Hood vents...

[anyonebutme]

so, what happens when it rains into your big vent? always wanted to do something like this..

engine gets wet. If you don't use OEM type plug boots, you'll lose your front 3 cylinders when they fill with water.

[Ange]

engine gets wet. If you don't use OEM type plug boots, you'll lose your front 3 cylinders when they fill with water.

could always run some rubber seal along the edges of the sparkplugcover to keep it waterproof

[KeithMac]

I came back from holiday once and it had been raining none stop apparently, doing some work to the car and pulled the front turbo intake pipe and it was full of water.. The rain had found its way through the stock hood blister, through the air filter and filled the intake..

Worste thing was I'd only put the stock bubble on for testing and was going back to filters over turbo inlets but didn't get chance before leaving.

Luckily I didn't start the car to move it before working on it..

Just a heads up, if you fit vents try and avoid water ingress into the air intake, not so bad for a dry day trackday car thats garaged but a daily driver parked outside could suffer!.

Look really nice though when all said and done, could swap between stock and vented hoods for track days.

[anyonebutme]

Pro tip: Just because I had to do this yesterday, reminds me. My car sits outside, so before start after storage, remove charge pipe, unplug MAS, start car and rev to blow all the water out the IC piping.

[Gray Haze]

Me personally, I'd take the vent, measure the flange area, and transfer that to a CF hood. Using a pencil grinder with a work aide, id recess the thickness of the vents flange area into the hood, then cut the inside area of the hood after at minimum 1" of flange area to be bonded, and use some structural adhesive like EA956 or equiv. With precise measurements and detail work, you could easily recess the flange into the outside mold line of the hood, and then bond it in place flush with really no need for much other work to get a good finish. This basically uses the same process as a step sanded composite repair.
20140107_090236[1].jpg Work Aide to hold pencil grinder to defined heights.
20140107_090243[1].jpg Another view with set screws and dust vent visible.
20140107_090342[1].jpg Bits helpful in step sanding, tapering, etc of hood surface. The carbide cutter set to a minimal depth works amazingly fast at removing layers of material. This is one of my perfered methods when doing structural composite repair in which ply stepping is required.
20140107_090414[1].jpg The rig setup to do work.

Its really easy to just transfer a pattern of the flange on the vent to the hood, step back the thickness of the vent, then cut the ID out, and bond in place. You could also taper both the hood and vent flange surfaces in a 20:1 ratio and easily obtain a flush mounted bond that will not fail. Using the above tools I have done structural repairs at a 60:1 taper ratio on structural airframe composites with great success.

[J. Fast]

The hood was mortise cut and the vent flushed up to the natural plane of the hood surface less a couple thou for epoxy shrinkage and fill. I'm going to run one single layer of CF over the whole thing for some added strength and reinforcement insurance. I've been trying to get back into the garage the last few weeks but it's been too cold to do any epoxy work so the hood is just chillin' (literally) till an couple consecutive overnights are above freezing.

Thank you for the tips on the repair work Grayson. Of course it's nothing as cool as an airplane or heli wing but it's fun. That's a nice setup you built there. I basically used the same thing. I used a trim router with a 3/8' diameter mortise blade. It's not as compact as the pen jig you built but for the big open flat surface cut areas it worked well. I had to revisit a few contour areas with a rasp cutter on a Dremel where the hood rolls down. The router foot was too wide to match the contour of the hood where it rolls down and was bridging.

Hopefully if the weather clears up soon I can get back to it.