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NB8A vs NC series 1 (2006) for daily and racing (MX-5 Cup)
I have had the NB8A since January and it is standard + Torsen v2 with 4.3 + race seat, tow points and fire ext.
Done 1 Supersprint at SMSP North, 1 track day at Wakefield and 1 'Hillclimb' at Ringwood.
I am about to have a 'half cage' and 6 point fitted.
Targeting MX-5 cup racing and possibly Targa Tasmania, need to stay registered as I love driving MX-5 on the road.
I don't like turbos and was thinking down the track of fitting a 2.5 to the NB but was told it is really not on.
I see that it is a common conversion for NCs.
I would not be doing that immediately but tomorrow I will be inspecting a registered 2006 Mazda MX-5 NC Series 1 Manual
Before I decide to buy it to replace the NB I need to be sure that is the way to go.
I know the NC is heavier but I think the extra power from the 2.0 more than compensates?
NC comes with LSD? Torsen or other?
NC gearbox and diff are stronger?
How do they compare for handling in standard form?
Assuming the same driver and tyres stock NC would do faster lap times? Say Wakefield how much faster?
I think the NC on the track will cost me about $3k more than the NB on the track.
Thoughts anyone?

Most of the Vic club lap records for Stock NC class are about 1 second per lap quicker than NB class records. (Some of our std NCs run springs also, and are about 2-4 secs quicker than the stock NBs)
Also most of our NB records are for an NB8B as these are noticeable faster than an NB8A..

So you could probably say you'll be 2 sec s alap quicker in a stock NC over a stock NB8A.


Tyres for NC will be 17s (or 16s) and will be much more expensive than the 15s on your NB.
NC is heavier (by between 50 & 100kg) so it would wear consumables more quickly, so would be more expensive to run.

Personally I would much rather race a stock NC than a stock NB8A. (even though I own and race a (not stock) NB8A) and even more so for daily usage. NCs are much nicer on the road.

A standard NC is way faster at least in NSW
About 2.5s a lap at Wakefield than any standard NB. Old records on the club website are a good gauge for this.
They are even a bit quicker than a standard NB SE. I have access to both. Magazine times also suggest this.

The NC chassis and drivetrain are far superior to a NB. Much stiffer and can handle more power. Plus better weight balance.
The 2 things I notice on track that are far superior to a NB is much better turn in with bugger all understeer and the braking is worlds apart.

At the weigh bridge at SMSP we found that the NC was actually lighter than NB8B's fitted with roll bars. My NB SE was the heaviest.
See this topic.
http://www.aus-cartalk.com/forum/viewtopic.php?f=68&t=72946&hilit=barge


The main disadvantage is that NC aftermarket parts for racing are less commonly available as they still are not that popular compared to NB's.
Also if you get a roll bar fitted you cannot use the soft top as the rear stays are in the way. Most ditch the softtop and fit a hardtop for this reason but NC ones a pricey.

Nuddy wrote:NB8A vs NC series 1 (2006) for daily and racing (MX-5 Cup)
I have had the NB8A since January and it is standard + Torsen v2 with 4.3 + race seat, tow points and fire ext.
Done 1 Supersprint at SMSP North, 1 track day at Wakefield and 1 'Hillclimb' at Ringwood.
I am about to have a 'half cage' and 6 point fitted.
Targeting MX-5 cup racing and possibly Targa Tasmania, need to stay registered as I love driving MX-5 on the road.
I don't like turbos and was thinking down the track of fitting a 2.5 to the NB but was told it is really not on.
I see that it is a common conversion for NCs.
I would not be doing that immediately but tomorrow I will be inspecting a registered 2006 Mazda MX-5 NC Series 1 Manual
Before I decide to buy it to replace the NB I need to be sure that is the way to go.
I know the NC is heavier but I think the extra power from the 2.0 more than compensates?
NC comes with LSD? Torsen or other?
NC gearbox and diff are stronger?
How do they compare for handling in standard form?
Assuming the same driver and tyres stock NC would do faster lap times? Say Wakefield how much faster?
I think the NC on the track will cost me about $3k more than the NB on the track.
Thoughts anyone?

As Luke said the the NC is way faster car with a better chassis, as you’d expect though for cars which were developed over a decade apart from each other and the NC in the 2000’s when technology had come a long way.

Parts are pretty cheap now for the NC due to a lot of them being at wreckers and the ability to swap RX8 parts on like the bigger brakes, sway bars and front hubs is handy.

To answer your questions:
I know the NC is heavier but I think the extra power from the 2.0 more than compensates? Yes, the NC is over a second faster on most tracks. It's not much heavier than an NB8B and as Luke pointed out if you put a roll bar/cage in both and put a hardtop on the NC should be lighter.
NC comes with LSD? Torsen or other? It does come with an LSD, but it’s a Tochigi Fuji Super LSD which is ‘torque sensing’ and not a Torsen. Pretty sure it was the same LSD as the late NB's.
NC gearbox and diff are stronger? The NC diff and gearbox are very solid, some people have issues with the third gear selector bushing in the gearbox but there is an easy fix for that which is a metal bushing replacement (I don’t think it’s a common thing TBH but thought I'd point it out).
How do they compare for handling in standard form? They run very soft suspension standard and it feels like you are driving a boat. Coilovers make a massive difference to the car as they let you use the amazing chassis of the car.
Assuming the same driver and tyres stock NC would do faster lap times? Say Wakefield how much faster? In the records it's over 2 seconds faster (viewtopic.php?t=36907), it's even 0.8 seconds faster in stock form than a stock NB with semi's, it should be called out that Luke is a great driver so it's probably skewed a bit but the difference in any case is big. Lightly modified they are way quicker too, I did a high 1:09 with coilovers, exhaust, tune, brake and semi’s in my car and Ralph has been down to a 1:09.52 but has done a bit more to his car..

I wrote this a couple of years ago about modifying the NC for the track if you are interested in reading about different modifications which add power, lose weight, improve handling etc.. viewtopic.php?t=69806.

If you are interested in buying an already completed car I’m selling my road registered NC for 18k which already has a Cusco LSD, half cage, carbon hardtop, Weds TC105N wheels (super lightweight wheels), MCA Reds, race seats, exhaust, tune etc.. which would be way cheaper than you building one yourself (the wing is removable). Just the wheels and coilovers cost me 5k let alone all the other stuff on the car..

Here is the for sale thread if you were interested viewtopic.php?f=73&t=72082

Pm sent.

My PBs at Wakefield Park give you a guide for the difference in times for stock MX-5s with non-R-spec tyres:

1992 NA6 with BD rollbar and Dunlop Star Spec Z1 - 1:15.80
It took me four years of working on my driving to whittle it down to this and only ever managed to crack the 15s at one event.

1999 NB8A 10AE (stock LSD and Bilsteins) with BD rollbar and Dunlop Star Spec Z1 - 1:15.45
My best result in four attempts. Probably another half a second in it for a 10AE but mine was a lemon and I got rid of it within two years of ownership. The all-time record for stock NB8A/NB8B (open diff) is 1:15.50.

2006 NC1 with Kumho KU36 - 1:12.41
I did a 1:13.17 on my first weekend in Apr 2016, and in the next five events, my times have ranged from 1:12.41 to 1:12.76.

IMHO, a stock NC1 soft-top is three seconds quicker around Wakefield Park than a stock NB with equivalent tyres. I'll dig out my GPS datalogging for each of these PBs and post up a comparison chart of speed vs distance.

Red = 1992 NA6 with BD rollbar and Dunlop Star Spec Z1 - 1:15.80
Blue = 1999 NB8A 10AE (stock LSD and Bilsteins) with BD rollbar and Dunlop Star Spec Z1 - 1:15.45
Green = 2006 NC1 with Kumho KU36 - 1:12.41

The NC has much quicker acceleration and much better braking. No ABS in NA6 and it didn't work in my 10AE. The NC has higher corner speed for the high speed turns 3, 6 and 9 due to outright speed at corner entry, but there's little difference in lateral G.

Speed vs distance by Bryan Shedden, on Flickr

LatG vs distance by Bryan Shedden, on Flickr

LongG vs distance by Bryan Shedden, on Flickr

I bought Dan's NC without the wing.
Drove the Putty road (both ways) on Sunday - very impressed.
Tomorrow doing CSCA supersprint SMSP North.
Sunday doing NSW supersprint Wakefield.
Monday doing MX-5 Cub track day Wakefield.

Congrats to you & Dan.

2 months down the track and lots of progress with the NC.
Putty Road run with the club on 7th May
Saturday 13th May CSCA Supersprint at SMSP North Circuit
Sunday 14th May NSW Supersprint at Wakefield
Monday 15th May Club Trackday at Wakefield (1:16.985)
Sunday 28th May MG Newcastle hillclimb - Ringwood
Friday 9th June Speed off the Streets - Wakefield (1:15.11 on Michelin Pilot Sports)
Sunday 18th June NSW Supersprint at SMSP North Circuit (1:22.8752 on Hankooks)
Saturday 24th June MX-5 Club trackday at SMSP South Circuit (1:10.681 on Federals)
Saturday 1st July CSCA Supersprint at Wakefield
Sunday 2nd July MX-5 Cup round 4 at Wakefield (1:14.6 on Federals)
Sunday 9th July MX-5 Club hillclimb - Ringwood

Next event will be Saturday 12th August CSCA Supersprint at SMSP Brabaham (extended) Circuit (4.5 km)
and then Sunday 20th August MX-5 Cup round 5 at Wakefield.

This car is brilliant and MX-5 Cup is great but I do need a little more acceleration down the straight
I can keep up with the backmarkers through the corners and under brakes but they all pull away down the straight.

Nuddy wrote:This car is brilliant and MX-5 Cup is great but I do need To improve my driving to overcome their hp advantage

the back markers are running in the 12s and Dan used to get in the 09s with this car, so focus on getting your driving up to speed before you worry about changing the car in any way.

Besides, its way more satisfying beating cars with more hp......

rascal wrote:the back markers are running in the 12s and Dan used to get in the 09s with this car, so focus on getting your driving up to speed before you worry about changing the car in any way.

Besides, its way more satisfying beating cars with more hp......

Lap times are made up of acceleration out of corners, braking into corners, speed through corners and speed down the straight speed down the straight.

One could brake early and go slowly through the corners then accelearate out of the corners and go fast down the straight to achieve a certain lap time. Then another with less power to accelerate out of corners and down the straight might achieve the same lap time by braking later and having higher corner speeds.
The result would be the same in a supersprint as long as each got a clean lap.

There's a big difference between racing and supersprints.
Take the same 2 examples and put them side by side on the grid. The more powerful one is maybe 2 carlengths ahead through turn 1. Less powerful might make that up under brakes and be on the tail of more powerful into turn 2. Then lose a little up the hill, and regain over the top through 4 and 5, lose a bit down the hill and pick up a bit under brakes into 8 then even flat though 9, lose a bit more. Gain under brakes again into 10, then watch more powerful pull away down the straight.
So for supersprints you can choose to spend on tyres, suspension, brakes etc. and have fun beating more powerful cars. And this makes sense with an MX-5 where you can spend a little to make a great handling and braking car even better. Or you can spend a lot to increase acceleration and speed on straights to get similar improvements in lap times.
Had I not wanted to go racing I would have stuck with thr NB8A and just improved tyres and suspension.
However I did want to go racing and would have needed to spend a lot it to get there, and I don't like turbochargers.
So I bought Dan's car and got there in less than 2 months without spending another cent on performance.
Now I am finding that in racing it is virtually impossible to make up for a significant acceleration deficit with cornering and braking.

Unless I can get another competitor to join MX-5 Cup with a similar powered car I think I need a little more acceleration out of corners and down the straight.

Nuddy wrote:Now I am finding that in racing it is virtually impossible to make up for a significant acceleration deficit with cornering and braking.

Unless I can get another competitor to join MX-5 Cup with a similar powered car I think I need a little more acceleration out of corners and down the straight.

I think you missed my point. Your car is capable of 1:09s and the back markers you are finding it hard to beat are 3 secs slower than that, EVEN WITH their extra power.
So whilst they do pull away on the straights you should have enough gain through the twisty bits to catch up and get under them and make enough gap before the next straight looms.

So rather than thinking your car needs more power, focus on getting seat time/driver training to bring down your current 1:14s and 1:15s to 1:10s and 1:11s and you should then find that the back markers are not so impossible to beat, even though they will still be quicker than you on the straights