Cooter Z28

Im gunna be doing a 6 or 8 point roll bar in my 86 IROC- Z28 and i was just wondering if any one had any suggestions. I plan on doing sfc as well and was wondering what would be the best way to run them if anybody has suggestions on those as well.
I still want to run my back seat and dont want to have to cut my door handles. Im not buying a kit from anyone im going to be building my own out of 1 5/8" .120 wall tubing. I dont want to have to cut to many interior panels if at all possible. If at all possible I want to hide the main hoop from the outside. Just need to know what the regulations are for how far the hoop has to be behind the seat. Also plan on building new LCA, pan hard bar, and torque arm mount, want to know if relocating the mounting point further back or just leave it up by the tail housing and any ideas on these would also be great.

customblackbird

iTrader: (15)

most cages wont affect the interior panels... my CEE 8pt did not affect anything, my door panels however i replaced with polished aluminum panels for like 80$ so im not sure about the door arm rests clearanceing. the look like they would clear tho since they stick away from the door enough to clear a speaker enclosure in the door panels i made. also just so you kno all 6-8pt roll bars have to be a minimum of 1.75" tubing, and a thickness of .120". 1 5/8" tubing is used on 10pt-12pt and full out cages. in order for the 6-8pt roll bar to be legal u need to use 1 3/4" tubing. welding the cage should be done with a 130amp at least mig or tig welder. DO NOT USE FLUX CORE welding wire.

everything else is easy. just move the main hoop farther back into the car so u dont see it from the outside. ppl do this all the time. u will notice that the 2 best spots for mounting are 1.) far enough out to be seen from the window, but will offer the most strength since the floor plate would be welded right to the floor where the rear subframe/LCA mounts are welded to the floor pan. you will effectively tie the rear subframes by mounting here. 2.) the mounting point right behind, on the "hump" of thin floor pan steel where the bracket for the rear seats is located. this will allow for a cleaner installation with the hoop set back far enough to not be seen from the outside. you will however not get the same strength as the 1st point in mounting that i described.

i would go with the 1st one unless u really care that much about how it sticks out. i think it looks better with it showing alil bit since our stock seating has us so far ahead before the door windows end... so it looks like where floating in the middle of our huge door windows lol. the roll bar will fill that up and make it look BAD @SS.

as far as instructions.. the rules have been posted on this site a few times by stephen... and the rules came with my CEE kit. there are a bunch that u need to adbide by but its not too bad. try to download the rules... maybe summit has the CEE kit instructions or something. i kno the bottom of the bar at the top of the hoop can not be lower than the top of your head with helmet on. the cross bar on the hoop for the seat belts can not be too low or too high (see illustration) for correct geometry of the seat belt harness to effectively hold you down in the seat in the event of an accident. the door bars have to cross between the shoulder and elbow of the driver when seated and hands are on the wheel. just a few.

as far as the suspension peices... i built my own tubular LCA and panhard bars... now just LCA;s they are simple when u have the stock peices off, the panhard bar is simple too unless u want it adjustable. i would look into the aftermarket, my panhard bar is now UMI with a spherical end. i would love to make some spherical end LCAs too. the panhard bar is tricky to make.... i got the shorty style jegster tubular one for cheap used (barely) but its 1/3 the length of the stocker,,, super light. strong and is a tunnel mount and gets the stress off the rear of the trans. UMI, SPhon, BMR etc all make tq arms that get the attachment off the rear of the trans and mount to a crossmemeber u weld in. the jegster fits the bill for me since it gives me alot more room for my dual exhaust.

also i dont get why u need the rear seats... unless its just for looks... when u put in a cage or roll bar DO NOT ALLOW PPL IN THE REAR SEATS! doesnt matter if they have helmets, body armor or 5 point racing harnesses... they will die if u hit anything basically. bones/heads shatter when u hit a roll bar with padding on it even at low speeds. if its just for looks u'll figure how to run it... but u prob wont use trans tunnel bars.

do searches of the roll bar installs. i posted everything and how i did it in the suspension or fabrication forum. and i just installed door bar swing out kits... so getting in and out is a breeze now... and its certified to 9.5s. good luck hope this all helped

AlkyIROC

As stated above, a roll bar needs to all be made from 1-3/4" tubing while a cage is allowed to use 1-5/8" plus smaller tubes.

Minimum thickness allowed is .118". There is always a plus or minus thickness with tubing. Anything from +.003 to -.007 and it's usually on the thinner side. If you spend the extra money for .120" DOM tubing then it will have less variation and be OK but mild steel .120" tubing will fail an inspection however until you need a full cage, you don't need an inspection. Minimum thickness tubing to buy is .134". This will be over the minimum allowed thickness even with the variabtion and won't be too thin around the bends.

Speaking of bends, how were you going to bend the tubing? Those inexpensive bow and arrow pipe benders will not bend tubing properly. They'll pinch the tube. They're designed to bend pipe, not tubing. To bend tubing, you need a proper tubing bender. The bender is cheap. The dies are expensive.

The S&W roll bar/cages are probably the best fitting and they can be custom ordered to clear door panels etc.

As for retaining the use of the rear seat. You need the crossbar behind the driver's seat. This makes access for passengers into the rear very difficult. Typically, if you need a roll bar in your car, you're not making it to carry a lot of passengers. You don't "need" a roll bar until you run quicker than 11.50. SFC however should be installed even in a 13 second car.

customblackbird

iTrader: (15)

oh sry... not sure why i said .120" wall thickness... mines .134" by comp enginneering. sry bout that.

also when doing a roll bar/cage... u will have to remove the gas tank which means taking out the rear end... welding the rear bars to the cargo floor is too close to the gas tank and can start a fire easily... safetly will tell u to remove it completely and make sure no gases are around... even the vapors from the tank can ignite from welding etc.

i agree SFC would be the first thing to do... i did it and made a ;huge diff in the car... i hope the cage makes it even better. also as stated that the bending is a big deal... i think EVILCARTMEN or evilcartman made his own roll bar 8pt... he did a good job

Cooter Z28

I was planning on keeping the back seats just because I just redid them. Im going to be doing all the work in my chassis fab class at WyoTech, so all the safety precautions will be taken care of. As for the bending its not mandral bent but we do have tubing benders there with all the dies, so no arrow tricks here. As for the Tubing size is that only if you run quicker then 11.50? I was wanting to stiffen the car to make the cornering and all that much better, not just straight line. The car is squirly as hell right now everything is so loose on it, bushings are shot and stuff like that. I have 4 straight weeks in the shop that I will be able to do everything. I just need to know what the best way to use my time and the budget I have to do everything with. Not sure what my budget is at the moment lmao.

The best set up for sfc ive seen so far is the UMI set up. I want to do something along those lines. Wondering if anybody has any sketches of an idea on this that would be great. Ive seen one on another post but was a little confused about the design. If anyone has any ideas I would appreciate them. The replys that you posted helped if everyone could keep them coming that would be great. Thanks

AlkyIROC

If you want a "street" roll bar, you can make it out of .090" tubing but it won't be legal to go below 11.50 in the 1/4 mile. If you want a "street" roll bar, you can make it out of 1-5/8" tubing or even 1-1/2" tubing but again, it's not legal below 11.50.

Why make it out of material that's below minimum specs? If you don't "need" the roll bar, it's just extra weight in the car. Eventually if you do need it, you would have to rip it out and install one that meets minimum specifications.

Cooter Z28

If I ever wanted to go below 11.50 at that point all i would really need to do is install a complete cage correct? And then go more motor to make the cage worth while haha. Thanks for the help again though.

AlkyIROC

A proper roll bar isn't required until 11.50 and is good down to 10.0 as long as the floor or firewall haven't been modified. 9.99 and quicker and you need the full cage. Slower than 11.50, you don't need a roll bar.

That's the same rules for NHRA and IHRA.

Cooter Z28

Ok thanks again

customblackbird

iTrader: (15)

when u mean the floor/firewall hasnt been modified.... does that mean anything cut into the floor... i ran thru floor SFC... would that count as modifying the floor? also did some HUGE rust repair on the floor and firewall... wojuld that count if it doesnt look stock?


i agree with stephen cooter. its pretty simple... wats the point in putting in a .090 cage/roll bar if your just gona have to rip it out (easier said than done) to install a real roll bar/cage down the line. i would just spend the 130-160$ from summit or gets and get a 6pt kit. then get the door bars from the other company posted above since they sell the door bars that clear the factory door panels/armrests etc. do it once and never have to worry about it. if u install a thin cage u wont get the same strength/all the benefits with a .090 vs the .134" stuff. again it would just be added weight. if u weld the roll bar base plates to the floor u gotta rip that all up again... not gona be worth it, i say just do it right, u can always add on to a 6-8pt to make it a 10pt or higher.

Cooter Z28

The only thing i was worried about was weight if i didnt need 1 3/4". I talked with my instructor today and he said that between 1 5/8" and 1 3/4" tubing i would maybe gain 10 pounds so Im just gunna go with the 1 3/4" and if i ever want to ill just add on the 1 5/8 tubing for a 10 or 12 point. So Im almost set, for the cage itself, just for the tubing is gunna be around $170 or so and then i have to price out the sfc. I was also wondering about the firewall and floor if I go straight to my sfc through the floor is that considered being modified? Also wondering if anyone has any pics of home made sub frame connectors as in if they had to cut through the floor to run them. I also plan on making a new panhard bar and LCA. I was gunna use 1" .156 wall so that way they are direct tap and I dont have to do weld in bungs. If any one has any suggestions on those that would be great to. Thanks again guys.

customblackbird

iTrader: (15)

mine are homemade... basiaclly just 2"x2"x .095" square steel tubing.. running from the front to subframe where the rocker supports meet the front subframe where the trans connects just farthest up towards the engine. i then cut into the floor and ran it right into the rear subframes, cut the subframes and layed the 2x2 tubing up into it and then welded it completely and into the floor that was knotched for it. its solid and are stronger than the aftermarket types since they dont incorporate the floor boards for there support.

do a search there have been many designs.

the cage should just be welded to the 6x6 plates that u get in the kits and then welded to the car floor boards etc. this should be fine since the entire floor pan of the car is essentially the "non frame of the car" lol. you could however connect the cage to the subframes you create but i dont think its completely neccessary. unless u had a full framed car then i would connect the hoop etc to the frame.

Cooter Z28

Do you have any pics of the sfc you made?

customblackbird

iTrader: (15)

umm i posted some. i started my pics on post 12.

https://www.thirdgen.org/forums/fabr...-eng-sfcs.html

stock subframes where notched for true dual 3" exhaust with 3" xpipe and 3" force muffler turndowns. the 2x2 steel is next to it, runs front to back. this really stiffened up my car and i just reinforced it (new welding in the pics, as well as the .134" roll bar tubing for extra stupport now that i fixed all the rust)

dont flam it for its looks, it tucks up higher than my deep trans pan, and its plenty strong, esp wit the 8pt roll bar i just stuck in.

first pic is the 2x2 running into the interior and shows how it was welded and cut into the floor boards, this ties the SFC and the floor board making the ALOT stronger. ppl try to stitch weld the aftermarkets like UMI and BMR/SPOHN to the floor boards for more strength but incorporating them into the floor is the max strength. also this is before i painted and cleaned up the bottom of the car. and the cage is tied into the SFC directly at the rear(hoop) and the front bars. the inner tunnel bars are bolted directly to the JEGSTER tunnel mount TQ arm tunnel brace, so its extremely rigid