Different Speedos

MN · Post by MN » Sun Jul 08, 2007 4:13 pm

I discovered yesterday that when I reached 180 on the speedo the engine started to cut out , just like it does with the rev limiter but in this case there were still 500 or more revs to the start of the red line. This happend a couple of times. And before anyone starts getting concerned this was on a closed road with full safety gear and perfectly legal.

I doubt I'll get that fast very often (first time in 3 years of motorsport with this "5") but is there a way to change that top speed cut out? I understand that some models have guages that read to 200 (or 220?) if so which and what is the conversion process to a 1990 NA?

SLYDIT · Post by **SLYDIT** » Sun Jul 08, 2007 8:19 pm

i Have heard that the speedos hava a simple pin in the speedo gauge mech behind the gauge face that activates the cutout at 180...removing the speed limit is a simple procedure of removing the wire to the pin on the gauge cluster...

Never tried it......... cant prove that this is the case either....worth a look.

Post by **jif** » Sun Jul 08, 2007 9:44 pm

the local models go up to 220km/h on the speedo

not that you'd ever hit that in stock-ish form!

badcf4 · Post by **badcf4** » Sun Jul 08, 2007 9:57 pm

SLYDIT wrote:i Have heard that the speedos hava a simple pin in the speedo gauge mech behind the gauge face that activates the cutout at 180...removing the speed limit is a simple procedure of removing the wire to the pin on the gauge cluster...

Never tried it......... cant prove that this is the case either....worth a look.

I know this is the case with alot of rotary model mazda's so it would be worth a look.

i belive it is a screw of sorts

Ian · Post by **Ian** » Mon Jul 09, 2007 10:52 am

Have personally removed the 180km limiter screw (clearly marked as such) on the rear of a 1986 RX7 turbo which enabled me to do 225kph.

Suggest you look at the rear of an MX5 speedo assembly at a wreckers as a first step...

Mine only does 175kph on the straight (thus far), but is NZ new, so don't anticipate any problems at 180 plus.....(apart from heart palpatations!)

Fletch · Post by **Fletch** » Mon Jul 09, 2007 11:26 am

Yes, early Eunos Roadter's have a screw on the back of the speedo circuit board that can be removed.

I've forgotten exactly what is written next to the screw, but its clearly labelled and easy to decipher.... "180 cut" or something like that?

Fletch.

brentweaver · Post by **brentweaver** » Mon Jul 09, 2007 1:09 pm

Hi Mark, Just Google Mazda MX5 speed limiter removal & it will take you to the clara.net site. This has other MX5 stuff somthing like the garage section of Miata.net
Hope this helps.
Brent Weaver

MX5PWR · Post by **MX5PWR** » Mon Jul 09, 2007 8:50 pm

I have just had a look at a spare instrument cluster I have in the garage that came out of an 1800 series I. There is a screw that that has 180km/h SW printed beside it. When the screw is removed, the contact is cut between the printed circuit and the speedo sensor. Had trouble running fast enough holding the instrument cluster to see if it works!!!!!

MN · Post by MN » Mon Jul 09, 2007 9:48 pm

Thanks very much guys I'll try it. Probably have to wait until next years Taranaki Rally to find out if it works - long down hill straight. Kind of interesting fanging it down a class B road barely 2 car widths wide and a less than smooth surface at that speed!

Post by **zorruno** » Thu Jul 12, 2007 5:12 pm

on 9/07/2007 8:55 p.m. MX5PWR wrote:

I have just had a look at a spare instrument cluster I have in the
garage that came out of an 1800 series I. There is a screw that that has
180km/h SW printed beside it. When the screw is removed, the contact is
cut between the printed circuit and the speedo sensor. Had trouble
running fast enough holding the instrument cluster to see if it works!!!!!
*:*

Do you have your camera handy? A pic would be useful...

Cheers
(Still on Christmas Island... and it is now raining - in the dry season)