PDA

View Full Version : Standard chassis material



Bugpac
09-19-2007, 07:13 PM
In most race rules i have seen for nearly any motorsport, they require a minimal wall thickness of .095, Rorty had mentioned .083 and i feel has the knowledge to back it up, But do the venues that cover the insurance premiums feel the same....

So the question is, Should we maintain the .095 wall thickness as set by most us sanctioned race bodys....
With this same question brings the question of the stock pilot, the wall thickness vary from .5? to whatever, IMO this need to be addressed were the stock honda pilot chassis in its original configuration, or reinforcment added but non removed, be allowed to race....IMO this would basiclly give pilots a pass, and they would be able to run the aftermarket arms and such...

An example the chief scrutinizer would have to take in account is if the chassis had built to a arm kits etc...Were the actual honda chassis was modified etc....

ultraman
09-19-2007, 07:18 PM
How do they check wall thickness at the track? Just curious. Pilots raced in the previous lite series, so why not this new one?

K-fab
09-19-2007, 07:23 PM
With the weight of our cars - under 1000 lbs, .083 should be more than sufficient.

I agree on the "Pilot Pass". *

The old Pilot roll cages were subject to tweaking with a minor roll over - but strangely enough, I've never seen one wad to the point of danger to the driver - seen some fairly damaged units, but they don't seem to encroach on the driver.

Obviously Honda figured out something... *To make it even more interesting on the Pilot - they're a bolt together cage. *Two front down bars, two rear down bars and then the main hoop. *The hoops not triangulated very well either. *But still, they don't seem to crush - just bend and tweak.

If you plan on racing a Pilot I really recommend getting a cage from ATV Racing (they're the only people making them that I know of) or making one of your own - all one piece, not bolt together and at least 1.25x.083 with quality diagonals and such. *It's not that hard - and if you've the talent to insert a sled engine, you're bound to be able to make a cage...

hero_saku39
09-19-2007, 07:26 PM
How do they check wall thickness at the track? Just curious. Pilots raced in the previous lite series, so why not this new one?

Everything is still getting faster. *These Pilots were not built for the speeds (or decelerations) they are seeing now.

Bugpac
09-19-2007, 07:35 PM
Im not saying pilots cant race, just saying that there made to minimal as is, and modification of hondas engineering could be hazardous to your health, *[smilie=biggrin.gif] *Now if some big wig chassis engineer brought one to the track with every tube cut out and replaced it would definetly have to be looked at...

We just have to set a standard....Like i said before, your standards need to be high enuff that the most diverse group of brain power *people can comply....

hero_saku39
09-19-2007, 07:46 PM
Im not saying pilots cant race, just saying that there made to minimal as is, and modification of hondas engineering could be hazardous to your health, *[smilie=biggrin.gif] *Now if some big wig chassis engineer brought one to the track with every tube cut out and replaced it would definetly have to be looked at...

We just have to set a standard....Like i said before, your standards need to be high enuff that the most diverse group of brain power *people can comply....

After recent events, I think if we are trying to accommodate the overwhelming masses (with regards to brain power), we might as well stop now. * [smilie=biggrin.gif]

Bugpac
09-19-2007, 07:47 PM
[smilie=biggrin.gif]

Example, 13 yr old kid first time with his stick welder etc etc, I can gather some youtube videos for "brain power" refrences i am talking about.... [smilie=biggrin.gif]

Rorty
09-19-2007, 10:33 PM
In my experience of Pilots and Odysseys, Honda got it about right; they're fine with the stock engines and suspension, but slot in more power and add longer arms and the chassis are no longer up to the task. Every Oddy chassis in TORC had been welded/re-welded/replaced. They were produced as 'fun karts' and never designed for racing.

If someone wants to race an Odyssey or Pilot, they should be catered for with bone stock Odyssey or Pilot classes - unless someone qualified can recommend the ATV Racing cage etc. (I haven't seen one, so I don't even know if it's remotely up to the task.)

In most motorsport where cages or any critical tubes are required to be inspected, it's carried out by inserting a gauge into a small hole in the relevant tubes.

ProtoDie
09-20-2007, 05:09 AM
IMO * * * * .095 on 1 1/4 tube (min dia with exception to Pilots)
* * * * * * * * .083 on 1 1/2 tube

DOM is good & strong, but I do not believe it is necessary to spec it.
No one has yet to my knowledge, but that is usually where discussions go.

.083 x 1 1/2" dia *ERW has more than proven itself to us.

For calculating weight

.095 x 1 1/4 weighs 1.172lbs per ft

.083" x *1 1/2 weighs 1.256 lbs per ft

If you use approx 80' of main rollcage tubing in your build,,,,,,,, then a car made out of 1 1/2 would weigh 6.72 lbs more than one out of 1 1/4

Thats not much weight differance

K-fab
09-20-2007, 06:27 AM
In my experience of Pilots and Odysseys, Honda got it about right; they're fine with the stock engines and suspension, but slot in more power and add longer arms and the chassis are no longer up to the task. Every Oddy chassis in TORC had been welded/re-welded/replaced. They were produced as 'fun karts' and never designed for racing.
Great points on the cage Bob. (you too Bug)
Once you start putting hp behind them and such - they are on the flimsy side - I also made note that I felt that if you race a Pilot you need to change the cage.


If someone wants to race an Odyssey or Pilot, they should be catered for with bone stock Odyssey or Pilot classes - unless someone qualified can recommend the ATV Racing cage etc. (I haven't seen one, so I don't even know if it's remotely up to the task.)I have had a couple of the ATV cages - they work very well - tested mine on more than one occasion. *It's a well built unit. *I also recommend welding it in place on the Pilot - it comes set up to bolt in place on the stock points of a Pilot, but welding is much better.

K-fab
09-20-2007, 06:33 AM
IMO * * * * .095 on 1 1/4 tube (min dia with exception to Pilots)
* * * * * * * * .083 on 1 1/2 tube

The cage and main frame on the Brigg's cars are made from 1.25 diam chromoly (best I can tell) but thickness??? *Main stuff is 1.25" diam (guessing .083 thickness) with 1" and smaller bracing. *

The cars passed MTGP, SODA & PACE's rules, so I feel safe in them and would say they should pass anyone's tech.

May I ask - if we end up stating 1.25 x .095 are you guys going to eliminate my cars from racing? (yet allow Pilots?)
I'm already worried about the 600 lb min rule...

ProtoDie
09-20-2007, 06:42 AM
[
The cars passed MTGP, SODA & PACE's rules, so I feel safe in them and would say they should pass anyone's tech.

If it passed all their rules, then it should be good.

.095 x 1 1/4 minimum was specified in some other class or track rules,,,,,but I do not remember which.

greasemnky
09-20-2007, 07:16 AM
Wait, you guys are saying if you take a car designed for 40hp, put in 80-100, it may not hold up in the subsequent crash? *[smilie=banghead.gif] Does that mean the escort I see running at milan with the blown V8 may not be as safe as a purpose built drag car *[smilie=shocker.gif]

I think one of the biggest problems is going to be adapting rules to fit cars that weren't built for a specific series. Most other series (aside from local dirt tracks), the cars were built specifically to run that series. Nascar, F1, SCORE, CORR, etc the cars are built after the rules are established. I think the rules either need to stay a little loose to encorporate all the premade/homebuilts. Or get really specfic, and have people build purpose built cars. I remember watching the super lites on friday night heat on ESPN, thats WHY I have a buggy now. I remember them all being very similar, and of course I was too young to know at the time, but I assume they were built FOR the series.

Watching the racing at bobs, its apparent, the cars are so diffrent, its hard to see them all be competitive in a series if the cars aren't all built to a standard. Worrying about what people have now shouldn't matter. This is going to require new cars to be really entertaining for any sort of audience. *Just my worthless 2 cents

Rorty
09-20-2007, 07:29 AM
.095 x 1 1/4 minimum was specified in some other class or track rules,,,,,but I do not remember which.

That's one of the greatest crimes against racing; "XYZ class runs 1.5" x .095" tubing so we should too". It's ignorance at its worst.

I'm guilty of specifying oversize materials in some of my designs, but that's for a combination of asthetics, appeasing public perceptions and reducing the amount of emails I receive from budding engineers. However, it would be nice to think that race sanctioning bodies would examine what it is that's being raced and set in place realistic material specs rather than lumping us in with what 3,000 lb race cars are built from.

minibajaman
09-20-2007, 11:00 AM
I think 1.25 x .083 is fine, hell 1.25 x .065 is fine as long as the spans aren't too long and the frame is properly braced and triangulated. *For safety though, I would say 1.25 x .083 to err on the stronger side. *This would only be for main roll cage members, bracing could be thinner/smaller. *Also the inspection should include looking at welds and bracing, because thick tube is worthless if the welds are shoddy or the bracing is incorrect or insufficient.

Rorty
09-20-2007, 01:46 PM
I think 1.25 x .083 is fine, hell 1.25 x .065 is fine as long as the spans aren't too long and the frame is properly braced and triangulated.

1.25" x .065" was the TORC requirement for the main cage and worked perfectly well over the years. We were very particular on the quality of welds - any cracked paint or fresh orange rust around a weld and off it went until it was properly repaired, but it was a very rare occurance.

ultraman
09-20-2007, 05:10 PM
I vote 1.25x.065 because thats what i used, and if it was good enough for TORC it should be for us. You can't allow a sled powered pilot to compete with thinner walled tubing, but not a homebuilt.My frame is properly braced and triangulated, and i would not be afraid of it in a roll over.

ProtoDie
09-20-2007, 05:29 PM
I'm sure it is fine as long as the design is good to go with thinner tubing, and your right about the pilots *being thinner & OK to race.

I wonder if it makes sense to establish the rules and specs according to what we think it should be for new cars and then find a way to "Grandfather" in existing cars like the pilots and others that may be just outside of the specs we are coming up with.

Some existing cars may get a "pass" on certain specs for awhile .

I am thinking this in a few catagories, not just tubing.

If they prove dominate because of this,,,,,,,,,,,,,,,,,,,,we pull out the rule book & take away their pass [smilie=mhihi.gif]


I just want to get more people to the track, have everybody driving a safe machine, and get some good racing going on.


Ultra,,,,,,,,,,,,,,,,,,,,,,,,,you almost did roll it over, and I could tell,,,,,,,,,,,,,you wassunt scared [smilie=bow.gif]

boostick4
12-22-2007, 08:27 PM
Rorty and minibajaman absolutely hit the nail on the head here.


[quote="ProtoDie\";p=\"44985":1d2khkuu].095 x 1 1/4 minimum was specified in some other class or track rules,,,,,but I do not remember which.

That's one of the greatest crimes against racing; "XYZ class runs 1.5" x .095" tubing so we should too". It's ignorance at its worst.

I'm guilty of specifying oversize materials in some of my designs, but that's for a combination of asthetics, appeasing public perceptions and reducing the amount of emails I receive from budding engineers. However, it would be nice to think that race sanctioning bodies would examine what it is that's being raced and set in place realistic material specs rather than lumping us in with what 3,000 lb race cars are built from.
[/quote:1d2khkuu]
For these size cars tubing like that is way overkill. Obviously the thickest tube is needed in the roll hoop and side impact structure, and should have a standard, but the whole car shouldn't be made of the same size tube.


I think 1.25 x .083 is fine, hell 1.25 x .065 is fine as long as the spans aren't too long and the frame is properly braced and triangulated. For safety though, I would say 1.25 x .083 to err on the stronger side. This would only be for main roll cage members, bracing could be thinner/smaller. Also the inspection should include looking at welds and bracing, because thick tube is worthless if the welds are shoddy or the bracing is incorrect or insufficient.



I think that all of us cannot be consumed into only one class. If it was started as one class it would only be a matter of time before the truly competitive cars showed their dominance and the rest would feel left out and want a separate class anyway. Weight is the biggest enemy of any race car and this IS supposed to be a race class/es so you would have people with the SAE BAJA, Pilot/Odyssey, Briggs built cars dominating the field while the more "portly" cars wouldn’t stand a chance. Possibly a sub 800lb/800cc class and a plus 801lb/801cc class....I don't know. Maybe a power/weight division some ware, but that would require expensive measurement equipment. Maybe a race/hobby division? I really do think some division should be made otherwise you’ll have someone in a 600lb race Pilot getting TACOED *[smilie=banghead.gif] *[smilie=ext_doc.gif] *[smilie=ext_crutch.gif] *[smilie=tr_rip.gif] by someone in a 1500lb homebuilt land barge. Some form of bumpers and side bars wouldn’t be a bad idea either.

Just thinking out loud,
Woody

Loboracer
10-05-2009, 03:49 AM
New to Mini Buggy here... and I openly admit that I'm still getting my feet wet with fab work...So you can take the two cents or leave it... but I've heard that you can apply different tube diameter/thickness/and material for that matter dependent on the potential load that the tube may come into "contact" with. (i.e. 4130 Chromoly for your top hoops with a thicker wall because it will be your primary protection in a rollover) but then reduce the specs and switch to DOM tube in general support lengths. In a nutshell... A well engineered car will have the necessary protection where it is needed and reduced protection where it is not. Lighter= Faster...right? I could be completely off base...but in my mind a combination of materials would be optimal... So long as it is all carefully planned.

jumpin jellybean
10-05-2009, 07:04 AM
:rolleyes::eek:hooray almost every post said the same thing design is most important with correct size tubing (strength wise):cool:but rules will never get set straight untill every one bitches about it enough. just my .02

K-fab
10-05-2009, 08:33 AM
New to Mini Buggy here... and I openly admit that I'm still getting my feet wet with fab work...So you can take the two cents or leave it... but I've heard that you can apply different tube diameter/thickness/and material for that matter dependent on the potential load that the tube may come into "contact" with. (i.e. 4130 Chromoly for your top hoops with a thicker wall because it will be your primary protection in a rollover) but then reduce the specs and switch to DOM tube in general support lengths. In a nutshell... A well engineered car will have the necessary protection where it is needed and reduced protection where it is not. Lighter= Faster...right? I could be completely off base...but in my mind a combination of materials would be optimal... So long as it is all carefully planned.We have another winner!!! [smilie=jumping.gif]
Who's gonna give him his cookie? (on going thing ....)

Great first post - welcome to the site.

You've nailed it. Use the correct material in the proper manner.

Thicker, larger and even chromoly for main frame items such as hoops and suspension mounting, smaller, thinner mild for bracing and such. It just makes sense.

I guess the sticking point to it all is "Just what is sufficient?" for the app.

From what I've seen over the years, 1.125 x .083 mild works as a basic, across the board size. I've even tested this one a couple of times.

LiveWire
10-05-2009, 09:11 AM
The Odyssey frame is doubled up in certain areas like where the main hoop connects to the main horizontal tube. It is also gusseted quite a bit at the tube intersections. The low points are the large window openings. It's not that they screwed up in design, but that entry ease was given a priority over strength there. The brace tubes from the front upper corners of the roof just connect into the B-pillar with no continuation behind them. There was probably a conscious decision that even though the B-pillar just bends in the middle, that it provides and acceptable resistance to the roof crumpling. It does not take much modification to significantly increase the strength of the cages. That is for an Odyssey which has a .065 cage. A Pilot is .048 with .065 main frame. Adding a tube in the front of the window opening shortens the span on the front tubes. A tube can be added to continue the gusset from the front of the roof down to the back of the frame. While the side to side gusseting is minimal, I have not seen the cages distort that way significantly. Mostly has been the front corner of the roof crush in. Strengthening the cage front to back may change that though.

I did not continue the roof gusset back on my own cage or add any extra tubes for that matter. I lowered the roof gussets down increasing their leverage. I also raised the side gussets up. They are still essentially dead tubes. However, for the B-pillar to bend where the roof gussets come in, the side to side gussets also have to bend. In a side to side roll, the roof gussets now have to bend if the B-pillars bend. A, B and C pillars are all tipped out widening the cage and leaving more room between my head and the ground if I land on the side as well as more room between my helmet and the cage. No more red marks on my helmet. The whole cage is .095 wall. The total weight is about the same due to getting rid of 8 of the cast bolt together couplers.
http://www.aftershockmotorsports.com/photos/lt350.jpg