I dont want to make your impressive achievement seem pointless, but was there a reason you didnt try to recalibrate the sprinter tach?
http://www.mindspring.com/~jayk3/toyota/tachmod.htm
This was a commolnly asked question on the old forums. Why does my 4 cyl tacho read funny now I have a 1J in there?? The answer is simple 6 cyl engines send more signals per revolution compared to a 4 cyl. meaning that you tacho will read approx 1/3 higher than it is supposed to.
There are several ways around this.
1. have the tacho calbrated to suit (TA22 tacho's off the top of my head can be modified)
2. Install Monster Bling Bling Tacho (which have switches to read 4, 6, 8 Cyl)
3. Don't have a Tacho
4. Try this swap. (ie install a 6 Cyl tacho in to existing 4 cyl)
I have done this to the Sprinter and it works a treat. this example is for Stitts "Dubbo or Bust" mobile which never had a Tacho (except for the Coupe and thus is uber rare and exy)
The Theory is simple Find a suitable tacho and swap it in. The reality not as simple as there are a few factors to concider. For the photographed example here There was no tach. so a suitable tacho face had to be found. in this case a TA22 tacho is the doner face. being 4 cyl still another 6 cyl unit had to be found and it has to have the same sweep as the TA22 face (ie the face of the TA22 tacho goes from 0 RPM to 8000 RPM through a 260 degree sweep. so a trip to pick and pay less was made to find a 6 cyl tach with the same sweep. A Crown MS112 is the doner.
In the case of the AE86 tacho I couldn't find a suitable sweep 6 cyl tacho so I found a 6 cyl tacho and face and swapped the whole lot.
This is the TA22 tacho that donated the face. it has the same rasied letters and points as the rest of the guages
This is the 6 cyl tacho unit from the MS112 which is screwed through the face of the tach with 2 screws (you can see this on most toyota Tachos) It appears that most Toyotas use the same 2 mounting bolts locations on the face on nearly all tachos from 80-mid 90's so there is a huge number of cars that can be a doner.
The TA22 face had an older style mounting system that was ground off using a dremel and the 2 mounting holes were re drilled to suit the new doner tacho unit.
The tacho unit bolted through the face of the TA22 gauge ( the pipe thing is a light that the TA22 uses (in this case will need some grinding down to suit the new housing as the Light will be reused)
The tacho unit and the face bolted together and the needle in place ready for test fit and installation back into the Dash Cluster.
( Note for Stitts Wagon now powered by p00 I have taken the liberty of using the old brake light from the TA22 and converted it to a BHG warning light. I have studied wiring diagrams, Surfed the net and found everything that happens in a p00 motor that contributes to Blowing headgaskets and done some special wiring so that when ANYTHING that happens that endangers the headgasket, the light will illuminate warning the driver that BHG is Immanent..... It is wired to the ignition switch.)
Test fitting back into the guage cluster it the new Tach doesn't look out of place keeping the theme of origonality for the car. All that needs to be done is the old clock that used to be there will be doner for the mounting brackets and clear plastic cover to make it fit as good as origonal.
This is the completed Sprinter Tacho. this was much simpler. the doner tacho unit was out of a JZA Supra and I used the Face as well as the unit and trimmed the face to suit the oil Pressure gauge and the Hi beam light. Here you can see 1 of the 2 screws that hold the tach unit to the face under the tail of the needle. this was basically pull the 4 cyl unit out put the 6 cyl unit in, even the wires reconnected with out issue. If you look closely you can see the outline of the Tacho face card over the origonal.
So basically what you have here is a cheap simple option for a 6 cyl tacho after you have done a conversion from a 4 to a 6. The same wouls apply for any other swap as well 6-4, 6-8 etc. Not bad for about $15 and about 2 hours of my time....
Beige.... The new Black!!!
I dont want to make your impressive achievement seem pointless, but was there a reason you didnt try to recalibrate the sprinter tach?
http://www.mindspring.com/~jayk3/toyota/tachmod.htm
Yes I did look at that site, However Not haveing a "reliable 6 cyl Tacho" to read from to get the accuracy and I had all of these parts on hand, and I didn't have the equiptment to do it as the site sugests I did it this way.
Beige.... The new Black!!!
i sell signal converters that can adjust
4cyl to 6
6 to 4
etc etc
and they can be very finely adjusted for exact calibration
I gave my tacho to a guy to recalibrate.
Cost me $25
Peewee
1985 MZ12 Soarer - 1UZ Powered
2013 86 GTS
Great how-to mate!!!
I'm also not trying to depreciate ur work, but just for anyone else thinking of other options... i can add 2.
The first is to use Jaycar's adjustable speedo kit (which is pretty expensive and bulky in my opinion) which can adjust speedo (squarewave) signals +/- 100%. I dont see why this wouldn't work with a tacho.
The second, much cheaper and smaller (and doesn't need calibration) option is to use 2 logic chips (74HC02 and 74HC74) and a voltage regulator (LM7805) which adds up to a pricely sum of $3.05, and convert the signal down by one and a half using flip-flops. I haven't actually done it with a real tacho, but have done the same thing with a squarewave in a completely different application... it shouldn't be any different. If anyone really thinks they would benifit from it, I could build it and confirm that it works. let me know.
Might prove a lot easier than the conversion mentioned above if u have a 4cyl tacho already in the dash and 6 cyl engine already under the bonnet.
Cheers
t.
Yes... i should point out that I am Aware of most of the above ways of doing this.
The reason for the conversion in the photos is the Car doesn't have a Tacho and one needed to be put in. the TA22 was suitable but not operating, So I did it this way.
Beige.... The new Black!!!
Good to see it going together thanks mate
As said its another way to do it
ST177 UZS131 Crown Royal 'G' the pimping limo like daily 1UZFE 144rwkw
DST17T MS53 68 Crown Custom Wagon 7MGTE 266rwkw
Kinda makes modifying the original tacho difficult then, doesn't it?Originally Posted by Lambolica
Good job Lambo.
The RA23's have a little potentiometre type thing on the back of the tacho. I just adjusted that till it matched up with my Dwell/tacho metre when i swapped from 4 to 6cyl! Easy!
Dylo
anyone done it in a hilux?
Now this info is Gold.
1971 2T-B Celica TA22 ST.
1973 2T-G Celica TA22, aka "The Unicorn".
1975 2T-G Celica TA27 GT
1976 2T-G Celica TA23, aka "The Colonel".
1985 3F Auto FJ62 Landcruiser
1989 7M-GTE MA70 Supra, aka "The Poopra"
History: Rods Classic Celica Sampler thread.
I find these ideas intriguing, I'd like to subscribe to your newsletter....
Nice work
I should also note, for those who have converted to the likes of a 1JZ or 4AGZE and your factory tacho isnt working, there are a couple of SIMPLE mods you can do to fix up the tacho rather than buy a tacho booster...
Link to fixing JZX70 tacho - http://masa-ya.jp/bike/jzx70g/tacho.html
** cant find link to doing the AE86 tacho, but the user "JP" on here has it on his webspace somewhere
Timbo, i've got a new topic to post that i'd like your input included please.
link - http://www.toymods.net/forums/showthread.php?t=18393
Last edited by The Witzl; 30-01-2007 at 10:46 AM.
...... butt scratcher?!
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