RebekahsZ Posted May 28, 2012 Share Posted May 28, 2012 (edited) I've got a carbon hood with cowl induction that is absolutely beautiful. That is, up to about 80mph - then the thing starts shaking relative to the rest of the car. There is a little play in the hinges if I pull up and down on the front of the hood, but not a lot. The rivets that hold the attachment brackets on are not loose. I removed the torsion bar-type spring from the front of the hood and am using the stock cable operated hood latch. I plan to get the car above 100mph at the track, and the hood worries me. Is this normal/acceptable for composite parts? What should I do about it, if anything? If I need to go the hood pin route, I assume I'll need to pin it front and back?? Pictures for solutions requested. Sounds like a PITA and I'd really rather work on mechanicals - I'm hoping somebody will say:"my hood shakes like crap, and has for years, but I regularly hit 150 at the track and it has never been a problem." Wishfull thinking? I look forward to your experiences and recommendations. Edited May 28, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
RB26powered74zcar Posted May 28, 2012 Share Posted May 28, 2012 I have a CF hood w/o the cowl, attached exactly as your's and it's steady as can be. Maybe due to the hood vent possibly?? I wish I had a solution to offer you.... Quote Link to comment Share on other sites More sharing options...
Sam280Z Posted May 28, 2012 Share Posted May 28, 2012 I'd re-install the springs. They take up the slack in the hinge linkage. Also, run the bumpers at the rear corners up to put a small amount of tension on the hood back there. You can use a piece of paper to gauge when the bumper is contacting the hood. It should take a tug to get the paper out. Sam Quote Link to comment Share on other sites More sharing options...
johnc Posted May 28, 2012 Share Posted May 28, 2012 Is this normal/acceptable for composite parts? Yes and no. All composite hoods will move a round a bit at speed. But the typical street oriented composite parts are designed for occasional use above 80mph. The S30 packs a lot of air into the engine compartment so these types of hoods tend to bow upwards at speeds above 80mph and move around on their mounts. The hood itself generally isn't stiff enough and flexes. With a lot of track use I've seen these street types of hoods actually blow off the car after they crack at the mounting points. Over 120 mph sustained requires some specific reinforcement to keep a composite on the car. Also, the hinges without the springs will allow the front of the hood to move up a bit which exacerbates the problem. You can use a hole saw and cut two 2.5" holes (one on each side) behind the strut towers into the wheel wells to help reduce the under hood pressures. Quote Link to comment Share on other sites More sharing options...
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