Shift light

kdfoust · 09:37 PM

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DSPTurtle · 04-30-2002, 09:33 AM

I wish I had your motor cause my 1.8L gets out of the car and tells me when to shift. Not really, but it does fall flat on its nose around 5500 so you have plenty of time to shift before the 6k limit. Sorry I can't answer your questions but I did get a laugh!!! Thanks

John Rogers · 04-30-2002, 09:59 AM

If you pull the tach out of the dash carefully you'll see the connector wire (black Purple stripe). Use a piggy back lug connector or a crimp type wire clemp and attach the signal wire from a shift light to this. The other wire on the shiftlight is a ground and can attach to the ground connection at the tach. I use an MSD shift light bought from Summit mail order and screwed it to the top corner of the curved area over the instruments. Run the wires in through the joint in the dash top. If you do not want to drill the dash, you could adapt a windshield mount for a radar detector such as Radio Shack sells but you could not race unless it is mounted solid. Good luck.

SummerSledSix · 04-30-2002, 10:17 AM

Shift indicators are usually those big honkin' tail lights so that you can use your peripheral vision to pick up the indicator and not have to take your eyes off the road . If this doesn't float your boat, note that the factory added some indicator lamps to the gauge panel (in between gauges) to the late model California cars for the CAT and AIR pump. You could just get a 12 volt indicator lamp from R/S or your FLAPS and wire it directly to your shift "computer". However, if you want to be covert about the whole thing, here's an idea:

Making your tach indicator lamps do double duty is a fairly easy scam; all you have to do is make a little "Y" adapter out of some diodes and spade lugs. For you logic weenies out there, this is the original "wired-OR". The diodes are gizmo's that allow current to flow only one way. You'll use two of them to allow 2 sources of current (your shift indicator and whatever originally turned on the lamp) to light up one lamp while preventing "backflow" of current from one current source into the other (which could make weird things happen, or good stuff stop happening).

This assumes whatever you are using to drive the shift indicator lamp produces a momentary plus voltage output, not a momentary connection to ground.

If this is the case, go to your local Radioshack and pick up a pair of power diodes, ie 1N4001 or 1N4002 (or -3). These will carry at least an amp each, plenty for the indicator lamps. While you're there, get some crimpable, insulated spade lugs of the size that fit the lamps in the back of the tach, and some heat shrink tubing. Note that the lugs come in 2 sizes (red and blue) to hold wires of different diameters. Get the larger of the two (blue, I think).

Grab the diodes and find the little band on the end of each. Line them up next to each other so the bands are on the same side. Stick the two banded ends in a lug (female?) that MATES with the lug on the back of the indicator lamp, ie the hi-beam lamp. Strip and stick the end of some stranded wire into the lug along with the diode ends (this helps make a reliable crimp with the solid diode ends). Crimp the lug. Cut off any stranded wire poking out from under the lug sleeve. (If you don't want to crimp this stuff, you can solder it instead, just make sure you get bare lugs then. If you solder, you can omit the stranded wire part too.)

Now get some of that heat shrink tubing and cut 2 pieces, one for each diode. Cut short so that about 1/4" is exposed on the uncrimped end of the diodes. Stick each of the free ends of the diodes into their own (male?) lugs, along with some of that stranded "filler" wire, trim the diode leads if necessary so that the heat shrink can tuck in under the insulating sleeve of the lug, and crimp. You should now have a complete "Y" adapter made from 2 diodes, 3 crimp lugs, and some heat shrink tubing. If you have any bare conductor showing, tape it, RTV it, or add more heat shrink.

Plug the lug with the 2 diodes in it onto your indicator lamp of choice. Plug the original indicator lamp wire onto either of the free ends. Plug your shift indicator output onto the one that's left. Go drive it, remember to keep your eyes on the road MOST of the time

If you want, you can make 2 adapters and drive both the hi-beam indicator and the turn signal indicator simultaneously.

kellzey · 04-30-2002, 03:48 PM

Me no understand diode and logic curcuits!

Want built shift light from duct tape and rust!

SummerSledSix · 05-01-2002, 05:28 AM

The tach light thing may be cute, but the big-light approach will be your most effective. There is a dedicated shift indicator on 911 tach's (at least the '84 I cannibalized), but it's very hard to see.

John Rogers · 05-01-2002, 05:37 AM

A huge shift light is really good at the start of a race when you are in the middle of a pack of cars and just can't seem to find the time to watch the tach since you are trying to pass those in front and those in back are trying to pass you! Most other times I have the peripheral vision enough to see the tach needle since I also use a large MSD recall tach. Another handy light to have if you are going to race is a huge red oil pressure warning light. There are commercial ones available or you can piggyback one off the little blue light in the combo gauge with a red side marker light from Pep Boys. Check the race car article I wrote on the PP site here and you'll see it. Good luck.