Educate me on NCs.

[Spac]

Took it to Marulan today.

It handles awfully.
No, actually, that's wrong - it is worse than awful. It is terrible. The Wife commented that her old Mazda 6 with 380,000km on it would be both faster and easier to drive.

It wants to understeer everywhere.
It understeers on turn in, it understeers mid corner, it understeers on corner exit.
It understeers under power, it understeers on trailing throttle.

If you throw it into the corner, it understeers mid-drift.
If you really throw it in, the line between understeer and spinning is incredibly fine.

I wound on as much negative camber as I could.
I fiddled with front toe settings.
I fiddled with tyre pressures.
It was very unresponsive to all of these changes.

Best lap time was 1:09.6... I got my road car 318ti E36 (more weight, less power, more kays) around there in 1:08s on a freezing cold day, so I was expecting something more like 1:05s from the NC.

The tyres are very old, very hard Goodyear Eagle F1s and they are clearly not helping. But I am reluctant to point the finger at them alone, given the lack of balance.
Shocks are factory Bilsteins, which (like the rest of the suspension/steering) appear to be in good condition.
It goes very well, stops well, just hates changing direction.

Any suggestions?

[rascal]

The tyres are very old, very hard Goodyear Eagle F1s

Any suggestions?

Get new tyres!
Trying to diagnose anything else is pointless..

[david_syd_au]

Is the rear swaybar connected?

[RS2000]

What sway bars are on it?

[Luke]

LOL
Everything about what you said above is just so wrong. It sounds like you took a FWD V6 Diesel station wagon around the track.

The biggest problem is where are the actual details?
So please lets look at this more scientifically so people can actually help you out.

1. What is the date code on the tyres?
2. What size are the tyres?
3. What tyre pressures were you running hot?
4. What are you actual alignment specs, Caster, Camber and Toe?
5. How many K's does the car have on it?
6. Is the car completely standard or are there modifications?

When I had a NC 07 LE the turn in was perfect. I could choose whether to make the car oversteer, understeer or be neutral just through brake, throttle and steering inputs. I literally only ever had the car in a half spin once and that was on the banked corner at Baskerville.
Had no problem pumping out lap after lap within 0.2 of a second for regularity. It is still the easiest car I have dríven on track. I had full confidence in it regardless of weather conditions.

BTW, I have done 1'02.4 in my ND on the new Marulan layout in the whole 6 laps I did in it.
Don't have a NC time as I got rid of it before the track changed. I would suspect 1'03s is highly possible in a standard NC. Guran should be able to confirm this as he was my number 1 NC competitor.
I only have 1s difference at Wakefield and 0.5s at SMSP South between the NC and ND.
I assume your BMW time is also on the new layout?
BTW, road cars on road tyres are faster in Winter than Summer. Hell most race cars are as well.

[Spac]

Stock swaybars, connected.

1. Tyres are 23rd week, 2008. They're harder and crustier than this implies. As I said, the lack of balance is what worries me more than the fact that they're hard and slippery.
2. 205/45R17s.
3. Pressures were everything from 26~35psi hot. Didn't seem to make any real difference.
4. Alignment varied constantly and significantly through the day, trying to find something that worked. Didn't seem to make any real difference.
5. 200,000km. No obvious age-related problems.
6. Suspension is standard (also has muffler, cold air intake, light FW but they're not relevant to the handling issues).

I'm not god's gift to driving, but I'm not a clueless gronk either. I can usually work out how to drive around problems, but this one beat me.

The BMW was also on the new track, and I've done about 100 more laps since then (so have my head around the lines much better). On the same damp day, I had a $300 NA S40 doing high 1:08s.

This car isn't doing what an MX-5 isn't supposed to do.

[RS2000]

Has the rear toe been checked?

[rascal]

You’ve got 11yo tyres that were average when brand new, and you are wondering why it won’t turn in? Seriously?
If your tires can’t generate any grip then you’ll never do anything other than understeer off the track cos oversteer requires some level of front grip to overpower the rear grip.
I reiterate my previous comment - GET NEW TYRES!!

[Luke]

Stock swaybars, connected.

1. Tyres are 23rd week, 2008. They're harder and crustier than this implies. As I said, the lack of balance is what worries me more than the fact that they're hard and slippery.
2. 205/45R17s.
3. Pressures were everything from 26~35psi hot. Didn't seem to make any real difference.
4. Alignment varied constantly and significantly through the day, trying to find something that worked. Didn't seem to make any real difference.
5. 200,000km. No obvious age-related problems.
6. Suspension is standard (also has muffler, cold air intake, light FW but they're not relevant to the handling issues).

I'm not god's gift to driving, but I'm not a clueless gronk either. I can usually work out how to drive around problems, but this one beat me.

The BMW was also on the new track, and I've done about 100 more laps since then (so have my head around the lines much better). On the same damp day, I had a $300 NA S40 doing high 1:08s.

This car isn't doing what an MX-5 isn't supposed to do.

1. TYRES!!!
2. Size is fine, if you are going to stay with OEM rims there are a lot of high end road tyres in 215/45/17 that are far cheaper then the equivalent 205's. Take a step up to Hankook RS4, Kumho V720, Yokohama AD08R, Dunlop Star Spec 3 etc. You can get a set of 4 from $700.
3. That pressure is to low for road tyres. 36 to 40psi hot is what you should have.
4. Adjusting the alignment as you go still tells us nothing. When you get tyres get this done.
Front: Caster +5 Degrees, Camber -1 degree(that is maximum you will get on standard setup), Toe 0, both sides.
Rear: Camber -1.5 degrees, Toe 1mm Toe In Both sides
5. That is a lot of K's in my book.
6. Ok suspension is standard. but with 200,000km's if all of it is original, I would say its all flogged out. Your shocks and bush's will not be all that fresh.

[Spac]

Stock swaybars, connected.

1. Tyres are 23rd week, 2008. They're harder and crustier than this implies. As I said, the lack of balance is what worries me more than the fact that they're hard and slippery.
2. 205/45R17s.
3. Pressures were everything from 26~35psi hot. Didn't seem to make any real difference.
4. Alignment varied constantly and significantly through the day, trying to find something that worked. Didn't seem to make any real difference.
5. 200,000km. No obvious age-related problems.
6. Suspension is standard (also has muffler, cold air intake, light FW but they're not relevant to the handling issues).

I'm not god's gift to driving, but I'm not a clueless gronk either. I can usually work out how to drive around problems, but this one beat me.

The BMW was also on the new track, and I've done about 100 more laps since then (so have my head around the lines much better). On the same damp day, I had a $300 NA S40 doing high 1:08s.

This car isn't doing what an MX-5 isn't supposed to do.

1. TYRES!!!
2. Size is fine, if you are going to stay with OEM rims there are a lot of high end road tyres in 215/45/17 that are far cheaper then the equivalent 205's. Take a step up to Hankook RS4, Kumho V720, Yokohama AD08R, Dunlop Star Spec 3 etc. You can get a set of 4 from $700.
3. That pressure is to low for road tyres. 36 to 40psi hot is what you should have.
4. Adjusting the alignment as you go still tells us nothing. When you get tyres get this done.
Front: Caster +5 Degrees, Camber -1 degree(that is maximum you will get on standard setup), Toe 0, both sides.
Rear: Camber -1.5 degrees, Toe 1mm Toe In Both sides
5. That is a lot of K's in my book.
6. Ok suspension is standard. but with 200,000km's if all of it is original, I would say its all flogged out. Your shocks and bush's will not be all that fresh.

Understood on all counts.

I was expecting the tyres to be slippery, but for the car to still be balanced and driveable. I was genuinely surprised at how bad it was - not only the lack of grip, but the lack of balance.

There is an upgrade path planned, I was mostly perplexed by its refusal to co-operate on any level.

[93_Clubman]

Shocks are factory Bilsteins, which (like the rest of the suspension/steering) appear to be in good condition.

Advice from Heasmans the Bilstein specialist in Sydney is that Bilstein allows for 5% wear in their product for every 100k kms. If the Bilsteins aren't leaking, then they should be within 10% of the original rate. Jonosx on here works for Heasmans rebuilding dampers etc: <jonathon.mckinnon@bilstein.com.au>

[Custardtart]

This is easy, TYRES TYRES TYRES - but then get a proper alignment done by a specialist. Max out the camber but more importantly, get it even across axles. 1 degree of toe out at the front will aid sharper turn in but isn't really necessary.

If you mainly road drive them go for something like Bridgetsone Re003's which are a good fast road tyre but work ok on track.

If the shocks are the original ones then they probably are stuffed but I'd try the tyres and alignment first up.

[RS2000]

I'm with Spac, thinking that the car should be balanced with old slippery tyres (assuming front & rear tyres are in the same condition).
I wouldn't think putting on new sticky tyres would change the cars balance. Sure there would be more grip, so the understeer would happen at higher cornering speeds. On a wet skid pan, or loose gravel, a good balanced car doesn't suddenly get horrible understeer because there is no grip.

[JBT]

Tyres x 10 and a good wheel alignment to start with.

I've just put Hankook RS-4s on mine - the difference between them and 2 year old Kumho HS71s (which are an OK street tyre) is astonishing.
I'm looking forward to seeing the difference they will make at our next track day on 8 Feb.

Whiteline adjustable sway bars will make it feel much better than stock.

[Tony]

I'll have a set of fresh, almost brand new 215/45R17 Bridgestone RE003's for sale in the very near future if that's of any use; $450.