RebekahsZ Posted March 23, 2014 Share Posted March 23, 2014 (edited) After numerous threads asking innumerable questions over the past several years, I finally have what I think is a legit roll bar in my 240z. This roll bar is intended to let me drag race up to 10.00 (or 135mph) in the 1/4-mile or 6.39 in the 1/8-mile at NHRA sanctioned bracket races (to include a future Drag Week), and to participate in ECTA standing mile land speed racing to 175mph. Additionally, I hoped to gain some chassis stiffening and to add support to the pinion of my RT mount - equipped R200 differential (which has torn out the floor of my car previously). I also wanted as much room on the diver side for seat adjustment and seat reclining, since I will have numerous co-drivers at autocross. It was also important to me to be able to be able to get in and out of the car, to have room for my clutch foot and perhaps a future dead pedal, and to be able to reach window cranks and door handles. I haven't used arm rests in years on this car (they were warped and rotten), so it was no problem for me to let them slide. The roll bar builder is a drag race chassis builder in Lexington, Alabama named Dave Key. This was his first Datsun to put a roll bar in; he is used to Mustangs and Camaros, etc. He offered chrome moly, but I decided to stick with DOM mild steel so that I wouldn't have to hunt up a tig welder every time I want to the bar modified for camera mounts, cup holders, etc. I paid him $1100 and it was in his shop 3 weeks, one week of which his bender was broken awaiting parts. I think he actually spent about 3, maybe 4 days on it. I plan to lower the seats 1 inch from their current position as soon as the car is back from getting some chassis mods, and I will likely lower the seats some more during my period of ownership (that is why the harness bar is a little too low for the current seat position. I will be using an AutoPower adjustable seat back brace to attach the seat back to the harness bar. The only thing I would like to have changed is the pinion support bars (I wish they weren't bent), but it was required on the driver side to clear the seat in the max rear position, and Dave figured that they should match on both sides. After the car gets a chance to go thru tech a few times, I would like to gusset the main hoop to the b-pillar at it's widest point under the quarter windows. The only negative to report so far is that my driver side door no longer lines up correctly-it is about 3/4" down at the striker. I am looking into new driver side door hinges if anybody has a source (haven't started looking). I have had problems with door closure for years, but it was never this bad. BTW-the door bar makes a PERFECT arm rest, and I think it will really help me to keep the car straighter while my body flails around jamming thru the gearbox. I just have to be careful not to bruise my elbow when autocrossing. To everyone who has given me advice-thank you so much. I did not tie the rear strut towers together in order to conserve storage space for carrying tires and tools to and from the track. I will post up a bunch of photos (split over two posts)-let the floggings begin! Edited March 23, 2014 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 23, 2014 Author Share Posted March 23, 2014 More photos. Quote Link to comment Share on other sites More sharing options...
raven12 Posted March 23, 2014 Share Posted March 23, 2014 Looks great! And for a VERY decent price. Quote Link to comment Share on other sites More sharing options...
We Bad Posted March 23, 2014 Share Posted March 23, 2014 Very nice! Quote Link to comment Share on other sites More sharing options...
johnc Posted March 23, 2014 Share Posted March 23, 2014 Looks good. Quote Link to comment Share on other sites More sharing options...
OldAndyAndTheSea Posted March 23, 2014 Share Posted March 23, 2014 Awesome! Looks so good, especially at that price point. Quote Link to comment Share on other sites More sharing options...
ritrebor Posted March 23, 2014 Share Posted March 23, 2014 Looks good. Now let's hope you never need it. Ritrebor Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 23, 2014 Author Share Posted March 23, 2014 Now the next question: to gusset at b-pillar or not? Hope to have it in paint by Z Attack in Nashville on April 12. Not looking forward to all the floor cleanup. My clean little car is trashed. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 24, 2014 Share Posted March 24, 2014 No need to gusset a roll bar. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 24, 2014 Author Share Posted March 24, 2014 Great. That means I can put some aluminum panels in (eventually) along the b-pillar for interior trim. Johnc, I can't believe you haven't used this bar as an opportunity for a few "teaching points." When I posted it, I was basically looking for you approval. But I feel a little cheated that you didn't take at least a couple of shots at it. Of course you know I asked a billion questions before I built it. Any suggestions for improvements before I paint it? There's still time. When dtivingvwith it, whenever a shadow passes between the bar and the body, I think "there's movement between the body and the bars." But when I put my finger between them, I don't feel it so I think it I'd just a shadow thing. I haven't jacked the car up or gone diagonally into my steep driveway yet. The drivers door not lining up was kind of freaky. New hinges on the way from 1tuffz's stash (thanks Dave). Quote Link to comment Share on other sites More sharing options...
SUNNY Z Posted March 24, 2014 Share Posted March 24, 2014 Looks good keith. Quote Link to comment Share on other sites More sharing options...
johnc Posted March 24, 2014 Share Posted March 24, 2014 Ok, the door bars are unsupported up front so, if a vehicle hits you in the side they will do nothing. But you are not racing with another vehicle on track so probably not an issue. The door bars should intersect straight into the front floor plate and not curved down to the plate. You want a direct load path. But, again, it meets the rules and, assuming the rule makers know what they are doing, you should be ok. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 24, 2014 Author Share Posted March 24, 2014 Thank you johnc. I really do seek to learn and to have others learn too, and I don't mind being the illustration. I would like to find a way to put a forward crossmember in somehow, but it was a compromise at best. I would love to have one as a front jacking point too. I have been trying to figure oit how to run a crossmember inside on the floor that perhaps tied into the tranny crossmember. But after a while all the compromises made the objective seem pointless. I may try to put a minihoop under the dash eventually if i install a mini heater to make room. The curve in the forward arrachment of the door bar was a compromise (at the request of the cage builder to shorten his weld snd simplify the complicated tube notching) and a compromise (for me)to maintain space for my clutch foot when off the pedal. It is welded to the rocker pretty well along the curve, so it should function effectively as a box like other folks have welded to their rockers. The bends in the harness bar and the diff support legs are compromises too for seat adjustment. Like you, I'm not a fan of curved bars. Have you ever had the addition of a cage alter door closure as it did mine? Quote Link to comment Share on other sites More sharing options...
johnc Posted March 24, 2014 Share Posted March 24, 2014 Have you ever had the addition of a cage alter door closure as it did mine? Not that I know of. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted March 24, 2014 Share Posted March 24, 2014 (edited) No need to gusset a roll bar. I had a friend add a gusset in the middle of his 4 point bar to the map light area. Said it stopped all the interior panels creaking in the back end of the car. Just some anecdotal data with a sample size of 1. Edited March 24, 2014 by JMortensen Quote Link to comment Share on other sites More sharing options...
1 tuff z Posted March 24, 2014 Share Posted March 24, 2014 Very nicely done Keith! Quote Link to comment Share on other sites More sharing options...
geno51 Posted March 25, 2014 Share Posted March 25, 2014 Keith, Cage looks awesome I am sending a lot of this information to my chassis guy. One thing I want it swing out door bars for my drag racing roll bar. Do you think that you could of incorporated this if you had chosen to ? Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted March 25, 2014 Author Share Posted March 25, 2014 Sure, geno51. I was thinking I might have to go swing out bars and a remove able steering wheel too, but it is remakeably easy to get in and out, although I may shorten my turn signal stick so I don't break it off. I'm on a diet, and that will hopefully help even more. Too much BBQ. But I'm trying to offset some of the weight I added to the car. Braille battery will help too, but I would really like to wait for the current battery to poop out first. Also, I probably don't need all the relaxing of the harness bar that I have. That would allow the diff bars to be more straight, which I would have preferred. I'm not certain that will help enough to justify the weight. You may come up with a better solution to that issue. I was planning to take car to be certified, but it turns out that isn't required until you go sub-10s. I'm still trying to play the game as close to the letter as I can so no track turns me away. Quote Link to comment Share on other sites More sharing options...
rsicard Posted April 6, 2014 Share Posted April 6, 2014 Sure, geno51. I was thinking I might have to go swing out bars and a remove able steering wheel too, but it is remakeably easy to get in and out, although I may shorten my turn signal stick so I don't break it off. I'm on a diet, and that will hopefully help even more. Too much BBQ. But I'm trying to offset some of the weight I added to the car. Braille battery will help too, but I would really like to wait for the current battery to poop out first. Also, I probably don't need all the relaxing of the harness bar that I have. That would allow the diff bars to be more straight, which I would have preferred. I'm not certain that will help enough to justify the weight. You may come up with a better solution to that issue. I was planning to take car to be certified, but it turns out that isn't required until you go sub-10s. I'm still trying to play the game as close to the letter as I can so no track turns me away. Keith: Now that your cage is in, and very nicely done, where will the drivers harness attach points be? Please post photos of the bottom of the main hoop welded attachments. Trying to get ideas as I have received a main hoop etc. for 4 point cage and will use the same Kirkey seats. Not trying to be annoying yet "....don't need all the relaxing of the harness bar..." and "...diff bard..." just don't understand the thinking contained here. Also, what is the purpose of the down bars going to the tunnel. Just wondering. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted April 6, 2014 Author Share Posted April 6, 2014 Sure! I will use a wrap-around shoulder harness with individual belts. It will wrap around the horizontal bar behind the shoulder holes in the seat. The lap belts will bolt to the stock threaded holes in the floor pan using the stock bolts. The crotch belt will be bolted to the floor thru the "frame rail" using big fender washers. The diagonal bars going to the tranny tunnel have two functions. One function is side impact support. The NHRA doesn't require a main hoop diagonal like SCCA does. NHRA rule book figured show those diagonals below the harness bar. So, I've tried to satisfy both SCCA and NHRA by having both a main hoop diagonal AND the two other little bars. Secondly, I installed them to hopefully keep my diff from coming thru the floor again. Quote Link to comment Share on other sites More sharing options...
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