I don't want to sound like a jerk, but seriously, get a rulebook before you start giving people advice on safety equipment that has to one day save their life.

Here are some quotes from the NHRA rulebook sitting in front of me. I don't have an IHRA rulebook, but I know for a fact that the "design" of the bar has the same specs.

"Roll bar must be adequately supported or cross braced to prevent forward or lateral collapse. Rear braces must be of the same diameter and wall thickness as the roll bar and intersect with the roll bar at a point no more than 5 inches from the top of the bar."

"All required rear braces must be installed at a minimum angle of 30 degrees from verticle and must be welded in."

If you tried to run a car at the track with no rear bars, you'd get laughed out the door.

 

Well, you are sounding like a jerk, Sal...Because I said I have a IHRA rulebook right here...It does not say anything about 30 degrees!!
Like I said you could still have a 30 degree forward brace bar to adequately support the main hoop from forward and lateral collapse!
IHRA doesn't even call them "rear bars" only support bars.

I think you had better go get an IHRA rulebook and read it before you go telling anyone about something you have no knowledge of!!

I am not giving anyone advice bad or otherwise,I am just saying what is IHRA legal...

As we all know IHRA and NHRA have different ideas on what is right!

Besides that...why don't you read what you just posted...that little blurb doesn't say rearward collapse does it??

It only says forward and lateral support!!!

 

Like I said, IHRA and NHRA share the same safety designs. IHRA differs in that they allow no bar to 11.50 instead of 11.99. But the constrution is all the same. If it weren't people wouldn't be able to run at either kind of track, and there are plenty of guys on this forum who race at both.

Aside from splitting rules, why on earth would anyone WANT to not have the rear bars? Is not going through the rear window worth your life? If you flip your truck and the force of impact is rearward at the main hoop, with no rear bars that whole proposed mess of front bars (which all mount at one point anyway) will get ripped from the chassis and cause the rearward collapse of the bar. I guess it's not that THAT big of a deal, since you'd be dead anyway when the roof crushed you, so who cares at that point. The truck looked good all that time until then.

 

BTW, I just looked at the IHRA rules, and they are WORD for WORD identical to the NHRA rules in regards to construction of roll bars/cages, with the one exception of the ET number 11.49 and 11.99.

 

Look Sal, This is BS...you said you DONT have an IHRA rulebook...I DO...don't tell me what it says....I am reading it myself!!

If your qoute was fron NHRA, then IHRA and NHRA DO NOT share the same rules...PERIOD!!

As far as the rearwars bar thing... that IS NOT my call...go argue with IHRA!!!

Like I said..IHRA makes no mention of a 30 degree rule or that "brace bars" must go rearward...only that they keep the main hoop from moving FORWARD and laterally!!
Aslong as the "brace bars" are attached to the main hoop within 5" from the top of the hoop, it makes no difference structurely if they go forward or rearward...unless you know a law of physics that I dont!! So dont tell me that forward bars are less safe to prevent FORWARD collapse!!
The rulebook says NOTHING about rearward collapse!! And they do not have to attach the frame at the same point as the diagonal bar(s)! There would only be one pass bar, that being the brace bar. The drivers side diagonal and the brace bar could attach to any point on the frame!

 

I found a reprint of the IHRA rules online at a drag racing site. They are, as I said, identical. I think your issue is that you are only reading part of the rules. The rules for roll bar/cage design reach into several areas of the rulebook, not just that one section you are reading.

But what do I know. I've only been doing roll cages and chassis work for years.

Uhhh, ok. Go kill yourself. The rest of us will do it the right way. Actually, you won't kill yourself, because you'll never be allowed down the track with no rear bars. You'd have a better chance of making a pass with NO bar.

 

Sal, I am aware of both sections of the rulebook pertaining to rollbars!
Neither section says 30 degrees in IHRA or that REARWARD bars are needed!!!

Like, I said...IHRA DOES NOT say the same thing as YOU SAY that NHRA does!!

Sal, I have a rollbar in my truck...I could care less...I'm just saying what IHRA will accept!!
You're arguement should be with IHRA..not me...I'm only the messenger here!!

I am not saying that you're bars aren't legal...overkill is always better...but we are talking about what is legal...not you're opinion of what is safe!!

 

rear bars look cool

 

The way to look at a cage is IF you are in a roll over[technically but not true]what will happen to the bars as weight is put on them in different planes?IF you want to get technically a vechicle does NOT roll over at a race track it FALLS from the air.LOOK at some of the vidoes!How many vehicle roll over.All that I have seen fall down and are doing barrel rolls in the air!!
So since I think I have a TRUE cage,that is what I DESIGNED it for..............FALLING onto a corner of a bar or cage.I think people are stupid to try and get by with a min. number of bars to save weight.It is your life and how do you think your family will feel knowing that 'he saved 12 lbs so he could get that extra tenth' while they are at your FUNERAL or hospital bed!!
I figured up the weight saving going from a 1.75 bar to a 2 inch bar it is less than .5 lbs per foot.BIG frigging deal.Add the bars,WHICH by the way will make your chassis stiffer too.So what you can say you lost in the added weight you more than made up for in the chassis.
I look at this as being a stupid dissucion [sp] unless you place no value on your life.Kinda like using a motorcycle helment for auto racing !!2 totally different types of crashes happen.YOU can spend thousands on moding your vehcile to go faster but to STUPID to make yourself safe while doing it!!STan

 

Stan, I do agree safer is better...But, the question was are rearward bars needed....and in IHRA they are NOT,atleast as it is written in the rulebook!

Sal, seees to want to make an issue out of the facts!

The fact is that IHRA does not require rearward bars!! Nowhere does it say rearward bars in IHRA!! They call them "brace bars" and say that they need Only to prevent forward and lateral collapse...This FACT cannot be changed, regardless of Sals or anyones opinion on the matter...that was my only point!!

 

So in the IHRA rulebook where it says, and I quote: "Rear braces must be of the same diameter and wall thickness as the roll bar and intersect with the roll bar at a point no more than 5 inches from the top of the bar", do you have some new definition of the word "rear" that the rest of the world doesn't know about? Or maybe this is opposite Sunday? And what about the official IHRA diagram of a proper roll bar, which clearly shows a main hoop, one drivers bar, and two rear bars? Are you just ignoring that as well?

 

Funny...you said you didn't have an IHRA rulebook....where are you qouting this from??

My 2005 IHRA rulebook doesn't say that!!


In the diagram it does not SAY anything about rear bars except that they must be within 5" from the top...they are just showing a "typical design"..NOT the ONLY design!

 

hey guys... I didn't intend to start an argument.

I only wanted to know whether they were required or not, and it has become apparent that it is much safer with them installed than not, REGARDLESS if they are required.

Why did I want to know this?
I thought it would be cheaper to go forward and keep the rear window intact, instead of buying a custom size piece of lexan. and then figuring out what you are going to do with a tonneau cover.
Or course you could use the soft cover, and use a zipper or velcro.

 

Actually, An otherwise similar "brace bar" is not stronger facing the rear than it is facing forward!!

It's a funny thing about metal...it doesn't get stronger or weaker depending on which way it is pointed!!

The rules say the hoop has to be supported to prevent FORWARD and lateral movement....Technically forward braces would be better and SAFER for this purpose!!!

 

Hey, you nailed it! Put a hundred forward bars in. Then that bar will NEVER collapse forward. Of course you'll still be dead when the main hoop collapses to the rear because you have no rear bars.

I still can't understand why you see nothing wrong with what you are telling people.

Here's a quick test for you... Stand straight up. Put one foot forward about a foot. Have someone push you from behind. You're not going anywhere. Now stay in that same position, and have someone push you from the front. Watch your head on the floor.