Combe Vid, Z4M, some poo, GT3RS & Aventador SV chases

[Haggisman]

Amazing video...those guys in their £200k machines must have thought wtf was going on with this little Z4 chasing them down the track. Brilliant stuff!

You should put on a track day for a few Zers and teach folk the limits of the car!

Did the same thing to some exotic cars at a recent track day here in my humble 3.0 E85. Training from an experienced race driver makes a huge difference. It’s great to “improve” the car through modifications but understanding the dynamics of car behaviour relative to driver input can give the biggest gains and driver satisfaction. (IMHO)

[Haggisman]

I see you run arc 8 wheels, are they staggered or a square set up?

staggered 8.5, 9.5.
[/quote]
Thanks for info, I was concerned about creating more understeer but I guess I could dial that out with suspension settings, more front neg camber, sway bar settings. The wider rears certainly look better and my car is predominantly a road car.

[BMWZ4MC]

Great videos. The little Zed did well keeping up with mighty competition - a combination of bravery, skill and a capable car I think.
However, there’s a point when you know it’s all about to go wrong but it’s already too late to catch it.... I’m always glad when I’ve got away with it - my last track day a Huracán went into the wall and a mate binned his F80 M3 causing $50k of damage. I had a huge sideways moment but thankfully it was only shared with the driver of the supercharged 6.2 litre Holden behind me and a marshall.

[ga41]

Great video.

[craig3.2]

Great video,and as said,shows what a nicely modified z4m can do in the right hands
Nice one

[Jembo]

Felt the greatest part of your vid was opening with a faux pas... a great reminder of how easy it is for things to go tits up over the limit.

Like to suggest were you to organise a coaching session, I’d be interested in your thoughts if I were to let you drive mine in terms of balance - it will never be a track whore, though interested to hear feedback on current mods

[TomK]

Thanks all again for the positive comments, as some have mentioned the z4m can be a capable track car.

Looks like the rear became unweighted on the entrance..

Exactly this, I've driven many laps now at combe, some in similar conditions but have never had that happen to me. Looking back at the video you can clearly see the car bounce and not recover for the 2nd bump (which btw you really don't notice when you're driving it (or at least numb nuts here didn't)). I put it down to the new suspension and not adjusting the rebound on the rears softer, everything was set in the middle for this. However the car had been sitting for a while in the pit lane for a red flag and the pressures would have been very low, 2nd lap, I probably should have made some allowance for it, but as I said I've never had any incling that the car would go there.
I was very lucky tbh, I should have lent into it more in hindsight, the last time I wrote off a car on track was after a suspension change so I should know better.

looks fun! do you think your second slide was due to following the SVs pace? rather than handling limits you had previously discovered?

Ok I'll admit... I was driving a bit ott with the aventador in front... forgive me! It's one of my failings as a driver that I see, in that I don't do the lap times that I can when I have the bit between my teeth as it were of chasing another car.
That corner in particular is a really tough one on the car, there is a bump in and around the apex, and in a rwd car it poses a lot of problems as you're trying to steer a lot and get on the power. In this particular lap I was just a bit to keen, again some adjustments to rebound on the dampers I think might help. On the other hand the turn in oversteer to that corner I experienced in the past seems to have largely disappeared. Suspension/geo wizardry seems to solve one problem but may create another, it's a fascinating balance i've come to realise over the years.

You should put on a track day for a few Zers and teach folk the limits of the car!

If I had infinite time available, yes, maybe! But to be honest having a whole bunch of cars at the same speed, whilst it sounds good might not in reality be so great. There's so many good track day options out there with 'like minded' people (imo the type of car doesn't really matter) having a great time, and most of them offering ARDS grade A instructors. I have a race licence but I most definitely don't nor would want to have an instructor licence.
That said it would be really beneficial for some if there were a bunch of us to book onto a trackday and share experiences between the cars either through the driver or passenger seat. I'd be quite happy for someone to compare the driving of mine to their own and try figure out how each could be improved. For me the biggest lap time gain hasn't been any power or suspension mods, it's all about the geo.....

Amazing video...those guys in their £200k machines must have thought wtf was going on with this little Z4 chasing them down the track. Brilliant stuff!

You should put on a track day for a few Zers and teach folk the limits of the car!

Did the same thing to some exotic cars at a recent track day here in my humble 3.0 E85. Training from an experienced race driver makes a huge difference. It’s great to “improve” the car through modifications but understanding the dynamics of car behaviour relative to driver input can give the biggest gains and driver satisfaction. (IMHO)

In my car's defence (and to some extent mine) neither of those cars were being driven by chumps. I don't know the GT3RS driver but I do know the Aventador guy, who's driven the track probably more times than me. He usually drives a carrera GT, and to give him his dues this was his second week with the aventador. No doubt both could have been driven quicker round there but the video shows that power isn't everything and some commitment on the brakes gets you a long way up the road, particularly when your car is worth 10x less than the opo

Thanks for info, I was concerned about creating more understeer but I guess I could dial that out with suspension settings, more front neg camber, sway bar settings. The wider rears certainly look better and my car is predominantly a road car.

Understeer in the chassis is far better dealt with in the geo than simply swapping wider tyres on the front on a car like this IMO.

Felt the greatest part of your vid was opening with a faux pas... a great reminder of how easy it is for things to go tits up over the limit.

Thanks, yes at times like that it all comes into focus what you do when you go out there. It's easy to look at a video after and say this and that, at the time things move a whole lot quicker I must have driven a couple of hundred laps round there now and each time you learn something new That's the fun of it.
Hope to see some more M's out on track soon.... I've never come across another one (other than spa) come on peeps! (or maybe I just need to go to more trackdays!.. donnigton 8th March if anyone;s around..)

[Babw]

This is superb Tom, Combe has to be one of my favourite tracks and I had a very similar off because the rear tracking bar had come loose. I've yet to drive my M roadster on track but I have driven a stock M coupe soon after they came out at Combe.

The one thing I remembered was how fun it was but also compared to my E46M at the time how much more concentration you needed because the car seemed to get deflected more likely due to the added stiffness and/or geo + quicker steering.

[MrPT]

some poo

Yep.

Great driving! I guess you have to expect to be caught out occasionally if you do a lot of track days. I like that, with the exception of the brown-trou moment, you keep it tidy and appear to have a bit in hand at all times. You see some nordschleife onboards where drivers are clearly on the ragged edge and chancing it beyond their skill level.

[brillomaster]

we call it a 'brown flag moment' had a big one last month, a mate got it wrong through the kink on the back straight at bedford - furthest i've ever been off the track! i did the same thing earlier in the day, but somehow kept it on the black stuff, definitely my biggest ever save.

been doing 8ish trackdays a year for the last 5 years now, brown flag moments are inevitable!

[RedUn]

Just caught this now, great video Tom

Have you fiddled with the KWs anymore? I've ended up running the dampers about 25% more than the KW starter values, it's firm but well composed

[IRD]

Very impressive! Great fun to watch.

[TomK]

Just caught this now, great video Tom

Have you fiddled with the KWs anymore? I've ended up running the dampers about 25% more than the KW starter values, it's firm but well composed

Thanks.
I went to donington a week or so after to figure out what was going on.
you can see here a comparison full speed lap at combe with the 2 different setups. The kw causes me to make a steering input that I don't make with the b12 setup (as a result you can see my head moving much more around 4.5 secs), that's also where the car let go in the wet.

Turns out I hadn't really read the setup guides and the rear dampers in both bump and rebound were set far too hard. I've backed them off to suggested rates of almost 3/4 soft and dropped the rebound slightly as my rear end is quite a bit lighter than stock now.
On the positive side you can also see the big improvements in stability when braking into quarry with the kw at the end. So overall, whilst it feels better now, there's definitely still more time to come I think, I'll be booked onto a combe day soon to see.
It was a frustrating day at Donington, far too many cars.. long time since I've done a javelin day, and it will be a long time to my next
Still there was a bit of fun to be had

[BMWZ4MC]

RedUn and Tom, would one of you mind posting the KW recommended settings for the Clubsports please. I fitted mine five years ago and somewhere along the line I’ve lost the paperwork. I’ve tried a spectrum of settings for road and different tracks, but it would be good to try those suggested by KW. Cheers.

[Attilio]

Hi TomK

wow! what a great video and what a piece of driving!!!

Your Z4M sounds fantastic!