Cockpit tube size/thickness discussion

[nutz4sand]

First off in that I am not to much into NHRA type drag racing as to know the rules at those levels but your saying they do NOT want them heat-treated after being constructed? I did not know that. But its likely IF thats the case cause there are not to many stresses on them. Heres why Isay that.

Originally Posted by masterfabr

Simple.The dragster travels what in it's lifetime? 500 miles MAX? On a smooth paved track no less. Very little stresses put on the chassis compared to an offroad car regardless of size. On the other hand the offroad car will see many hard hits and jumps and (hopefully) many many miles of very stressful use. The .058 is fine for the once in a dragcars lifetime crash at protecting the driver. The offroad car will see many nearly the same impacts in it's lifetime. Again ,the intended usage will dictate what's appropriate to use. The .058 for a drag car will save your life.I know! Sorry for pic quality.It's a pic of a 22 year old pic.

Do I believe that? Not really to aweful much. I know most drag chassis are not gonna be jumped a lot (not intentionally anyway) but the stresses put on the launch are horrendous. Especially any car with enough grunt to lift the fronts. Due to the traction of huge slicksand the prepped track it could be argued they deal with more stress at that point than a lot of off road units ever will even landing off a jump.

I quite messing with hotrod cars when the cops were dinging me day and night and got into offroad drag racing in the dunes for fun. (Lots less tickets!) After multiple Banshees and a few others I started messing with buggies and after getting tired of VW stuff's basic problems startied tinkering with minis and "other" powerplants with and drivetrains that did not come in a beetle.

I like many others here I am trying to learn so try to help me understand. Yah I do get a little "questiony" when I see a LOT of split opinions on a subject. I guess I should not even bother with this as I would not use Chro-mo as I do not properly know how to weld it as some may. Plus I think its overpriced "Bling Bling". But I would hate to see soemone go after Chro-mo for the "coolness" factor then end up killed as they do not know how to do something as well as you may. I never so much meant to offend you. I meant it when I said I hope you luck holds. That goes for any motor head. Mr Kalitta died in a chassis that was Chro-mo. Would anything else in the chassis have saved him? Likely not. He was just unlucky due to a few factors of which I am sure I do not know all of. Bill

p.s. I also feel that any driver going over 300 MPH in the quarter mile IS riding on his lucky tail no matter what the car is made of! But thats a different thing.

[masterfabr]

Trying to keep things in perspective here we need to always consider all factors when deciding on tube sizes/wall thicknesses/alloy. Large/fast cars call for larger tubing or more extensive triangulation.Smaller/slower cars lend themselves to smaller tube and/or less triangulation. It's always a balancing act.Then we have to decide if we want parts such as suspension/wheels/tie rods or whatever to be sacrificial(energy dissipating) in the interest of safety when running flat out while racing in the event of a mishap. OR if we want things like suspension components to stay attached in the event of a mishap so we can "get back home" without walking.As ALWAYS there is no one single correct answer.It ALWAYS depends on many factors.
Yoshi,you are dead wrong as to why the cars you cite broke.It had NOTHING to do with them being from 4130.It was from poor design. Plain and simple.The ONLY way for 4130 to break in an incident when dom of thicker wall would not would be if the car pretty severely car flexes on impact. Poor design/insufficient triangulation were the cause that allowed the flex. Probably poorly designed to achieve easy entry/exit or aesthetics.Maybe from just plain old stupidity. On the other hand the car I posted the pics of had each and every suspension component torn off the chassis.The engine was nearly torn out also.Bounced and flipped over 800' at Tulsa Intl Raceway in 1986.EACH AND EVERY weld passed mag inspection after the crash and was rebuilt.The car is being raced to this day. It was from 4130 and some of the hits were over 20g's. The ENTIRE chassis was tweaked only 3/8 ths of an inch at the right rear corner. Had it been from mild the chassis would have been junk. NOTHING wrong with mild OR 4130 properly used.BUILDERS CHOICE.

[Bugpac]

Amazing, there are others with .060 or less....

[masterfabr]

Originally Posted by nutz4sand

First off in that I am not to much into NHRA type drag racing as to know the rules at those levels but your saying they do NOT want them heat-treated after being constructed? I did not know that. But its likely IF thats the case cause there are not to many stresses on them. Heres why Isay that.



Do I believe that? Not really to aweful much. I know most drag chassis are not gonna be jumped a lot (not intentionally anyway) but the stresses put on the launch are horrendous. Especially any car with enough grunt to lift the fronts. Due to the traction of huge slicksand the prepped track it could be argued they deal with more stress at that point than a lot of off road units ever will even landing off a jump.

I quite messing with hotrod cars when the cops were dinging me day and night and got into offroad drag racing in the dunes for fun. (Lots less tickets!) After multiple Banshees and a few others I started messing with buggies and after getting tired of VW stuff's basic problems startied tinkering with minis and "other" powerplants with and drivetrains that did not come in a beetle.

I like many others here I am trying to learn so try to help me understand. Yah I do get a little "questiony" when I see a LOT of split opinions on a subject. I guess I should not even bother with this as I would not use Chro-mo as I do not properly know how to weld it as some may. Plus I think its overpriced "Bling Bling". But I would hate to see soemone go after Chro-mo for the "coolness" factor then end up killed as they do not know how to do something as well as you may. I never so much meant to offend you. I meant it when I said I hope you luck holds. That goes for any motor head. Mr Kalitta died in a chassis that was Chro-mo. Would anything else in the chassis have saved him? Likely not. He was just unlucky due to a few factors of which I am sure I do not know all of. Bill

p.s. I also feel that any driver going over 300 MPH in the quarter mile IS riding on his lucky tail no matter what the car is made of! But thats a different thing.

What's with quoting me to prove a point and then saying you don't believe it? Anyway you are incorrect about how sever the launch is. I run full datalogging including g forces in all 3 axis. Acceleration max g force is approx 2.5 g's for less than 1/4 second.Max g force has been approx 3 g's vertical on a VERY rough track. At MOKAN DRAGWAY in Joplin the things so rough in the shutdown area that my RED will literally have ALL 4 wheels a foot off the ground a couple times for a hundred feet or more before the return road. 3 g's is all it gets. I can guarantee you that I've felt a lot harder hits in an offroad car. The ONLY time I've felt as hard of a hit is when I wrecked the door car and it saw approx.20 g's twice in the wreck that flipped and endoed for 800'. IMO only of course off road is much more severe on components.

[yummi]

CORR 2008 Rulebook

[arrowhead]

Oh God I'm gonna die!

[bdkw1]

Yummi

ACCR-36 Roll Bars (Cage)
A. Round steel seamless or D.O.M. tubing is compulsory for the
basic roll cage construction, and must be CORR approved.
Aluminum and/or other composite soft metals are not
allowable.

This does not exclude 4130, only seamed tubing. Most CORR trucks are 4130.....

[masterfabr]

Round steel seamless or DOM. And your point is?????I don't see 4130 being excluded. 4130 IS round seamless tube.They don't even spec ANY alloy.

[masterfabr]

You beat me to it! Some people are so eager to win this debate they've stopped thinking.

[yummi]

Originally Posted by bdkw1

Yummi

This does not exclude 4130, only seamed tubing. Most CORR trucks are 4130.....

I noticed that. So, it appears to be a matter of choice on the material. (Master, don’t let that go to your head )

However, it is pretty specific on the wall thickness and weight of car. Having watched the guy endo end over end on the front stretch over this last weekend, likely a good guideline on gussets, wall thickness etc. As a sanctioning body goes, looks like these guys have the knowledge to figure it out.


BTY, turn the music OFF – it is, well, not country…

YouTube - Corr crashes