Landracing Forum
Bonneville Salt Flats Discussion => SCTA Rule Questions => Topic started by: xxobuick on July 22, 2013, 03:42:11 PM
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Hello Guys and Gals:
We were just going over the rule book with a fine tooth comb and found something we don't quite understand. We are running one piece aluminum wheels up front and in the back. They are both 4" wide. We are running Front Runner Tires.
Now are question is in the lug nut area. The rule book states for all cars under 200 mph, which ours is, and the record is 138 or there abouts. It states that the smallest part of the hex of a lug nut shall be larger than the largest part of the taper of the wheel mounting hole. Lug nuts shall torque totally against a a wheels tapered surface with a minimum of 5/8" of stud engagement.
So the taper of the wheel is about .800" diameter where the lug nut seats. Our lug nuts are .930" Diameter, so I believe we are good there, and we have extended studs that stick way out, so we have the .625" Stud engagement.
Now down on the page it also states about non ferrous wheels needing a 1/4" thick steel plate or large OD washers that are under the nuts.
So does that mean the first paragraph under 2.G wheels only applies to steel wheels?
So does that also mean that you cannot run taper seat lug nuts and wheels with non ferrous wheels?
Would we have to modify our wheels to use the 1/4" retaining plate with flat nuts and make the wheel "hub concentric" rather than "lug concentric"?
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What exactly are you running for wheels? Are they cast or forged? Spun? A lot of racing wheels have big thick steel insert rings inside of them... do yours?
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They are a cast aluminum one piece wheel. No steel insert.
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I believe we used "mag" style lug nuts on our aluminum wheels with steel plate combo. The plate and the wheels were machined to locate off the shank of the nut. Could you machine the taper off the wheels and then machine in a flat spot to accept a big heavy washer?
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Yea, we can do that. I was just clarifying if thats what "needed" to be done to satisfy the rules. The rules on this subject are not the clearest. I guess we will do that then. I was just curious if anyone else has run aluminum cast wheels with a taper seat lug nut.
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If you are concerned this is what I would do and have done. After long studs are installed, attach the wheels as normal using proper taper nuts. Make a 1/4" plate with your hole pattern, place it on the long studs and install 1" lug nuts flat face down. The rear of my roadster has been this way for 15 years. Front the same way with a hole for the hub. . . . . . . Good Luck.
PS: I use this for non-taperd wheels too
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I have the same wheels, the only way to get them to center properly is with the bulge tapared nuts which is mandated by the manufacture. I spent 100 bucks for a machine shop to whittle out hub spacers for them, and they wouldn't center properly. They center the wheel with the tapered lug holes, and then just punch an oversized hole in them to fit all applications, and models.
Steve
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If you are concerned this is what I would do and have done. After long studs are installed, attach the wheels as normal using proper taper nuts. Make a 1/4" plate with your hole pattern, place it on the long studs and install 1" lug nuts flat face down. The rear of my roadster has been this way for 15 years. Front the same way with a hole for the hub. . . . . . . Good Luck.
PS: I use this for non-taperd wheels too
I used this exact same method and it worked perfectly. I had the plates cut by DC Water Jet. It was pretty painless once I accepted the idea that I had to do it.
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Thanks guys. I will make flanges to go over the existing tapered lug nuts and then use a flat flanged nut to retain it all. So essentially there will be 10 lug nuts on a 5 lug wheel.
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The wheel won't come off! easily!
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XXO- At 138 mph and under a 29" tire I'm not sure what is needed. I started using the second plates when I went to "factory" aluminum wheels and over 200. I also first put on the plates with 29" diameter steel wheels and Firstone front runners at 160.
As Dan always says " the minimum is in the rule book"....... Good luck..have fun..go fast....
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... be safe. :wink:
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Years ago. when we were running 15" diameter wheels on the back of our lakester, I MADE lugnuts from straight shanks of "longish" 3/4" Grade 8 capscrews by machining off the threaded portion, turning down the unthreaded shank to 11/16". "gun-drilling" the head and 11/16" shank and threading the bored holes to 1/2"NF. I ended up with 1 1/8" hex headed lugnuts for mag type wheels....it meets the letter, if not the intent of the rule - which was NOT originally intended to apply to mag type wheels (which is whwere many inspectors took it to also apply.
I posted elsewhere on a similar topic about other alternate methods of complying with this rule.
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There you go, Fastman I agree with you 100%.
The rule probably came about when someone had a 10 gauge aluminuim wheel which they left on the car over a year or maybe two, and the combination of the disimiler metals along with the salt made for a bad electolisis problem and the wheel failed at speed. So the rule was written to combat that issue. The mag type 3/4" thick aluminum wheels were not intended to fall under this, mounting them any other way than the manufacturers intent is not good.
Jimmy's fix would get you past the inspector with no common sense, but that is about all it is doing, maybe giving you a lower center of gravity, with the extra wieght.
I found the correctly tapered 1" lug nuts, for mine but the tapered hole is recessed about an 1/8' inch and it eats up two much of the lugnut lands to properly torque with the bigger socket.
Steve
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That's a bit of a stretch there Steve. The intent of the rule is to increase the lug nut clamping area on non-ferrous wheels. What can happen is in a spin where there is a lot of side load being applied to the wheel, the lug nuts can pull through the wheel. The best way to combat this is to better distribute the clamping force that retains the wheel thus the requirement for plates or big washers. The rule book says all non-ferrous wheels so that's that. If someone thinks it should be different they should submit a rule change (which are due by Sept 1 BTW).
Adding a plate on top of the lug nuts that hold on the wheel doesn't do any good if the plate isn't touching the wheel.
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Nathan,
In 2010 when teching SCTA cars at Speed Week, I brought this up when a lakester with my same wheels came into tech. I asked the seasonsed veteran I was teching with about the lack of clarity in the rule book, he said that if they are tapered the washer rule does'nt apply. I have been wanting to make the rule more clear, cause I can put on the manufacturers bulge tapered nuts, and then one at a time replace them with the 1" lug nuts, and steel washers, but I don't feel good about running the car this way. I will bring a wheel and lug combo's to speed week, and when you have some slack time will disuss the problem with you and maybe some new wording I will submit to the rules committee.
I will be teching bikes again this year.
Steve
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Steve--I think most of us in Tech would like to get together and hear/see your ideas. Have you run any of this past Kiwi Steve yet?
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No, DW and I discussed it at length at WOS in 2009. When I was teching at SW in 2010 Steve put me with a seasoned SCTA tech that told me the one inch nut, plate, or washers, didn't apply with tapered lug aluminum wheels. I assumed that since we were looking at the same wheels on a lakester, and he passed tech, that my fuzzy rule understanding went away. Seen them on a lot more cars since then using the conical seat lug nuts.
Steve
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Seems pretty back and white in the book... If the nut touches the wheel you gotta have something behind it. Only exception I've seen are aluminum racing wheels that have steel rings/inserts in them.
The idea that someone else passed tech with xyz on their car doesn't automatically mean xyz is now legal for all other cars. There have been cars that have gotten through tech for many many years with undersized tubing. Just because those cars got through tech doesn't make all other cars with undersized tubing legal now.
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So, how would aluminum wheels with the UniLug tapered washer and tapered with a straight shank be called?
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It appears from your photos that a "tapered" lug is being screwed on to a FLAT uniwasher. I would never do that. The edges just by normal tightening would bow out. The unilug wheels I have had used a flat edge on the lug to press on the uniwasher.
You would be better off the make bushings from lugs and then putting the unilug washer and additional thicker large diameter washer under a 1" lug flat side down. You should have plenty of room for that with longer studs...Good Luck
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Depending on the speed expected, I don't think I would even entertain the thought about running unilug wheels at speed on the salt or even cast wheels for that matter.
Just my $.02
Ron
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I just used a pic I found. My UniLugs have tapered steel washers. There 2 washers available, 1 with the hole centered, and 1 with the offset. By turning the washer around you get 4.5" spacing and 5" spacing. The centered washers give you 4.75" spacing. The washers are a good fit on the ID for the shank of the nut, and the tapered section. I suppose you could flip the washers to use a flat nut seat, but I prefer the tapered.
I should have used a pic like this.
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The wheels and lugs I have are not unilug wheels, they are made by Center Line and called auto drag, Summit sells them under their name as D-force II's. They use a conical seat bulge lug nut, and there is no way they are going to pull through a 3/4" thick aluminum wheel with a side load. Nathan there are a lot of things that change with technoligy, if the Swiss would have excepted that, they would still have the world market on watches. :roll:
Steve
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Once again I find myself assuming incorrectly. I was loading the wheel into my truck, and noticed it says made in china on the back. I figured they were centerline wheels, because they look just like the centerline wheels, unless the centerline auto drags are made in china also, they must be chinese knock offs sold by summit. :-o They seem to be a very solid built race wheel though, I trust them a lot more than a two piece wheel.
Steve
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Summit, Jegs, Harbor Freight - all same same. Pay your money, take your chanes.
DW
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Geee's Dan don't try to cheer me up, now I got to check out my Summit ignition, I thought it was a Mallory, just cause it looks just like a Mallory. I can honestly say everything else on my car is USA, wait the T-56 has metric bolts hooking it up to the adaptor plate, and my crew chief was made in New Zealand. :-P
Steve
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Nathan there are a lot of things that change with technoligy, if the Swiss would have excepted that, they would still have the world market on watches. :roll:
Steve, I'm not sure where technology comes into play on a cast aluminum wheel and 5 studs/nuts. Isn't that 100+ year old "technology"? :wink:
They use a conical seat bulge lug nut, and there is no way they are going to pull through a 3/4" thick aluminum wheel with a side load.
You may be right about the lug nuts not pulling through a 3/4" thick aluminum wheel but we as inspectors inspect to the book... and Rule 1A tells us that we inspect to the book - no more, no less. I believe 1A was originally intended to "protect" competitors from being forced to comply with unwritten rules, as such. 1A is a double edge sword in that it does limit the reach of any one tech inspector but it then forces us to rely heavily on the printed word in the rule book. Subsequent to that, this now means the rule book must be right and tight and things like lug nuts on aluminum wheels may need to be looked at closer. Are your wheels exempt from the washer/plate rule? Maybe in practice they might be but by the words in the book, which we tech to, they aren't.
To be further discussed while winding down in tech after the storm of cars has passed and we miserable inspectors enjoy some fuel samples... see ya on the salt.
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Nathan there are a lot of things that change with technoligy, if the Swiss would have excepted that, they would still have the world market on watches. :roll:
Steve, I'm not sure where technology comes into play on a cast aluminum wheel and 5 studs/nuts. Isn't that 100+ year old "technology"? :wink:
They use a conical seat bulge lug nut, and there is no way they are going to pull through a 3/4" thick aluminum wheel with a side load.
You may be right about the lug nuts not pulling through a 3/4" thick aluminum wheel but we as inspectors inspect to the book... and Rule 1A tells us that we inspect to the book - no more, no less. I believe 1A was originally intended to "protect" competitors from being forced to comply with unwritten rules, as such. 1A is a double edge sword in that it does limit the reach of any one tech inspector but it then forces us to rely heavily on the printed word in the rule book. Subsequent to that, this now means the rule book must be right and tight and things like lug nuts on aluminum wheels may need to be looked at closer. Are your wheels exempt from the washer/plate rule? Maybe in practice they might be but by the words in the book, which we tech to, they aren't.
To be further discussed while winding down in tech after the storm of cars has passed and we miserable inspectors enjoy some fuel samples... see ya on the salt.
Unfortunately, even 1A does not protect you from the "our interpretation is" aspect of some teching (and some paragraphs of the rule book). Which became a "change it" directive (or you fail tech). (And got the same answer from chief inspector for what that is worth) Anyway, there are a lot of spots where clarification would save some grief, I expect. Everyone is just doing the best they can and I appreciate what the inspectors do trying to save my sorry neck. :)
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A sample of what actually passes tech at speed week. 5, 3/8 bolts holding on the wheel. Also many cars racing that hat taper seat lug nuts only.
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Are you sure the 3/8 bolts weren't capturing a spindle mount hub for either Anglia or early Ford spindles.
Sure looks like that to me!
Very common in the industry for spindle mount front wheels BUT NOT DRIVE wheels.
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I will get photos tomorrow of cars running with simple tapered lug nuts seating on the aluminum.
Also a wheel bolted to a hub is esentally just that and the rule book states all non ferrous wheels that are bolted.
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Those are spindle mounts. Others that passed tech with lug nuts directly to wheels probably had a speed limit (I did this for at least one car). Would you rather pass tech without exception or have a speed limit? Competitors choice.
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If I understand correctly all aluminum wheels need a steel plate under the mounting lug nuts. Since the wheels I want to run on my lakester are factory production Ford held down by a tapered lug nut I was planing on holding the wheels on by using one inch hex lug nuts. The wheels are the ones used for the spare tires on the Mustang GT they are spun aluminum disks with a series of holes around the outer face and are welded to the aluminum rim completly. The studs I use are long so adding a steel plate above the lug nuts is possible. But adding this plate and five more nuts above the existing nuts could possibly add a balance problem at speed. Is that the proper way to mount these aluminum wheels?
Ronnieroadster
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A sample of what actually passes tech at speed week. 5, 3/8 bolts holding on the wheel. Also many cars racing that hat taper seat lug nuts only.
t
That is a picture of my front wheel. If you do not understand what you are looking at ask. That is a Centerline SPINDLE MOUNT wheel. IE it does not have lug nuts or studs. Before you spew BS on here maybe you should take the time to have someone explain to you how something is done outside of your narrow scope of experience. Vince Norton
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Are you sure the 3/8 bolts weren't capturing a spindle mount hub for either Anglia or early Ford spindles.
Sure looks like that to me!
Very common in the industry for spindle mount front wheels BUT NOT DRIVE wheels.
You are correct Ford spindles. The Anglia's are to small, IMO for what I am doing.
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Ronnieroadster: That's what I do and have done for years. An additional plate with lugs holding it on using the flat side down. I do it on tire/wheel combinations under and over 29".
It was mandentory on what were called "milk truck wheels" 18" with 30" tires back in the 50's. Those wheels were known to have oversize holes......Good Luck