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After multiple track days here in Florida dealing with stupid heat, I needed / wanted a vented hood to help with cooling & for a bit of lift reduction.
The heat at Sebring in the summer is stifling, and really want the car stuck to the pavement coming out of NASCAR turn 4 at Daytona.
Love the first class $$-$$$$ high end carbon fiber hoods from ACP World Challenge, LG Motorsports, Black Dog & Halltech.
The lower cost hoods I looked at just didn't have the vented area I wanted. Many have big "decorative" louvers, but small actual vents.
Not to mention all the horror stories of trying to make them fit, heavy weight and the cost of painting.
Liked the idea of making an extractor hood & adding louvering to a hood myself. After quite a bit of searching found some nice custom aluminum vents from John at Trackspec Motorsports. http://www.trackspecmotorsports.com/
These vents seemed like just the ticket. Nice custom C6 or C5 specific design louvers that were developed and tested on GT2 corvettes for flow and durability. Enough sq/in area to make a big difference in under hood temps.
Retail is $299 for the set & come nicely finished, with pilot holes, templates for installation and advice from someone that cares.
I can't emphasize enough how great this shops communication and costumer service has been.
Consulted an engineer buddy, did some air flow modeling, looked at C6 airflow graphs. Then gave up and positioned templates where they just seemed best to me taking into account radiator edge, boundary airflow & support structure.
Positioned center panel leading edge "not cut" 13 7/8" back from center front edge. Side panels with a slight 1/8" offset 6 3/8" at front side and 6 1/2" at rear side from edge of hood to edge of panel. Side panels 24" back from front ege of hood on same plane. This positioned the side cuts just into the supporting rib.
If I were to install another one I may position the center louver about 3/8" fwd.? Didnt want the aft edges to overlap the edge of the hump but could safely go another inch or 2 fwd.
Note: Hole that fell inside center hood rib. Would have been better in center of support or on either side, not on the edge.
This put center panel first vent just aft of radiator for maximum cooling.
Cut holes in hood slightly undersized using a jig saw and fine tooth metal blade. Note: A fine tooth wood blade dulled after 2 inches.
Used a 1/2" sanding drum to rough out edges.
Last edited by blkbrd69; 08-19-2014 at 08:23 PM.
Reason: dimensions
Drilled 1/8" holes in hood and louvers, applied curve to louvers to match hood contour, deburred holes then mocked up and secured louvers using 36 Cleco fasteners to mark for final edge sanding.
Remember when drilling and attaching something to a compound curve, work from the center and go out as you firmly secure. http://www.yardstore.com/browse.cfm/2,398.html http://www.yardstore.com/browse.cfm/4,3773.html
Final trimmed, applied smooth radius to inside curves using multiple sanding rolls and dowels. Then chamfered an angle in hood cut edges so inside of louvers and hood were smooth transitions.
Enlarged 2 holes on hood so I could put back up washers on aft rivets of small louvers.
Protect your eyes, lungs and skin while cutting and sanding as its nasty stuff. I taped garbage bags to backside of hood and used a shop vac on front side while cutting and sanding,
After final prep on holes and hood edges, I painted any bare glass or exposed red paint with matte finish black paint.
Nice work!! I have a set of these on my C5 as well and they're indeed a great product. I'll also echo your sentiment about John and his crew being top-notch to deal with, extremely nice people and obviously passionate about customer service. Can't wait to see the hood back on your car!
Being a daily driver Florida street / HPDE car. I fabricated an alternator rain trough out of thin scrap stainless I had on hand.
Aluminum or high temp. plastic may be better as SS sucks to work with?
Note; Back up washers and SS 1/8" rivets should have plenty of strength, overkill really, but used to driven rivets, Hi-locks or CherryMax.
Used 2 grip lengths as needed to go through supports for 2 rivets on small louvers.
I was concerned about cutting out the center rib and huge holes, but with the louvers installed the hood is about the same stiffness and weight.
Was very easy to install and align hood on car "with my wife's help".
Mark bolt washer locations on hinge and put marks on original hood to act as reference points.
Don't have any road-course track temperature or handling data yet, Sebring and Daytona as soon as the rains stop. Vents do move quite a bit of hot air and have dropped temps on the street.
Do not test how much air your fan is moving by putting your hand on top of vent. Dont ask how hot they get? Hot air, header heat and Florida sun.
Matt,
Great job.. I"m a little pi$$ed. I was hoping to be the first in FLA with these.
Maybe I'll run into you at Sebring at Kids Run For Life 2014 in September??
jim
Finished my installation last night. The louvers are just slightly behind the radiator shroud and I did not cut any of the hood bracing. Will get to test them out on track mid-Sep.
These units are very high quality pieces. John does a great job making these.
Fasteners;
I used 1/8" stainless steel pop rivets with back up ss washers. Certified rivets, not the stuff you buy at a box store.
Most 1/8" aluminum "pop" rivets are non structural and don't have the strength I wanted, would have to step up to #5's and then they just "looked" to big. Cherries would be to strong.
Normally would have used countersunk solid rivets, but this is really a low speed application and button heads are just easy.
Positioning;
Due to flow modeling, I put the center vent as far fwd as I though I could given the edge curve of the center bulge. After installation and finding how easily the vents took the compound curve I "could" have gone a bit forward. As currently installed they position the front vent leading edge directly over the rear edge of the radiator. Impossible to verify a couple of inches either way without a bunch of pitot probes taking traverse readings unless someone wants to lend me a wind tunnel or do some dynamic flow modeling, we are only talking about a couple of inches of water pressure?
Rain gutter;
I only used ss as that is what I had on hand next to the brake.
It is a bit longer with a bit more angle than it needs to be. If I did it again it would be thin 6065, 2024 or even plastic and a bit shorter with a bit less angle and have nice vent cuts on the sides as well.
Web sight should be up soon. Some info on his face book page.
Read above posts and ask why I had some of the first ones?
08-11-2014, 10:56 AM
Picture tutorial on Installing Trackspec Motorsports C6 vented hood extractor louvers
I should just let you done it for me 
