New guy

[madandy]

Gidday...

I've decided to buy myself another MX5.
I had one a few years ago before down trading to buy house, start family blah blah blah.

Any way - Gonna buy a cheap 1600cc & make it a little track attacker. Can buy old one for $2500, working with a 5k total budget. . Things like brakes, rollbar/half cage, suspension & bracing plus some track only rubber on separate rims. Some extra power too though I realise the engine may be due for a bit of freshening up inside in a 18 odd year old car with upwards of 200kms on it.

I've noticed a couple of NZ new examples the redline starts at 6500rpm and is solid from 7000rpm whereas a couple of imports I've seen have 7200rpm redlines. Can anyone tell me what the deal is with that?? Mine was imported but I can't remember where the redline was - dont think it was 6500 though!

Any ideas or advice will be appreciated.

cheers
Andy

[Ian]

Hi and welcome...

I track a NA NZ new 1.8...and the engine cut out is at 7,200. My understanding is that all NAs are the same...
I try to run to about 7100 between gear changes on the track. Oh for a close ratiop gear set from FM (like Keith Smiths!)

Ian

[madandy]

Hi Ian & thanks for your quick reply.

I wondered if the NZ na6 I'm referring to has had an auto to manual swap as the redline deff starts at 6500rpm...do the autos redline lower?

[madandy]

Oh, I forgot to ask about the na6 versus na8. Is the 1800 worth paying a bit more for to get the extra hp, bigger brakes, are there any other extras and is the extra weight really noticeable?

[Ian]

Unsure about an auto redline but I wouldn't think they would differ. An auto owner could clarify for you.
The 1600/1800 debate is a somewhat subjective one. So here goes...you can upgrade 1600 brakes readily at relatively little cost and it is very common for track cars to have this done. If you can find an 1800 without aircon (mine was a delete option) and to a lesser degree without power steer ( p/s mandatory with all 1800s ex factory, I believe - most if not all NZ new 1600 had manual steering racks), there is little extra weight in an 1800 untill you start picking up options such as dual airbags, fancy stereos etc. Yes the extra chassis bracing in an 1800 weighs a little but most 1600 owners put these on as a first step to improving handling. The brace behind the seats weighs a few pounds but comes out when you have a cage installed. The 1800 fuel tank is 3 litre bigger so might weigh another pound! The elec windows/mirrors ad remote boot release are minor increases over an early 1600 without them. The 1800 gearbox is a little stronger and is the only one which will accept a FM Quaife gear set. The 1800 diff is considerably stronger and usefull esp if you decide to go forced induction. An 1800 ends itself to an early NB head swap at a later stage...
BUT, 1598 v 1839 (remember race engine builders often overbore for no other reason than to get a few more cc, and a lot less cc increase than the 141cc increase between these two engines!) provides a notable increase in torque.......very usefull and on the track. A 1600 Jap import with all the typical extras would weigh as much as my NZ new 1800 (without air con) I am sure...
Hope this helps.

[madandy]

Thanks Ian. A well argued reply.
The 1800's are proving tougher to find but it sounds like its worth it if I can find a good one.

There are some damn tempting 1600's though so I may have to change the engine one day, so sad.

[zorruno]

I have a 1.8 NB... I love it, and have had it since 99.

If I was doing it all again though with what I have learned over the years, I'd buy a cheap, early 1.6... and save all the extra money to make it exactly what I wanted.

I spend a long time, and too much money at the time to find a 1.8L black/black NA with nice alloys and a few extra bits.

I could have fully painted it, bought new top, added some go fast mods, 1.8 brakes, shocks, bars etc all for about the same price as what I paid, and have about what I have now.

But obviously, it all depends on:
1. How much spare money you have
2. How much spare time you have to get the work done yourself (if not yourself, then see 1)

cheers

[Grant]

Just had a look at my (1998 NB 1800) auto red line It is 7200rpm.
I also have a 1992 auto 1600 but my sister in law has it at present so can't
check.

Grant.

[madandy]

Here's a pic of the rev counter of the car that's got me puzzled:

[Dammit I can't post a pic cause I'm a noob! lol.]

I can't understand it and the owners saythey don't know a thing & its been in their family since 37,000kms.

[madandy]

I have a 1.8 NB... I love it, and have had it since 99.

If I was doing it all again though with what I have learned over the years, I'd buy a cheap, early 1.6... and save all the extra money to make it exactly what I wanted.

I spend a long time, and too much money at the time to find a 1.8L black/black NA with nice alloys and a few extra bits.

I could have fully painted it, bought new top, added some go fast mods, 1.8 brakes, shocks, bars etc all for about the same price as what I paid, and have about what I have now.

But obviously, it all depends on:
1. How much spare money you have
2. How much spare time you have to get the work done yourself (if not yourself, then see 1)

cheers

Thanks for your input.
I'd be doing all the work myself.

I want the lightest possible start point and with my budget what your suggesting is probably my best option.

[Grant]

I forgot that the NA1.6 auto motor possibly does have a lower redline as
they are slightly different to the manual motor. Not sure what the
diffrences are now but they are designed to give a bit more torque at lower
rpm to help compensate for the losses in the auto transmission. Don't know
about the 1.8 though. Certainly the auto box in my 1998 NB is much better
than that in the 1992 NA. Much better changes and generally more refined.
Plus has a hold function so can be held in any gear.

Grant.

[biff]

This may be worth a look, Mazda MX-5 Miata: Find it. Fix it. Trick it. by Keith Tanner
Biff

[SLYDIT]

dont worry about differences in redline.
you can easily remove the rev limit and lean out the fuel mixture (the stock car runs super rich) by simply changing the ecu's clocking crystal from a 4 MHZ one to a 4.4Mhz one.

its a very cheap mod to do

[madandy]

Ok that's cool to know. I've found a nice red NZ new na6 manual with hardtop, 153kms, non power steer, manual windows & no a/c
Its the one with the 6500rom redline

Maybe I'll fit a 1.8L down the track or just add boost when I can afford to make a track reliable set-up.
First priority is to set it up for corning...

[madandy]

So I came home fom Hamilton tonight with a NZ new 1990 MX5 First registered in 1991 with full ownership and service history
It revs past 7000rpm so I needn't have worried about the semi-redline at 6500rpm and solid red at 7000rpm.
Needs some TLC on drivers side from a minor scuff with a barrier on the desert road, better brakes and new suspension & tyres. All things I'd planed to do for track preparation anyhoo

Very happy to have a wee project and look forward to returning her to her former glory + some. .