Mechacnical Speedo Cable with Aristo A340?

sethron71

sethron71

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Hey guys getting really close on finishing up a swap I am working on. It is Aristo 2JZ-GTE w/ A340 into 88' MA70. I have everything wired up as per the million posts and diagrams. One thing I am not sure about is the Speedo Cable and then the buffered signal that is sent from the Dash to the ECU. If the factory cable does not mount up and power the dash then is the signal from the dash useless? What have others done to get a speed signal to the ECU? We have a Rev/Speed Meter for display but need to make sure I have the right speed for the ECU(or does this just come from the A340 and is pre-wired?) and is there a way to use the stock cable?

So basically has anyone figured out how to use the factory MA70 speedo cable to power the dash speed gauge with the Aristo A340?

Thanks
Seth
 
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Satan

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Yeah.... The MKIII mechanical/stock speedo becomes useless. I bought (but hadn't used) an Apexi RSM & a Driftmotion digital sending unit (this has the gear and replaces the MKIII cable, at the R154 tranny... 3-wires). You can also use the digital output from the 2JZ auto tranny's stock speed sender, to the ECU & Apexi RSM..... (the tranny should have one, I think). I'll have to double-check, but thought the 2JZ ECU also has an output signal, that you can then connect to a digital dash/display or other device.
 
Jeff Lange

Jeff Lange

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I am confused. Why can't you use the A70 speedo cable with the Aristo's A340?

The speed signal output by the A70 speed sensor in the speedometer will be correct for the Aristo's ECU input.

Jeff
 
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Satan

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I thought the A340 is the tranny that comes with the 2JZ-GTE... which I thought has a digital sender (to the ECU). If you were using an auto from an MKIII, the cable would be there instead, attached to the speedo, with a speed signal output to the ECU (cruise, etc).

When I first got my front clip, I was considering using the auto tranny...

The 2JZ-GE W58 uses a sender which is similar to the Driftmotion one, which has a speed gear and sends a digital signal to the ECU (needs a bracket fabbed up to use w/R154), but I do not know if the AUTO senders are interchangeable, to the point where you can attach the mechanical cable to it.
 
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sethron71

sethron71

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Because there is no mechanical drive on the Aristo A340 to drive the MA70 Speedo cable. If you don't drive the cable then the Dash can not be out putting a speed signal to feed the Aristo ECU. Am I looking at this wrong?

This seems to be the solution:
Cable-X-3012 Cable X 30: Electronic VSS To Mechanical Speedometer Drive Screw-on

I can adapt one of these to power the stock dash.

Seth
 
Jeff Lange

Jeff Lange

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Right, there is no spot to mount the cable, because the speed sensor is in that spot, but you take the speed sensor out, and put your A70's mechanical speedometer driven gear and sleeve into its spot so that you can connect your cable to it.

Jeff
 
Jeff Lange

Jeff Lange

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Yes, this would be done from the outside. Remove speed sensor, install cable adapter.

Maybe find one used from someone on the forums? (You'll need a matching driven gear, meaning you'll want one from a 7M-GTE car).

Part numbers if you just want to buy the parts required:

33403-69195 - Driven Gear (18-tooth to mesh with the Aristo's 6-tooth drive gear)
33404-30040 - Driven Gear Shaft Sleeve / Speedometer Cable Adapter
33485-30020 - Shaft Sleeve Retainer Plate
91611-60814 - Sleeve Retainer Plate Bolt

Jeff
 
sethron71

sethron71

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Hey Satan,
Also want to thank you for your peer review write up. One thing I went around and around on was the starter. I will post all my diagrams and such once I get this thing back in. I have an Aristo Harness so most the diagrams at Supra.NL didn't match but after going through a ton of different threads, diagrams, and manuals I think I got it all together! We will see when I put it in and try to crank it!

Seth
 
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Satan

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sethron71;1926291 said:
Hey Satan,
Also want to thank you for your peer review write up. One thing I went around and around on was the starter. I will post all my diagrams and such once I get this thing back in. I have an Aristo Harness so most the diagrams at Supra.NL didn't match but after going through a ton of different threads, diagrams, and manuals I think I got it all together! We will see when I put it in and try to crank it!

Seth
Click to expand...

Awesome, glad it helped. Am finishing a replacement harness for mine and ended up having to do the starter-relay mod thing. So, I added the Bosch relay near the ECU connections, using the starter signal wire (at the glove box vs. engine bay). So am very familiar with that circuit right now... LMK if U still have any questions.

GOOD LUCK on startup!
 
sethron71

sethron71

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Hey guys got the parts.

Only issue is this retaining plate is too short.
33485-30020 - Shaft Sleeve Retainer Plate

Doesn't reach from the bolt to the shaft sleeve. As well even if it was longer the shaft sleeve would have been too far out because the o-ring was slightly exposed. So I pushed the sleeve in further and plasma cut a larger plate that actually goes around the the sleeve to contain it. Not sure if there is just another part that would work better but I made it work. Gear and sleeve went in no problem!

But just sharing my findings. I will post pics a bit later to show how I modded it.

Seth
 
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Satan

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In for pics too...

I have a 2JZ W58 speed sensor that I am thinking about using (instead of the Driftmotion VSS) and would like to compare... All I may need is the MKIII gear and fab up a small bracket for it to bolt/stay on the R154.

BTW, there're so many variables involved with using a different nylon gears, and differentials (auto, turbo, N/A, etc), that I still actually plan to use a GPS for displaying "actual" speed, along with the Apexi RSM I've been hanging on to (once I start to drive it, I'll post up any differences I find).
 
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