Has anyone here tried doing custom bracing on car's critical components or weak "flex" areas, I know a roll cage can usually tie all these areas at once but my car is on a diet and im just looking for the most critical parts that needed to be supported.

I have plans on doing a x brace on top of the car, only reason for this is because im going to get the glass roof removed and replaced with aluminum like ptuning TA car and need some kind of support up there.


Anyone have some input?

 

With the function of a roll cage, you'd not sacrifice anything by the extra 80-100 pounds of the cage. Plus you'd get a lot better tie in with the cage then random "bracing" to the car. Also, this extra weight can be easily countered by carbon fiber or even fiberglass body parts.

What are your plans with this car? I've seen you post a lot of random items and cannot piece together your plan. And I want to make sure before I assume its some half-done street racer car.

 

The plans for my car pretty straight forward, Its going to be run in TA sessions by 2011/2012 season in southeast,My goals for the car are a little more different than rather brute power, I am going to do a NA build on e85, I wont be getting no more then 230/240whp in the end so every bit of weight counts to me, I have the car completely gutted, talking to shops about getting a aluminum cover for the glass fixed roof, removed simply everything in the car as far as creature comforts,sound deadning, any extra brackets or what not. I am not sponsored or having a big money bucket for the car so just trying to make this project work.

So far just with engine build alone its going to be around 6000+ (bc stroker kit, bc cams os valves and machine and head work), and with everything I take out I think the 160lb cage will just be overkill for my setup.

Will be running in modified class, even though I know its suicide for my numbers
240whp / end curb weight guess? maybe 2500 if i get lucky.

 

A cage won't weigh 160 pounds man.

http://www.rhinoforums.net/roll-cage...7lbs-foot.html Not tailored to the tC exactly, but it gives you an idea. Just skimming throug it looked like to do an entire rhino was roughly 76 pounds. It all depends on how much footage you need and what metal you use.

I'm not saying these braces you speak of are not usefull however. I'm just saying buck for buck, pound for pound, a roll cage will give you more strength and rigidity vs. random bracing in the car. Plus the added safety.

http://www.valvoline.com/car-care/au.../pht20040301rb Another interesting article. Roll cage vs. Roll bar. (another option)

https://www.scionlife.com/forums/scion-tc-1g-suspension-handling-1615/tc-roll-bars-roll-cages-now-available-36405/

 

I looked at the stuff autopower had, I deff wouldn't be going with a bolt in cage, that to me defeats the purpose of the cage as it doesn't keep you safe, or actually strengthen the chassis.

But you do have a point and I think I am going to look into at least a 4 point cage.
I have to go over some rulebooks and check out min diameter tubing and material I can use. Hopefully can get by with only adding around 80 to 90lbs.

 

You might also look at the kaminari roof pieces as well in

FRP:

http://kaminari.com/scion-tc-roof-frp

and Carbon fiber:

http://kaminari.com/scion-tc-roof-carbon

Might end up looking cleaner and being cheaper than an aluminium piece made by a shop.

 

From the site I really cant tell if there is any difference between the FRP and CF piece in weight, or is it just for the aesthetically pleasing look?
Would there be any actual difference in these compared to aluminum sheet? I know no one on here really actually knows but a guesstimate in weight differences would be appreciated.

Just trying to make sure that Ptuning didn't do this because it took off more weight than kamanari's pieces.

Too bad no one makes a dry carbon piece

 

Depending on the thickness of the aluminum - and the shop you work with - going with aluminum is lighter and cheaper than going with FRP/CF. If you're using it just to make a roof and have the required bracing in the car (likely a full cage at this point) you'll be fine running a really really thin sheet of aluminum. Beyond that, it's cheap and easy to find. You can go anywhere in the world with a template for the shape of the roof and have a metal shop cut you a sheet of aluminum. If you need to replace that FRP/CF roof you've gotta special order one and wait for it to be made and shipped. I have nothing against FRP/CF, aluminum is just a better choice for this job in my opinion.

Considering that you're looking to run this car in time attack series I'd recommend looking up the saftey requirements for the class that you'd like to be running in. If you're in modified, find the rules and treat those regulations like the word of god. Bring the rule book to a shop and have them fab up your cage/bar to those exact specifications.

The weight gained from a properly built cage/bar is more than worth it for the safety that it provides you on the track.

The difference between going with a cage over a bar really depends on your budget and overall goals with the car. If this is going to be a dedicated race car that sees little-to-none street time (i.e. driving itself to/from the track only) then a cage is likely more what you're looking for and will help stiffen the car more. If you plan on retaining this as a street car for a while a 4 (or 5) point roll cage is probably better. Still not entirely safe for street driving, but marginally safer if it's going to retain license plates.

Keep in mind that you're putting giant metal pipes into the cabin and if you're on the street without a helmet and get into an accident your soft noggin' is going to slam into those unyielding metal pipes. Some people recommend putting those foam pads on the pipes for a street car and this makes me laugh. If you think those little foam things are going to stop you from receiving a serious injury go get an aluminum baseball bat then wrap some foam around it...now have your best friend wind up and crack you over the head as hard as possible with the bat. Think the foam is going to help? The baseball bat won't even be exerting enough force to simulate a real accident, but it'll still give you a mighty concussion at the very least.

 

Oh, and don't go with bolt-in no matter what you do. Welded and reinforced mounting points or nothing. The only thing you gain with bolt-in cages/bars is weight.

Example of why a bolt-in cage is worthless.

http://jalopnik.com/5390934/mustang-cover-boy-tries-to-corner-flips-over-tire-wall

 

If you do go c/f, it will be stronger than frp.

 

u can also do plexiglass one sheet on top thats wat i did and it light and very cheap i got it for $60 from home depot and 10 for window sealant

 

and i have a straight track car so i used plexiglass in place of all the glass

 

you can also try a sheet of abs. easy to get in sizes up to 96x48, and its a thermoplastic (high temp moldable, but generally non flammable), same stuff im making my splitter and flat underbody trays from, so far im loving it, and best part is you can get a sheet for ~90.

TYLER

 

Thank you for the advice, I have the newest rule book out to date for redline time attack printed out but I do not know if these specifications will work for any other events, like scca events or any other private track events.

As for the rollcage and street driving, I want to get the top support bar,(one horizontal to our head) as high up as possible, this is going to be a dedicated track car BUT im not saying I wont take it out every now and then, So I want to keep the actual design simple but functional. I also do not want to have my harness wrapped around the bar but rather on eye bolts directly on to the car, I have heard that this illegal. Can anyone clear that up for me?

I will be using aluminum sheet ( painted ) tacked onto the the original frame holding the original panorama glass roof, mine is a little different because it is the spec model tc. I am using a company that does cages for 4x4 trucks here locally to do my cage, they will be incorporating the xbraces on top but im not sure if it will auctually be supporting the roof. Right now car is getting a estimate on a 5 point, what prices are fair when it comes to these cages?

That mustang didn't even look like it had a cage at all, This is why, to me anyways, autopower bolt in cages are dead weight.

 

The last time I read through the Redline TA book it reminded me a lot of the SCCA and NASA books for time trial contests and I'm sure they're pretty similar. I'd recommend giving the SCCA and NASA rule books a skim, but most likely you'll be close. If you're really worried about being able to compete in the other leagues I'd "overbuild" it and build it for the higher level stuff without going outside the RTA book's rules for your class.

Don't want to sound like a broken record, but saftey is important. In an accident your body acts like a big flexible bag o' meat and it can deform and stretch a LONG way in directions and angles you didn't think would be possible. Even if you mount the bar up and out of the way, you're still at risk of getting into a headbutting contest with it. Just an FYI, I'll let you make your own decisions about the saftey of running it on the street.

Wrapping belts around bars is not a bad thing. There's some strange stigma that popped up about this on the internet somewhere, but this is quite often the recommended setup from harness manufacturers. You can use the eye bolts into the car, but you'll have to make sure that the bolts are in a position on the floor that are reinforced enough to take the strain of suspending you in a crash. Most spots on the floor of the car aren't suitable for this job and that's why you've heard about it being illegal before.

Wrapping the belts around a properly built rollbar/cage's harness bar will help you have the right angle for the belts (good for not compressing your spine in a crash..mentioned earlier in this thread) and it'll give you a nice simple way to mount your belts that is accepted in almost every league I've ever seen.


I don't know much about the difference between the Spec and non-Spec roof apparatus, but I'd be a little nervous making a structurally weak spot in the roof without a full ceiling structure built into the cage (which would definitely make it more expensive and less safe on the street). Aluminum will make a great cover for the roof, but won't do anything for you when it rolls over. The cage will be the only thing stopping your head from impacting the pavement when upside down if you've got that aluminum roof.

Decent 5pt cages can range from like $2,000 to $5,000+ depending on the type of steel, size of tubing, and skill/fame of the cage builder. Don't skimp on the cost of your cage though; your life might depend on it someday and you don't want to be halfway through a roll and think to yourself "Thank god I saved $500 bucks..."

I couldn't believe the damage. You can actually see the bottom of the cage puncture through the floor of the car when it's upside down and that's almost as terrifying as the crushed roof. If one of the support bars had broken off the main hoop it would've turned into a nice big hollow spear ready to skewer you into a human shishkabob. Weld in 100%.

 

Agreed, weld in cage, and on high stress, high angle joints, make sure they add a triangle or buttress plate. helps the joint against shear which is usually what does the simple roll cages in, the cage afterall is only as strong as its weakest link, and the 10lbs extra worth of plate does wonders. Been in a track car that ate some tires and decided it wanted to try driving upside down, then on its side. Gotta tell you had the joints not been buttressed me and the driver would definitely not have walked away from it.

TYLER