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Discussion Starter · #1 ·
Hi,

I have a 1.8 Eunos with the 112mph limiter. What would be required to remove it? Would say like a piggyback like Emanage remove it at all?
 

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RSNick is NickRS backwards, wtf?
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Hi,

I have a 1.8 Eunos with the 112mph limiter. What would be required to remove it? Would say like a piggyback like Emanage remove it at all?
With a Eunos you will have the 180kph speedo. Soooo, you would be doing 170kph(ish) before the limiter limited. If you have a dongle in your speedo drive to convert kph to mph it is not an issue.



Otherwise if your speedo face plate has been removed and a mph scale sheet fitted then there is a small screw fitted in the internals of the speedo that needs to be removed. Do a search on this site for instructions.
 

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Isn't the screw only on the 1.6?
OP has 1.8.
I believe the limiter is part of the ECU on the 1.8, not sure that a piggyback ECU would override the limiter.
h
 

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I thought that only worked on the 1.6? I have mph on the dials plus the background is blue, do this mean that it has had a sheet fitted?

Standard is black dials with green lighting and KPH on the imports.
The imports are required to have a MPH speedo to be legal, so new MPH faces have been fitted and the background lighting probably changed at the same time.
h
 

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That's the 1.6 fix! Not done it myself but a couple of the guys on here reckon there's a small black box in the dash of the 1.8 that you remove to de-limit the car! There is a thread somewhere on the forum - or I'm sure one of the guys in the know will answer eventually - this one is asked quite regularly!
 

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Discussion Starter · #8 ·
Been looking, seems quite interesting. Also I somehow got sidetracked and started looking at changing the ecu crystal too.
 
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Speed Limiter - Removal

Japanese spec Roadsters have speedometers which are marked with a maximum speed of 180KPH (112.5MPH) as opposed to 220KPH in other metric countries and their top speed is artificially limited to this speed (180kmh). To get rid of this limiter, you have to remove a screw from the printed circuit board behind the speedometer.. Looking at the printed circuit board , there are two big multi-connectors ,each with 12 connections. They are labeled 'a' to 'l' and 'A' to 'L'. The 'G' connection is marked 180kp/h sw and, if you follow it up the board, it leads to a screw. Removing this screw disables the speed limiter.

Hope this helps
 

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Again this is for the 1.6, not the 1.8!
 

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Happily expanding the To Do list since 1997
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It was Bob Hall (about as authoritative as it's possible to get on MX-5 development) who said years ago that Mazda were obliged to change the original 1.6 speed limiter (screw removal, described above) because the Japanese authorities decided that making it so easy to disable was not acceptable. I don't think he specified exactly when the change took place.

My (Sept. '93 built) 1.8 has a space on the back of the gauges where the 180 limit screw ought to be, but it's not there. My car also does not appear to be restricted to 180km/h. I don't know whether the modification came later or whether mine was perhaps modified by the original Japanese owner.

I imagine it can't be too hard to find out how to defeat a later version, since there must still be a signal from the speedometer to tell the ECU the car's going over 180. You can definitely defeat it with a replacement ECU or speedo (though they're expensive options) or by using one of those converters which turn a kph speedo to mph.
 

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Discussion Starter · #12 ·
Yup I can't think of anything else that would require the VSS to the ecu other than the limiter, so I should in theory just be able to chop that wire.
 

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Discussion Starter · #13 ·
Right well I took the speedo apart today. I found a reed valve between the 2 outputs for the speedo. So I decided to cut it out after seeing someone else saying theirs didnt have it. I have only driven round a little and the speed is working all fine still so that is all good! I have no idea yet whether the limiter works, will have to test it.

Before


After


Will report back when I have tested it!
 

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Discussion Starter · #14 ·
Well just to confirm, the mod does work perfectly. Has been proven via gps that it does remove the limiter for the car.
 

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Congratulations on the find!
 

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Indeed Congrats....although if you tested it on the queens highways and byways your a certified Grade A dickhead...absolutely no defense for driving at that speed on British roads
 
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As a follow up ive found a readup for the 1.8 eunos that mentions the limiter is governed at the ecu and snipping the green/white wire would do the trick unless you happen to have cruise control !!! Ive also found another readup that recons there is a srew in the speedo circuit AND you also snip the green/white wire......I dare say im sure there will be a readup out there that will include these 2 and a pin in the speedo body (as above)
Having said all that,why am i even interested as my eunos hit 124 on the rolling road.NO LIMITER HERE
 

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Can anyone give a conclusive answer please ? I have a 1.8 mk2 1998 turbo and although the speedo is reading in MPH it is still restricted to 112mph I have read various threads and cannot find a conclusive answer how to remove this limiter......
It says on the thread above cut a green and white wire at the back of the speedo sensor I have read on another thread that it is a white and black wire is there anyone who has done this already who can confirm please.
I don't want to start cutting wires and risk getting the wrong one.........and before anyone wonders I do lots of track days and don't want to be hitting the limiter all the time.........

Thanks
 

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The pictures above show the reed switch which closes at 180 km/h, so removing that has the same effect as removing the screw on the back of the instrument panel. This de-restricts early cars but my understanding is that later cars (approximately around the time of the 1.8's introduction, but not sure) don't just rely on this switch to determine their speed.

There is also another wire taking a speed signal to the ECU which I believe sends a stream of pulses from the speedo. On my '94 it's a green/red wire, going to ECU pin 1M. I don't know how the ECU would react if this signal was cut.
 

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Can anyone give a conclusive answer please ? I have a 1.8 mk2 1998 turbo and although the speedo is reading in MPH it is still restricted to 112mph I have read various threads and cannot find a conclusive answer how to remove this limiter......
It says on the thread above cut a green and white wire at the back of the speedo sensor I have read on another thread that it is a white and black wire is there anyone who has done this already who can confirm please.
I don't want to start cutting wires and risk getting the wrong one.........and before anyone wonders I do lots of track days and don't want to be hitting the limiter all the time.........

Thanks
The instructions above won't work at all for an Mk2. The gauge cluster doesn't have a reed switch in it, so that won't work. What you can do, is cut the wire going to terminal 2D on the ECU. This is the speed signal going to the ECU.
 
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