Question about roll bars

[arob]

What is the difference / benefit (if any) from having the diagonal connecting the forward 2 vertical bars v. rearward 2 vertical bars?

For example:

This
http://i5.photobucket.com/albums/y189/rtalastas/Roll%20Bars/DasSportWeekender2.jpg

Versus this
http://i5.photobucket.com/albums/y189/rtalastas/Roll%20Bars/DasSportNut1.jpg

[smdubovsky]

*IF* the attachment point strength/stiffness for the front & rear feet are the same then there is little difference other than convenience - the rear diagonal allows you to carry stuff in the back seat easier. Either one could keep the upper part from displacing left/right in an accident. Though, its not so easy an exercise to figure out which part of a 911 is stronger! I'd vote for the front arch since almost all of those attach to the frame box section on the sills. The rear feet often attach to weaker locations unless they go though the firewall to the frame sections (but then its a full on racecar w/ a cage;) )

[jsilverm]

If you are going to race you are required to have a diagonal connecting from the top of the drivers side to the bottom of the passenger side of the forward bars. If the car rolls this will provide more structure to provide a stiffer structure. The rear braces do not need a diagonal but it will make them stronger. Youll see a lot of roll cages with an X between the 2 braces for even more stiffness. Personally I would much prefer to have the diagonal in the main hoop (the forward bars) than the rear braces. That is how my current bar is set up but when i have it converted to a full cage I plan on having an X bar put in the rear braces to stiffen those up as well.

[arob]

*IF* the attachment point strength/stiffness for the front & rear feet are the same then there is little difference other than convenience - the rear diagonal allows you to carry stuff in the back seat easier. Either one could keep the upper part from displacing left/right in an accident. Though, its not so easy an exercise to figure out which part of a 911 is stronger! I'd vote for the front arch since almost all of those attach to the frame box section on the sills. The rear feet often attach to weaker locations unless they go though the firewall to the frame sections (but then its a full on racecar w/ a cage;) )

Ugh, I'm nowhere close to being "there", i.e. racer status. I'm trying to go the cheapest / safest / most correct route. Does that even exist? :?

[Trak Ratt]

Not really. The older bars mounted to the floors and that's not considered good anymore. My new cage mounts to the longitudinals behind the front door A pillar and behind the B pillar. Though technically a bolt-in it still required cutting holes in longitudials to weld "feet" into place. Cage bolts to feet. I ran with the old style bar for years. An other point is that a rollbar will likely limit rearward seat movement. So if tall seating position w/helmet will suck.

[smdubovsky]

I'm trying to go the cheapest / safest / most correct route. Does that even exist? :?

No;) As long as you don't buy an autopower (which bolts to the thin floor - ugh!) you probably can't go wrong.

[arob]

Not really. The older bars mounted to the floors and that's not considered good anymore. My new cage mounts to the longitudinals behind the front door A pillar and behind the B pillar. Though technically a bolt-in it still required cutting holes in longitudials to weld "feet" into place. Cage bolts to feet. I ran with the old style bar for years. An other point is that a rollbar will likely limit rearward seat movement. So if tall seating position w/helmet will suck.

Thanks, DR.

I'll most likely go with the "bolt-to-welded-feet" route. Do you have any shop recommendations for welding the plates?

I think I'm pretty safe with seat position / height, for I'm only 5'10" and the seat was lowered (rails cut out) by the original owner. He must have been a tall person. IIRC, I've currently got about 1.5-2.5" clearance with helmet on.

[arob]

No;) As long as you don't buy an autopower (which bolts to the thin floor - ugh!) you probably can't go wrong.

As Piper is out of my budget, I'm going with DAS.

[jsilverm]

As Piper is out of my budget, I'm going with DAS.NOt sur eon the 911 fitments, but OG Racing sells a nice roll bar for the 924/944. It was actually cheaper for me to have piper make one though after install was factored in.

[type954]

[QUOTE=arob;192164]Thanks, DR.

I'll most likely go with the "bolt-to-welded-feet" route. Do you have any shop recommendations for welding the plates?
QUOTE]

your SC is too nice to turn into a track car. you need another car for fun......

[BlackTalon]

your SC is too nice to turn into a track car. you need another car for fun......Yeah -- I hear 944s are great track cars -- and they are great to learn on! :lol:

It's a 25+ year old car -- let it have it's fun now. Lord knows it deserves it! :lol:

[arob]

Yeah -- I hear 944s are great track cars -- and they are great to learn on! :lol:

It's a 25+ year old car -- let it have it's fun now. Lord knows it deserves it! :lol:

Wait - So skip the whole roll bar idea altogether? Or, should I just get a "bolt-in" type for now, where the integrity of the interior isn't compromised? Or, don't touch this one and get a 944 to take to the track? My whole idea is to have a safer car while I do DE's with THIS car. There is no way my wife would let me get another car... :?

[Jazzbass]

Wait - So skip the whole roll bar idea altogether?
No
Or, should I just get a "bolt-in" type for now, where the integrity of the interior isn't compromised?
Yes. See, you're still in the denial phase. In this phase the bolt in type is best because it gives you that fuzzy feeling of "this isn't permanent" and "I can go back to street driving anytime I want". In 3 years when we're helping you weld in a cage, bolt in a fiberglass sunroof and cutting your strut towers for more camber, we'll have a good laugh about your "bolt in" rollbar.

Or, don't touch this one and get a 944 to take to the track?
Oh, good god no.

[BlackTalon]

Rob -- I have the DASsport roll bar in my Targa. The fit isn't that great (not tight enough to the roof line), but their coupe bars are better. It's a good 'comprise' way to go, as Jazz stated in his post.

[arob]

Okay. Bolt-in it will be.

[Trak Ratt]

Well OK then....
Just happen to have a nifty floor mount, bolt in roll bar for sale :p Don't listen to me or Stephen the floor mounts are the way to go ;)

[arob]

Thanks David - I'll take you up on it. Does this weekend work for you?

[Trak Ratt]

Thanks David - I'll take you up on it. Does this weekend work for you?
Sunday's looking good. We can likely reuse most of my hardware too. A liitle work with a wire bruse and i know those threads will clean right up. BTW one of the bottom floor plates fell off but a couple of large washers should do the trick :D We can talk about how you can use those stock seats with harnesses too ;)

[Dr K]

Rob,
Check out Safety Devices, too. They have great fit. They, too, are weld in plates, bolt to the plates. I plan to leave the roll bar in place, and bolt the front (cage) portions in and out for summer/winter driving (i.e. track season/not track season).

Peter

[racer]

My gosh.. you are going to cut up another SC? Those cars are so old, they are about to become the "new" longhood. Values will skyrocket and Europeans will snap them up. No one ever thought mid years would go up in value.. but they are.. Ahh screw it.. its just and SC.

Safety devices makes a nice cage. DAS is nice too. No reason to be too "cheap" when it comes to additional weight and potential safety. Do you know how much a Piper piece would be?

I look forward to meeting someone who actually, and regularly, removes the front half of there "removeable" cage. Seems once in, they rarely come out. ;)

[Trak Ratt]

I look forward to meeting someone who actually, and regularly, removes the front half of there "removeable" cage. Seems once in, they rarely come out. ;)i've taken mine out 4-5 times in the last 3 weeks... lol

[Dr K]

I look forward to meeting someone who actually, and regularly, removes the front half of there "removeable" cage. Seems once in, they rarely come out. ;)I don't know how "regular" out in fall, in in spring is in your definition, but that's what I plan to do. Let's see how hard it is and how long it takes.

Peter

[arob]

I'm done. That was easy. Didn't even need bolts.
http://i5.photobucket.com/albums/y189/rtalastas/Das%20Roll%20Bar/DasRollBar009.jpg

Kidding. Now, looking for a shop to weld the plates in? Any suggestions?

Also, suggestions on finish for the bar? I'm thinking a can of Rust-Oleum, then another rattle can of black? I found the thread regarding ASCo., but just trying to build my options.

[Trak Ratt]

I'm think'n about a "hammered" finish on my cage. I'm taking it back out tomorrow so I'll need to decide. Powder coating is nice and durable but wait till you get the feet welded and have fitted the harnesses and camera mount. Just to make sure everything fits ;)

[jsilverm]

I'm thinking a can of Rust-Oleum, then another rattle can of black? You could just use rustoleum rattle cans and be done with it. Youll need to touch up the paint every once in a while though as its not very durable.

[Vicegrip]

I have Rusto-hammer finished a few bars. Looks OK, dries very fast and can be touched up if you want. I plan on Rusto-hammer finish on the entire inside of the track car I am building. Cheap and easy to do in sections and redo if I change my mind on something.

I am not fond of of the nut plates that come with some of the bars. They require you to drill large holes in the longs for the nuts to fit in. This has to be done before final dial down fit can be made too.
I take steel plate, drill and tap holes and then weld the plate in place. Then I carefully drill the longs through the plate holes and run the tap through. Now the plate and longs are threaded for the bolts. Much faster fit up and weld in too. Bar with plates on the feet goes in once for fit and tack then back in after the feet are welded in and you are done.
All you need to do is bolt the threaded plated to the bar feet and set in place then tack the plates down. Remove the bar for MIG gun or Tig torch access and finish up the welds. Nut plates don't let you do this as they stick up or you have to pre drill big hard to get lined up holes the the longs so you can have wiggle room. Why remove metal from right under the base of the main hoop where you need it?