we could use the high E string of Ernie Ball electric guitar strings. That pretty much narrows it down to a tightly controlled diameter/composition of wire to eliminate that as a variable for mass.

 

I was thinking of getting some small diameter wire rope from home depot, and hook "eyes". Maybe even get some crims to make loops at the ends of the wire ropes. We could definitely consider using a guitar string that is ~0.009" diameter, but those aren't that long and may not "swing" as long as longer wires...

 

I'm going to hang mine in the garage (not my living room). I only need to make one mark for zero, and one mark for ~10 degrees and I can probably use a thumbtack.

 

We can probably "normalize" any difference in size / weight of the plate by subtracting the empty plate time from the time recorded with an object.

 

I've never seen one of these made or in operation either...but in theory it should work great.

 

I really want to try this design and I think it is the best so far. Plus, Tony D's or Cygnusx's ideas don't involve "a laser"

 

[johnc]

Oh gawd, what have I started!

 

Tony D told me that sprung center clutches explode all the time, lock up your engine, and throw your car over the guardrail into oncoming traffic right in front of a school bus full of little children! You'll die if you put a sprung clutch in your car and dozens of soccer moms will spit on your grave.

 

BTW... I ran a Tilton aluminum flywheel with a Nissan Motorsports pressure plate and Nissan Motorsports competition spring center clutch for 25,000 miles of autocross and track racing over a 5 year period without a single problem. That was behind a 200 hp L28 that we regularly shifted at 7,000 rpm.

Edited April 18, 2009 by johnc

[woldson]

Yea..but... there has not been a school bus with screaming children out on that track yet,,has there......

[Tony D]

Those VW's are much more tortorous than some paltry Auto-X 240 Engine!

 

And they only go when your wife is driving.

 

Let me refer you to my WIFE and you defend a decision to buy a spring center disc for her car EVER again!

 

(Now you know why I do the clutch changes after dark, and keep the boxes out of sight!)

 

If you have ever heard "Does that clutch have those damn springs on it like the VW Clutch did?" You would understand my pain!

 

Limping home along Magnolia Blvd from Riverside to Corona through Home Gardens 'garumpha-garupmha-garumpha' in a VW Microbus with no Air Conditioning in August down a nary wide enough emergency lane and then having to cross traffic with a left turn.... I do that to her again, and it's curtians for my 401K!

[roger280zx]

I do that to her again, and it's curtians for my 401K!

 

401K... I remember those.

[rejracer]

I have a few questions concerning mounting a pressure plate to an aluminum flywheel:

 

I am planning on buying ARP studs and nuts to mount the pressure plate to the flywheel. The reason for this is to accomplish the following:

A. get maximum thread engagement

B. protect the aluminum threads during installation

C. eliminate any possibility of bolts bottoming out.

 

My questions:

1. Is there any reason a stud/nut combination will not work in this application?

2. What type of nut should I use, standard nut with washer or a flanged nut?

3. Should a lockwasher be used?

 

I am planning on using a stud with a flanged nut unless someone can provide good reasons not to.

[winquist]

Just wanted to post my simple 2 cents’

 

I run a 240Z in the FIA racing historic scene in Europe. I run a Rebello engine pushing around 270HP at 7.000 rpm. I have been running with two setups:

1# Fidanza flywheel with a Centerforce II clutch – the Centerforce gave up after 65 race miles, it just could not stand the fast shifting and power.

2# Fidanza flywheel with an ACT 6 puck clutch – now that was fun …after 21 race miles (running with Mr. John Morton in Copenhagen) the pressure plate pulled itself (threads gone in the flywheel) out of the Fidanza alu flywheel (fantastic sound when that happens). Everything was off cause destroyed !!!

 

Now I am going for at steel flywheel, AP or Tilton 2 plate clutch Hope that will cope for my harsh driving

 

Anyone had the chance to test the JUN ultra lightweight flywheel ?

 

Rgds

 

Stefan

[rejracer]

ARP studs and nuts were not available for what I am wanting to do. I ended up using Class 14.9 M8.1.25x25mm socket hex screws from bolt depot and class 10.9 matching thread nuts. I took the assembly down to the local racing supply/machine shop to get their input, and they said go for it, and had them install / locktight the studs in, and then zero balance the flywheel. they then balanced it with the pressure plate on as well. they had to take material off both flywheel and pressure plate, and even added weight to other spots on the PP.

 

I hope it's smooth.

 

I've been having PC problems, otherwise I would post up pics.

 

Winquist, were you running a 225 or 240mm clutch?

[Tony D]

Wingquist, contact Adrian at VA Motorsports Engineering in Holland. (Posts here as Z-Spec I think...) He uses the AP parts on his own flywheel... a photo exists at this page:

 

http://www.va-motorsport.com/index.php?page=7A

 

He also races FIA with some Shelbys, and has prepped several Z's as you will see from the link.

 

Good Luck!

[winquist]

I ran a 225 mm setup (by the way - I have great pictures of the ACT clutch cover "flexing" after internal "explotion" ))

 

Thanks Tony - I know Adrian, he made my new rollcage ;-.)

 

I'v just ordered the Jun Ultralight flywheel as well as a AP Racing twin plate paddel clutch - I that wont work, I'll sell all my Datsun bits and start enjoying some rollerskates instead

 

ha ha

[Tony D]

No rollerskates, just do like Frank280ZX did and put a BMW M5 V-8 in the chassis along with the six speed manual and BMW Diffy! (Ad can help with that as well...he he he)

 

Did he supply your chassis as well? Or did you send your existing chassis to him for the cage work?

 

We DEFINATELY need photos of clutch explosions! PHO-TO! PHO-TO! PHO-TO!

(Natives are restless, now it's off to Hooter's Shanghai for Hootie Hour. I will return and post inebriated later this evening! LOL)

[winquist]

He he ...well if I should go that route, I would go for the BMW straigt 6 from the M-model

 

No - AJ did the complete cage in his own car, and the I had it welded in here in Denmark where I live. The chasi was paint stipped, and I am actually going to pick it up from the paintshop in about 16 hours 39 minutes and zero sec.

 

look forward to see the result

 

Say hi at Hooters - havnt been there for 8 years ;-(

[woldson]

LOL!!

Wonder if I will be able to tell the difference???

[Flexicoker]

http://www.helix-autosport.com/

 

That company has some pretty small diameter dual/triple disk solid hub organic clutches. Not cheap, and you would need a custom flywheel (unless they make one for our car) but I think it would be pretty awesome.