fatbillybob

My take on the alloy seats is similar to Redline. In fact he was the one to convince me to buy it. I sold my OMP carbon 8lb shell for this 20lb aluminium seat that cost nearly the same as the carbon seat. Now that was painful! But I am glad I made the switch. The first thing I will say is that the fit of a custom seat is second to none. My butt feels now things I never felt before. You have to try custom to appreciate it and the Ultrashield is a custom seat. Pads in the carbon seat just could not get me as good a fit. So your mileage may vary on that one but man what a difference. If your butt feels more and you don't slide in the seat you go faster. Circle track guys have more issues with walls than road racers. Road racer barriers are more vaired. Circle guys have mostly concrete. They know something about containing drivers. I think GBaker will atest to the fact that the guys getting the most hurt are the circle guys. Composite seat makers just are not making containment as extreme as the metal guys. They can but they have not. I have sat in the viper racetech and the cobra seat and they are pretty good. Probably as good as we need in road race. Ther is a tradeoff between containment and egress. The more containment the more difficult the egress. I figure I have to survive the hit first before I have to egress so I chose containment. I understand but do not know this to be fact but believe the metal seats can be used without back brace and that plastic over a certain age needs back brace. Personally, I think that back brace is part of a proper safety system so i would use it in either case. Also plastic has spring and memory and I am not sure that is a good thing in an impact. I know metal deforms with no memory but if properly supported then this is not an issue. I also think that proper support is part of the safety system where the seat is actually connected to the cage not the car. Dual users just can't use a full containment seat for daily driving. It is too restrictive. So there is another compromise. From a practical standpoint the metal is the metal when you drill it and put bolts through it when you mount it. Plastic does not like that as much. Often times drilling holes and bolting plastic yield spider fractures in plastic unreinforced holes so you have to be a bit more careful when you drill and bolt it. In fact I don't think plastic manufactureres want you to bolt back braces to seats which further allows their whipping memory nature. metal seats you can securly fasten and just drill and bolt. I think metal can give you the most "tub like" feel and connection of seat to cage that you can get in a tintop.

RedlineMan

Comparable to the top composite seats. Frankly, I don't know why the plastic seats are so expensive? They pop those things out like Tupperware! If you ever look at what goes into making an alloy seat, they are a bargain.

Well... Duh... That's kind of a given no matter what seat you use, eh? They're ALL tough to get right. Alloy seats are MUCH easier to mount though, by the way. You have the option of attaching where you want; side, bottom, front/back, and modding it if necessary. Not with a plastic seat.

Yeh... sort of. You have to be careful with that, though. It's not just a matter of whipping up some epoxy and glueing things together. Resins are inert once they harden, and you cannot chemically fuse old and new assemblies easily, if at all. You are creating attachments ONTO the existing surface, not FUSING the pieces together. Doing composite repair correctly is probably HARDER than TIG'ing aluminum.

That bracing is exceedinlgy simple to do. All you need is something to keep the seat from moving side-to-side. Very simple. Look at my cage thread and you'll see how simple.

There are always trade offs. As FBB says, first you have to survive. Getting tossed out of a wing seat and whacking your head on something when you might have been held in by a containment seat is worth a little extra effort at getting out in my opinion.

FBB made some other good points, like the cement walls the roundy round guys deal with. Also, sports car racers look at things like driver changes and such. Still, I think that the sports car crowd may have to suffer some fatalities like the NASCAR boys did before they are fully awakened. Looking at some of the in-car from Daytona... it was just scary how minimal some of their setups are.

A.Wayne

EScuse me guy's ,

THe seat is for sitting the belts are for containment , depending on the seat or choosing a seat based on containment is incorrect ( can we say DaleE.)

The seat should support you in place as comfortable as you want , then you snug the belts for containment. Also the composite seats are proven safe and are tested and crashed tested to prove that via their FIA Seal , the alloy seats are not. I had looked at the alloy seat as a few associates had made the switch, but was put off by the fact of the xtra bracing and that the seat had no form of testing done on them.
In the event of a shunt the memory and flexing of the composite seat goes a long way in protecting you vs a rigid seat .

Premier Motorsp

What about metal fatigue?

I always crack the Recaro side brackets after a year or so, and they are 5/6mm thick. What happens to these aluminum seats when you put a high mass driver (me) in a high G car?

Chris Cervelli
Premier Motorsports

RedlineMan

Absolutely 100% correct...

...If you are talking 1970's thinking. Things have come a ways since then. You're a bit behind the curve, my friend.

I have no idea what the Earnhardt reference means.

RedlineMan

Metal fatigue, plastic fatigue...

I would say that the seat brackets see different stresses than the seat itself, and that is not a direct correlation between them. The brackets get ALL the load, in a concentrated area with no triangulation or spread of forces, rocking side to side, whereas the seat only sees partial loading in certain areas. What the backets attach to, and how, would have a lot to do with how the seat itself faired.

Of course you are quite correct that these things need to be checked, especially for us big'uns, but I'm not sure I'd be more comfortable in a plastic seat in that regard. Maybe the FIA thinks so too?

A.Wayne

Then i guess you drive with your belts loose!

RedlineMan

Hey All;

Here are the shoulder fences completed. The .095x3x.625 reinforcement is welded to the seat all the way around.



That sucker is STIFF!

Premier Motorsp

That looks stiff. My question about metal fatigue was mostly about the bolt holes where the side brackets mount. I guess it has big plates there to prevent cracking?

Rearding plastic fatigue: I think composites are immune to fatigue because the fibers very effectively stop crack propagation. I haven't had any Recaro seat failures and I have tried!

I think John's solution works here but now this seat is $1500 and weighs 3X what a Recaro weighs. Other than modability, what is the benefit of these AL seats?

Chris Cervelli
Premier Motorsports

Greg Fishman

Why would you not just do this? (Check the Safer System Additions at the bottom of the page)
http://www.stockcarproducts.com/seats5.htm

I would rather trust myself in a Recaro composite seat than an alumium one with things tack onto it that have not been tested.

RedlineMan

Frankly, I don't see a 3/16th thick piece of 5052 (a moderately ductile alloy) cracking. I don't even see where there is much stress on it at all to be honest. most of the stress - as you have noted - will be in the bracketry, it seems to me.

I am left to wonder then why the FIA only gives you 5 years on one if they are immune to aging or degradation?

The only true full containment seats are aluminum. If you beleive in containment, then your choice is more or less made. If the plastic seat makers came out with a true full containment seat, I would be tempted.

RedlineMan

Good looking stuff. I had not seen the LaJoie add on equipment. Thanks for the link.

If you believe in full containment, your choice is aluminum. My additions here are rendered with 6 feet of continuous weld. Tacked indeed!

Geo

Wait until SFI gets around to seats. We'll be replacing seats (aluminum or composite) every 2 years.

Nice work John. I like the fact a brace will bolt to you added bracing instead of the back of the seat proper. Almost enticing.

At one time I was toying with the idea of building a composite seat. I'm thinking about it again. Perhaps once the car is done (with a FIA composite seat) I'll start working on molds. I'm mainly thinking about fit, containment, and lowering my height in the cockpit an especially the height of my legs under the steering wheel.

RedlineMan

Well, my bracket that attaches to the lateral seat brace does bolt to the exisiting seat proper, just above the new reinforcing beam for the shoulder containment (see my cage thread). In fact, I spent the day redoing it. Before it had outer brackets that projected down and bolted where the beam is now. I cut those off and made them extend out to the sides, onto the shoulder fences instead. Pics to come. Tomorrow; the halo!

I'm very surprised that none of the big plastic seat manufacturers have gotten on the containment bandwagon. I think there is a market for them. The only one that comes close to an alloy full containment seat is the Racetech Viper. Now, I've only seen pictures, but it just does not look very substantial in terms of containment relative to an alloy seat.

I actually think the Recaro Pro Racer is dangerous. Head containment but only shoulder support. Dumb. Just my opinion, mind you.

John Veninger

John,
When are you going to sell the pieces already cut so I can TIG them onto my seat?
Nice job!