Shift Light.... with a difference :D

[eurisko]

Yeap, ive just spent 3 days designing and building a 'new' kind of shift light for my tacho.

Buy the end of today ill have pictures and a video to show you guys what i mean, but as of right now ill give you guys a bit of a hint of what it will look like.

This is possibly the coolest invention ever made.... and now i will have it in my car! 

Because its a spur of the moment kinda thing, I didnt get a chance to actually photograph its construction and whatnot, but ill see if i can explain how i did it soon.

The idea was stolen off a nobel m15....

http://www.youtube.com/watch?v=2mIHVpfNwPo

And goto 1:12 to 1:18.... 

EDIT: The circutry hasnt been built yet, but the hardware has, so im heading to jaycar after work to get all the bits and pieces for the mod!


EDIT: VIEW IT W0RKING HERE!! http://www.youtube.com/watch?v=MIPuuvuWhxI

[chr1S]

ahaha that's crazy , ive never thought of that... at all !

[Ka-Bluey]

That would be cool if you could pull it off.

[eurisko]

Well, the tacho has already been modified and is working, and i just got back from jaycar with the chips and circutry needed to drive it.

Tommorrow ill solder it all up and have a crack, hopefully she'll work! (Testing the led's it looks fucking awsome... im surprised at how good it actually looks!)

More soon...

[Jono]

Looks like a really good idea... but I'd think of it more as a redline than shift light because you wouldn't see it in your peripheral vision... unless you put in a heap of red LEDs 

[Colby]

Now watch this one and wait till right near the end in the TVR.  Thats my idea of a shift light
http://www.youtube.com/watch?v=AVb1FX7DWqQ&mode=related&search=

[eurisko]

Looks like a really good idea... but I'd think of it more as a redline than shift light because you wouldn't see it in your peripheral vision... unless you put in a heap of red LEDs 

Hehehe nah nah.... im not using your regular LEDs you can get at jaycar mate.... im using the good stuff... $35 a pop for these bad boys, you cant look at them directly, because they WILL blind you!

Pics tonight.... 

EDIT: I just saw that clip. Ive seen it before, but it will only work with those kind of 3D projection type digital displays.... like on a echo. But.... maybe you should have a crack ey?

[Wolf In Sheep’s Clothing]

How about this idea for u13 owners with HUD. A hud colour change for a shift light.

[Colby]

man colour range for the HUD would be awsome.  Although i'm not sure how clearly colours come ouit on the HUD.  But that would be great too!
I'm keen to see the outcome of the needle, looks like it could be sweet!

[eurisko]

Well, its installed and working! 

Ill take a video of it after i eat lunch (yes im aware of the time  ) and post it up! Teeheee

It looks awsome! 

EDIT:

View it here!!
http://www.youtube.com/watch?v=MIPuuvuWhxI

[Jecks]

that is bloody brilliant... 2 thumbs up and an erection...

[Kranzy]

that is bloody brilliant... 2 thumbs up and an erection...

I agree bloody fantastic.

[JelloBello]

wow. That is really cool.

I'm eagerly awaiting the write-up . . . If there's going to be one?

[eurisko]

Yeah mate, there will be a write up... but no photos unfortunately... 

Like i said, i did it pretty much spur of the moment and mostly at work, so i didnt get a chance to take photos.

I havent had a spin at night, but im going to right now.... so ill give a review in about 30 mins!

Keep you all posted! 

[eurisko]

oh, and thanks for the feedback guys!

The camera makes it look a lot more "white" than it really is.... ill try and get better footage!

[Rake]

Thats awesome

[eurisko]

Just a quick tutorial. Same post on my project section, but ill repost here just for ease of readability.

I used these types of LEDs. They are extremely small and produce an obscene amount of light.



Taking apart the dash and pulling off the cluster, removed needle, black plastic face and circut board from the perspex frame. (All small screws)

I marked out the location for the leds next to the needle hole, and dremeled the square cutout very carefully. Dont remove too much material, or youll be stuffed!

I also bent the legs flat, and using a triangular shaped mill bit, made indents into the back of the perspex, so the leds will sit flush and not interfere with the spring for the needle.

I used ribbon cable to solder onto the leds because it is very flat and thin. After they were soldered, the leds were placed into the holes and hot glued into place.

With the wires in place, 2 small holes were made into the black face of the tacho, letting the leds pop out.

Everything was put back together and tested!

The orange backing from the needle was removed with a razor blade, and white out was put in its place. (Model paint is also used by some ppl, but i didnt have any  )

With the hardware done, i went to jaycar and bought a frequency switch kit.

Making that, the leds were connected to the relay (green led on the n/c or normally closed pin, and the red on the normally open pin).

A small 1k variable trimpot was placed in series to allow for light intesity variation.

Power for both the lights and circuit was tapped from the Cigarette lighter power supply (Dont do what i did and try the power from the dashboard lights.... they drain too much and dont let the circut or leds run).

Plug it all in, and your off!

 

Hopefully thats sorta enough to get you on the right track.

I still have heaps of these LEDs left (i have about 6 blue, 3 red and 3 green Leds, and like 20 white ones)... so i might be able to help you guys out if i have the time 

otherwise, i might use them for other projects!

[Jono]

Very nice, I'm impressed 

One little tip though, hot glue isn't the best thing to use in a car, especially with the heat of summer coming up. If you're going to use hot glue then back it up with silicon, and make sure the glue won't do any damage if it warms up and runs down wherever.

But yeah... looks brilliant!

How is it to drive with at night?

[Wolf In Sheep’s Clothing]

Very cool!

[MAG86]

 a big order of McKarma to you....

absolutly brilliant...

I will DEFINITLY be doing this!!!

[weasel]

very nice

can you set when it swaps to red or is it just preset??

and tell you what if you want pics for the tutorial, you could always modify a dash for me and take photos in the process

[eurisko]

very nice

can you set when it swaps to red or is it just preset??

and tell you what if you want pics for the tutorial, you could always modify a dash for me and take photos in the process

Yeah, ive set it to 4500 to give me a bit of warning that im thrashing it... but you can set it to anything.

And ill do it no worries.... *cha ching* 

[MAG86]

with the circuit, is there a way to have multiple triggers?

like a white LED for 0 to 3500 rpm, blue for 3500 to 4500 rpm, then a bright arse red one for after 4500 rpm?

[kERo66]

with the circuit, is there a way to have multiple triggers?

like a white LED for 0 to 3500 rpm, blue for 3500 to 4500 rpm, then a bright arse red one for after 4500 rpm?

thats an idea, depends on the switch thing your using, by the sounds it only has open and closed so only 2 but im sure there is a way around that.

how much approx for materials and if we were to get you to do it for us what would be the labour?

[MAG86]

the kit is $35. those good LEDs i have no-idea , maybe $5 each,

so materials around $45..... then there's a good hour building the kit, then all the mucking around with the dash, about 3 to 4 hours all up....(including installation)

$45 materials
$60 labour (@ $20/hr)

$110 would be a good price for the work done (including install) of course as more are made the less time it takes to make, so a GROUP BUY would definitly decrease the final price eh! for individual kits, ready made to install yourself... I would aim for $65 to $70, for one kit.... maybe $50 if like 10 are to be made...

But hey this IS eurikso's idea, i will let him do the marketing and stuff....
(Hey eurikso Im pretty good with electronics too if you ever need a hand  )

[kERo66]

its actually 35 for a led i believe and he has 2 so its probably going to be more

[MAG86]

man you can get a pacl of 50 luxeons pretty cheap off e-bay...
i really dont think they would be $35 each... i could be wrong though!

[omad]

It's not really a shift light if it comes on at 4500, unless you do actually change at that.

The idea is great, though. I wouldn't mind another light stage if it was possible to do so.

How does the kit acutally trigger the light change? I'd be interested to see if you could do the same thing for the speedo and set that to 100 or 110km/h.

[MAG86]

the kit is made to switch on or off a device when a pre-set frequency is reached, the tacho operates on pulses of electicity ...A speedo is a pulse output too ... im sure it will work on a speedo....

You could have 3 or more buttons(or a dial with marked speeds) on the dash or steering wheel, which switch the level of the relay to go off at 60km/h 80km/h or 100km/h

i think this is a great way to avoid speeding... i would definitly see the benefit of this on long drives, like when you  look down and go "...shit im going 120km/h, i wasnt looking at the speedo, *FLASH*.... oh SHIT"
which happened to me during a 3 hour drive....

I am positive the kit can only trigger at one pre-set point, but it can turn on more than 1 device. (like a beeper)
for more than 1 trigger point (multiple relays) another kit would need to be added, or use a completely different one.....

on a single kit you could switch the inputs and outputs, like speedo OR tacho ( including their lights) but not both on at the same time...

oh im ordering one as soon as i get paid....

[eurisko]

I talked to my boss and the other electrical engineer at work today, and I realised the LEDs cost about $6 bucks each, not $35 (that was the price for a set, not one... my bad guys!  )

The circuit is designed only for one output... but talking with the engineer, he can help me redesign it to allow multiple inputs/outputs....

I might post a quick poll to see if its worth either selling a diy kit, or maybe an exchange type program (send me your tacho, ill send it back modified with the kit)... or something else...

Depending on how much I can source the kit from (or make my own), how many ppl are interested, it could be from 100 bucks to 50... including full modification, kit and associated hardware and full instructions...

But thats upto you guys 

[kERo66]

im interested but your in sydney, so would be a diy kit for me i think

[SMI7HY]

thats awesome mate, well done   

[weasel]

if you are gonna do this thing or a diy version, how hard would it be to light up all the needles on the dash??  so you could have all lit needles (oil,fuel,temp,speed and tacho) but only the tacho would change colour

i can't imagine it would be too hard to do

[pedro666]

thats ACE, would be keen for one.. awsome.

[rathies]

i just want green needles. +karma mate. I'm not suggesting that it can't be refined or knocking your good work, but the glow coming out from under the needle, it can be shielded somehow so it doesn't shine on the face of the dial right?

[ashman01]

Im interested!

[eurisko]

i just want green needles. +karma mate. I'm not suggesting that it can't be refined or knocking your good work, but the glow coming out from under the needle, it can be shielded somehow so it doesn't shine on the face of the dial right?

Hehehe yeah it can. The LEDs are pretty powerfull, and reflect everywhere... but i have a solution... if i can be bothered to pull apart my dash this weekend.

And as for the other needles. Damned straight! Its pretty easy (speedo might be a bit more complex... but it can be done)

So yeah. All needles is possible.

Hell, i have a spare dash right here. I might just do it for fun!

Thanks for the feedback guys! 

[MAG86]

heya mate good work 

I would love the instructions on a multiple output kit.... and you are now my official source of LEDs....

Looks like you have something going here eh!

[Wolf In Sheep’s Clothing]

with this kit would it be possible to say rather than changing the colour of the led when it gets to a defined level, change the intensity of the led.

eg.

The needle is red all the time, but when the needle gets to the red line it becomes a brighter red?

Excuse my ignorance I don't know too much about electrical stuffs.

[MAG86]

yep, easy as.... could even flash if you wanted it too... could even make neons in your footwell light up, basically anything that can be switched on or off...

man this kit can even be used as an adjustable rev limiter, if you had an immobiliser kit installed ( with modifications of course)

cant wait...

[JelloBello]

And as for the other needles. Damned straight! Its pretty easy (speedo might be a bit more complex... but it can be done)

You're quite right about the speedo, as i'm sure you've seen it's a pretty tight fit between the plastic and the odo/speedo stuff behind it . . . nothing a dremel can't fix

As soon as i find myself a dash with a tacho i'll be doing this mod, might even go pick up the kit from jaycar in the near future.

[Budgie]

Eurisko, you posted up that you were going to do this the night before I was about to fly out to QLD for a holiday.  I come back and you've done it and it looks fucking awesome!

If it can be done using a JDM tacho, I would be 100% interesting in one of these mate.

I really admire your hard work mate, it looks great

[eurisko]

In the process of designing a multiple output board.

That means, one input, and upto 10 different outputs! 

If it works, be prepared for some craaaazyyyy shit!

[JelloBello]

That means, one input, and upto 10 different outputs! 

woah... when you say 10 different outputs does that mean you can set 10 different frequencies? or Is it just one set frequency which switches 10 devices all at one?

either way that's insane... you could make the backlights of your dash change from someting like blue to red when you hit a certain RPM (or speed?)

[eurisko]

Both! 

Specifically tho, i mean each device will be triggered at different frequencies, sequentially. So, if the design is set out correctly, you can set how slowly or quickly it goes through the outputs.

 

[Loop]

Both! 

Specifically tho, i mean each device will be triggered at different frequencies, sequentially. So, if the design is set out correctly, you can set how slowly or quickly it goes through the outputs.

 

Cool ... I've been looking for a shift light that has multiple sequential LEDs .. you reckon you coul get the last one to flash when it triggers?

[Jono]

Just add on a little flasher circuit

[SAIUN]

I suppose it would cost way too much, but has anyone thought about hooking the tacho up to all the lights in your car?

Imagine when you hit 6,000 rpm the whole dash and all the interior neons change colour!  My eyes! 

[omad]

I suppose it would cost way too much, but has anyone thought about hooking the tacho up to all the lights in your car?

Imagine when you hit 6,000 rpm the whole dash and all the interior neons change colour!  My eyes! 

Wiring the whole car would be a pain in the ass, but other than that it's not that difficult to sort out. Just get the circuit on the kit to trigger a relay which handles the rest of the lights. Easy in theory, just a bitch of a wiring job.

[eurisko]

I suppose it would cost way too much, but has anyone thought about hooking the tacho up to all the lights in your car?

Imagine when you hit 6,000 rpm the whole dash and all the interior neons change colour!  My eyes! 

Heheh nah the circuit im designing is very simple and shouldnt add 20 bucks to the design, all up. The cost is being reduced everyday when i find new and exciting things

Ill have a prototype built this weekend, and ready to show to you guys!

The kit will have an expansion board, that will let u increase the outputs from 10 - 30 devices! Its getting bigger and bigger everyday!

and when i say 30 devices, i mean INDIVIDUAL devices. As in, you can have 30 different coloured LEDs, buzzers, anything!

oh and one more thing, the final design will most likely be Surface Mount Devices, making it incredibly small, and cheap to manufacture!

[Jono]

Hey do you know how the circuit works? does it convert frequency into voltage and then when that voltage gets high enough it triggers the relay?

Is the circuit affected by heat in any way?

This might help with my LED tachos I was going to build ages ago.

[JelloBello]

buzzers

that's what i'm talking about

[eurisko]

Hey do you know how the circuit works? does it convert frequency into voltage and then when that voltage gets high enough it triggers the relay?

Is the circuit affected by heat in any way?

This might help with my LED tachos I was going to build ages ago.

Yeap, exactly how it works jono. It uses a frequency to voltage converter that drives a relay once a threshold is met. But thats the circuit im running now, which is very complex and limited. The one im designing does away with the relay, allowing huge flexibility. It also simplifies the Jaycar circuit.

No, its not heat sensitive, and the jaycar unit on the other hand can support any load (huge amps too because of the big ass relay it uses).

What kinda tacho u looking at building... maybe i can help?

[Jono]

There was an eoi about them in the for sale section last year

which has since disappeared off the end of the list

[omad]

Heheh nah the circuit im designing is very simple and shouldnt add 20 bucks to the design, all up. The cost is being reduced everyday when i find new and exciting things

Ill have a prototype built this weekend, and ready to show to you guys!

The kit will have an expansion board, that will let u increase the outputs from 10 - 30 devices! Its getting bigger and bigger everyday!

and when i say 30 devices, i mean INDIVIDUAL devices. As in, you can have 30 different coloured LEDs, buzzers, anything!

oh and one more thing, the final design will most likely be Surface Mount Devices, making it incredibly small, and cheap to manufacture!

Not to try and put a dampener on your efforts, but don't you think that maybe 10-30 intervals is a bit much? I'd settle for just 3. The only thing I could think you'd want a couple more on would be the speedo. Even then, just having 2 colours with an adjustable level would be great.

[eurisko]

Not to try and put a dampener on your efforts, but don't you think that maybe 10-30 intervals is a bit much? I'd settle for just 3. The only thing I could think you'd want a couple more on would be the speedo. Even then, just having 2 colours with an adjustable level would be great.

Well, actually its alot easier to make it with 10 outputs than 3... if you can believe that! 

Im making this circuit for ultimate flexibility... so say for example, you want a bar tacho in addition to the regular tacho, you can do that!

The price difference is minor, and in my opinion, you get better value for it.

[chr1S]

time for takumi's speed alert buzzer he uses ..

the attesa has it when u leave the lights on hehehe, i lvoe that noise

[Jono]

time for takumi's speed alert buzzer he uses ..

the attesa has it when u leave the lights on hehehe, i lvoe that noise

Most of the imports I've driven have a speed alert on them set to about 110km/h.

Cut one wire and it's gone... ahh the sweet sweet sound of silence at 120km/h

[chr1S]

aww man that ting tong ting tong is so relaxing :p.

[rathies]

rofl, that funny jingling sound. I heard it once when I was test driving a MKIII supra. I thought it was something bad.

Don't you think 30 outputs is overkill jono? i guess you could use a few to trigger a spark plug at the end of the exhaust sytem, that would bring about the need for excessive fuel to be floating around too..soo another output can trigger an auxillary fuel pump! its 110% illeagal but you'd have some flames.

[eurisko]

Lol... just to clarify, it will have the ABILITY to have 30 outputs... but standard kits will only have 10.

This will allow you to have 2, 3 or more lights, or any number of separate outputs.

An add on board will be needed to increase its range. Each succesive board will change the sensitivty by 30db. That means 2 boards will have a 60db range, 3 will have 90db....

The sensitivity of each individual board is independant. Ill have a prototype built this weekend... I still see there is some interest so ill hurry it up.

I might just end up giving this thing away... lol i cant really be bothered trying to make a few extra bucks from this.... lol

*Shrugs*

 

[Jono]

Don't you think 30 outputs is overkill jono?

Who say what now   Eurisko is making the kits 

i guess you could use a few to trigger a spark plug at the end of the exhaust sytem, that would bring about the need for excessive fuel to be floating around too..soo another output can trigger an auxillary fuel pump! its 110% illeagal but you'd have some flames.

I did something like that on a road bike a while ago, only it cut the spark to the engine and ran a coil with a wire in the exhaust pipe. Ended up getting 40cm long blue flames, pretty cool at night 

[Colby]

Do i hear flame throwers? i know its highly illegal, but that would be pretty bloody cool.  Especially since it is switchable.. good way to stop those tail gaters

[Jono]

This was on my drivewa... I mean in a controlled environment

The flames weren't just a blue fuzz like the pic shows, they were more like conventional flames with swirly patterns and stuff, only blue instead of yellow.

[MAG86]

Whats the go so far matey!

Ive been hanging out for more info for a few weeks now!

Any chance of a prototype??

[eurisko]

Sorry bout that champ, Like i said, the design is made, but ive been kinda focused on the head conversion.

If you want, ill draw up the design (schematic) tonight, and post it up tomorrow. I dont think ill get time to proto it anytime soon, so you and everyone else can have a looksie.

Sound good?

[MAG86]

SHWEET!

Thanks and karma+

[Loop]

It's tomorrow already

[eurisko]

Hahahah I did the drawings last night, and realised how appauling my handwriting is. Ill use a ruler this time, and actually take my time!

Itll come guys, and its worth it! 

[eurisko]

I know i know. Relax. LOL! 

Here it is fellas.... unprototyped, but you get the gist.

Use the power supply to power all IC's.

The input filter is connected to the Tacho input, then the output goes to the Voltage to current converter (LM2917). That connects to the Bar graph driver (LM3196)

Thats it. The LED's connect to the 10 outputs from the Bar driver. This circuit is set on DOT mode, as in one LED will drive at a time. To change to BAR mode, which illuminates all LEDs sequentially, connect pin 9 to +Ve. For more info, check the technical data on National Semiconductor.





Ill write up a proper detailed explaination tomorrow.

Cheers guys. 

[Jono]

That's very similar to the LED tacho I made a while back... same IC's and stuff.

Good work mate

[eurisko]

*Nods*

The first chip, is a frequency to voltage converter, which changes the frequency of pulses from the ecu, to a linear voltage.

The second chip, is the bar/led driver, which gets a voltage, and switches outputs accordingly.

I cbf right now... big night last night  but ill go through the adjustments that can be made on the circuits.

On chip one, it sets up the sensitivity of the circuit... the gain basically.

Chip 2 has 2 adjustments, one is again sensitivity, which is like the gain or how quickly it will switch the outputs. The second set, is for LED brightness. This you may need to setup differently according to the LED current. It has a large adjustment, but check the specs just to make sure.

Its not a hard circuit to make, and purely analog, a digital circuit was in the works... but like ive said earlier, i really cant be bothered trying to make a few extra bucks for the hassle. :p

I have a more important project right now 

[HIRO]

I'v said it once and I will say it again Eurisko. . . Wicked!  When I first seen it Pintara Boy showed your tacho mod on U-Tube while he was on line talking to you. Played the video over and over again, bloody awsome. I am going to do it for sure.

[eurisko]

Thanks mate, hopefully my explanations are clear enough to follow!

Heres a quick update. I added adjustable brightness control, which lets u make it REALLY bright, or dim. I prefer dim, so its not as distracting, but bright is for the "Uela bro! Fast and furious!" moments 

http://www.youtube.com/watch?v=jh_m2vu8aJc

Meh... thank chr15 for making me make the video 

[Virus]

argh and im still trying to source a I/C cant wait to get this done. Lemme know if u can get that one we were talking about.

[chr1S]

it's a fukn S

[eurisko]

Im sure it is *nods sarcastically* 

lol

Other than that, what IC virus? If you want, just buy the jaycar kit, much easier and works 100%

Otherwise, the IC's should be readily available anywhere....

Edit: IC means instrument cluster.... *shakes head* Disregard the above comments... :S

[chr1S]

bahaha, noobie 

[Virus]

Every Instrument cluster i find is either fucked or i cant get it :S

Edit: Scrap that, looks like ive got one :D

[Dimenx]

Um... I have a question, how do you actually take out the needle? I tried to take it out, but that was kind of glued and I was afraid to break something, so I left that neegle alone 

[JelloBello]

The needles normally come off pretty easily... there's no glue involved at all

just get a good grip on the black bit of the needle and give it a pull while slightly twisting it... if that fails then perhaps try some pliers?

[Jono]

Carefully slide a screw driver under the black part of the needle and twist it to pop the needle off.

[Dimenx]

 

I was just trying to avoid taking the needle out... with the axis still in it 

Thanks for the tip 

[Gibbo]

yes i know this thread is old. lol , cheers for all the hard wrk . was looking for a stealth tacho/ shift light 

[chr1S]

what a f'n useless post, you could of pm'd him that ffs.

[Unbalanced_]

Wow, that looks pretty cool. Im glad someone re-ignited this post, I hadnt seen it before, and now im glad i did.

[nokey]

that looks fucking sweet,good idea never thought of that.

[horndog]

I know i know. Relax. LOL! 

Here it is fellas.... unprototyped, but you get the gist.

Use the power supply to power all IC's.

The input filter is connected to the Tacho input, then the output goes to the Voltage to current converter (LM2917). That connects to the Bar graph driver (LM3196)

Thats it. The LED's connect to the 10 outputs from the Bar driver. This circuit is set on DOT mode, as in one LED will drive at a time. To change to BAR mode, which illuminates all LEDs sequentially, connect pin 9 to +Ve. For more info, check the technical data on National Semiconductor.





Ill write up a proper detailed explaination tomorrow.

Cheers guys. 

   
I saw your post on the above shift light schematic. I want to build one for my motorbike for drag racing. Can I just use the LM2917 without the LM3196?
I just want an array of highh bright LEDS to come on at the desired RPM which I want to make selectable via trimpots? I want to be able to activate the lights up to a frequency of 1000hz.

[edecisions]

I know i know. Relax. LOL! 

Here it is fellas.... unprototyped, but you get the gist.

Use the power supply to power all IC's.

The input filter is connected to the Tacho input, then the output goes to the Voltage to current converter (LM2917). That connects to the Bar graph driver (LM3196)

Thats it. The LED's connect to the 10 outputs from the Bar driver. This circuit is set on DOT mode, as in one LED will drive at a time. To change to BAR mode, which illuminates all LEDs sequentially, connect pin 9 to +Ve. For more info, check the technical data on National Semiconductor.



Ill write up a proper detailed explaination tomorrow.

Cheers guys. 

I'm working on a simular project, I used the Typical Applications from page 10 of the lm2917 for a Voltage drive meter indicating engine RPM, seems to work good from 0RPM to 2200RPM, once I hit 2200 rpm the output voltage drops off and the leds start to turn off till I show 0RPM

My input is connected to the TACH out on a GM HEI, when I put my HZ meter to the port I get 1KHZ to 4KHZ throu 3000 RPM, I'm sure that I'm getting such a high reading because its showing all 8 Cyl's, if I devide by 8 I get 125hz to 500hz for a single cyl.

My question is, how do I correct the issue at high RPM that causes my voltage to drop to zero rather than to continue to climb, I get to about 4V at the point where it drops.

Ken

[edecisions]

This is just a follow up, I solved the issue with my HEI and thought I'd leave some info here for anyone else that might be having the same issue.

Issue was on my HEI as I'd rev the engine the voltage would go up as it should, then at the higher end the voltage would fall off to zero.

The answer was on page 7 of the datasheet for the lm2917, fmax- I2/c1xVcc, dropping the current flow of the input signal by using a smaller resister to drain off current resolved the issue, so I'm one happy guy.