true520 Posted November 18, 2011 Share Posted November 18, 2011 Hey guys, My 18 year old son has a 2001 330 Ci... and with all this talk of me taking my e36 M3 to the tracks, he is regretting not buying a hard top. (because we know a convertible is required to have a roll cage) BUT, I just left a body shop that has experience building roll cages. Thus far he has specialized in Drag cars tho. Anyone have any ideas, or even better...PICs of a roll bar installed in a BMW 330 convertible. Since this car will be his DD, he would really like something that we can remove with little effort after the event weekends. Thanks a bunch Quote Link to comment Share on other sites More sharing options...
TurboShortBus Posted November 18, 2011 Share Posted November 18, 2011 When it comes to building road race cages, be careful with shops that mostly have drag race experience, as they don't always know what they are doing. Then again, there are road race shops out there who don't know what they are doing, either. A shop that can only bend 1 5/8" diameter tubing is a dead giveaway that they are drag-only. Look at previous examples of their work. Do you want a roll bar or a roll cage? There is a big difference. A 2-point bar is just a main hoop. 4-point bars have the main hoop and 2 rear kickers, and 6-point bars add the angled side bars next to the driver/passenger. A full cage has the overhead bars and the bars that go down the A-pillar. Mark Quote Link to comment Share on other sites More sharing options...
true520 Posted November 18, 2011 Author Share Posted November 18, 2011 This shop guy started talking above my head in the cage dept right away...he was asking what tube thickness that was needed, and how many points... the only cage he had in his shop was a chrome-olly...? LOL Anyways, you just explained the "points" for me. Thanks. I would assume we need at-least a 4 point... seems like it would be safer than just a loop. BUT, where would we place the back two kickers...? I quess we could just remove his back seats..?? I am not sure what cage we will need. Of course, this mainly for my son's safety and TT tech inspection. Quote Link to comment Share on other sites More sharing options...
jason Posted November 18, 2011 Share Posted November 18, 2011 Dual purpose cars can turn into a real nightmare. Dual purpose convertibles ARE a nightmare. It is very hard to get a roll bar that: 1. Actually provides rollover protection. 2. Is far enough away from the driver that it won't crack their head open in a wreck on the street. 3. Allows the top to work. Which of those are you willing to compromise on? Quote Link to comment Share on other sites More sharing options...
TurboShortBus Posted November 18, 2011 Share Posted November 18, 2011 There is no need for chrome moly tubing for your setup. Without getting into the physics of it (Google that info if you must, as there is no reason to repeat it here), just use mild steel. I have a 6-point roll bar in my 1994 Mustang convertible that I built in 1995. I'm a bit wiser now, and I know where the shortcuts were taken. Also, if the car goes over, the windshield could still pancake and punch me in the face, so the bar isn't 100% effective. I used to drag race the hell out of it, but it's not going on a road course like this. It's just a nice-weather tire-squealer (like this afternoon). Padding is an absolute must on any sort of a bar, especially if you aren't wearing a helmet (on the street). Even then, you wouldn't want to get your unprotected bell rung by a padded steel bar. Check out this roll bar thread over at Corner-Carvers.com. You might need to be a member to see some of the photos. Carefully read everything before posting anything there. http://www.corner-carvers.com/forums/showthread.php?t=20586 Mark Quote Link to comment Share on other sites More sharing options...
true520 Posted November 18, 2011 Author Share Posted November 18, 2011 Which of those are you willing to compromise on? Well, I must say, we had decided to just leave his car alone and try to use the M3 for double duty... (ie, he does HPD1 and I do HPDE2) ... and if we do good, enter a fe TTC classes of course. BUT, while I was talking to the body shop guy, he suggested we put in a bar that can easily be removed... especially since it is a convertible top. I am now thinking we could just take the back seats out, bolt the bar in...then of course, take the bar back out on Sunday evenings so it wont be in his way during the work week. Is a removable bar (bolted in) leagal in TT classes, or does it need to be a welded in bar? Quote Link to comment Share on other sites More sharing options...
jason Posted November 18, 2011 Share Posted November 18, 2011 The less attached you are to the interior bits, the easier it will be. The more you take it in and out, you'll grow less attached to all those interior bits. Quote Link to comment Share on other sites More sharing options...
TurboShortBus Posted November 18, 2011 Share Posted November 18, 2011 TT falls under HPDE rules, so refer to them for roll bar guidelines. Bolt-in roll bar FAIL: I'm not sure how both people managed to crawl out of that one. I would not be satisfied with any bolt-in setup for track use, especially ones with small mounting plates. They will easily punch through 22 gauge sheetmetal floorpans, as shown above. Mark Quote Link to comment Share on other sites More sharing options...
true520 Posted November 18, 2011 Author Share Posted November 18, 2011 I'm not sure how both people managed to crawl out of that one. I would not be satisfied with any bolt-in setup for track use, especially ones with small mounting plates. They will easily punch through 22 gauge sheetmetal floorpans, as shown above. Wow... glad both people crawled out of there...!! And, I just assumed it would "bolt" to the frame..? Mine will. LOL Quote Link to comment Share on other sites More sharing options...
jason Posted November 19, 2011 Share Posted November 19, 2011 Depending on your fab skills, you could make your bolt on attachments at the same places a weld-in cage attaches. Of course, those attachment points would have to be welded on the car first. So you'll have to gut the car to do all that welding, then trim the interior bits to fit around the mounting points. By that point you might as well weld the cage in. I know this because I tried it for years. Gave up and bought a car with a roof. Quote Link to comment Share on other sites More sharing options...
TurboShortBus Posted November 19, 2011 Share Posted November 19, 2011 And, I just assumed it would "bolt" to the frame..? Mine will. LOL There isn't much of a "frame" in a unibody car. A few structural shapes here and there, but no traditional frame. Mark Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted November 19, 2011 Share Posted November 19, 2011 I'm a big fan of dedicated (or at least semi-dedicated) track cars. Pick up something inexpensive with a roof and go to town on it in HPDE. Bonus - if you manage to tear it up real bad or wreck it, you're out a very small amount of money. Street insurance doesn't cover track incidents these days. More fun to drive a slow car in a fast manner on the track than to drive a fast car on the street slowly so you don't get ticketed all the time. Quote Link to comment Share on other sites More sharing options...
true520 Posted November 19, 2011 Author Share Posted November 19, 2011 Yeah, after talking it over a little more, (and reading the NASA forum replys too) ...Myself, the son and wife, think we will just wait and see how much he gets into it with my e36. He may not even catch the track bugt like I had... Then, if he "just has" to take a car of his own out on the track, We will sell off the convertible in the spring and get a coupe. Of course, he is all about an e46 M3 right now, but I am thinking more along the lines of another 330. LOL Thanks again for all the input. Quote Link to comment Share on other sites More sharing options...
TurboShortBus Posted November 19, 2011 Share Posted November 19, 2011 Then, if he "just has" to take a car of his own out on the track, We will sell off the convertible in the spring and get a coupe. Or, just keep the 'vert as the grocery getter and get an el cheapo E30 for track use. Mark Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted November 19, 2011 Share Posted November 19, 2011 E30s are fun Quote Link to comment Share on other sites More sharing options...
ScottBell Posted November 21, 2011 Share Posted November 21, 2011 Hey guys, My 18 year old son has a 2001 330 Ci... and with all this talk of me taking my e36 M3 to the tracks, he is regretting not buying a hard top. (because we know a convertible is required to have a roll cage) BUT, I just left a body shop that has experience building roll cages. Thus far he has specialized in Drag cars tho. Anyone have any ideas, or even better...PICs of a roll bar installed in a BMW 330 convertible. Since this car will be his DD, he would really like something that we can remove with little effort after the event weekends. Thanks a bunch Problem solved Here is the list of approved convertibles that do not need additional roll-over protection: Porsche 996 Porsche 997 Porsche Boxster BMW Z3 (Optional) BMW Z4 BMW E36 (Optional) BMW E46 BMW E90 BMW 6 Series BMW 1 Series Chrysler Crossfire Dodge Viper Ferrari 355 Ferrari 360 MINI Cooper (2009+) Mercedes SL (1990+) Mercedes CLK Mercedes E Class Mercedes C Class VW New Beetle Saab 9-3 (2004+) Honda S2000 Infiniti G37 Volvo C70 Audi A4 Lamborghini Murcielago Aston Martin DB9, DBS Jaguar XK8/XKR VW Eos Quote Link to comment Share on other sites More sharing options...
TurboShortBus Posted November 21, 2011 Share Posted November 21, 2011 From what I have seen of many convertibles with approved OEM roll-over protection, an average-height driver still has their helmet above the top of the roll-over structure, which isn't the best setup. The Honda S2000 immediately comes to mind. Mark Quote Link to comment Share on other sites More sharing options...
Cobra4B Posted November 21, 2011 Share Posted November 21, 2011 Just buy a spec e30 or a cheap e36 and build it. Quote Link to comment Share on other sites More sharing options...
jimbow Posted November 21, 2011 Share Posted November 21, 2011 I'm a big fan of dedicated (or at least semi-dedicated) track cars. Pick up something inexpensive with a roof and go to town on it in HPDE. Bonus - if you manage to tear it up real bad or wreck it, you're out a very small amount of money. Street insurance doesn't cover track incidents these days. More fun to drive a slow car in a fast manner on the track than to drive a fast car on the street slowly so you don't get ticketed all the time. I could not agree more. I instructed a student in a Volkswagon Rabbit, AUTOMATIC this past weekend. We pull up on grid ahead of cars with a ton more horsepower and he says "Man I'm going to get passed a lot this session". I tell him not necessarily. He kept his foot in it in the turns, executed them well and as long as he didn't lose momentum he was pasing faster cars comming out of 7, 12 and 5 at Road Atlanta. He had the biggest grin on his face when we were done. He got passed by a few higher HP cars, but he held his own. In a frontwheel drive Rabbit! With an automatic! On narrow street tires! Quote Link to comment Share on other sites More sharing options...
Varkwso Posted November 23, 2011 Share Posted November 23, 2011 Or a C5. Buddy just picked up a 99 Coupe for $7000. Cannot beat the bang for the buck. TTB, PTA and TTA champs cannot be wrong... It is a fast momentum car... Quote Link to comment Share on other sites More sharing options...
jimbow Posted November 23, 2011 Share Posted November 23, 2011 Or a C5. Buddy just picked up a 99 Coupe for $7000. Cannot beat the bang for the buck. TTB, PTA and TTA champs cannot be wrong... It is a fast momentum car... Why can't I find these deals??? Quote Link to comment Share on other sites More sharing options...
Cobra4B Posted November 23, 2011 Share Posted November 23, 2011 Or a C5. Buddy just picked up a 99 Coupe for $7000. Cannot beat the bang for the buck. TTB, PTA and TTA champs cannot be wrong... It is a fast momentum car... Why can't I find these deals??? You snooze you loose That is a screamin' deal though. Quote Link to comment Share on other sites More sharing options...
Varkwso Posted November 23, 2011 Share Posted November 23, 2011 Or a C5. Buddy just picked up a 99 Coupe for $7000. Cannot beat the bang for the buck. TTB, PTA and TTA champs cannot be wrong... It is a fast momentum car... Why can't I find these deals??? It was even in Atlanta... Quote Link to comment Share on other sites More sharing options...
true520 Posted November 24, 2011 Author Share Posted November 24, 2011 Problem solved Here is the list of approved convertibles that do not need additional roll-over protection: Porsche 996 Porsche 997 Porsche Boxster BMW Z3 (Optional) BMW Z4 BMW E36 (Optional) BMW E46 No Kidding.... Well, I may just let him do his driving school and maybe a round of HPDE 1 before we start shopping for something else then. He is 18...so thus far all he has come up with as a "good replacement" is 20,000 cars.... KIDS! LoL Thanks for the heads up... And, my little BMW has came up with a few more problems to get fixed, so it will definitely be next season before we get out to the tracks. We are planning on attending the Road A event in Dec...but just as spectators. Quote Link to comment Share on other sites More sharing options...
kbrew8991 Posted November 25, 2011 Share Posted November 25, 2011 good way to get your feet wet and see what's going on without the pressure of trying to run yourselves - good idea Quote Link to comment Share on other sites More sharing options...
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