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wheel size

Posted: Sun May 13, 2007 10:10 pm
by w3stie
What is the requirement for wheel size? I remember hearing that really fast runs like Ross mCGlashan's Aussie INvader had specially designed wheels to take the centrifugal force. Of course that's 600 + mph and jet powered.

What is required for 200 mph?

Posted: Sun May 13, 2007 10:53 pm
by DirtyDave
:roll: :roll: :roll: :roll: :roll: HAYABUSA 8) 8) 8) 8)

Posted: Mon May 14, 2007 2:01 am
by David Leikvold
W3stie, for any speed you just need double safety beaded steel rims with the centres welded to the rim all the way round. Bob Ellis previously recommended a mob in Brisbane that can supply the right welded wheels but I can't remember who they are, I'm sure Bob will be happy to tell you. If you'd rather find your own, the right rims are easy to spot, even with a tyre mounted, JJ will be stamped in the rim next to the valve hole with the rim size. It's been a long time since I made a living from tyres so I think you'd be hard pressed to find a rim now that wasn't a JJ.
If the tyre is gone you'll also see a small raised ridge about an inch in from each side of the rim that is designed to stop the tyre sliding away from the edge of the rim unless considerable force is applied. And obviously, you'll need a centre that touches the rim for the full circle.
You can run alloy wheels but the rule book prefers steel, presumably because they're harder to crack and easier to inspect. If you do go looking for used wheels, try to find a tyre shop that does a lot of mag wheel work for a car dealer, they should have plenty of as new steel wheels they don't want. They should be happy to spin them on a balancer for you to prove they're actually still round. Used wheels wouldn't be worth buying unless they were hardly used and you knew someone who could weld them without distortion.
For answers to any other questions you have you can download the rule book from this site and peruse it at your leisure, it has just about everything you'll need to know. When translated from the American, some minor details can seem a little vague or ambiguous, so check with Bob (the chief scrutineer) before you spend lots of money.
As for the tyres for the rims, shaved V or Z rated road tyres are OK up to 200 mph. The rule book has yet to be updated to include W or Y rated tyres which are even stronger, but harder to find in skinny sizes. Ignoring any traction issues, skinny tyres are generally held to be better than super wide low profile tyres because the centrifugal force at 200 mph makes wide tyres grow radially a bit more than skinny ones and even though I think it would be virtually impossible when correctly inflated and mounted on the right rims, you don't ever want one popping off the bead.
In case you were wondering, a tube in a tubeless tyre is a bad idea and would not hold the tyre on the bead any better than a tubeless tyre. And if the centrifugal force did somehow manage to pop a tyre off the bead a tube would not keep the tyre inflated, it would fail within seconds. And in the extremely unlikely event of getting a puncture on the carefully groomed salt, (perhaps from a bit of split pin or a stick blown onto the lake, or half a conrod!) a tubed tyre will deflate within seconds and destroy the tyre before you can stop the car. A tubeless tyre is much more likely to survive and just develop an annoying slow leak.
One more thing, if you decide to run used road tyres, (it seems such a shame to shave off half the rubber of an expensive new tyre) always inspect the tyre very carefully, particularly the inside of the used tyre for puncture repair patches, which are usually round but sometimes square. Carefully run your hand, protected by a clean rag, around the inside of the tyre to find any foreign objects sticking into the tyre that haven't previously been noticed. If there is a dark ring on the outer sidewalls, or any evidence of chafing inside, the tyre has been run flat and is useless. Don't ever use a repaired tyre as the repair will inevitably sever some steel belts and weaken the tyre. They're still OK for road use but I wouldn't use them for genuine high speed use.
Over 200 mph you need the 15" Goodyear Eagle LSR tube-type tyres, which I believe are available from North Terrace Tyres in Adelaide. I think they're about $500 each.
I met Rosco McGlashan at the Brisbane Motor Show some years ago when he was displaying the last Aussie Invader. He told me the large diameter, specially forged, high strength aluminium alloy discs he'd had made for wheels cost him $20,000 each. Seems like a lot of money, but they sure looked expensive.

Posted: Mon May 14, 2007 11:00 am
by w3stie
Thanks for that excellent info David. :D Do you know if there is a minimum recommended wheel size? If I wanted to to build a streamliner, I'd want the smallest wheels I could get away with to reduce the frontal area, but that would mean higher RPM on the wheel and more stress. So could I go as low as 13" wheels?

Posted: Mon May 14, 2007 10:29 pm
by David Leikvold
W3stie,
Wheel sizes are pretty much governed by what tyres are available and how fast you want to run. I have checked a few tyre company websites recently for Z rated tyres in 13" and 14" but they're well hidden. You will find some V-rated 14s in 60 series, e.g. a 185/60VR14 would be about 570mm tall and 185mm wide on a 6" rim. But it's no use if you can do over 200 mph. Check out Landracing.com and elsewhere for pictures of Jack Costella's Nebulous Theorem 111 streamliner. If you look hard enough there are pictures of his front wheels and steering arrangement.
If you can't find them, ring me and I'll send you a photocopy (I am a technophobe!) Jack uses solid aluminium billet wheel discs that don't use a tyre, so his speed is unlimited. The car can do 300 mph. The previous model, Neb 11, now owned by Rick Yaccouci, runs taller solid billets at Bonneville and very small Goodyear tyres on 5" diameter rims at El Mirage, where speeds are a bit slower. You can find them on the North Terrace website but be warned, they were built for 1990's Top Fuel cars only and are not speed rated, i.e. they won't cope with sustained high speeds. The Rice-Vigeant lakester and many others use those skinny Front Runners that are now on Top Fuel cars but they aren't speed rated either and are so skinny you can't use front brakes.
You might want to consider something like Al Teague's beautiful and very narrow car, it can run tall and wide Goodyear Eagle LSR tyres and still go 400+ mph.

tyres

Posted: Tue May 15, 2007 1:15 am
by Dr Goggles
I'll try and keep this short.

Goodyear landspeeds are mostly 15 inch , are rated to 300mph and our 28 inch pair cost 1500 bucks.Cars have run over 240mph at B'ville on frontrunners.Wide tyres suffer from planing at very high speed and as DL said there is less support for the tread layer when centripetal force causes it to "grow" that force is exerted on the bead which can pull them toward the centre of the rim and cause sudden and catastrophic deflation.

If you are building a steamliner you will be covering most of the wheel so it's size is irrelevant .Higher diameter wheels give you two things ,gearing and an increased contact patch .These are both valuable when you are trying to go fast on a surface with less than ideal traction.

Go to Landracing.com and search for tyre topics , you won't run out of reading material in a hurry there ,don't sit at home and dream up solutions when you can be reading the thoughts and experiences of hundreds of the seasoned players you will find at LSR.com....all the big names are there....Nish , Burkland , Costella ......Jack Dolan will blow your mind and he knows his onions.

Re: tyres

Posted: Tue May 15, 2007 9:31 pm
by Greg Watters
Dr Goggles wrote:.

......Jack Dolan will blow your mind and he knows his onions.



And after a while you will understand what he is saying :)

Posted: Wed May 16, 2007 12:26 pm
by Lynchy
Dr Goggles wrote:
.

......Jack Dolan will blow your mind and he knows his onions.



And after a while you will understand what he is saying


Still waiting for that to happen.... I'm trying to locate a gibberish to english dictionary, would also be useful when on the drink.

Brakes?

Posted: Fri May 18, 2007 6:52 am
by Dr Goggles
David Leikvold wrote:The Rice-Vigeant lakester and many others use those skinny Front Runners that are now on Top Fuel cars but they aren't speed rated either and are so skinny you can't use front brakes.
.


there aren't too many lakesters or streamliners with front brakes....

my neighbor has a speach impediment and while staring at the bellytank with a mixture of awe and alarm he said " 'Ow you gonna dop it ?" he had to say it a few more times before I realised he'd noticed it only had two rear drums and was concerned as to how we would STOP it , :wink: .

Posted: Fri May 18, 2007 12:28 pm
by Lynchy
A few people I work with seemed all concerned as to how you slow a car down from 200 or 250 mph. Then you show them the lake on Google Earth and how long the track is versus how long the lake is. Not so concerned after that.

Posted: Fri May 18, 2007 6:48 pm
by w3stie
errr, how long is the track?

The track

Posted: Fri May 18, 2007 8:22 pm
by Dr Goggles
.......last year they cut it to fourteen miles , longer than usual because of the Ack Attack and it's FIM bid...don't quote me but I think it used to be between 7 and 9 . First trap b/w 3 and 3&1/4 then at the miles after that....only the heavy hitters are still accellerating at five miles

Therein is part of the rub about the salt Westie.....it ain't a 1/4 mile....'chutes aren't used regularly because it's easier to back off and roll than repack one......

Front brakes

Posted: Sat May 19, 2007 12:00 am
by David Leikvold
And there's plenty more salt after the scraped length if you don't mind a bumpy ride so I understand your point about not really needing racer brakes at Lake Gairdner, Doc. I've always been a fan of front brakes and I can't get comfy with not having any. Way back when they were legal in sprint karts I had some nifty American front disc brakes and could usually pick up one position per lap at the Gold Coast track outbraking people into the hairpin at the end of the straight. But I digress.
The main reason I'm keen on them is I read that Nolan White was killed when both his parachutes tore off his streamliner at Bonneville a few years back. Apparently his brakes couldn't slow his car much before they overheated so he was forced to go looking for soft salt when he started running out of track. Unfortunately the car dug in and pencil rolled to a stop from about 300mph. Even Andy Green lost a chute on one run in what is arguably the best prepared salt racer ever. But both these cars were well over 300mph when they struck trouble.
Whatever car I finish up building first will probably not even go fast enough to need a chute but it will have four wheel ventilated discs and appropriate pads. Better to have them and not need them than the other way round.

the difference

Posted: Sat May 19, 2007 12:00 pm
by Dr Goggles
First of all , our car hasn't run .Neither have I. Our design and build has been based on a massive amount of study of the history and development of salt specific cars and more particularly Belly-tankers.I don't and won't profess to know everything about this stuff but I'm doing my utmost to keep my mind and ears open , if an argument makes sense I'm interested and if it's relevant to what we ( me and the Reverend) are doing then I'm there.

Dave Leikvold wrote:
"The main reason I'm keen on them is I read that Nolan White was killed when both his parachutes tore off his streamliner at Bonneville a few years back. Apparently his brakes couldn't slow his car much before they overheated so he was forced to go looking for soft salt when he started running out of track. Unfortunately the car dug in and pencil rolled to a stop from about 300mph. Even Andy Green lost a chute on one run in what is arguably the best prepared salt racer ever. But both these cars were well over 300mph when they struck trouble. "


Good point Dave ,however , these stories relate to narrow track streamliners ( narrow in relation to wheelbase) which are prone to the pencil roll .The other relevant point here is that there is no reason to ignore front brakes on a streamliner when they are covered by bodywork anyway...The rules defining a lakester which is what belly-tanks fall under is that the body work shall not extend beyond the inner edge of the wheels.Our car has a track width of approx. 1600mm and it's C.O.G in the vertical plane is roughly at axle height . Avoiding front brakes for us cleans up the front axle considerably and also has one tiny additional feature........ in the event of the car getting out of shape while rolling ( not under power) a tap on the brakes will have the effect of aligning it with the direction of travel as opposed to a full-on four wheel flat skid. Our car will never approach 300 mph , the record in our class( E/GL) is held by Jack Kelly ( U.S) at about 236 and he runs a small block that will rev to 9k and at 75 has been at it for a while.....one day we'll get near that but in the meantime we're fairly confident that the format of our car is relatively safe based on the history of accidents in the class.

It is good to see others doing their homework on the history rather than trying to translate drag racing to the salt. I have at times raised an eyebrow at some of the design issues employed by the Rice-Vigeant team, early on they had trouble with a NACA duct( used in a low pressure point as an inlet) and their crash showed up a severe weight distribution problem.....however, THEY'RE RACING ! and I'm writing :lol:

having a go

Posted: Sat May 19, 2007 4:06 pm
by David Leikvold
Yeah, Doc, you're writing but you're also building which puts you well ahead of me. I won't be able to start building anything until after Christmas as I don't have the space yet. You make a good point about relative speeds and stability of lakesters and streamliners. The danger of pencil rolls makes me less than keen to build a streamliner.
Chris Hanlon said elsewhere in this forum that the only time you really need good brakes is if you're on fire (!!) or you've chucked a rod and you're dropping oil. I like the idea of tapping the back brakes to pull the car straight, it would probably work nearly as well as a parachute unless they locked up.
Perhaps having two separate brake systems might be better (not for your car, I'm just thinking out loud now). A foot pedal for the rears because that would be the natural reaction in an attention-getting situation and a hand lever to operate the front brakes if they were ever needed. I like the idea of having two calipers on each rear disc with separate master cylinders. I even saw someone online who had water cooling spray jets for the brakes.
Once you've got your car sorted why don't you make a set of wheel covers and run the car in E/GS as well. Then fit nitrous and chase the FL and FS records as well.