proxlamus© Posted April 20, 2010 Share Posted April 20, 2010 (edited) So im debating between a full and half cage.. I realize that a half cage is recommended for any car that is ever used on the street, but after watching tons of WRC racing.. Ive realized that these cars are driven for many many many many miles between the rally stages and they don't wear helmets.. the WRC cars have the seats mounted very low with plenty of headroom above their heads and the halo/roll bar Help me make sense of this.. in the event of an accident, if my head moves it will smack the roll bar.. without a roll bar and my head moves an extra 1 1/2" my head will hit the upper door frame?!?! I just dont see the big difference an 1 1/2" will make.. especially with nice padding!? Has anyone used SIDE seat mounts and mounted the seats super low and had issues with head room?! Edited April 20, 2010 by PrOxLaMuS© Quote Link to comment Share on other sites More sharing options...
TheMission Posted April 20, 2010 Share Posted April 20, 2010 If you don't like your brain... full roll cage without a helmet... Generally, Most people aren't likely to hit metal portions of a door in a medium impact, but put a bar right near your head travel and get a minor sideswipe and kiss your brain goodbye. (You'd also be surprised at how far you REALLY move in a collision) - I don't know how low you'd have to mount the seats, but then you're looking at hitting the lower door frame with your head, which would probably hurt a bit too. I've never met a person of any reasonable knowledge in the racing world that would ever suggest a street car with a full cage and not wearing a helmet... way, way too much risk, especially compared to the "possible" benefit of a full cage... Why a full cage? It seems to be significant overkill for any street ride and although it'd look nifty, the risks of it, plus the cash/time of making it "somewhat" safer seem to not be really worth it. Quote Link to comment Share on other sites More sharing options...
LoneStarS30Z Posted April 20, 2010 Share Posted April 20, 2010 Agreed with above. I've never been in accident wearing helmet or a roll cage, but I've had a couple of instances, one an off track excursion, and the other nailing a big bump in the track during a drift event which ended up with me smacking my helmeted melon into the roof. Another reason you may be overlooking why the WRC seats are so low is because they're trying to achieve a low center of gravity. In some instances they go as far as making the steering wheels extend quite a bit farther than stock and even moving the seats mounting positions back to their desired location all in the name of center of gravity. Quote Link to comment Share on other sites More sharing options...
T-Bone028 Posted April 20, 2010 Share Posted April 20, 2010 Let me just say this, I dont have a full cage, but I do have a roll bar in my car. It is not padded and I drive it on the weekends on the street. If I were to ever get in an accident, I would most likely still hit my head despite the 4 pt harness I use to keep me in place. The other day, a friend of mine went for a ride with me in my Z. I didnt give him any warning and I gunned it. The force of acceleration snapped his head back enough for him to hit his head on the roll-bar. My car is not the fastest car in the world. If just the acceleration out of my stroker is enough to make someone hit their head, I'm sure the forces of impact would be more than substantial for me or my passengers to be severely injured. I will be putting padding on it in the near future. Quote Link to comment Share on other sites More sharing options...
johnc Posted April 20, 2010 Share Posted April 20, 2010 So im debating between a full and half cage.. I realize that a half cage is recommended for any car that is ever used on the street, but after watching tons of WRC racing.. Ive realized that these cars are driven for many many many many miles between the rally stages and they don't wear helmets.. Help me make sense of this.. in the event of an accident, if my head moves it will smack the roll bar.. without a roll bar and my head moves an extra 1 1/2" my head will hit the upper door frame?!?! I just dont see the big difference an 1 1/2" will make.. especially with nice padding!? Has anyone used SIDE seat mounts and mounted the seats super low and had issues with head room?! Well, that's a first. Never before have I heard of anyone comparing a street driven 240Z with a purpose built WRC rally car in a safety discussion. You appear to have already made up your mind and are now just fishing to get someone to give you an "Internet OK" while using a irrelevant example as proof. Good luck with that. EDIT: I know that's sounds bit harsh, but... but... Geez! Quote Link to comment Share on other sites More sharing options...
Globerunner513 Posted April 20, 2010 Share Posted April 20, 2010 Just to add, Subaru's typically have a lot of extra head room. Even with stock seats my friend has a street driven subi with a cage (show car...the cage would probably collapse in an accident). Regardless, the cage sits much higher than I think any cage in a z car. Add the high roof, with very very low seats, and you get the illusion that there isn't any safety concern. IMHO Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted April 20, 2010 Author Share Posted April 20, 2010 (edited) Well, that's a first. Never before have I heard of anyone comparing a street driven 240Z with a purpose built WRC rally car in a safety discussion. You appear to have already made up your mind and are now just fishing to get someone to give you an "Internet OK" while using a irrelevant example as proof. Good luck with that. EDIT: I know that's sounds bit harsh, but... but... Geez! Oh John, Im not comparing a 240z to a WRC car.. I just wanted to bring up a WRC car as an example of modifying the floor-pan, the seats and the seat mounts to allow adequate headroom for a cage. I was hoping to see that maybe someone may have done the same. I have not made up my mind until now and I'm glad people are chiming in their opinions.. I have decided to go with only a half cage, after hearing the opinions of people who talk from experience. Thanks guys! Edited April 20, 2010 by PrOxLaMuS© Quote Link to comment Share on other sites More sharing options...
heavy85 Posted April 21, 2010 Share Posted April 21, 2010 Your missing that the Z is relatively short. I'm ~6'2" and always had head clearance issues with a helmet on. I cut out the seat mounts and use 1" square tubing on the floor to mount the seat. I also switched to an aluminum seat which is very thin. I had to raise the seat off the floor an inch or two to be able to see over the steering wheel. No matter how low you mount the seat it will never be low enough ... especially if you like to see over the dash. There just isn't enough headroom to make it work out like the reference cars. Cameron Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 15, 2010 Author Share Posted May 15, 2010 Does anyone have any experience sitting in a seat similar to this?! With a taller rear upright and the side head bolsters I am hoping that if I had a full cage, these side bolsters would limit my head from smacking the cage and instead restricted my head movement... and the bolsters/support are cut away to improve visibility?! Quote Link to comment Share on other sites More sharing options...
Mayolives Posted May 16, 2010 Share Posted May 16, 2010 QUOTE "Has anyone used SIDE seat mounts and mounted the seats super low and had issues with head room?" I think John has hit the nail on the head by believing your are asking for Internet approval for going with a very unsafe idea. You seam to be a good guy and contribute to HybridZ. But if you no longer want to be around, give the cage a try. Cages and street driving are just a common since big No No. My fully caged car has the seat mounted on the sides and is as low as it can be. It sets on the floor! It's "down and back" and I'm 5'11". When I'm in the car with the belts super tight, with practicly no allowable body movement, I still have very little head room. I should have moved the diagonal bar over a little when we built the car but to change it now would not be easy. The diagonal bar is of course, on the same plane as the rest of the cage. These car just don't have much head room and certainly not as much as the newer designed rally cars that have many inches up there. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 17, 2010 Author Share Posted May 17, 2010 I really appreciate everyone input. I'm not necessarily looking for internet approval, rather I'm looking to hear feedback from people with experience. I've concluded that the S30 is not the right car to have as a street-able caged car... in the pics I posted its obvious that newer cars allow more head room and more space to mount a roll cage with out any issues with head room. I've decided to go with a half cage for my purposes. Thank you everyone!! Quote Link to comment Share on other sites More sharing options...
johnc Posted May 17, 2010 Share Posted May 17, 2010 Does anyone have any experience sitting in a seat similar to this?! With a taller rear upright and the side head bolsters I am hoping that if I had a full cage, these side bolsters would limit my head from smacking the cage and instead restricted my head movement... and the bolsters/support are cut away to improve visibility?! I fitted that exact seat into a 240Z for a customer (standard width). We had to cut a notch on the upper part of the inner door sheet metal to get the door to close and the roll up windows didn't anymore. Luckily it was a race car and we planned on removing the windows and all internal mechanisms as part of a a double door bar install. As with Tom's post above, I had to build seat mounts the were flush with the top of the floor pan. The owner didn't need sliders so we saved an inch of headroom and he actually fit pretty well. One of the big issue with race seats is the trans tunnel shape. It flares out wider at the front edge of most race seat installs which makes it appear that you have more room then you really do. Measured across where your butt sits there's 21.5" of room on the floor. But up near the front of the seat base, where the trans tunnel gets wider, you have about 19" of floor space - so that's the real, practical number regarding seat base width unless you're willing to clock the seat about 7 degrees to the left (that makes for an odd driving position). The door panel is an additional 1.50" out from the vertical plane of the inner rocker so the total, non-interfering shoulder width of the seat is about 22". Any additional seat width above the shoulders runs into the narrowing tumblehome of the roof. Floor pan to roof, again where your butt sits, is about 43" at a 10 degree recline. Typical race seat thickness is about 2" with your butt compressing the padding. If your seat bottom touches the floor (not a good idea from a safety standpoint) you're got 41" for your torso, head, and helmet. For me, I'm 69" tall with a 31" inseam. That gives about 38" of torso, head, etc. Add in 2" for helmet thickness and I've got 1" clearance to the roof. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted May 17, 2010 Author Share Posted May 17, 2010 John, Thank you for taking the time to reply in such detail. Excellent input =) Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted August 30, 2011 Author Share Posted August 30, 2011 (edited) Thread brought back from the dead! Question - SCCA GCR Section 9.4 mentions that roll cage are available in 2 primary designs... Low Hoop (top of steering wheel) High Hoop (top of windshield) Obviously from what I concluded years ago in the posts above, a half cage would suffice for any street use. However, would it be safe to say, that if I ran a main hoop and a low hoop under the windshield.. could this be considered a "roll cage" rather then a "roll bar"? Running the Main Hoop, 2 rear braces, a diagonal brace, door bars and low hoop seem to me like a complete "low hoop" roll cage! If this is true, why don't more people do this option? (other then the obvious, more frontal driver protection on a roll over) Edited August 30, 2011 by proxlamus© Quote Link to comment Share on other sites More sharing options...
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