[Mk2] [Turbo] Rev 2 Turbo Speedo Replacement

[markstevieandmads]

I have finally got round to sorting my power steering/km2mph converter problem.

I have a nice set of plasma dials on my standard turbo clocks with the converter wired in to the back of the clocks. The problem is I do a bit of motorway driving and it gets a bit scary when the power steering doesnt turn off when it is supposed to especially when the weather is the way it is this time of year!

So i got hold of some UK 160mph clocks and i want to use these to convert my jap clocks properly and wire the converter at the ecu end, thus sorting out the above problem.

However i am not too sure how to go about it.

Id like to keep my plasma dials and the proper mileage (uk clocks show 156k ,my jap clocks are at 124k).

Ive heard of unscrewing the actual speedo drive from the jap clocks and putting the uk clocks in there and so keeping my plasma dials and only changing the innards.

Does anyone have an idiots guide on how to do this?

Also, how do i either change or keep the original milometer to keep the original mileage?

Last question - What wires do i need to wire the converter into at the ecu end? Are they the same colours as at the end clock end?

Thanks in advance. Hope to get this done this week.

[acf8181]

I'm interested in the response as well.....my import n/a's steering feels unnervingly light on the motorway, i'd put it down to tyres (but never experienced it with previous UK mr2's)

[Pauln]

Electronic speedo clusters (Rev2+)

I'm not an expert on this, but from what I've read whilst trying to sort out my own cars this is what I learnt.

Putting aside the fact that the NA cluster has a voltmeter and the Turbo in theory has a working boost gauge (not that mine has ever moved), you can not just swap one cluster for the other.

Apart from anything else, the layout of the warning lights is different on the NA compared to the Turbo, so there are likely to be associated wiring issues. The turbo cluster is also fitted with an extra circuit board to operate the boost gauge.

But as far as I'm aware the gauges themselves are directly interchangeable, apart from the boost and voltmeter gauges.

When it comes to converting a JDM speedo in kph to mph I believe there are a number of options. The most common are:

Fit a new mph speedo face that had been designed to give the "correct" readout in mph for any given position of the needle without any need for an electronic converter. With this option the power steering will continue to function as intended for the JDM market, but the odometer will continue to read in kph.

Replace the actual speedo gauge with one from a UK car. This automatically uses the standard pulses received to display the speed in mph, and the odometer will log the miles driven. With this option you don't need to fit an after market kph to mph converter, and the power steering will continue to function normally. But unfortunately the limiter circuit will be triggered by the UK speedo. To get around this you can fit a delimiter at the input to the ecu.

Clamp a Steph delimiter across the four terminals on a JDM speedo. This will convert the pulses received so the gauge reads mph, whilst maintaining the correct signal to the power steering to allow it to operate normally. These are only available second hand, and you need to be quick to grab one when they come up.

Finally you can fit the basic style of electronic converter to a JDM speedo which will allow the gauge to display your speed in mph, but the downside is that when fitted in the speedo cluster they adjust the pulses and confuse the power steering.

For my own part, on my NA I simply went for a dial face change using Lockwood white dials, but they do tend to over read. I've also lived to regret the change to backlit white faces, especially around dusk.

I now have a turbo which is again fitted with white dials and some sort of converter. Until I take the cluster out I don't know what type. But my plan is to assemble a replacement Turbo cluster using Speedhut dials taken from an NA cluster, and fit a Steph Delimiter to sort everything out.

I'll also be replacing the turbo boost gauge with an NA voltmeter which will involve a couple of minor changes to the wiring of the additional boost gauge circuit board, but I will at least end up with a useful gauge.

Hope that helps clarify things a bit.

Paul

[markstevieandmads]

Thanks.
I appreciate your detailed response however you have missed the option of using a NA speedo and wiring the "cheaper / generic" converter to the ecu end of the loom which is what I was looking at doing. I have read this will sort the power steering issue I have been having.

I like the dials I have (plasma dials) so was hoping to keep these and just change the "innards" of the speedo section of the cluster for the NA "innards".
However ,im not too sure what is involved with this.
I also have the problem of "clocking" the NA mileometer to read the same as my JDM miles. I appreciate this could be used for illegal purposes so would take advise via PM if need be.

Thanks

[Pauln]

Sorry if I din't make it clear. If you're fitting an NA speedo gauge into a tubby cluster this will automatically read out correctly in mph, and the odometer will read in miles, and the power steering will operate normally without out the need to install any sort of kph/mph converter behind the cluster.

The downside is that you will switch on the "UK" limiter.

If you want to remove that limit and already have a converter/delimiter you can use this to remove the speed restriction.

My understanding is that the delimiter needs to be "spliced in" between the speed input feed in the ecu harness and the ecu. You'll also probably need to provide +12v and earth feeds for the delimiter in that new location.

In terms of changing the odometer reading to match that of your existing speedo, the following link might be useful:
Link

I've not tried this myself yet, but I intend taking photos of both sets of gauges as evidence that the mileage hasn't been lowered during the swap over. I believe it's only an offence to change the reading if you are deliberately trying to reduce the mileage clocked to pass the car off as having covered fewer miles than it actually has.

[markstevieandmads]

Thanks Pauln. That explains it more to me. Im getting confused between a converter and a delimiter.

Think i will strip out the JDM dials and see what i got wired into the back.

I did want to convert the useless boost gauge to a voltmeter but I havent got a matching face for it so it would look odd with my plasma dials so will leave this for now.
I just want to get my power steering working properly.

[acf8181]

Electronic speedo clusters (Rev2+)

Fit a new mph speedo face that had been designed to give the "correct" readout in mph for any given position of the needle without any need for an electronic converter. With this option the power steering will continue to function as intended for the JDM market, but the odometer will continue to read in kph.

and is the speed limiter still working with this set up?

p.s. cheers for all the info, is most helpful

[Pauln]

and is the speed limiter still working with this set up?

p.s. cheers for all the info, is most helpful

This is just a simple physical change of the layout of the dial face. The speedo needle will still be in exactly the same physical position when you reach 80 kph as it was before, it's just that the dial will now show that this is 50 mph.

As there are no changes electronically the JDM speed limit will remain unchanged at around 190 kph or 118 mph. This is a function of the ecu, so the only way to change that is to fool the ecu into thinking your travelling slower than you really are, and that requires electronics.

The pulse created by the speed sensor is used by the speedo, the power steering and the ecu. So for example you could use electronics to fool a jdm speedo and the ecu into thinking 180 mph is only 180 kph, but the power steering needs to know the real speed you are travelling, otherwise it ain't going to switch off when it should.

Paul

[acf8181]

gotcha...thanks again

think i have option one performed on mine, but whether there is a spped limiter mod am unsure as didn't even get tht speed on track!

Wanna change to rev5 clocks at some point so will do the second option then i think.

As for whether i have a mod that messing with my pas.....is it possible to just unplug a fuse for the PAS to permanently turn it off to test the theory?

[Pauln]

I've not not experience the light handling from the power steering not switching off myself, but from what others have said I think you'd soon know if you had that problem.

If you've a 110 mph speedo on an NA that's reasonably accurate, and the odometer is still clocking up in km rather than miles, it's unlikely that you'll have a converter/limiter fitted any where -so there shouldn't be a problem with the power steering not turning off at high speed.

Paul

[nathan.z]

Hey Paul,

You seem very knowledgable regarding speedometers so thought best to post in this thread. My situation:

Rev 2 Turbo has 110MPH dials when purchased however KMH is reading as MPH meaning I have to squint and read the smaller inner numbers to gather a reading. The mileage appears to count miles and I've never hit a limiter.

I bought and installed the 160mph speedo (Speedo only, not the whole cluster) and it is still reading KMH as MPH.

What do I need todo so that my 160mph dials read correctly? Alternatively should I buy a 180mph face and just replace my 110mph face, or swap the 160mph face onto the 110mph face?

Cheers, Nathan

[Pauln]

So just to be clear, are you saying when imported it had a speedo with kph on the outside and mph in smaller print on the inside. The top speed shown on the outer scale was 180kph and on the smaller inner scale was 110mph?

If so, and the inner smaller scale was giving your speed in mph reasonably accurately, that suggests it was the original JDM speedo and that the odometer should have been measuring Kms rather than miles. Are you sure the odometer was reading miles, 'cause that's real odd?

With regards the 160mph speedo clock, what car was that removed from?

Was it a JDM spec car or a UK spec car?

If a UK spec car, it should automatically read mph.

The fact that it appears to still be reading kph suggests that it was actually a JDM speedo out of a car that had a kph to mph converter fitted, but that the converter was not sold with it.

You could just buy a kph to mph converter and wire that up to your 180kph speedo. The outer scale would then read in mph. But unless you can get hold of a Steph bolt on unit you'll start having issues with the power steering not turning off at speed.

You could fit a speedo out of a UK car which should sort everything out without messing up the power steering. But that won't disable the JDM limit.

The cheapest option is to simply replace the dial face on your 180kmph with one that has a max speed of 110mph. In which case the power steering will continue to work correctly, but the JDM limit will still be in place.

Talking of the JDM limit, as you said you didn't experience this with your first speedo, it might be worth pulling back the carpet in the boot to see if a delimiter has been fitted at the epu, or it's been modified in some other way.

Paul

[markstevieandmads]

Update

I've finally got round to stripping out my spare UK Speedo and have taken out my jap cluster

The wiring to the jap cluster had something connected to it. I'm guessing one wire goes to 12v and another to 0v and then the purple wire had been cut and this device had been spliced in between the old purple wires

So is this device the kmh to mph converter?



And if this the convertor I guess I can install my UK Speedo into my jap cluster and do away with this device and resolder the purple wire back together. This will then give me back my correct power steering?

And if I'm so far correct what do I then need to remove the 112mph limiter that I belbeliei would need to wire at the ecu end?

[thomp1983]

That is a convertor/delimeter albeit alot smaller than mine. Yes reconnect the purple wire. Sure bob hatton covered wiring the delimiter in at the ecu end somewhere.

Also your not missing any undertrays are you? My jdm car doesn't suffer the power steering issue but i do have a floaty front end due to no undertrays on my border bumper. Id also look into retrofitting speed flaps they help alot with front end feel

Found this while digging around covers fitting the delimiter at the ecu

http://www.mr2oc.co.uk/know-your-2-know ... bartid=154

[DottySkee]

Very helpful thread guys thank you. I'll be doing this soon as it's annoying having kph clocks converted to mph as I'm planning on going to Spa next year and I want to be able to read kph too.

Guess 160mph clocks are on the christms shopping list!

For the delimiter to wire in at the ECU, is it the same bit of kit from GTSChris you put in behind the speedo, just wiring it in at the ECU to alter the pulses there instead of at the speedo? Or a completely different bit of kit?

[Pauln]

The question is how is your current kph speedo converted to mph?

If it's still the original 180kph dial and someone has simply put a bit of black tape across the "k" and it is giving your true mph, the chances are that a delimiter has been already fitted behind the dial.

If the previous owner has simply swapped the dial face, I'm surprised that it doesn't read mph and kph, as I've not come across a mph only replacement dial face - but that's not to say that they don't exist.

Either way, you can either swap the complete speedo gauge for a UK one, or change the dial face for an appropriate one with mph on the outside and kph inside.

As far as I'm aware the same delimiter can be used at the speedo or the ecu as it's just a case of where it changes the pulses.

Paul

[DottySkee]

The question is how is your current kph speedo converted to mph?

If it's still the original 180kph dial and someone has simply put a bit of black tape across the "k" and it is giving your true mph, the chances are that a delimiter has been already fitted behind the dial.

If the previous owner has simply swapped the dial face, I'm surprised that it doesn't read mph and kph, as I've not come across a mph only replacement dial face - but that's not to say that they don't exist.

Either way, you can either swap the complete speedo gauge for a UK one, or change the dial face for an appropriate one with mph on the outside and kph inside.

As far as I'm aware the same delimiter can be used at the speedo or the ecu as it's just a case of where it changes the pulses.

Paul

Cheers Paul.

Yes it's kph clocks with some sticky tape over the K so I'd guess the delimiter is in behind the dial.

That's good I can probably reuse the same delimiter though, best get shopping for some 160mph clocks!

[markstevieandmads]

Update 2:

I installed my uk speedo cluster into the position of where my old jap one was. i also used the old plasma front so everything matches again. I made sure i removed the old converter/delimiter and rejoined the purple wires by soldering and heat shrink. I also managed to change the uk mileometer to match the jap one so my mileage is the same.
So as far as i am concerned the power steering issue is solved however i now have a limit of 112mph (not a problem at the mo but i will be doing track days this year).

The other problem i had was calibrating the speedo correctly. I ended up plugging the clocks back in with the plastic cover removed and while driving at a steady 20mph according to my gps (on a very quiet closed down industrial estate) i installed the needle in the correct place. It took a few goes to get it right but im now happy that its accurate enough according to my gps.

[Pauln]

Now you've got the speedo and power steering sorted, I believe you should be able to remove the JDM limit by now fitting your redundant converter/delimiter at the ECU.

As someone has posted above, please see the following for more info:

Stef Derner's Guide

Paul

[markstevieandmads]

Cheers

can anyone confirm what colour pin 9 is on the 22pin connector for a rev 2 turbo please. Not sure if im reading it right and want to do it right before chopping the cable lol