924Board.org

[Peter]

This is a write-up on how to measure and mark a hood for the installation of a functioning hood scoop. However, it applies to any situation where you have to cut a hood, door etc to precise measurements when you can’t access the “accessory” behind the panel while you are cutting.

Step One:
The accessory must be mounted in a fixed location. Here, the IC was already installed.

Step Two:
Open the hood (or door, etc) and run twine/string to act as plum lines. As per the PIC below, four pieces of twine run North, South, East & West, interesting at each of the four corners of the IC. Mark each corner of the twine as it intersects the IC with a mark. As per the pics, I used red paint.




Step Three:
Use two pieces of tape at each end of the twine. One piece of tape is used to hold down the twine to the car. Pull the twine tight, and tape it to the car. The other piece of twine is the marker. It is placed under the twine (next to the hold-down piece of tape) and is used to mark the location of the twine as it lies across the tape. As per the pic bleow, the blue tape and the twine have both been marked with a black pen mark across them. [The rational is that after the twine is removed, the hood is closed, and the twine is re-stretched over the hood, with the black pen marks marking the exact location at which the twine was originally placed and therefore indicating the exact location of the IC as per the red marks in Step Two above. Read on, it gets clearer.





Step Four:
Make sure that each end of twine has marker tape and is properly marked. Verify that the hold-down tape has not allowed the twine to slip: this will cause your markings to be off and you will not be cutting above the IC.

Step Five:
Remove only one piece of hold-down tape from each piece of twine, leaving the other side hold-down tape in place. Move the twine aside and close the hood. Then reattach the twine to the hold-down tape at the location it was prevoulsy removed from. The marker tape has a black pen mark. Just align the black pen mark on your marker tape to the black pen mark on the twine. The red marks that designated the exact location of the IC should match up on the closed hood. It will not be perfect, because the closed hood adds some height to throw of the markings by 2mm or so.




Step Six:
Mark the area to be cut with tape.



Step Seven:
Protect the rest of your car from cutting shavings. Also, place a metal plate or other suitable metal under the hood in the area where you will be cutting to protect the IC and other engine parts from accidentally being cut.




Step Eight:
Use proper tools and proper safety procedures. I found that a pneumatic die cutter with 3.5” cutting disc for metal works best. Don’t forget gloves, ear and face protection.




Step Nine:
Say a prayer (hey, it can’t hurt) and do the cutting. When you are finished, you have a nice hole.




Step Ten:
Trial fit your hood scoop by laying it over the opening.




Step Eleven:
Mount your hood scoop, with glue, bolts, double stick tape, etc.
I chose bolts, which I painted at the same time I painted my hood scoop.
The finished product can be seen at http://www.924board.org/viewtopic.php?t=19266&postdays=0&postorder=asc&start=75
Enjoy, and don’t be afraid to experiment with your car.

[Peter_in_AU]

WOW!! Peter that is great! Thanks.
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1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you

[Peter]

[endwrench]

Hey, great idea with the strings! Simple but effective. Could have used the knowledge in the past. Still, it had to be a little scary cutting into that pretty new paint

BTW, the scoop looks much better than I imagined it would.

Todd
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....

[Peter]

[Ozzie]

Looks good.

You can't jump a gorge in 2 hops. Take a big leap if its neeeded.
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance