RebekahsZ Posted January 8, 2013 Share Posted January 8, 2013 Finally! Johnc has gotten so mellow in his old age that he has to be baited and prodded out of hibernation. That is the perspective I have been craving. Thank you. I know im overly sensitive but i left my last conversation with cobramatt feeling very shamed/scolded for having a fast car without a roll cage. But, i think he was still kind of worked ip over the bad track antics that he saw at the zfest at Barber. You folks are the best! Quote Link to comment Share on other sites More sharing options...
wasey Posted June 6, 2013 Share Posted June 6, 2013 Sorry to bring up an old thread. But figured it was better than starting a new one and this one already had a lot of good info. My 77 280z is nearing completion with an LQ4/4L60 swap and was contemplating doing a full roll cage. The car will be primarily a street car, followed by fairly frequent drag racing and then the occasional track day (willow springs, maybe laguna seca). After reading this thread and looking at the NHRA rules I know I will never need one. Moving on, I am currently aiming for low 12's/high 11's in the 1/4 and in the future I might build the car to dip into the 10's. I have friends/family that can fab up a custom cage/roll bar, does anybody have recommendations/pictures of a setup that will protect me and my chassis and not destroy my interior??? Thank you in advance. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 6, 2013 Share Posted June 6, 2013 Check out Dan's car (74_5.0L_Z is his username, look at his gallery). He did a roll bar and door bars without having the A pillar and halo, which is the part you're likely to hit your head on. He actually has a full tube frame front end, but you could go a little less extreme with a dash height hoop in the front and a regular hoop behind the driver, and X door bars connecting. Could go through the firewall out to the front struts if you were feeling ambitious. Quote Link to comment Share on other sites More sharing options...
Zzeal Posted June 13, 2013 Share Posted June 13, 2013 I agree, having a full cage in a street driven car is generally not a good idea... but, if you can snug the bars up against the lid and mount the seats as low as possible (pic of lowered seat mount) you end up with a decent amount of noggin clearance. Also, size does matter, and at 5'-9" I'm not sitting tall in the saddle either. So now I could be all safely harnessed into my Z, head room galore, having a great time... until someone rear ends me...gas tank ruptures, and I'm toast. This came to mind (again) as I read this week about the NHTSA going after Chrysler for producing cars (Jeeps) with fuel tanks located behind the rear axle. Steve Quote Link to comment Share on other sites More sharing options...
wasey Posted June 16, 2013 Share Posted June 16, 2013 Thanks JMortensen and Zzeal for the responses. Do you have more pics Zzeal? I am 5'11 with a longer torso. Quote Link to comment Share on other sites More sharing options...
Zzeal Posted June 17, 2013 Share Posted June 17, 2013 Hey wasey, just sent you a PM. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 14, 2013 Share Posted August 14, 2013 Getting closer to building new rollbar. I'm listening to and hearing all the stuff about hitting my head. AND, I don't think I'm likely to get the car under 10 seconds in the quarter with the way I'm tearing things up with just my current power level, so I would be NHRA legal to 9.99 with just a 6-point rollbar that includes door bars. I really want to try to get some chassis stiffening (doors don't close well). Anybody have any pointers on where to make the forward leg of the door bar attach to the Z chassis? I'm torn between attaching it to the inner rocker panel vs. attaching it to as far as possible down in the footwell. Post pictures of your favorite design. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 14, 2013 Share Posted August 14, 2013 The problem with door bars is getting access to weld around the whole tube. I ended up cutting holes in the fenderwells and in the door jamb for access. If you want foot protection I think my bar from the bottom of the A tube pillar to the front strut tower does double duty and gives decent foot protection and adds to the chassis quite a bit. In your case, just do a dash hoop like you would see in an older convertible, then run the bar from the bottom of that to the strut tower. Might have to be a little choosy with your placement to avoid the brake and clutch masters. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 15, 2013 Share Posted August 15, 2013 Thanks Jon! When you gonna finish that dang car? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 15, 2013 Share Posted August 15, 2013 Well, if I keep buying parts like I have been I'll run out of parts to buy. Then I'll have to make excuses as to why I'm not assembling them. It's getting closer. Quote Link to comment Share on other sites More sharing options...
johnc Posted August 16, 2013 Share Posted August 16, 2013 Another door bar issue is that the NHRA style of 6 point cage with the door bar up into the footwell is:There is no lateral support for the front of that bar in a vehicle to vehicle side impact. The front of that bar is going to bend inward with the rocker panel and floor pan and take out your legs. With a full roll cage you have the front hoop and knee bar to transfer load across the car. If you can build a low front hoop/knee bar structure behind the dash that will help a lot with side impact safety. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 16, 2013 Share Posted August 16, 2013 Yes sir, we have discussed that before and I agree. This darn car is so full of compromises and the rollbar/cage will be a compromise too. Realistically with my lifestyle, this is a drag/autocross/2track day a year/drive to work to keep battery charged car. I'd like to stiffen up some but the minimum rule book I will try to confirm to is NHRA/IHRA for drag. I want to have heat again someday and a radio, so that makes a knee bar unlikely. I recall our discussions about roll cages and smacking the head. And I REALLY don't want to pull my dash (I hurt for weeks after working under there). So I think I'm gonna do the best I can with a six point (plus every pound costs hp). So, I'm really looking at where I should attach the forward legs to stiffen best if that is all I do. Rocker? Firewall? Junction of rocker and firewall down in the corner of the foot well? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 16, 2013 Share Posted August 16, 2013 Use lighter tube for the stiffeners. Mine are 1.625 x .065. 1.08 lb per foot. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 16, 2013 Share Posted August 16, 2013 How much more is chrome moly (percentage)? With my modest power I don't want to get fat. I'm on a personal diet (again) to try to lose some easy pounds. Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 16, 2013 Share Posted August 16, 2013 JMortensen-you don't have room for people in that car! Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 16, 2013 Share Posted August 16, 2013 JMortensen-you don't have room for people in that car! Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted August 16, 2013 Share Posted August 16, 2013 Oops Quote Link to comment Share on other sites More sharing options...
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