Wing Tube

[azjc]

Looking to replace the front wing tube in my spare nose… it’s a bit on the heavy side. What would be considered normal / acceptable? Current tube is 1.125” in dia. with a .100 wall and it appears to be cold rolled steel… weighs about 5#. Some options:

Cold rolled .100 wall is about 1.04 # per Ft. (what I have)

4130 .058” about .75#
4130 .035” about .40#

2024 aluminum .095 about .37#.
" “ “ .065 about .26#.

Guess I could pull my good nose apart, but before I do I thought I see what the norm is.

[Purple Frog]

Averill knows...

[Larry]

Chrome-moly steel, .029 is the lightest, strongest way to go!

Larry Oliver
International Racing Products

[azjc]

Averill knows...

... Figured that, but he's hard to call from work

[kea]

1.125" X .065" DOM

[rickjohnson356]

the front wing tube on my car is aluminum. Lots less weight than steel!

any problem with lack of structural strength or other issues??

[Purple Frog]

I have seen aluminum wing poles collapse at about the black flag station on Road Atlanta's back straight. I believe it was Todd Bowman's car in March of '99. Allowed me my first ever regional win.

I believe aluminum can work, if sized to carry the ~300 pounds at 143 mph.

[RobLav]

This time, I decided to try aluminum in my full length front wing on my new car. 6061-T6 at .090 thick. It sure is a lot lighter, but I worry about stress reversals. In a full length wing, as oppossed to the half front wings, the skin is taking some of the stresses. And that's why I decided to try it.

[kea]

Rob,
Part of the equation here, is the OD of the tube. What works in .090" at one OD, may not, at a slightly smaller dimension. The steel tube does have some flexibility, where a more ridged material might be more likely to just break.

[azjc]

This time, I decided to try aluminum in my full length front wing on my new car. 6061-T6 at .090 thick. It sure is a lot lighter, but I worry about stress reversals. In a full length wing, as oppossed to the half front wings, the skin is taking some of the stresses. And that's why I decided to try it.

That's one reason I was looking at 2024 instead of 6061, should handle the stress much better. I do have "half" wings, so the wing it's self doesn't give much support. 2024 has a yield strength that is roughly 10 percent higher and an ultimate strength of roughly 50 percent higher than 6061.

2024 T3

Ultimate Tensile Strength, psi70,000
Yield Strength, psi50,000
Brinell Hardness120
Rockwell HardnessB75

6061 T6

Ultimate Tensile Strength, psi45,000
Yield Strength, psi40,000
Brinell Hardness95
Rockwell HardnessB60

4130

Ultimate Tensile Strength, psi97,200
Yield Strength, psi63,100
Elongation25.5%
Rockwell HardnessB92

DOM

Ultimate Tensile Strength, psi87,000
Yield Strength, psi72,000
Elongation10.0%
Rockwell HardnessB89

My spare nose/wing is MUCH heavier then my best one... reducing the weight of the tube will help quite a bit, also make it safer in that the tube is much stronger then anything on my car or anyone I'd come into contact with.

[RussMcB]

One time I bumped the car ahead in the early part of lap 1 in a race. The right front wing was bent upwards pretty drastically. The race went full course yellow. I was glad that a crew guy on pit road was able to "step" on my wing and get it relatively flat again. I was able to continue without much drama. IIRC, later I gave it a good straightening and it was fine. It may still be on the car.

[rickb99]

My spare nose/wing is MUCH heavier then my best one... reducing the weight of the tube will help quite a bit.

Which flavor of nose is your spare AZ?

We have "pointy" modern nose withi Averill wings. In the process of garage activities last weekend, Jeff picked up our original old snub nose with the original old wings (not what he wants to run), but we did notice this old 'thing' was lighter then the new modern nose. Not sure of the weight difference but it's 'noticable'. It could be because of the shorter less functional wings on the car as sold.

But that's not why I'm making a post. I'm curious on another angle of this.

1.
How much weight savings do you figure the change in material will give you?

2.
As we are about 50 pounds over weight (with the new 1200 min) with the modern nose, I'm trying to figure out how to get some weight off the car. The 87-92 Reynards came in 'factory trim' with a 60/40 back to front weight distribution. Obviously pretty biased toward the rear already as is true in a lot of formula cars.

What I'm wondering is, is the trade off of whatever weight savings you can make on the front (be it wing tubes or whatever) really an improvement considering your increasing the rear weight bias? Or, can the small weight savings on the front be offset with a lower ride height and maybe rake change?

Of course if this were an unsprung weight reduction in wheels, calipers, etc. this wouldn't be a question.

We also ran 2008 with the full rear clam shell. That thing is pretty heavy. I'm going to encourage Jeff to try a few sessions without it this year.

I'm thinking the best improvement would be to have a foundry cast us an aluminum block! KIDDING CRB ! ! !

[azjc]

Which flavor of nose is your spare AZ?

1.
How much weight savings do you figure the change in material will give you?

2.
As we are about 50 pounds over weight (with the new 1200 min) with the modern nose, I'm trying to figure out how to get some weight off the car.

I've not bothered to figure out which nose is which... guess I could post pictures or check the records that came with the car. This one is more "pointy" (and in need of a few repairs - tube is very loose on one side), my newest may be an original design but done in light weight material, I've also got a well used raised nose.

Wheight savings - think of the lever ratio (I've not calculated it) and where the weight is, the worse area you can: way out front. In the range of 3# if I go the way I'm leaning to, but it would be more when you consider the lever ratio

Car is now drivable again (first time since I bought it) so it goes on the scales this weekend to set corner weights (and alignment) so I'll know the weight then.

In a way this about having a big ugly heavy tube where something lighter would be better . Also don't like the way it appears to be way too stiff, I'd rather have somthing that gives when needed (like a crush box ).

I do have an original rear wing that came with the spares - it's tube is WAY lighter, maybe I'll check it's size too.

[SWMyers]

As we are about 50 pounds over weight (with the new 1200 min) with the modern nose, I'm trying to figure out how to get some weight off the car. The 87-92 Reynards came in 'factory trim' with a 60/40 back to front weight distribution. Obviously pretty biased toward the rear already as is true in a lot of formula cars.

You should be able to get closer to minimum. I've seen a Reynard with a welded steel floor pan under 1200 lbs. A couple of areas you might want to look at. The original brake rotors are very heavy. A set of thin rotors with aluminum hats could save 2+ lbs. each. Lightened CV's can save a some as well, when you consider you have 4 of them. Aluminum radiators help too. Also, you may want to take a look at your body work. I've seen some big differences in some of the main cockpit pieces, depending on who made is and how many times its been repaired.

[jabro1000]

Thanks for the advice Steve; I'd be up for taking weight off the car any way possible, unfortunately we have lightened CV's and aluminum rads on the car as of right now. I have looked into drilled brake rotors and would like make that swap at some point, but I suspect the bulk our issue is 1) bodywork, and 2) I'm a pretty good size kid at 6'2" 205 lbs (vegetarian and work out /run daily); not much of that weight is coming off unless I literally resort to a strict diet of tree bark and dirt or, as Rick Johnson suggested to me last summer, go in for a strategic amputation.

[kea]

I love drill rotors, I like the increased brake pad sales.
Like Steve said, there is possibly some big weight differences in the body panels, depending on how many times it's been "repaired". And the alloy hat/rotor combination, can save a fair amount of weight, to the later (90) style Reynard rotors, but will be minimal to those original early (88) rotors, which had large holes in the hat area.

[rickb99]

I love drill rotors, I like the increased brake pad sales.

Gosh Keith! Just what we need is spending more money on brake pads. The KFP's are holding up really well at the moment, thank you very much!

ICP's lightened rotors and hats. Very good stuff and all unsprung weight at that. But a huge investment for us.

I just now put that rear clam shell on a scale. That's 10 pounds of body work right there and it would take weight off the 'correct' end of the car! A trade off in external aerodynamic flow (maybe) versus the associated pressure build up (and heat) in the engine compartment. I think it's worth trying some laps without it.

Who knows, if it works, might have to order a 24/25 4th

[azjc]

My "good" nose is from Larry Oliver & light weight, 1 side pod (new style) and 1 engine cover are new & light weight (engine cover from Larry also), other side pod and engine cover are older and heavier (not much), main body is quite light. Has the rotors with large holes in hat area but nothing else that I can see to lighten the car (no alum rad's), no major repairs to make it heavier. With mods to car so I can fit there was a net gain of about 4#.

W/ 3 gal of fuel, 6 quarts oil, trans, diff & coolant topped off, all bodywork on ready to race the car weighs exactly 1,200# with my son in the car. He weighed 207#, I weigh 195# so with my gear on the car should weigh right about 1,200#... at least that is what my M.A.D. scales show .

We'll find out the real weight when I take it down for an annual SCCA tech. Local tech people said they'd be glad to weigh (and tech) it during a race weekend, just bring it down & they'd do it between sessions.

[azjc]

I love drill rotors, I like the increased brake pad sales.
Like Steve said, there is possibly some big weight differences in the body panels, depending on how many times it's been "repaired". And the alloy hat/rotor combination, can save a fair amount of weight, to the later (90) style Reynard rotors, but will be minimal to those original early (88) rotors, which had large holes in the hat area.

On the BMW's we used to see drilled rotors crack between the holes, but using Alpina rotors with the holes cast into it there was no problem.

[rickb99]

W/ 3 gal of fuel, 6 quarts oil, trans, diff & coolant topped off, all bodywork on ready to race the car weighs exactly 1,200# with my son in the car. He weighed 207#,

Well I'm sure those drilled hats wouldn't save us 40 pounds

3 gallons of fuel won't cut it for us. We run 20 minute practice sessions and 30 minute races with typically 2.25 mile pace laps and a long run to pre-grid. I figure a touch over 4 gallons for a race (but that is prerace so it doesn't count).

What we really need is a GOOD accurate weight. Last year we only went across a 'post race' verification beam scale once (running FS so not really needed) and came out at 1253. This year we have an FC class and need to hit the 1200, or try any way.

[azjc]

3 gallons of fuel won't cut it for us. We run 20 minute practice sessions and 30 minute races with typically 2.25 mile pace laps and a long run to pre-grid.

Weight is taken at the end of the session or race... so if I had a gal of fuel left at the end I'd be under weight... providing my scales are accurate .

[kea]

azjc. If you decide to change to alloy Rad's, so you can ballast the car (like in the front), just give me a call.

[R. Pare]

In seleting a tube material, remember that not only is strength necessary - in particular fatigue strength - but stiffness is critical, especially on cars where the wing is in very close proximity to the the ground. Sticking in an alu pole when it was designed for steel could cause the wing to drag on the ground.

Steel has a slightly better stiffness/weight ratio than aluminium (depending on the alloy), so to get the same stiffness, the aluminium pole has to be at least as heavy, if not heavier - assuming, of course, that you are limited to the same OD in either version.

[kea]

Thank you Richard, for bring that important point up.

[azjc]

azjc. If you decide to change to alloy Rad's, so you can ballast the car (like in the front), just give me a call.

That's on my list for the future... should have the car back on the track mid March, run it a bit in the Pro Auto Sport /ASA to shake it down. Then SCCA school to relicense in September, run thru the end of the '09 ~'10 season (spring for us in hot AZ)... then do a complete tear down so I can do all those things I've been putting on a list while going thru the car over the last few months.

But I'm still having fun, been great therapy in a world full of stress ... but looking forward to actually driving the car more then around the neighborhood!