anyone used a speedo calibrator gadget on r34s ok? if so, which

[syd_gtr]

so the cluster takes an ac signal input and outputs two square wave pulse trains to the rest of the car.

I asked Dakota if their gadget accepts AC and they said yeah it does, and will output a squared off sine wave…

so I am wondering if the dakota one will work ok. If the cluster is expecting an AC triangle of varying volts will it be ok with whatever a correction black box puts out? I do not want to splice into wiring, then find out it does not work…

[joshuaho96]

Isn’t there a speedo calibration resistor network on the back of the gauge cluster? Or is it more complicated than the R33 in that regard?

[Kinkstaah]

I used a Dakota digital converter for my speedo in my LS conversion.

Specifically, I fed the dash the output from the LS ECU, so it is not getting it from the gearbox anymore.

I previously used a Jaycar signal converter and let me just say holy hell the Dakota one is well worth the money and is super nice and does work (in MY application).

It can handle multiple connections but I didn't need it for the Tacho as this can be tuned in the ECU itself.

[syd_gtr]

If someone can see an adjustment option on the back of the r34 dash circuit board then they're doing better than me. Also who knew Nissan decided to add a "4wd oil temp" light but didn't implement it?

Yeah the Dakota seems like perfect as it has bluetooth adjustment and it has the twin function of RPM and Speedo in one unit. However in the case where the dash does the job of not only displaying speed, but also converting the speedo signal for output into attessa etc, there is an extra possible problem & I'm wondering if anyone has used one in this particular scenario. I don't even really understand why my stock dash is out. It is reading 115 at 100 but stock ratios, and v close to stock tire circumference. 

Edited June 24, 2021 by syd_gtr

[GTSBoy]

I was going to say I wouldn't try to feed the Dakota square wave signal to the dash. But....if what they are saying about the output being a squared off sine wave means that it is still an AC signal (ie varies from -ve to +ve voltage) then it might work. The Dash circuitry is looking for a frequency of the voltage crossing zero volts. I t=don't think it's looking for rising or falling edges or peaks or any of the other possible features of a sawtooth / sine wave signal. Just the zero volt crossings. So therefore, if the Dakota's signal contains those crossings, it could well work.

What won't work is if the squared off sine wave is all on the +ve voltage side - which is what the square PWM signal that the dash outputs is. That's a different way of conveying information. The AC signal is about frequency as proxy for speed (which is easy to understand in your head) and the PWM signal is about equivalent average voltage as proxy for speed (which is easy to convert to a computer understandable value).

If I were you I would beg, borrow or steal an oscilloscope and check out what your speed sensor is doing at some known/calculated road speeds and compare with the charts in the manual. If they are on spec then the problem is in the speedo head and you might be better off taking it to an instrument workshop to get it fixed rather than bandaiding the incoming signal. This because if the speedo head is crook it could continue to degenerate and you'd have to keep tweaking the bandaid in order to maintain correct reading, right up until it stops working altogether or you reach the end of the range of correction available. It might be something as simple as a dry solder joint or a dud capacitor.

[syd_gtr]

I do not mind taking the dash cluster to be adjusted however have not found anyone that knows what they are doing with it.

The error has been constant for a decade+, and is in RPM as well, (needle vs ecutalk) so I do not think it is the sender, and I do not see how it can be in the cluster firmware, so that means it is in the little units behind the two needles. If they can be adjusted for error, thats great. can they? I cant find any evidence of that service, with lots of google effort.

 

edit: asking humphery instruments in the gong what they reckon. will update

Edited June 24, 2021 by syd_gtr

[GTSBoy]

39 minutes ago, syd_gtr said:

If they can be adjusted for error, thats great. can they? I cant find any evidence of that service,

In Adelaide I can think of several instrument workshops that specialise in fixing this stuff.

One on Torrens Rd, been there forever, might be shut now - might have moved to Main Nth Road Prospect. Called Gauge Works.

VDO Instruments used to repair other brand/OEM iinstruments as well as their own.

There's a few guys advertising from outside the (Adelaide) metro area also. And I see a couple in Melbourne. There has to be someone in Sydney. A quick google shows these 3

[syd_gtr]

thanks

well dakota got back to me and said if the input is AC then the modified output will be AC as well. (it will cross ground).

for the price, which buys probably an hour or two at a re-calibration shop, am getting close to just trying it then will sell it used, if it doesn't work.