Side panels and other upgrades

[HazelNut]

Does Hazelnut = Puder?

seriously jim? of course its me.

[jimh3063]

Hazelnut, the guy you were referring to was Adam Zimmerman. A great guy.
He spun at the top of the hill at Lime Rock and got T-Boned.
Too bad, really good guy with a few kids and a wife left behind.

[jimh3063]

Brendan:
I stand corrected on my Golf statement. With the Fat Boys all things are possible.
Jimmy

[Jnovak]

Jimmy, I think you are underestimating the value of Kevlar add-on to the inside of the body work and an anti-intrusion seat insert. Anything can be damaged with a big enough hit, however I am confident that multiple layers of Kevlar on the inside of the body panels & a well designed kevlar seat insert inside the cockpit will be a very safe package. You can also add a few fasteners to the body chassis interface to make certain the body is not significantly moved in an accident.

No doubt this will add some weight but there is no solution that will give you what you need without additional weight & cost.

Thanks ... Jay Novak

[jimh3063]

Jay:
You may be right. I just need to do more research. I have had a lot thrown at me in a few days. Some makes a lot of sense to me and some is just plain old bull****.

Thanks for your input. I'd be curious to hear what Darren has to say since I think he works with composites on a daily basis.

Jimmy

[HazelNut]

Hazelnut, the guy you were referring to was Adam Zimmerman. A great guy.
He spun at the top of the hill at Lime Rock and got T-Boned.
Too bad, really good guy with a few kids and a wife left behind.

yeah I met him a few times. Good guy, young wife and kids as I recall. My buddy James rented that car a week prior at pocono and was scheduled to do an enduro with Adam the week after he was killed. After Adam was killed, in a car he was supposed to be driving, it was enough to convince him to quit racing.

[HazelNut]

Brendan:
I stand corrected on my Golf statement. With the Fat Boys all things are possible.
Jimmy

charles refuses to play. The town course actually has a beer girl who drives around this mobile golfcart/bar from hole to hole. You'd think hat would be enough for him to play.

(sorry about the in thread chit chatting and OT stuff)

[HazelNut]

Jimmy;
It is experiences such as these that I base my opposition to "hybrid" frame construction. In a hybrid chassis, the joints are the weak link. In a properly designed tube frame or composite tub, the load bearing members determine the strength not the joints. Composite tubs have evolved to the point where they are 2 main sections and a series of bulkheads. The joint for the 2 main sections is wide, simple and in a low stress area. I see the hybrid as being less than either a tube frame or a composite tub.

Just to prove that I'm not entirely posting off topic stuff:

is the above a statement of fact, or your opinion? If it's a fact that a hybrid design is not up to the task, can you please provide some evidence to back this up?

[jimh3063]

Brendan:
Be careful. Asking people to prove what they say to be true here can be taken as subversive and anti-establishment You may have to join me in timeout.
Jimmy

[Wren]

4) Safety is less important than rigidity in our class.

I read this entire thread and did not manage to find that anywhere in here.

Multiple people have already told you to add kevlar to the inside of your body panels and you said you don't want to.

You have lots of options to improve safety inside of the current rules we have.

[HazelNut]

subversive and anti-establishment

well then, just call me mr. maquis.

But seriously, aside from any radon controversy there is major merit to discussing this. If a hybrid really isn't up to task and there is proof of this, lets see it and euthanize the concept ASAP.

If there is no evidecent of this, then we either need to find some, OR if it can't be found and these things can legitimately be produced for less money while also providing additional safety, we should really be discussing exploring including hybrid construction as an option. With that we need to include to testing regime and a study to determine the variosu safety factors associated with the various construction methods.

As was pointed out earlier by I believe richard, club racing is dying. Maintaining the status quoe only draws out the long slow death. I don't know if this is the answer but perhaps new construction methods and newer technology might interest a few drivers under the age of 50. Lord knows when I had a pinto I sure got tired of explaining to people "despite the ancient engine, no it's not from the 80s, this is a "modern" race car"

[HazelNut]

well then, just call me mr. maquis.

I will also respond to Sr. Guevara, or in a few months, once we storm the capital, Generalissimo.......

[jimh3063]

I read this entire thread and did not manage to find that anywhere in here.

Multiple people have already told you to add kevlar to the inside of your body panels and you said you don't want to.

You have lots of options to improve safety inside of the current rules we have.

---


Wren:
I know 2 things for sure.
1) Richard probably knows more than I about these things.

2) Straight from his fingers.
the chances are rather small that something like a halfshaft is going to hit a tube and not all that empty space in between. Weitzenhof got damned lucky when the halfshaft that penetrated the keval panels hit the tube and bounced back out.

I'm pretty sure he meant to say kevlar. I'll let him speak to that.
I'm also pretty sure he said "penetrated the keval panels"

As much as I appreciate this verbal jousting I need to sign off for the evening.

Jimmy

[Jnovak]

delete

[Josh Pitt]

can someone here give me some pointers as to how to go about adding kevlar, and doing it myself.
i have a grasp on working with fiberglass and would like to add some kevlar into my car.
thanks

[Wren]

---


Wren:
I know 2 things for sure.
1) Richard probably knows more than I about these things.

2) Straight from his fingers.
the chances are rather small that something like a halfshaft is going to hit a tube and not all that empty space in between. Weitzenhof got damned lucky when the halfshaft that penetrated the keval panels hit the tube and bounced back out.

I'm pretty sure he meant to say kevlar. I'll let him speak to that.
I'm also pretty sure he said "penetrated the keval panels"

As much as I appreciate this verbal jousting I need to sign off for the evening.

Jimmy

That's hardly the same thing as safety is less important than rigidity.

More kevlar would have probably prevented it.

[Jnovak]

If adequate Kevlar will stop a .40 cal bullet it will stop an axle.

Thanks ... Jay Novak

[HazelNut]

If adequate Kevlar will stop a .40 cal bullet it will stop an axle.

Thanks ... Jay Novak

i'm not an engineer but I believe that is kind of an apples to oranges comparison. It woudl be kind of like saying a safer barrier that is designed to stop a crashing indycar at 220, will also stop a fully loaded tractor trailer going 55. It might work, but it's not designed or specced to do that and it might not be as effective as it could be.

What we're after here is an optimized solution that will stop the careening misplaced halfshaft or other jagged gnarled hunk of airborne metal.

[HazelNut]

can someone here give me some pointers as to how to go about adding kevlar, and doing it myself.
i have a grasp on working with fiberglass and would like to add some kevlar into my car.
thanks

you MUST buy the magic kevlar shears otherwise you'll never be able to cut the stuff. It's some majorly tough fabric.

[racecr]

What is the life span of kevlar in a racing car?
We throw vest away after 3-4 years, recommend by the manufacture.

a 5-6 year old vest let a 45 slug go right thru it.. (not close range) just testing-not being worn
would side panels have the same issue,

[jimh3063]

Hey I came across these guys while doing research on Radon. They seem to certainly have the creds to help us with this issue.
Two of them have a PhD's in mechanical engineering
One was an Assistant Professor of Mechanical and Aerospace Engineering at the University of California
One has a ton of composite experience.

http://www.technq.com/Personnel.html

I think they'd be more than qualified to help us with our problem.

Jimmy

[Hardingfv32]

I believe Kevlar is as slippery as it is tough. The blades need to be serrated.

Can it be properly bonded to polyester resin? I'm assuming the Kevlar requires epoxy resin.

Brian

[Wren]

Hey I came across these guys while doing research on Radon. They seem to certainly have the creds to help us with this issue.
Two of them have a PhD's in mechanical engineering
One was an Assistant Professor of Mechanical and Aerospace Engineering at the University of California
One has a ton of composite experience.

http://www.technq.com/Personnel.html

I think they'd be more than qualified to help us with our problem.

Jimmy

Weren't you the guy just asking someone else to leave the Radon out of it?

[S Lathrop]

Just to prove that I'm not entirely posting off topic stuff:

is the above a statement of fact, or your opinion? If it's a fact that a hybrid design is not up to the task, can you please provide some evidence to back this up?

Do you have the experience to prove me wrong? I think I can do an adequate job backing up my opinion with hard facts. All you have to do is look at the evolution of chassis design from aluminum monocoque through composite tubs of today. You obviously did not understand the example I provided in my earlier post. That example should be within you experience, the belly pan on any FF or FC if it is riveted and/or bonded.

[Dennis McCarthy]

Steve I think Brendan's question is fair, what experience do you have with hybrid construction?

You've given examples of several cars back in the late sixties that had riveted skins that were outlawed then.

Knowing cars from that era, they probably had aluminum pop rivets at best as well.

Given that hybrid construction was outlawed back then instead of being fostered, who has built and tested a real hybrid car using modern materials that has been properly engineered?

I doubt retrofitting cars with safety panels would be an across the board solution.

If the panels don't add anything but safety, cost and weight, no one is going to install them unless they are mandated. I think we can all agree that is probably not going to happen anytime soon.

Given a new FC is north of 85K, this sport is not for the faint of wallet for anyone wanting to drive a new car.

If we are truly committed to safer race cars, it's going to take a generational change to new rules and designs.

[Darrin Teeter]

Daryl:
Is there an easy way to mount intrusion panels between the outer bodywork and the tube frame of the cockpit that won't lessen the strength of the panel and be legal? I don't know enough about composites to know if what I was proposing would hurt the integrity of the panel. I'd also be curious about your suggestions to accomplish my goal outside of what I mentioned.

Just kidding about the viagra.

Jimmy

Daryl:
Sorry I got my names confused. I meant to direct my question to Darrin Tweeter.

Jimmy

That's my other brother Daryl (what was the name of that stupid show?).
Oh, and that's Teeter, not Tweeter. I'm insulted, take a time out....just kidding.

I'm way behind on this thread, also getting ready for PRI. As far as your question regarding the best method to fasten a panel, there are a lot of ways to put skin on the bones. Composites aren't very good in bearing strength or point loads (think holes with fasteners). Neither is wood, but they make things like roller coasters and bridges out of the stuff with proper design. One can't make blanket statements about materials because it is possible to make any material unsafe through poor design. We make lots of carbon panels that fasten to things like airplanes, unmanned vehicles, etc. and through the miracle of proper analysis and design techniques, they don't fall off. Increasing the bearing area by using larger diameter holes, adding flanged/bonded bushings, countersunk holes, metal or composite doublers, embedded shear plates and a host of other techniques can be easily done to transfer the point load to the rest of the panel. These can all be done in your garage if you like.

I can't see a simple way to attach an anti-intrusion panel of sufficient thickness without stiffening the chassis to some extent, but I'm not sure that's really a concern given the 6" rule. In the recent Radon project we compared three chassis designs: a tube frame with no panels, a tube frame with carbon panels, and a tube frame with aluminum panels.
All were designed to give the same target torsional stiffness and meet the F2000 rules. Surprisingly, at least to some of us, they all ended up about the same weight. The solution with the carbon panels was not the lightest, but it was by far the safest, and also happened to be the cheapest, most elegant solution. Whoever came up with the 6" spacing rule was either very smart or very lucky.

In general, if you want to add a side impact panel, it first needs to be thick and rigid enough to keep from wadding up like a dish-rag when that halfshaft comes knocking. It must also engage enough of the rest of the structure to distribute the load, just in case there is another car attached to said halfshaft. Two plies of Kevlar won't stop much more than a stray lugnut. You will need quite a bit more, say 1/8" minimum.
That's about 12 plies of 5 oz Kevlar. (BTW, Kevlar is about twice the price of other para-aramid equivalents and many carbon fabrics.) No matter how you attach this panel, it will be MUCH LESS STIFF than attaching similar clearly legal aluminum or steel panels, but MUCH MUCH safer.

In any case, adding any additional safety panels to your car is a moot point unless the recent COA ruling is overturned.

Darrin

[Darrin Teeter]

What is the life span of kevlar in a racing car?
We throw vest away after 3-4 years, recommend by the manufacture.

a 5-6 year old vest let a 45 slug go right thru it.. (not close range) just testing-not being worn
would side panels have the same issue,

Kevlar & some other ballistic fibers lose some of their properties when exposed to humidity, heat or UV light.

Zylon was the miracle fiber until some officers down south left their vests in the trunk & the combination of heat/humidity was fatal. That has resulted in a roughly $30M settlement & the product being pulled from the market. Zylon is still mandated in IRL & F1 for side impact protection I believe.

In a composite panel using these fibers, you need to overdesign a bit & it is a good practice to seal any exposed edges with resin. Kevlar & other para-aramids are not very good in compression either, so that should be considered in structural applications.

[Darrin Teeter]

[

Jimmy;
It is experiences such as these that I base my opposition to "hybrid" frame construction. In a hybrid chassis, the joints are the weak link. In a properly designed tube frame or composite tub, the load bearing members determine the strength not the joints. Composite tubs have evolved to the point where they are 2 main sections and a series of bulkheads. The joint for the 2 main sections is wide, simple and in a low stress area. I see the hybrid as being less than either a tube frame or a composite tub.

[FONT=Verdana][FONT=Verdana]Steve,[/FONT]

[/FONT]With all due respect, that is a very generalized statement. A joint can be the "weak link" but properly designed it can be the strongest link as well. Using your “properly designed” tube frame example, a poorly designed weld can just as easily be the failure point. You do not tack weld the tubes and expect the joint to hold. Similarly, panel attachment points have to be engineered properly (although it's not rocket science, at least not for the past couple of decades).

I don't see anyone claiming that the riveted and bonded floor pans used in most cars (Citations included, I believe) are a dangerous failure point and have to be replaced several times a year.

Airbus, Cessna & others use very similar "hybrid" construction with composite panels attached to metal frames in their aircraft, and they don't seem to be falling out of the sky.

Despite all this talk of "hybrid" versus "pure tube frames," all the FC cars I've seen at the race track use "panelized" construction: stressed floor pans, riveted front bulkheads, skinned main bulkheads, bolted-together bell housings. If the rules really did require "pure tube frames" then all modern FC cars would be illegal. And you couldn't stress the engine, either.
[FONT=Verdana]
[FONT=Verdana]Darrin[/FONT]
[/FONT]

[jimh3063]

Weren't you the guy just asking someone else to leave the Radon out of it?

Wren:
I'm dead serious. They're probably more than qualified to help. Those guys are pretty knowledgeable people who could be considered subject matter experts in their respective fields. If they can help me with my VD what do I care where they're from. I care what they know. Whats wrong with asking a knowledgeable person his thoughts on a subject. I do it all day everyday. I find is makes my life a lot easier. I'll take help where I can get it. If there are others on this board with those level credentials, I'm all ears to them as well. I will listen to anyone who can help me who knows what they are talking about. I think at this point to solve my immediate problem, I'm going to look into what it would take to implements Jay's recommendations. I don't think it's the best solution but it is the best I can do right now. I'd like to see the reg's changed to make the area around the "cockpit" open as it applies to rigidity caused by intrusion panels, if that means a safer car. I thought someone had mentioned the not so rigid part of a VD was the rear of the car anyway. That's not the part I'm trying to change.

Jimmy

[HazelNut]

Do you have the experience to prove me wrong? I think I can do an adequate job backing up my opinion with hard facts. All you have to do is look at the evolution of chassis design from aluminum monocoque through composite tubs of today. You obviously did not understand the example I provided in my earlier post. That example should be within you experience, the belly pan on any FF or FC if it is riveted and/or bonded.

cool your jets turbo. I'm not trying to "prove you wrong", no need to get defensive.

I'm just asking a question.

I like the idea of a hybrid design, but I don't know if it's up to task or not. I've clearly stated I'm not an engineer. You've plainly stated that hybrids aren't up to the task. I want to know if that's your opinion or if it's fact. If it's opinion your very entitled to that, however it can't be passed off as a "fact". If it is fact please provide the proof (objective, repeatable, verifiable, test results) so that we can move our conversation forward.

As for belly pans. I'm a pretty ****ty mechanic and I always worked on my own cars and I've been known to offroad plenty. In fact going airborne launching off the rumble strips at the exit of the esses at road atlanta gives me a bit of a "happy tingle" in my pants. And that's pretty much like dragging the belly across an asphalt cheese grater lap after lap after lap. I was always able to keep the belly (aluminum or steel) on the car for at least a full season. The car goes down to a bare chassis every winter anyway so if I need to do a floor so be it. It's only an extra few days work.

[jimh3063]

After sleeping on the problem, I may have come to a viable solution Brendan.
Crazy glue the road kill trapped in Charles car after a long trip to RA on the sides pf the cockpit.

[S Lathrop]

Steve I think Brendan's question is fair, what experience do you have with hybrid construction?

You've given examples of several cars back in the late sixties that had riveted skins that were outlawed then.

Knowing cars from that era, they probably had aluminum pop rivets at best as well.

Given that hybrid construction was outlawed back then instead of being fostered, who has built and tested a real hybrid car using modern materials that has been properly engineered?

I doubt retrofitting cars with safety panels would be an across the board solution.

If the panels don't add anything but safety, cost and weight, no one is going to install them unless they are mandated. I think we can all agree that is probably not going to happen anytime soon.

Given a new FC is north of 85K, this sport is not for the faint of wallet for anyone wanting to drive a new car.

If we are truly committed to safer race cars, it's going to take a generational change to new rules and designs.

Dennis;

I am not certain that Brendan intended the question to be fair.

But more to the point, I have spent decades engineering in FA first and then Indy Lights. Most of my work has been with the T97 Lola, and the Dallara. I have worked on some very competitive cars and have wins on both oval and road courses. I think that qualifies as experience with composite cars. Building cars does not pay all the bills.

Directly related to this issue, I spent time in 2004 working on a Stohr DSR for a customer in Chicago. We won the divisional championship and qualified finished third and the run offs. I ran a torsion test on the Stohr when I started that project. That experience was a big help when I started the FB/F1000 Citation.

I have done torsion tests on most of the cars that I have engineered. I use the data for setups.

I think the Stohr qualifies as a true hybrid chassis?

On another subject, you put your finger on the real issue, $85K cars. The customer pool for cars that expensive is very limited. I don't have any customers that can afford or want to afford that expense. The only way FC survives is through having competitive cars that are available for half that. People can get on the track with good equipment for under $20K. I believe that this is why FC still survives.

If you really want to do something that is more modern, then why not go to F3 chassis but use FC engines, wheels, and tires. A new F3 chassis is about $85K especially if it were built for the F2000 market. Used cars are available for half the cost of new. I think that with the F3 aero rules and narrow track, the cars might make a very good match for the current FC. Something like this is a logical way for the class to go forward.

Short of doing a slow transition to F3 type cars, why change the way we build cars just so we can sell a few new cars and may be loose more existing competitors?

Improving safety is an other subject as well and I tink that is what we are discussing here.

[jimh3063]

Steve:
I do actually own of the chassis you speak of. I am more than willing to take photos of it or any part of it anyone has the desire to see.

I will say that those cars are very expensive to fix after a crash. I don't think that our class is ready for that expense at the non pro level to run this level of car. I think the mere level of expense to fix one of them will actually change peoples driving styles.

I will say, I feel VERY safe in it. It's built at a level that I've seen no where else. Really afraid of ****ing it up though for reason stated above.

I will say though, once you take a close look at those cars, you will change your whole opinion on what's out there.

Jimmy

[HazelNut]

After sleeping on the problem, I may have come to a viable solution Brendan.
Crazy glue the road kill trapped in Charles car after a long trip to RA on the sides pf the cockpit.

it's not roadkill, the dead animal on his car are protection idols that our team shaman places there during the sacrificial blessing. It's the final step to prep the car, set corner weights, then call this guy

[S Lathrop]

Steve:
I do actually own of the chassis you speak of. I am more than willing to take photos of it or any part of it anyone has the desire to see.

I will say that those cars are very expensive to fix after a crash. I don't think that our class is ready for that expense at the non pro level to run this level of car. I think the mere level of expense to fix one of them will actually change peoples driving styles.

I will say, I feel VERY safe in it. It's built at a level that I've seen no where else. Really afraid of ****ing it up though for reason stated above.

Jimmy

You have stumbled on to a truth. If we keep the side panels as non-structural then we avoid the high cost of repairing composite tubs. Elan has panels for a very reasonable cost.

Darrin has the experience to help here. It appears that there are some real possibilities. IRL added panels to the outside of the IPS cars. That is something we might discuss.

Darrin; the 6 inch fastening rule was from David Bruns.

[jimh3063]

Steve:
As I has mentioned before, I had left a vmail yesterday concerning their panels.
If anyone has hooks into Elan and can get pics and pricing, please do and post.

Jimmy

[HazelNut]

Dennis;
I am not certain that Brendan intended the question to be fair.

Brendan did intend for the question to be fair. If Brendan meant to be snarky he's just be snarky. Brendan is interested in exploring options. If hybrids are a cheaper, better, safer, more modern solution we should be looking at them. If they aren't we need to prove that they aren't, kill the concept and move on. I want to see FC thrive, I want to see racing thrive, instead we're watching it die on the vine.

And yes Brendan is aware that Brendan is referring to himself in the 3rd person.

I have done torsion tests on most of the cars that I have engineered. I use the data for setups.

I think the Stohr qualifies as a true hybrid chassis?

SWEET!!! can we see this data and how it compares to similar pure tube frame sports racer? I'd also like to see some kind of comparative testing on saftey factors as well as cost of maintenance (chassis wear items) and chassis repair items.

On another subject, you put your finger on the real issue, $85K cars. The customer pool for cars that expensive is very limited. I don't have any customers that can afford or want to afford that expense. The only way FC survives is through having competitive cars that are available for half that. People can get on the track with good equipment for under $20K. I believe that this is why FC still survives.

40k you say? I'm highly doubtful of that. Were you able to build and sell a highly competative car for FC (or equivalent class, I was 5 in 1985, so I wasn't up on my legacy class designations) for 20k back then?
http://www.dollartimes.com/calculators/inflation.htm

If you really want to do something that is more modern, then why not go to F3 chassis but use FC engines, wheels, and tires. A new F3 chassis is about $85K especially if it were built for the F2000 market. Used cars are available for half the cost of new. I think that with the F3 aero rules and narrow track, the cars might make a very good match for the current FC. Something like this is a logical way for the class to go forward.

Short of doing a slow transition to F3 type cars, why change the way we build cars just so we can sell a few new cars and may be loose more existing competitors?

the concept is cool but the full tub (based on my readings, we should also gather empirical data to back this up as well) does seem to be an issue in terms of repair and maintenance, especially post big crash. If we had data to say otherwise and they turn out to be serviceable and cost effective and adaptable to the class and adaptable this is also something that should be looked at.

also baytos tried to float this concept for the cooper series and it was cool but proved to be unfeasable for whatever reasons.



I'm interested in survival and growth of the class (and open wheel in general). I'm not sure what that will take, but all the fighting and hair splitting isn't helping anything. We need to look to the future.

[jimh3063]

Steve:
I just want to make sure there is no confusion with people who read this thread, the Dallara F3 chassis is a full carbon tub. No tubes, no hybrid construction of any kind.

I think working in the confines of a tube frame with composite outer panels (cockpit) is what I've been trying to say all along. I personally don't' have the knowledge on how to pull this off but I'm sure one of the propeller heads on this board does.

As far as stumbling on a truth. It's truth I've know for quite some time. That's why the Dallara comes out of the garage only once in a while.

Like I said before though, it's at a build/quality level that I've seen no where else short of an ALMS prototype.

Jimmy

[S Lathrop]

Brendan;

Two points:

1. The absolute cost of a car is not the issue. A better way to look at it is the cost of a car compared to US medium income. When cars cost about 50% of medium income you sell a lot. That was the case with FF in the 70's. I had several years where I sold over 20 cars per year. By comparison, Haas did 150 Lola's in one of those years. Cars such as Formula Atlantics that cost more sold a lot less. I will guess that the cost point for selling a reasonable number of cars for a class like FC is some place between 50% and 100% of medium income. Above that sales decline fast.

2. I have been doing my torsion tests since the late 70's when I built the Z14 FSV, an aluminum monocoque design. To the point here, the Stohr was about 20% less than the 94 FF/FC Citation. For comparison the Swift 008 was less than 3 times the strength of the same car.

[Hardingfv32]

Should we start putting everyone through metal detectors at the track so we can "feel safe"? Can you attach a number to "feel safe" that the car designers can target?

The fact is the Dallara "looks safe". There is no science describing how safe any race car is. No standard for the meaning of safe.

We do know that the errant half shaft coming through the cockpit side is an extremely rare event. It is simply not cost effective to prevent such events. We don't actually have any science telling us how to prevent them.

Brian