rdsk8ter Posted April 12, 2008 Share Posted April 12, 2008 I'm not sure when I am going to be out his way again but I will call him in the morning and see if he can snap some pics and email them to me. Dragonfly I would love to see them too Quote Link to comment Share on other sites More sharing options...
katman Posted April 12, 2008 Share Posted April 12, 2008 This seems like a huge waste of time to me. Most of the real racing done with Z's these days is in ITS and EP. Old days was CP or GT2. None of these cars added a bar to the inside of the rocker. Now some people will run one of their door bars down on top of the rocker, which I almost agree with, but there's so much else to worry about. What kind of racing is this for? Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted April 13, 2008 Author Share Posted April 13, 2008 This is actually for a drag car. No class. Just building a street strip car. I mainly wanted to reinforce the rockers for safety. Justin Quote Link to comment Share on other sites More sharing options...
Careless Posted April 13, 2008 Share Posted April 13, 2008 What kind of racing is this for? I think it's the kind of racing where cars hit each other... sometimes in the rocker panel area... doesn't sound like a waste of time to me Quote Link to comment Share on other sites More sharing options...
katman Posted April 13, 2008 Share Posted April 13, 2008 This is actually for a drag car. No class. Just building a street strip car. I mainly wanted to reinforce the rockers for safety. Justin Won't be in any NHRA sanctioned class then? Oh, you also say this: "Then I can mount the cage to this and still stay NHRA legal." Then it will need a cage meeting NHRA specs or not, and for what class? Is your seat going to be at the normal height or down on the floor? Let's figure out what the legal requirements are for where you're racing, then there may be some more important places to put that metal. Putting it in the rocker won't appreciably affect your torsional stiffness, nor is it usually a player in a T-bone or a rollover. Be glad to help but need more specifics. Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted April 13, 2008 Author Share Posted April 13, 2008 I'm putting a in a 8.50 certified cage for NHRA (8 point cage). It will be made from 1.625 X 0.085 wall thickness chromoly tubing. My seats will be mounted down on the floor for more head clearance to the roof bars. Regards, Justin Quote Link to comment Share on other sites More sharing options...
katman Posted April 14, 2008 Share Posted April 14, 2008 That's not a lot of tube. For ITS we use 1-3/4 x .095 wall. What's the design look like? Lot of NHRA legal cages I've seen don't even have a diagonal in the main hoop, that's the first thing I'd change. Are you limited in where/how you tie the cage to the unibody? Got a link to the rules? Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted April 14, 2008 Author Share Posted April 14, 2008 The rules are here: http://www.nhrasportcompact.com/2007/rules/2007rules.zip Also, heres a basic rendering I did in CAD of the cage I'll be putting in it: As you stated, there is no diagonal bar in the main hoop. Its not required. I think you can add additional bars as long as you have the required bars. Regards, Justin Quote Link to comment Share on other sites More sharing options...
katman Posted April 15, 2008 Share Posted April 15, 2008 Nice drawing. A few suggestions. For drag I don't see you needing T-bone protection like we do in road racing, therefore no elaborate door bars needed (although it looks like the rules require one on the driver side, I could be wrong). I think your main worry would be rollover (tire blows at speed for instance), and for that I'd really really want a diagonal in the main hoop. The two diagonals that go down to the tranny tunnel don't do squat, you're just adding weight with them (however, looks like the rules show them, more proof the NHRA has no structural engineers on staff). I generally don't like the X in the back, as it's weight up high that isn't necessary, UNLESS you have a tall driver and are taking advantage of the fact that the NHRA rules are stupid enough to let you get away without a diagonal in the plane of the main hoop. Which I gather is the case, so the X is the next best thing even though it's proly half as effective. An X for door bars on each side would give you some much needed torsional stiffness, as would a Top End Perf. type triangulated front strut bar. If it was a road race car I'd move the front horizontal down to about an inch off the tranny tunnel to help distribute the T-bone loads and help keep the floorboard from folding up, but since that proly isn't a big player in this app it's okay where it is (although again, it's weight up high that isn't really doing anything- the front half of the cage is just going to collapse in a rollover anyway, especially with no door bars). You don't say how fast this thing is going to be, but my guess is for drag racing your probability of crashing is very low, and the type and speed of crash you'll have will be much less severe than what we'd expect in road racing (concrete wall at 120 mph almost perpendicular, courtesy of Road Atlanta turn 12 for instance), so I'd go with minimum weight, maximum convenience (kinda like what you got), forget the additional rocker tubes, get it on the track and street asap and have fun sooner. Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted April 15, 2008 Author Share Posted April 15, 2008 I'm going to be doing x braced door bars on the driver and passenger side. I don't need the x brace in the back AFAIK. The motor combo I'm putting together should put down 1100whp. Should be enough to go 160's in the 1/4 from calculators I've seen. I just want the whole car to be as safe as possible. I'm not super concerned with adding weight in the rockers. I was planning to mount the main roll hoop to the 2X2 rocker bars, aswell as the A pillar down tubes. I figure this will make the car more rigid and keep the cage as far out of the passenger compartment as possible. I will be welding in two tubes that connect the rockers side to side. This will function as my seat mounts. I really would like to do a 25.2 chassis spec, but its alot more bars then I'd like. I'm just trying to build a chassis that will be safe, with minimal impact on the drivers compartment. I will be driving this car on the street so I'm trying to tuck the cage against the roof as right as possible. Also, I'm going to mount the seats as low as I can to keep my head away from the roof bars. I'll post pictures later of the revised cage as I intend to build it. Regards, Justin Quote Link to comment Share on other sites More sharing options...
garvice Posted April 15, 2008 Share Posted April 15, 2008 1100whp and your planning on having it street registrable? Man, I hope for your own safety that you have more self control then me. Quote Link to comment Share on other sites More sharing options...
katman Posted April 15, 2008 Share Posted April 15, 2008 I'm going to be doing x braced door bars on the driver and passenger side. I don't need the x brace in the back AFAIK. The motor combo I'm putting together should put down 1100whp. Should be enough to go 160's in the 1/4 from calculators I've seen. I just want the whole car to be as safe as possible. I'm not super concerned with adding weight in the rockers. I was planning to mount the main roll hoop to the 2X2 rocker bars, aswell as the A pillar down tubes. I figure this will make the car more rigid and keep the cage as far out of the passenger compartment as possible. I will be welding in two tubes that connect the rockers side to side. This will function as my seat mounts. I really would like to do a 25.2 chassis spec, but its alot more bars then I'd like. I'm just trying to build a chassis that will be safe, with minimal impact on the drivers compartment. I will be driving this car on the street so I'm trying to tuck the cage against the roof as right as possible. Also, I'm going to mount the seats as low as I can to keep my head away from the roof bars. I'll post pictures later of the revised cage as I intend to build it. Regards, Justin Oh, only 1100hp. Me thinks we just upped the ante to a lot more cage than you have shown. I'll check in for the revised pic. Quote Link to comment Share on other sites More sharing options...
Careless Posted April 16, 2008 Share Posted April 16, 2008 i know. only 1100hp. here I was, thinking it would be an astronomical number, like 1101hp. woah is me. can't wait to see this thing Quote Link to comment Share on other sites More sharing options...
JustinOlson Posted April 20, 2008 Author Share Posted April 20, 2008 Here is my cage model so far. I'm going to add a set of swing out door bars along with tubes going forward and back to the strut towers. Quote Link to comment Share on other sites More sharing options...
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