http://cgi.ebay.com/ebaymotors/SILVER-BLUE...609165518QQrdZ1

Above link sends you to a product called universal 3a racing shift light, which is not so universal since it needs a aftermarket 3a racing tach to work, but the seller "forgot" to mention it...

anyways, i ended up paying $25 for a aluminium tube with 4 led in it Can not return the product so i got to make it work.. here is how i want to do it:

OEM tach gets an input voltage corresponding to the rpms(please correct me if im wrong) if i run a variable resistor from that input to the base of a transistor that would switch 9V to the LEDs, then I will start the car and set the resistance to the low end and rev the car up i will get enough current to the base of the transistor to switch on the LEDs in shiftlight somewhere in low rpm range... then with increasing resistance i will get the LEDs to go on later in rpm range, and that is how i am going to adjust.

Am i going to make the tach read unaccuratley? Does tach input wire uses voltage as the only reference to rpms? Is this going to work at all? Thanks for reading/responses!

Good info here:
http://www.6gc.net/forums/index.php?showto...&hl=shift+light

thanks for the link but that is not what Im looking for



My shift light is just a set of 4 LEDs in series, it does not have "the third wire that connects to the rpm signal" it only has + and - so dont buy this ebay POS... Im trying to make it work but i don't know what kind of signal does the RPM signal wire sends to the OEM tach, is it voltage, pulse frequency? anyone?

what about this i know its a stupid name, but it looks like it has a green wire.
http://cgi.ebay.com/ebaymotors/BLACK-Alumi...1QQcmdZViewItem

^ he is right that shift light has a green wire also, however its listed to be adustable from 3k to 12k probably reads the rpm signal and goes to whatever settings its suppose to.

Side Note: whats the purpose of a shift light, seems like the only need for it is if someone is just learning to drive a stick shift? I mean its pretty easy to tell when to shift if your driving normaly, and it only takes a few launches to konw when to shift for the best acceleration.

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LMAO "BLACK Aluminum SHIFT LIGHT TURBO BLOW OFF VALVE" that is indeed a stupid name for a shift light, but looks like it could work so try it out and let me know if it works

Anyone wants to show me the connector pinout for gauge cluster where i can see rpm signal wire? I'll try to come up with something and if it works that means anyone can build in a shiftlight for $5 and mount it anywhere where you can fit a LED... now one in the cluster with some factory look to it would be nice...

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Yea back on topic my so called "shift light" has only 2 wires...

Side Note: shiftlights are nice when you have lots of power thats throwing your tach needle with the speed of light in first and second gear and your trying to get the max. precision with min. eyes on the tach.. I think it was talked about in this thread:
http://www.6gc.net/forums/index.php?showto...&hl=shift+light

^ that link takes me to the forums home page?

well I kinda think of them the same as i do a 7" tach, does nothing more then make your mods list longer, no offence to anyone. but if your thorwing down lots of power I hope your ready to handel it, and not going off a little light.

side note: check out this other auction from the same seller: drift knob Nissan S13/S14 Silvia 240sx Spin Turn Knob

"Hand break do not lock for park unless the spin turn knob is pull" I cant say i turst the seller.

wooooo yeahhh sweet mod

This post has been edited by creis: Feb 3, 2006 - 1:48 AM

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it does sound like it could be useful, but obviously they are just trying to rip people off.

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Yea my link doesnt work but click on the link that 97lestyousay posted earlier and you will understand the advantage of a shift light, tach is different coz you can not tell where in rpm band you are without looking at it, shift light is like !FLASH! in the corner of your eye telling you that you got 0.0002 second to shift before you redline it, either way if its adjustable per gear then ill bet you any money that you will not get nearly as close to perfect shifting in WOT in a curvy road without a shift light, as you would with a shift light

well i'm not putting down any massive power or anything, but i can shift at the right rpm's without looking no problem (but again my needel does not move the speed of light)

just seems usless to me, your better of lurning your cars acceleration ablilities then just shifting to a light.

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wow every is so off topic.

well your idea will not work, because you are taking power away from the gauge cluster by adding a transistor. You need an extrenal power source for the LEDs. If you take any current from the tach wire, it will throw off the gauge. Remember we are dealing with a small changes of volts or ohms here. Any brute force methiod will not work.

The only way to get this to work is to get a small microchip that can monitor the the voltage. Then when the voltage is correct it will turn on your shift light.

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Do you just tell by sound? It is for racing. Consistancy is the key in bracket racing.
Shift Lights serve a very good purpose.