DIY: Aerocatch Hood pin install with pics
Welcome to my DIY! The following was installed on a 2002 E46 M3 with a Vorstiener Carbon Fiber hood with vents.
This guide is to show you how to install Aerocatch Hoodpins on your E46 BMW. I mounted mine in a specific location, so if you don't like that location, skip to step 6 and start there.
Time Required: If you do it slowly and methodically, 4-6 hrs.
-Aerocatch hood pin kit
-Dremel with cutting discs AND sanding discs/tips
-Drill + various bits
-Sanding/anti-particulate mask (and kind of respiratory mask will do)
-Gloves (latex and work gloves)
-Something to cut your anchor bolts down (Dremel may work)
-2.5mm Allen wrench/hex key
-7mm wrench (socket wont work)
-17mm wrench x2 (or equivalent, see step 22)
-1 role of painter's tape
-WD-40 or some sort of spray-on lubricator
-Clear silicone rtv/all weather sealant
-grease/shaving cream (or equivalent, see step 7)
Gather all of the items above.
STEP 2: Open your aerocatch kit. Check out the bolts/washers/nuts and look at the latch mechanism. Lubricate the latch mechanism with WD-40 or equivalent.
STEP 3: You will now pick where your anchor bolts will be. These are the bolts that attach to your car, and the hood comes down over and the latches attach to. This also decides exactly where your latches will be. I found a spot on my cross/member that, when drilled through, was easy to access from the bottom on both sides. Also, it made the latches NOT conflict with my hood vents (vorsteiner CF hood). So if you'd like this location (see finished pictures at the end), then continue with this section of the DIY. I choose this location:
Mark on one side where your bolt will be with the sharpie. Use an x or an O, I don't care. Once you mark it, use the measuring tape and measure nearby symmetrical landmarks on the car. This is to make sure you mark nearly the exact same spot on the other side of the car. I used the spikey rubber cap thingie about 1 inch away, I used the bolts on the headlight assembly, and I used the fender of the car. Use whatever you can, and get it as close to symmetric as you can. This makes the final result spaced appropriately.
STEP 4: Once the drilling spots are marked, take a drill, and start with a small bit. Drill into your x, and once a small hole is made on each side, use a larger bit, and so on all the way up to the right dimension. This is right around 1/2 inch. To find this exact dimension (I couldn't remember it for this DIY) take your bits, and put them against the bottom of the bolt to make sure it will drill the right size hole.
STEP 5: Now we need to cut the bolt down to size. They're too long for this mounting location. The headlight housing gets in the way. Take your two bolts, and put two nuts on them and screw them down almost all the way. Put the bolt into a vice, and use a dremel or cutting tool to cut about 1-2" off the bolt. I cut about 2" off. You may have to as well, but this will vary per hood/car. I'm not sure about other cars other than the M3. Size it accordingly.
STEP 6: Once the right size holes are drilled, take your bolts and put them into the holes. Secure it with the bolts/washers supplied (one washer+bolt combo on top, and one underneath). Now set the bolt to the right height so the tip of the bolt will hit the underside of your hood when your hood is almost closed (preferably in the "just popped the hood" position).
STEP 7: put some grease/shaving cream on the tip of the bolt. Close the hood almost all the way down so that the bolt tips touch the hood, and then open the hood back up. Now there is a grease mark on the hood! Wipe that away and replace it with a sharpie mark.
STEP 8: Now cover the area around the mark you made on the hood with painter's tape. Be sure to transfer the mark onto the painter's tape. Also, cover the top of the hood where youll be working on with painter's tape as well. (Ignore the hole in the hood in the picture below
STEP 9: (Take this step only if you have extra Carbon Fiber underbody/exo-skeleton in the way of the top layer of the hood) Take your aerocatch latch, and put it up to the painter's tape. Align the sharpie mark with the place the anchor bolt will eventually go in on the latch. It's a small oval hole on the bottom of the latch. Face to the latch so the smaller end is towards the front of the hood (towards the direction airflow is coming from when the car will be in motion). Remember you are on the underside of the hood so it will be upside down. Use the sharpie and mark off the amount of excess CF underbody you need to cut away.
The more you cut, the easier it will be to attach the very small screws/bolts once the process is finished.
Before cutting, don your mask/gloves/goggles. Carbon fiber is very much like fiberglass, and the particulates will F you up royally. When cutting, lay down rags or a blanket to protect your engine bay from dust and fibers.
STEP 10: Tape up the surface again (if applicable), and re-mark it with grease on the tip of the bolt (if applicable).
Wipe the grease away, and mark out with a sharpie an area large enough for the bolt to fit through.
STEP 11: Use the dremel to cut into the Carbon Fiber and make a hole large enough for the bolt to fit through, but NO LARGER. Remember, you can always cut more, but never less. When completed, raise the bolt height up and close your hood and make sure the bolt fits through and pokes out of the hole.
STEP 12: Take your aerocatch kit, and grab the cardboard cutouts that come with the kit. They are perfectly sized, and have crosshairs on them to be used as a template. Lay the template down over the hood and line it up so the crosshairs frame the bolt sticking through the hood.
Use the sharpie to mark out the outline of the cutout. THIS IS THE STEP WHERE YOU ALIGN THE HOODPIN TO YOUR LIKING. Point it how you want: in out, sideways. Whatever you want. I decided to point it slightly at an angle.
(Note: Some of these pictures are from both sides of the hood. Not all pictures are from the same sides)
STEP 13: Don your protective gear (mask, goggles, gloves, longsleeves), and get the dremel. Lay down the rags all over the engine bay underneath the cutting spot. Remove the anchor bolt to make cutting easier. Close the hood or bring it almost all the way down to the "just popped" position. What I did was cut out a rectangular shape that was inside the sharpie lines (since the dremel cutoff disks are a little big, and can't do the curvy lines of the latch shape). Remove the piece you cut out, and switch the cutoff disc for a sanding bit on the dremel. Sand down the edges until almost all of the material up to the sharpie mark is gone. Take your latch, and test fit it into the hole you've made. The hole should be too small at first. Use the sanding bit on the dremel to make it bigger bit by bit where it needs to be. The latch should JUST fit in when done. This allows the screw holes to be far enough away from the main hole. As you can see from this photo, some of my screw holes were too close to the main hole I made: (Note: There's also silicone on the edges in this picture, don't worry, you'll get to that soon)
STEP 14: Once you have the latch fitting into the hole you've made, it's time to mark the screw holes. Put the latch in, and use the sharpie to mark into each screw hole for drilling. Also, at this step you can open the latch and make sure the latch and the anchor bolt line up properly. If they're close enough to lining up, you can bang the anchor bolt to fit later. If they're way off, you did something wrong.
STEP 15: Don your protective gear, and get the drill. Use the latch or the small screws supplied to pick out the right drill bit. Once you have the right drill bit, drill all 6 holes where you marked into the hood.
STEP 16: Open the hood and put the aerocatch into it's hole. Put the screws through and make sure they fit. If not, drill a little more, and widen the holes and line them up and such. Now grab your silicone and latex gloves. Spread the silicone on all the edges of the surfaces you've cut (minus the bolt holes).
STEP 17: Take off the tape on all surfaces.
STEP 18: Spread a thin bead onto the bottom side of the aerocatch latch in the 90 degree surface all the way around where the edge of the hole you cut will meet the latch surface. Put the latch into the hole and wipe away excess silicone from the bolt holes.
STEP 19: Take the six black bolts, and put them through their holes on the top so you can see the bottom of the bolts on the underside of the hood. Now you need to attach a washer and nut to each black bolt.
Make sure the small black rubber ring on the threads of the nut faces downward. They are self-tightening nuts so they wont become loose over time.
In order to get the washer AND nut on, I used pliers to maneuver the washer onto the bottom of the bolt, and then use my other hand to get the nut on.
STEP 20: Use the 2.5 mm allen wrench on the top and the 7mm wrench on the bottom to tighten to nuts down. I used the open face of the 7mm wrench on the bolts because it was a tight fit. Tighten all the bolts down to your liking. It should be just about flush to the hood. Don't tighten it too much, because the hood is curved and the latch is not so therefore you shouldn't overtighten the latch to deform the hood and possibly crack it.
STEP 21: Now that your latch is secured and on, you need to properly set the height of the anchor bolt. Put the anchor bolt back on (both sets of washers/nuts), leave the aerocatch latch in the open position, and close the hood. Attempt to close the latch and catch the pin through the bolt. If you're like me, it won't work on the first try.
This took a bit of trial and error. Find out which way the anchor bolt needs to go, and raise or lower it to make the pin go through. If it has to go to the right or left, bang on it with a wrench or hammer (which will slightly bend the head of the anchor bolt) to get it into position.
STEP 22: Once the height and alignment if perfect, and the hood latch pin catches and the latch closes with the hood closed, you just need to tighten the anchor bolt down so it's set. I used two 17 mm wrenches, one to hold the bottom nut in place, and the other to tighten the top nut.
You can also put a screw driver through the bolt head, and then tighten just the top nut down. Make sure the bolt head is 90 degrees to the hood latch after you tighten everything down because it can change sometimes.
FINAL: After you tighten it down, check to make sure it still latches properly, and BOOM you're done! CLEAN everything back up. Get a car wash maybe. Up to you.
The other side is almost identical, so repeat the same process. The left side of the car (passenger side) has a kind of tight fit for your hands, so you can remove the washer fluid spout and tube from it's holder and push it to the side.
Take your time, go slow, follow the steps and have all the tools handy. Once you're done, enjoy having your composite hood insurance, and go as fast as you want whenever you want! If you have questions, please ask!
Looks ace! Brave work cutting into that!
Good job; looks easy but Im sure you gotta really be careful and take your time! Good write-up.
What does ur car look like now.
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Beautifully done! Great, easy to understand step-by-step. Functional and not only that I think it looks sharp. I'll be doing the same when I get my vented hood. Thanks for posting...
By the way, what's the best place to get those hood pins? Isn't it an English company?
looks dope =]
EDIT: Found the website I bought them from: http://www.deftracing.com/aerocatch_hood_pins/index.htm
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very detailed and cool diy! Question, im genuinely curious, whats the need for hood pins?
Then you say, why hood pins? Well, this can be broken down into 2 parts as well.
1) Because the entire hood is lighter, there is more stress on the latch mechanism. Why, you ask? Well, a heavier hood exerts more downward force on your latch mechanism than the lightweight composite hoods do. When you are driving, airflow that gets under your hood from the front will exert upward force on your entire hood (because our hoods, like most, have the hinges in the back and latch in the front) which therefore exerts upward force on your latch. This force from the airflow (which is higher at higher speeds) is counteracted by the strength of the latch mechanism and the overall weight of the hood. With a composite hood, there is less weight and therefore more of that upward force has to be counteracted by your latch mechanism. There are a few different kinds of hood latch mechanisms on different types of cars. On OUR cars (E46's) the latch is MOUNTED to the hood, with screws/bolts, and as you bring your hood down, the latch clicks into the metal bar on the body of the car. On some other cars, this is reversed, and the latch is on the body of the car with the metal bar/ring being on the hood itself. On our cars, that latch on the hood itself is the failure point that hood pins will act as backup to. Why does the latch need to have backup you might ask?
2) Because the hood is a composite material (carbon fiber in this case), you cannot just weld the latch onto it obviously. It has to be bolted onto the carbon fiber itself. Carbon fiber is a brittle material. It cracks and bends very easily unlike metal. Although it has enormous tinsel strength, lateral forces will bend and eventually break it much quicker than steel. The airflow force on the latch will stress the carbon fiber around the mounting points on the latch. Another factor here that does not help is the thickness of the material.
All factors considered, Carbon fiber is strong. Under low stress conditions, the latch has a high probability of not failing. This means slower speeds and smooth roads. BUT we all know that we like to go fast, and roads are not always smooth. IF you hit a bump, pothole, etc., the latch COULD be damaged. Obviously this is not normal, and usually doesn't happen, but even if it did, you most likely wouldn't notice stress cracks on the underside of your hood around the latch right away, now would you? Because of CF's brittle nature, this scenario is much more plausible than with a stock hood. If your latch was damaged, or if you were driving into let's say a 30mph headwind going 95mph (definitely also possibly), your latch could fail. If that happens and you don't have hood pins, that hood is flying up. It will either completely blind you or fly off and possibly blind someone else, hit something, make someone swerve, etc. Regardless, it will scare the **** out of you as well, and possibly cause you to crash just from that alone.
In conclusion, hood pins are anchored to your car's frame/body and act as secondary latches. They prevent your hood from flying up during a latch failure. That is why I think they are necessary.
STORY: I had a Lexus IS300 over the summer with a recently bought CF hood. The hood CAME with pins, which I was happy about. TWO DAYS after I bought the hood and put it on (and 3 hours of fiddling with it to get the fitment right), a lady in a forerunner decided she really needed her coffee and took a left into a dunkin donuts from the other side of the road without checking to see if anyone (me) was driving in the opposite direction. I slammed my brakes, but it was too late and I hit her going 35 and this is what happened to the car:
The hood pins held the hood down even after the impact destroyed the latch assembly. That hood would have flown off if there weren't any pins on there. I used the money I got from the accident to buy the M3 I have now, and my first move was BUY AND INSTALL HOODPINS. Hope this helps you decide whether or not you need hood pins! :thumbsup:
looks really good man, let me give you a suggestion, i used these on my old car, fantastic design, but PLEASE! get new bolts for the top part of the latch, in about 3 days they will go to **** and get rusty. The screws they give you are trash.
See Tamper Resistant Fastner Kit at bottom of page.
Also on this page there is a comment on how precise you need to be in cutting the hole for top mount vs bottom mount.
Hmmm..... not a fan of how it looks. There's just too much on the hood now.
Nice detailed DIY though.
No problem man, i noticed it with a lot of the "black coated" screws or whatever you call them, the coating will literally wipe off... The bolts that came with my momo hub for my old car did the same exact thing
I was like hood pins,ohhh nooo. But damn those look good.
Great post! I'm installing mine this weekend and really appreciate the effort you put in to share what you know. Cheers brother!
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