I need some advice on Roll cage fab

[AJohn6]

I have a question for the chassis experts on here. I have a '71 C10 which is currently under the knife. My plan is to build a pro-touring style truck that is capable of mid 10's in the 1/4 mile. I do not have a good knowledge base of chassis/roll cage rules and would like your help. I purchased the 1 5/8 EWS 10 point cage from S&W and need to get good advice before I start cutting things up. *** Also the firewall is modified.

1. Do the outriggers have to be welded to the frame or can they have a plate welded to the end and then be bolted to the frame with grade 8 hardware?

2. Or.. can the outriggers be welded to the frame and the main hope/windshield runner be bolted to the outrigger with grade 8 hardware.

3. If running, let's say, 10.5 in the 1/4 are the rear braces (from main hoop to rear frame) needed?

4. Is there a maximum distance that the rear braces can drop down from the main hoop before it has to go out of the cab of the truck?

The reason I ask #1 & 2 is I would still like to be able to remove the cab after putting the cage in. And the reason for #3 is I want to avoid having anything come out of the back of the cab.

Thanks in advance,

-Adam

[Marv D]

Adam I feel you pain....

(someone please run a sanity check on all this as I'm oput of town and don't have access to the rule book,, but best i remember...)

Anything quicker than 11.5 must gave a roll BAR

BUT......

If you have modified more than 2 sq feet (VERIFY THE AREA LIMIT but I'm pretty sure its 2sq ft) of the floor or firewall, you have to have a CAGE,, not a bar.

I do not believe there is any option for a bolt in anything when you have a factory frame (only in a unibody car) You can have a swing-out side bar, but unless I'm mistaken everything else has to be welded,,, incuding outriggers off the frame.

If your required by the rules to have a cage, you MUST have a window net (Window nets are now on a SFI 2year expiration btw)

You HAVE to have the rear bars or build a funny car style cage inside the cab.

The rear bars MUST attach to the main hoop within 6" of the top of the hoop (if down the uprights) MINIMUM angle at attachment is 30 ° (it specifically says the rear bars must be constructed to pevent the main hoop from collapsing,, they don't allow a lot of lee-way)

But lets drop back 5 and start with power,, your probably going to have to have somewhere north of 650-700HP to get a heavy (near stock 71 is close to 4000#?) to 10.5 Don't expest too 'streetable' of a ride unless your building a turbo BBC

700HP is going to put a serious twist on a stock chassis. I can understand the desire to make a 'bolt in' ordeal,, but even if you could.....you are going to want rigidity at 10.5's and I'd expect 120-125mph+

[AJohn6]

Originally Posted by Marv D

Adam I feel you pain....

(someone please run a sanity check on all this as I'm oput of town and don't have access to the rule book,, but best i remember...)

Anything quicker than 11.5 must gave a roll BAR

BUT......

If you have modified more than 2 sq feet (VERIFY THE AREA LIMIT but I'm pretty sure its 2sq ft) of the floor or firewall, you have to have a CAGE,, not a bar.

I do not believe there is any option for a bolt in anything when you have a factory frame (only in a unibody car) You can have a swing-out side bar, but unless I'm mistaken everything else has to be welded,,, incuding outriggers off the frame.

If your required by the rules to have a cage, you MUST have a window net (Window nets are now on a SFI 2year expiration btw)

You HAVE to have the rear bars or build a funny car style cage inside the cab.

The rear bars MUST attach to the main hoop within 6" of the top of the hoop (if down the uprights) MINIMUM angle at attachment is 30 ° (it specifically says the rear bars must be constructed to pevent the main hoop from collapsing,, they don't allow a lot of lee-way)

But lets drop back 5 and start with power,, your probably going to have to have somewhere north of 650-700HP to get a heavy (near stock 71 is close to 4000#?) to 10.5 Don't expest too 'streetable' of a ride unless your building a turbo BBC

700HP is going to put a serious twist on a stock chassis. I can understand the desire to make a 'bolt in' ordeal,, but even if you could.....you are going to want rigidity at 10.5's and I'd expect 120-125mph+

Thank you, you were one of the guys on here that I have been cyber stalking. My plan on the motor is a 6.0 LS bored/stroked to a 413 and a 4L80 and converter built by Monster trans and running a twin turbo setup. I want to be able to tune the motor for the track via boost levels and utilizing HP Tuner software. I have a 10 point cage from S&W and I just got it yesterday before this ice storm hit us.

I completely cut out and replaced my firewall and had to raise the tranny hump about 3".

Do the rear bars have to look like the red lines in the drawing or can they be bent to look like the black lines? And can you clarify what you mean by minimum angle at attachment of 30*?

If you have any question or want to see my work check out the last couple pages of my build thread, the link is in my sig.

Thanks again,

-Adam

[Marv D]

Ohhh yeah 400+" LS and twins.. I think there is 700 in there for sure!

Yeah what get's you is the 30° from the main hoop (Verticle) . The red line is what.. 45°?, your black line is only ?? 5°. 30 is more like just a sliver off of the 45 (sucks right!)

I'm fighting the same quandrum. I didn't want to hack the back of the cab... but really there is no alternativce short of a funny car cage inside the cab.,, well or a throttle stop.

[AJohn6]

Originally Posted by Marv D

Ohhh yeah 400+" LS and twins.. I think there is 700 in there for sure!

Yeah what get's you is the 30° from the main hoop (Verticle) . The red line is what.. 45°?, your black line is only ?? 5°. 30 is more like just a sliver off of the 45 (sucks right!)

I'm fighting the same quandrum. I didn't want to hack the back of the cab... but really there is no alternativce short of a funny car cage inside the cab.,, well or a throttle stop.

Haha... Throttle stop, what's that?

I think I am starting to smell what you're stepping in. The main hoop is 0*then the the rear bars have to attach to that at a 30* angle. Are there any bends allowed in the bar after that point or does it have to be straight and then welded to the frame? I plan on having the cage inspected prior to painting so if it is needed I can rework it.

Again I really appreciate the help,

-Adam

[Marv D]

Get your hands on a rule book. I'm shooting from the hip on some of this but the bar / cage rules are seriously etched in stone. I have a 10.60 truck with a full cage that is just flat NOT LEGAL. I've slipped by tech a few times and ran it all out, but the cage construction specs are for your own good. You know that,, you just don't want to hack the back of the truck up. I can relate. But build a complete 7.50 funny car cage inside the cab, or hack the back of the cab. I havent found any alternatives ,,, hence the stinking throttle stop!

I'm investigating IHRA as both NHRA tracks here in AZ will be closed before summer. One IHRA track in Tucson is all we got so I'm just stating to delve off into IHRA

Just a few off the top of my head... and this is speaking of a NHRA track.

The main hoop has to be 6" above and 4" behind the drivers helmet, then those rear struts have to attach at the 30° MINIMUM ANGLE.the side bar MUST pass between the drivers shoulder and elbow when he is sitting in the seat
Because you altered the stock firewall, I believe you HAVE TO have a dash bar in your cage now,
and a window net
and a flexplate shield
and a trans blanket
and a engine diaper

[AJohn6]

You just brought up a point I never thought about IHRA vs NHRA. After a quick search I found out that the tracks nearest me that I would go to are all IHRA tracks. I didn't even think about that.

Thanks again,
-Adam

[Marv D]

IHRA rule book is easier to find on line
Page 90 starts the bar rules

http://www.mydigitalpublication.com/...tion/?i=136499

Note at top of page it says all vehicles with full frame must have bar welded to frame,,, sounds like no bolting anything in. but in the text it says OR BOLTED to frame ??

[AJohn6]

Originally Posted by Marv D

IHRA rule book is easier to find on line
Page 90 starts the bar rules

http://www.mydigitalpublication.com/...tion/?i=136499

Note at top of page it says all vehicles with full frame must have bar welded to frame,,, sounds like no bolting anything in. but in the text it says OR BOLTED to frame ??

When I searched for the NHRA rule book it was almost impossible to find without buying one and I got it everyone need to make a dollar but IHRA does it the right way and you can download it straight from the website. I feel that it is wrong to charge for the rule book if I download it.

In the diagrams for both the roll bar and roll cage it says "must be welded to frame". I see where it says "bolted or welded" but it is in the roll bar text section and not the roll cage text section. In the roll cage text section though, I can't find anything about the cage/frame attachment. I may call the tech inspection guys at the local track and see if they can further clarify.

[hotrod 80]

Also from what i understand 25-2 , 25-3 &25-5 rules have changed

[AJohn6]

Originally Posted by hotrod 80

Also from what i understand 25-2 , 25-3 &25-5 rules have changed

Haha, I'm a total newbie with these terms. Can you clarify what that means? Also is it a change since the 2013 book was posted?

-Adam

[hotrod 80]

Originally Posted by AJohn6

Haha, I'm a total newbie with these terms. Can you clarify what that means? Also is it a change since the 2013 book was posted?

-Adam

No these are the 2013 rules . At 10.50 your ok .

[moggey01]

Sometimes it is good to think about the future. You will always be trying to go faster. I will show you a pic of a car that had a legal NHRA cage. This car ran 254 mph with it. They changed to a Bonneville spec cage for 300 mph. The car has since ran 263. At the Texas Mile something went way wrong, and the driver walked away with bruises! The car barrel rolled on fire at 220.

[BR3W CITY]

Marv, whats with the 4" behind the helmet rule? In my 66 I think it would be impossible to be 4" behind my head and still be IN the cab...I have like 2 inches behind my head without a helmet on. I'd have to put the main hoop behind the cab like a freaking 70's off-roader.

[Marv D]

is it 4",, I have an old rule book scan here handy that sayd 5" above and 6" behind.
I'll have to figure out my NHRA login and see if it's changed. And YES, its a STUPID rule for us truck guys!

[AJohn6]

Originally Posted by moggey01

Sometimes it is good to think about the future. You will always be trying to go faster. I will show you a pic of a car that had a legal NHRA cage. This car ran 254 mph with it. They changed to a Bonneville spec cage for 300 mph. The car has since ran 263. At the Texas Mile something went way wrong, and the driver walked away with bruises! The car barrel rolled on fire at 220.

Thanks for the advice. Marv D helped me out in the process as well as a race shop nearby. I ended up getting the 10 point cage from S&W and am going to install it the right way. One of the guys in the shop did the same thing and made a real nice insert where the bars go through the cab.

Originally Posted by BR3W CITY

Marv, whats with the 4" behind the helmet rule? In my 66 I think it would be impossible to be 4" behind my head and still be IN the cab...I have like 2 inches behind my head without a helmet on. I'd have to put the main hoop behind the cab like a freaking 70's off-roader.

Originally Posted by Marv D

is it 4",, I have an old rule book scan here handy that sayd 5" above and 6" behind.
I'll have to figure out my NHRA login and see if it's changed. And YES, its a STUPID rule for us truck guys!

I used the IHRA rule book which can be found online and downloaded for free. It is very close if not the same as the NHRA rule book I found.

[Captainfab]

What I'm seeing, says a maximum of 5" above and 6" behind the drivers helmet. So the main hoop should be able to be closer than those measurements. It does say it has to be at least 3" above the drivers helmet, however I don't see a minimum allowable behind the helmet measurement.

Originally Posted by Marv D

is it 4",, I have an old rule book scan here handy that sayd 5" above and 6" behind.
I'll have to figure out my NHRA login and see if it's changed. And YES, its a STUPID rule for us truck guys!

[Marv D]

Right on Captian,, on the right hand page for cage in full bodied cars it says driver must be in front of the main hoop,, Your dead on in it's a MAXIMUM,,, and minimum would be 'anything' as long as it's not behind. I should have paid closer attention.
As already said, PLAN FOR THE FUTURE (the bar rule is simply the beginnings of a cage) Build it like it's the beginnings of a 8.50 car 'eventually' and save yourself a LOT of headache and $'s

[vin63]

Originally Posted by AJohn6

.. I purchased the 1 5/8 EWS 10 point cage from S&W and need to get good advice before I start cutting things up...

If it's not too late, I would sonic test the tubing before constructing the cage. I have noticed a lot of variation in wall thickness of electric welded seam tubing...so much so, that I only use DOM mild steel tubing, if the customer does not want to go with 4130. Nothing worse than constructing the cage and finding out after-the-fact that the wall thickness does not pass the sonic test.

Also, the only way around running downward bars from the main hoop back is to construct the cage as a roadster spec, which still does not make anything removable as far as the cab is concerned.

[AJohn6]

Originally Posted by vin63

If it's not too late, I would sonic test the tubing before constructing the cage. I have noticed a lot of variation in wall thickness of electric welded seam tubing...so much so, that I only use DOM mild steel tubing, if the customer does not want to go with 4130. Nothing worse than constructing the cage and finding out after-the-fact that the wall thickness does not pass the sonic test.

Also, the only way around running downward bars from the main hoop back is to construct the cage as a roadster spec, which still does not make anything removable as far as the cab is concerned.

Thanks for your advice but I am not going to get it x-rayed. I only have the roll cage for the safety aspect and not getting kicked out of the local track when I do run it. When I talked to S&W they said that problem was with the DOM and not the EWS which I hope is the case. When I called, my intention was to purchase the DOM kit but they brought this up and talked me into buying the less expensive alternative, in this case EWS.

-Adam

[vin63]

Who said anything about x-rays? You do realize that you have to have the cage (you have to build a cage with 1.625 diameter tubing) certified, which means the tech inspector, as part of his inspection, sonic tests the tubing for wall thickness, right?

[mongoose]

i know you're wanting to put it down the 1/4 mile.. but you are doing a pro touring build up..

are you planning on racing it anywhere else? like a road course or ORR? the only reason i ask is nhra is very lenient on their roll cage rules compared to any other sanctioning body ie no one else let you use erw.. only dom and way bigger tubing.. but yeah if you are i'd double check with them to see if they care there's a cage in it.. you might not need the cage for what you're racing but if it's there they might want it to be legal for you to race kind of thing.

[AJohn6]

Originally Posted by mongoose

i know you're wanting to put it down the 1/4 mile.. but you are doing a pro touring build up..

are you planning on racing it anywhere else? like a road course or ORR? the only reason i ask is nhra is very lenient on their roll cage rules compared to any other sanctioning body ie no one else let you use erw.. only dom and way bigger tubing.. but yeah if you are i'd double check with them to see if they care there's a cage in it.. you might not need the cage for what you're racing but if it's there they might want it to be legal for you to race kind of thing.

The truck is not a race truck.... I repeat not a race truck. Haha. I only want to be able to run a 10.00 or slower and not get kicked off the track. Any other "racing" could be at an auto cross event.

Originally Posted by vin63

Who said anything about x-rays? You do realize that you have to have the cage (you have to build a cage with 1.625 diameter tubing) certified, which means the tech inspector, as part of his inspection, sonic tests the tubing for wall thickness, right?

Ok, I miss spoke. What I meant was sonic test.

[vin63]

Originally Posted by AJohn6

... I only have the roll cage for the safety aspect and not getting kicked out of the local track when I do run it...

Originally Posted by AJohn6

...I only want to be able to run a 10.00 or slower and not get kicked off the track...

You're not going to get to run on an NHRA/IHRA track if you're cage is not certified...the sactioning bodies don't let just anybody throw together a roll cage without following specs. The way NHRA looks at it, and some of the road racing organizations I deal with on the safety equipment side of things, a poorly constructed roll cage is more dangerous than no roll cage. But, hey, good luck with that.

[AJohn6]

vin63,

I got it, thank you. I am putting the cage together the way it should be and the way the rules say to. I have already bought the cage and started to put it together so it really doesn't matter now about getting DOM unless you want to buy another cage for me. You can stop trying to prove that you are smarter than me at this, I know you are. I am just a beginner at installing a roll cage and I am learning. I did my due diligence in researching this and this is the end result I came up with. Why would you assume it would be a "poorly constructed roll cage"? I don't appreciate your pretentious attitude. I know how to weld and fabricate so I take that comment as an insult. I am certain my cage will pass inspection if and when the time comes. Again, thank you for your advice sir.

-Adam