FrankenFerrari - V12 Ferrari 308

I just tried to calibrate the tach and discovered it stops at 8k.  Years ago the ferrari tach died and they are stupid expensive to get fixed so I bought a tach at the parts store, ripped out the guts and installed then in the ferrari housing.  The numbers were close enough to right....but now I can program whatever I want so I added a calibration.  Last run I played with the range I was using  so it read mostly right but today I made the cal method better and loaded a little program to test it.....the tach stops at 8k. ☹️  I guess I figured that was fine when the redline was 7700....I'm going to need to buy a 10k tach and redo the guts swap it appears.

wait, I was just reminded the right thing to do is reprint the tach face so it goes to 11!

Still no word on the block tach mods it is.

I did have a "spare"....which means a 2nd broken broken one all in bits...I think this is the original and badly faded, perfect for a redo.

Last time i worked on this I was looking for a tach with similar number spacing so it would read about right, but this time what I really need is enough sweep.  So, I made a high tech measurement

and went shopping on amazon

This one is better than what I have, but still not enough as I don't want to count on being able to drive it past the final number

Winner-winner chicken dinner, more than enough!  I wanted something smallish so I know the gut will clear the indicator lights at the bottom of the factory face so this seems perfect, even the screw holes look close, and just $14 delivered so its in budget. This is a 13k tach, but the numbers don't matter, I will use the ECU to calibrate it to match the new face.

Next I need to create the artwork I want on the face...it has the work art in it so its not really my thing but I'll give it a go.

mke said:

Next I need to create the artwork I want on the face...it has the work art in it so its not really my thing but I'll give it a go.

If you don't want to do the artwork yourself, you can probably find someone on fiverr to knock this out for you in short order. This would be a 30 minute job for someone skilled in Adobe Illustrator.

In reply to Syscrush :

probably.....but I already started, I see how far I get before I give up.  I did the sketch for the hash marks and they look right.  my plan is use the center and highbeam holes to register the transfer correctly on the faceplate.  hopefully have something decent by the end of the weekend.

finished the numbers tonight....I think they look pretty good...and it goods to 11.  Changing the colors makes them look a little slimmer than OEM for some reason....may need to fatten them up, but they are drawn not just pasted images so its easy to adjust anything but it looks right with the background off .  The rest of the stuff I'm going to try to paste on, we'll see how that goes.

I think that's the face.  the small font stuff disappears in the render with the black background on but that is just a software thing.

decided the numbers weren't quite fat enough to look right

Transfers ordered.  The cheap price is for 20 day max to ship then cheap shipping is 10 days, so by the end of Jan I guess....unless its 20 business days then mid Feb, $76.

I realized why the images looked different with the background on or off....hide edges command was needed.  Then the fight to go from CAD to graphic.  Th transfer place had a link to an illustrator like program "inkscape" which I literally could not figure out how to make it do anything, anything at all useful or otherwise.  I exported the model as an STL, paint3D imported that and exported a pgn, I found "GIMP" which imported the png and the pdf template from the transfer place as xcf, and once I figured out the correct scaling I could edit the graphic in .xcf format, paste it the  now xcf template, then export the finished product as a pdf again because the transfer place doesn't support xcf....but that was good because then I could open the pdf with adobe and print it 1:1 to confirm everything looked right.  

Clearly there must be an easier way but this worked I think and here is the result.  There was room so I decided extra harsh marks would be the best way to register the 3 prints on the the face.  The white I left full, again for registrations to see where everything will be before transferring anything.

Tonight I ripped apart the new Chinese tach, fixed the a few cold solder joints on the board, ground the board to fit the Veglia mechanism, added a jump because my grinding removed a trace and the tach is working.  All easier than I expected. I'll strip and repaint the face and its ready for the transfers I ordered.

It just occurred to me that the tach doesn't need a circuit board at all.  8 volt zener on the power to the gauge drive coil, other side to the ECU with pwm ground which it already has, same as I have the other gauges working.  All the other stuff is to let the tach read a coil signal which it doesn't need to do anymore, so I wasted $14 on the Chinese tach....live and learn. 

mke said:

It just occurred to me that the tach doesn't need a circuit board at all.  8 volt zener on the power to the gauge drive coil, other side to the ECU with pwm ground which it already has, same as I have the other gauges working.  All the other stuff is to let the tach read a coil signal which it doesn't need to do anymore, so I wasted $14 on the Chinese tach....live and learn. 

I was wondering if you couldn't just do a voltmeter or stepper for no additional effort.

Syscrush said:

I was wondering if you couldn't just do a voltmeter or stepper for no additional effort.

The thing is I'm a mechanical engineer with very limited electronic knowledge or skill. 15-20 ago when the tach 1st died I  googled up a tch circuit and built it ...I got the tach to work but the calibration was unstable which led me to just buy a tach to rip the guts out of.  I know more today than I did then and now I know that circuit probably had a voltage regulation issue and today when I tried to steal the zener from it I realized why....the zener was fried because it looks like I substituted and wasn't smart enough back then to know I also needed to adjust the current limiting resistor so I probably fried the zener as soon as I powered it up and no voltage regulation means unstable calibration.

Trying to decide what voltage to use in the tach...today I'm smart enough to go out and measure how much voltage the mechanism needs to operate....1.5V vs. the chinese tach that need 5V to go go full scale.  Digikey or mouser I could get the exact right parts for a few cents plus $10 shipping, amazon  will send me a a 20 pk of a good enough part for $5...or it does work the way I have it unless I want to try to get it calibrated internally so any ecu could drive it.  Not sure.

Talked to the machine shop today, they tried to hone the block but there honing head won't reach the bottom of the cylinders.  We discusses a bit and they will try something else but not until next week and it that doesn't work it will probably come back to me to hone myself....one way or the other it will be back next week I believe.

Merry Christmas, mke.

Long time listener, first time caller.  I think this thread is my new favorite book.  After catching up on the last few months of work I found myself wanting to Google "books/threads like 'FrankenFerrari' " to find more!

Keep up the good work (and documentation for those of us living vi ariously through your exploits)!

It turns out the tach doesn't need anything but the drive coil to work just fine...it needs to be cleaned  to free up the mechanism a bit after sitting apart for 20 years but other than that its good.  I just connected the ground wire and the signal and put a 5V pullup thru a 240 Ohm resistor, the PWM in the cal table it about 92 at zero, 15 at 11k so the resistor is pretty near perfect.

mke said:

It turns out the tach doesn't need anything but the drive coil to work just fine...it needs to be cleaned  to free up the mechanism a bit after sitting apart for 20 years but other than that its good..

So this was a lie.  Cleaning helped a bit but what the real problem was, not being an electronics type I don't completely understand but in the 15-25% duty cycle range the mechanism changes how it acts creating a 1500ish rpm dead band.  Tried different frequencies from 10hz to 40khz which move where it occurred a little, tried a capacitor which seemed to make it worse and I final gave up trying to understand it and changed the pullup resistor to send a bit more voltage so I never need to go to the problem zone and that solved it.  I can't believe how much time I wasted on it.

All tis staring at the tach has me, for the 1st time in my life, being a believer in shift lights because now I know better than to trust the tach...it can lag or  it can just be off a bit but the shift light will match the ecu shift point every time.  I'll get the shift light setup tomorrow.....at least as far as the tach is concerned.  Shift point changes with gear selection so I need to add something to let the ecu know what gear is selected.  I remember writing something way back for this but I guess I never finished it because its not in the main program that I used last ti the engine was running.  But Ill get the ECU controlling the brake waring light on the tach as a simple rpm based shift light so I can call the wiring done at least.

I did not actually get the shift light working today.  I had the shift light and the exhaust valve to connect and 2 output pins let....no wait....where is the 2nd one?  gone to coil #11 it seems.  I forgot that way the engine lab guys gave me instructions on how to get 12 coil pins when the spec sheet says 10, it cost a HS output pin.  hmmmmm.....I was able to rewire the relay panel nd reclaim 1 output. 

Connected up the a wire for the shift light

Added a wire for the exhaust valve...decide to test the valve....it clicks but doesn't do anything??? fast forward an hour and I realize  the little solenoid is switching air ports and the valve itself, a pneumatic valve, need high pressure air to operate.....DOH!  There is a chance I don't need a valve, the vacuum actuators on the valves go at about 5 inhg....decided to leave the wire and see if I need to find a new valve once the engine is running again.

Which brings me to a moment I've been dreading.....wrapping up the wires in the trunk and making it look at least intentional if not neat.  It was everything I fear it would be, much like 10lb of E36 M3 in a 5lb bag....but it went.  Shift light tomorrow.

I'll call the machine shop again tomorrow I guess but in the mean time working down the list.

The shift light is working...of course it says "Brake Failure" not "Shift"....may look for a solution to that before the tach gets reassembled

I relocated the new fuse panel a bit higher to make the cover fit better.

Then it was time to pull apart the steering column to have a look at why the headlight up/down selector was flopping/popping to down and why the wiper switch stalk has been in teh door panel since I got the car.

The lights up/down part was just a matter of bending the contacts a bit but ....hmmmm ....old  crumpling plastic...not exactly sure what to do about this....I'm sure a drink will help though.

So after much thought I decided to see if I could just zip-tie them back together....as in weld them back together using a soldering iron and nylon zip-ties as filler.  They seem fine now.  I did switch from zip-ties as the filler to ABS which was easier to work with, a little lower melting point so I could keep the base material a little firmer, I kind of blended it into an alloy in the fill zone.  

Next I'll make sure everything is working before I torque the main nut down....but it looks good and probably 10 or 15 cents including the spray paint I dressed up the levers with.

Least expensive Ferrari fix ever!

Filled the fuss box and everything electric seems to work....mostly.  The fuss panel is all new so I was a but nervous.  Haven't seen the lights up or on in many years.  All the column switches seem to be working so that's good.

It took me about an hour to figure out why the radio was on but silent...I'd rewired the main power the amps to be neater so I assumed I buggered it somehow, turned out to be pin pulled out of the harness in the radio itself, probably when I pulled it to run the new wires to the dash.  

Then there is the power windows which do "work"...as long as I pull firmly up while holding the switch.....its past time I pull them apart to clean and grease them.  I guess that will consume the weekend.

Then there is just the issue of no engine......

the first door is in bits....

Dynamat goes in way easier than it come out

pretty sure the rear window guide is supposed to have a bolt

Pretty sure they wires are supposed to be attached ....

This is probably not that exciting to any non ferrari 308 owner but after about 10 hours of disassembly, cleaning, greasing, reassembly and adjusting, I got th the driver side window to go up and done without manual assistance.   This one had stopped completely, even assistance no longer moved it.....the "grease" was much more a hard wax like substance than grease.  I decided foolishly to pull the whole window which meant pulling the front frame....which meant cutting a couple bolts to get it out then extraction them so it could be reassembled.  but it works now and just needs the door panel back on.  I decided to let the broken power window go for now and jut removed the power lock stuff that has never worked....I think its suppose to unlock the passenger door when I unlock the drivers side but...I can live with out that

That's a hell of a snowblower.

Nader said:

That's a hell of a snowblower.

Yeah....I don't know what I was thinking when I bought that.  I keep thinking I need to drag it up to my father's in Rochester NY where is snows and have him sell it for me and get something less stupid.

I just went and measure voltage at the window motor the drivers side is 10V down, 8.5V up.  The passenger side is slower even after cleaning and about 8.5 down and 7-7.5V up.  no wonder they are slow.  This is with the charger on the battery so 13.7 at the battery.  

The wires going to the door are decent size at 16g so that is not the issue....that leaves the switch and connectors along the way.  The little solid state window accelerator really boxes they sell aren't really going to solve the problem either as the power still goes through the switch.  The ground doesn't so I guess 1/2 the voltage drop which is an improvement but the right answer is the switch controlling power relays so the switch is out of the power circuit completely and the power wires get shorter.  I  may take a look at it today.....the front console is hitting the throttle pedal and needs attention so I'll have at least that off anyway.  Fitting this means pulling new wires from the switch to the relay panel and pulling the window power wires out of the center and to the relay panel...I'm sure that are wrapped and tied....just time.

Others came to the same solution and after all my rewiring I have 5 empty relay slots....I guess I know what I'm going to due today.