Z4M at Knockhill

[Babw]

enjoyed the debate however.

I'm not finished yet!

Your informed opinion tells us you like both cars, they handle differently but you like that. The GTR is an awesome peace of engineering, I admire it, but I wouldn't want a GTR due to the way it produces its performance through a very clever drivetrain and suspension. I'd rather go the other direction, ie. towards a Lotus Elise but I like the usability of the Z4M.
What your informed opinion does not give you is a correct assumption on how the GTR performs as well as it does.
The engineers explanation leans more to marketing than anything else, imo. If any car weighed half as much as it does but everything else stayed, it would go quicker over a lap of a dry track. Bringing snow into the equation is just ridiculas.

Less weight is better isn't a Gran Turismo way of thinking, it's more of a Colin Chapman way of thinking.
If any car is born from the Gran Turismo generation it's the GTR, the menu system was designed by Polyphony....

Ok then enlighten me.

What's so clever about it's suspension?

How does it's clever drivetrain help it produce it's performance? You think it's all wheel drive that helps it launch from a stop and out of slow speed corners? Some evidence would be great.

You realise it's nearest competitor the 911 Turbo S weighs 1650kg right? It's actually faster than a 911 GT3 RS over some circuits in Europe.

But you're definitely wrong about if a car weighs half as much it would go quicker. If it doesn't have significantly more downforce then it definitely won't go quicker, the extra power can't be applied to the tarmac. Any car naturally has lift as it has some drag factor so the faster the car goes the more detrimental it will be. You can't change direction, accelerate or brake effectively if there isn't contact from the tyres to the ground...

(We had an Audi V10 plus which had more power lighter weight and 4WD. It certainly was not faster than a GTR in any circumstance.)

From 70-0 stopping distances -

Z4M - 152ft (steel)
GTR - 153ft (steel)
M4 - 150ft (carbon ceramics)

Is it the clever suspension and drivetrain that helps with the braking also? Considering GTR has 300kg on them all it does pretty well no? Why?

 

[Beedub]

you may not be finished.... but i am

When you continue to talk about weight likes its a commodity theirs no point continuing... why do race series use weight to penalise certain cars? Why is the GT3 GTR car 300+ kg lighter...

The GTR uses MUCH better braking tech and TYRE tech than the ancient Z4m... tbh i expected much better stopping times than it... yet it cant match a car from a decade a go with single pot sliding callipers?? You CANT hide what that mass is doing and YOUR posting those times like they are a good thing?? The z4 is the is the one that impressed me with your numbers...

The GTR is an epic machine I'm not saying anything other , but don't ever for one minute think all that weight is a good thing...

FWIW an INDEPENDANT test of the aftermarket BBKs on an e92 m3 with decent tyres only FRONT kits getting the times down to 133ft... That doesnt have 4wd or clever suspension but its still a bloater?? Just high quality bolt on aftermarket goodies. Like i said the z4m with some choice bolt-ons can really shine, and it REALLY does....

http://www.m3post.com/forums/showthread.php?t=1061808

 

[Beedub]

Hell if the GTR does what it does with the weight penalty i cant imagine what ones like with some weight out of it.... id guess incredible and be able to do it for longer.

The things i see the serious track drivers do on the GTRs is the alcon CCX or carbon rotors #weightreduction , remove the back seats and get some tillets up front #weight reduction, Smaller lighter forged wheels #weightreduction, the list goes on, but every one of those car thats really serious about putting in the times is trying to get some of that weight shed..

according to the nissan specs the cars are 1700kg, thats the same as my macan Pdk, thats a good thing??

On your point RE the turbo S porsche... the turbo model is hailed as the everyday supercar, the halo models use LOW weight , weight saving Everywhere , maybe even a lower lap time at certain venues but a much much better overall package for circuit use and feel.

The GTR at 1500kg would be unstoppable as a road car and track weapon.

 

[Babw]

A GTR at 1500kg isn't as easy to drive quickly and feels far less planted than a 1700kg GTR. I know because I've driven one, at the hands of a very skilled driver sure it's faster but I'm a decent driver and in my hands I was lapping slower than a full fat GTR. The lap times got better once I learned the car but in continuous lapping the times started to creep back up because there was less margin for error. I did about 40 laps in each car. We're talking about the real world, any car where it makes it easier for a human to control constantly will be a faster car. The lighter car was less stable on the brakes and more oversteer moments. Ask any racing driver if oversteer is "fun", they would say it's "slow" and would say it needs more downforce or weight.

We're not talking about out and out race cars here, I'm talking about road cars that can lap quickly. A GT2 car feels less eventful at speed than an M4 due to the weight on the tyres from the aero, this is the concept the GTR has used but for a road cars just high speed tyre contact isn't important; slow speed as well.

Do you realise when launching a GTR it is 100% rear wheel drive? What clever 4wd system? The party piece of the GTR for which many assume is due to it being all wheel drive is not that at all! It's actually because of the transaxle casing (weight) and the inertia over the rear tyres which allows the car to hook up so well. Same as a Porsche, actually since the 911 Turbos have been getting heavier they've been getting better traction. Something like an R8 can't launch as hard out of slow speed corners because the tyres just don't have the traction even though the engine is in the middle. BMW's have no hope with the engine in the front.

Don't bring straw man argument like I'm saying infinite weight is better. But if you have a plan from the outset and design every aspect of the car around grip and traction then weight can definitely be managed.

The number of pistons don't increase braking performance in a single effort once brakes and tyres are up to temperature - fact. Actually brakes don't stop the car, they slow the rotation of the tyres which stop the car due to increasing friction against the ground. BMW's have much worse braking performance than a Porsche of similar weight due to the "perfect 50/50" weight balance at static becoming a massive pendulum swinging forward increasing inertia and lack of weight over the rear tyres. When you brake any car pitches forward, a car with a larger proportion of weight at the back pitches forward less.

What brakes better, a car with 4 wheels on the ground or a car with 2 wheels?

I see you've managed to avoid the M4 example with even more advance braking and similar tyres and lighter weight which has much less proportionate braking performance....

 

[Beedub]

A GTR at 1500kg isn't as easy to drive quickly and feels far less planted than a 1700kg GTR. I know because I've driven one, at the hands of a very skilled driver sure it's faster but I'm a decent driver and in my hands I was lapping slower than a full fat GTR. The lap times got better once I learned the car but in continuous lapping the times started to creep back up because there was less margin for error. I did about 40 laps in each car. We're talking about the real world, any car where it makes it easier for a human to control constantly will be a faster car. The lighter car was less stable on the brakes and more oversteer moments. Ask any racing driver if oversteer is "fun", they would say it's "slow" and would say it needs more downforce or weight.

We're not talking about out and out race cars here, I'm talking about road cars that can lap quickly. A GT2 car feels less eventful at speed than an M4 due to the weight on the tyres from the aero, this is the concept the GTR has used but for a road cars just high speed tyre contact isn't important; slow speed as well.

Do you realise when launching a GTR it is 100% rear wheel drive? What clever 4wd system? The party piece of the GTR for which many assume is due to it being all wheel drive is not that at all! It's actually because of the transaxle casing (weight) and the inertia over the rear tyres which allows the car to hook up so well. Same as a Porsche, actually since the 911 Turbos have been getting heavier they've been getting better traction. Something like an R8 can't launch as hard out of slow speed corners because the tyres just don't have the traction even though the engine is in the middle. BMW's have no hope with the engine in the front.

Don't bring straw man argument like I'm saying infinite weight is better. But if you have a plan from the outset and design every aspect of the car around grip and traction then weight can definitely be managed.

The number of pistons don't increase braking performance in a single effort once brakes and tyres are up to temperature - fact. Actually brakes don't stop the car, they slow the rotation of the tyres which stop the car due to increasing friction against the ground. BMW's have much worse braking performance than a Porsche of similar weight due to the "perfect 50/50" weight balance at static becoming a massive pendulum swinging forward increasing inertia and lack of weight over the rear tyres. When you brake any car pitches forward, a car with a larger proportion of weight at the back pitches forward less.

I see you've managed to avoid the M4 example with even more advance braking and similar tyres and lighter weight which has much less proportionate braking performance....

If the GTR launches in total Rwd mode why do you see failures like this??

http://www.gtrlife.com/forums/topic/99810-boom-goes-the-front-diffprop-shaft/

 

[Babw]

lol what? You can break anything that moves. It's clearly a track car that's been used well, I've broken driveshafts on my old M3 and never launched it. That's a pretty poor comeback Beedub, clutching at straws now.

On launching the GTR is 100% RWD, same as the Porsche. Unless you're launching in reverse of course...

 

[Beedub]

lol what? You can break anything that moves. It's clearly a track car that's been used well, I've broken driveshafts on my old M3 and never launched it. That's a pretty poor comeback Beedub, clutching at straws now.

On launching the GTR is 100% RWD, same as the Porsche. Unless you're launching in reverse of course...

lol... if the car is launching in RWD the front Diffs and props wouldnt fail like they do..... on the S/C z4ms we split the rear shafts, parts that are under stress break, the GTR does NOT launch in RWD mode thats why syvecs and probably others developed a "burnout" mode to disengage from the front diff or however they do it... it may have a bias towards the rear but its not 100% RWD

https://www.youtube.com/watch?v=d-I0AFa94L8&feature=youtu.be


again... why do you see this question pop in so often after a few launches if its only RWD in launch mode...

clutching at straws or are you just talking out your arse??

http://www.gtr.co.uk/forum/175546-loss-4wd-when-wheel-spinning.html

If your GTR is launching in 100% rwd as you say then.. according to these type of threads its doing so to protect the clutch packs from overheating......

ill have to take your word for it on the 1500kg GTR, personally id guess that its unbeatable really and won't need huge power increases to "MANAGE" the weight.


either way we are going round in circles. you win. heavier is better. Like i said before fair play for not loosing your rag like most would, you kept on the subject and kept it factual :thumbs:

all I'm saying is, you MAY surprise yourself if you ever get to drive or ride in a properly sorted z4m as from my experience they really punch well above their pay grade.

 

[Babw]

I'm sorry but your basic of lack of understanding of car dynamics are showing now.

The official line is at launch is 98% rear but I've seen the logs and often it's 100%. Why? Because when you launch from a stop the car pitches backwards heavily. There's no point sending anymore power to the front as the front tyres have barely any contact to the ground.

Why don't you try putting 100kg in the boot of your Z4M and try some launch tests then tell me I'm talking out of my arse. Even a F1 car with a massive amount of front wing on still pitches backwards when launching with reduced front tire grip.

I don't disagree with anything you say about the Z4M, I have no ambition to explore the lapping potential of it. I'm sure adding aftermarket products increases the ability but taking it to a proper race engineer who can log your changes on track to laptimes will make it even faster :wink:

 

[Beedub]

I'm sorry but your basic of lack of understanding of car dynamics are showing now.

The official line is at launch is 98% rear but I've seen the logs and often it's 100%. Why? Because when you launch from a stop the car pitches backwards heavily. There's no point sending anymore power to the front as the front tyres have barely any contact to the ground.

Why don't you try putting 100kg in the boot of your Z4M and try some tests then tell me I'm talking out of my arse. Even a F1 car with a massive amount of front wing on still pitches backwards when launching with reduced front tire grip.

ok. :tumbleweed:

what i want to see is more of clark!!! he's a beast behind the wheel!!

 

[Babw]

Interesting you say the car in the video needs more power Beedub because it doesn't seem to be putting the power it has down that well. I would get some rear wing and then some stickier tyres.

 

[Beedub]

I thought it was doing great tbh..

 

[Easty-5]

Interesting you say the car in the video needs more power Beedub because it doesn't seem to be putting the power it has down that well. I would get some rear wing and then some stickier tyres.

Overheating Nankang tyres can be partially blamed for lack of grip.

This thread has taken off in a pretty different direction :rofl: Calm down ladies!

 

[Beedub]

Interesting you say the car in the video needs more power Beedub because it doesn't seem to be putting the power it has down that well. I would get some rear wing and then some stickier tyres.

Overheating Nankang tyres can be partially blamed for lack of grip.

This thread has taken off in a pretty different direction :rofl: Calm down ladies!

Nuffin to calm down about its a forum and that was an on topic debate.... when it gets silly is when person insults are thrown, That type of heated discussion is what this place NEEDS imo :thumbs:

just look at the first page in this ///M specific forum, its died a death over the last 1.5 years, all i ever read about is cosmetic changes and lowering springs... :headbang:

 

[Babw]

It wasn't particularly heated and I agree with Beedub, always good to see how opinions differ on car design/setup.

 

[Easty-5]

If you want to see Clark driving in a competitive setting then here is a video of one of his last races. He is driving his S54 CSL powered E36.

https://www.youtube.com/watch?v=XduvEuuHxaA

 

[ga41]

...just look at the first page in this ///M specific forum, its died a death over the last 1.5 years, all i ever read about is cosmetic changes and lowering springs... :headbang:

Well it is a 10 year old car model now... Getting rarer too. Excitement starting to fade...

 

[Beedub]

...just look at the first page in this ///M specific forum, its died a death over the last 1.5 years, all i ever read about is cosmetic changes and lowering springs... :headbang:

Well it is a 10 year old car model now... Getting rarer too. Excitement starting to fade...

Tell that to the r34, r33 , r32, supra, rx 7 forums..... jus different owner types... my excitement as grown for a rare car thats got some really nice aspects about it that we won't be seeing again, like that S6....

 

[ga41]

It's exactly that, a different type of owner. Those forums you mention are fueled by the modding community which is much more established for them.

 

[Clark]

Hi.

I'm Clark :driving:

After Jamie sending me some details of the chat that has arisen since the posting of my driving at knockhill, I thought I'd join in the conversation,

Firstly though - thanks for the compliments, not sure how justified they are, my driving is mega rusty just now - but thank you!

Now....... Onto the GTR/Z4M chat!

I guess the starting point should be the facts at hand, then I'll go on to provide some experience based opinions.

Jamie's z4 is probably costing sub 20k, the engine is well maintained but standard, it has a nice air intake and a good exhaust, but I'd take a stab at it producing pretty standard power. Most factory fresh s54's struggle to produce 320bhp when you actually dyno them. It has a nice set of KW clubsports, which are set all round to bang in the middle of the adjustment scale as a base to work from. The tyres are budget trackday tyres, which I'd confidently say (whilst great VFM) do not provide the same level of grip and predictability as the OEM contisport 3's. The brakes are OEM, with castrol SRF and a good set of CL pads.

Now, onto the GTR.....

I know it has over 700bhp, trick suspension, really big brakes and proper tyres. The whole thing is probably a little over 3x the cost involved in the z4 as it stands.


To give you a bit of background on me - before I provide my opinions (and that's all they are)

I've owned a lot of BMW's, here are some of the notable ones!

E30 318is - I won my class is the scottish hillclimb championship with this car, I've owned it for 11 years and it's pretty special to me!
E30 318is (I'm building up a nice road car with this one)
E36 m3 saloon (Evo) sold it a few years ago when they were worth nothing!
E36 m3 Racecar, S54'd Geoff steel airbox, CSL cams, JC racing diff and so on.
E92 m3 (good car, a bit dull, did 186 on a trip to the ring)
E39 m5 (cracking car, I had big, loud H+S pipes, drove it to Spain and up through France - lovely cruiser)
Z3mc - spent a lot of time driving one of these on the road and track (not actually my car though)

And of course... My favourite the interlagos Z4MC - the only car I regret selling and I'll have another - I found the owner of my old one.. I'll maybe get it back some day.

So - it's fair to say in very much a BMW guy! However, I've driven a few things on and off the track, a little list of memorable ones below.

GTR (yes one of those)
DC2 Racecar
911 GT3 (997 gen1)
E30 m3 track car
Lotus 340r
Lotus Elise S2 (my 1st track car)
Lotus Elise S2 with a supercharged honda lump
New Cayman S PDK
F430 F1
Tuscan Speed Six
Sagaris
M4
Dax busa turbo

Anyway. I'm sure there are others, but you get the idea!


Some of the GTR related comments here are just comical.

The GTR has a mega brain and puts the power to whatever wheels are asking for it, it's a great car if you want to get in it, go for a mad blast in any weather and not really have to use much brain to do so, they are a pretty capable car for something that weighs and handles like a houseboat. I've yet to see one driven to capacity - to the point where my e92 reg plate was black with soot thanks to a GTR straight line hero at the ring on my 1st time there. Every time we entered a turn I had to avoid running into the back of him, he wouldn't let me past on the straights etc. This made for a very slow and frustrating lap, followed by an argument in the Carpark.... This is pretty much how I sum up GTR's - they get a bad name and they shouldn't. It's the large percentage of twats that own them. (This isn't all of the owners nor is it limited to GTR's - most 911 turbo owners are the same too)

The Z4M in standard form is a lot of car for the money out of the box. My coupe was pretty standard, suspension wise anyway.

It's a more exciting and involving to drive imo, yes, it can be a bit lairy, but on a trackday, what do you want? Record Lap times? If you want lap times go racing.

The mix of cars that the z4 can rub shoulders with is huge, bearing in mind it's an old car now!

In that vid it keeps a stage 1 Golf R in check and the GTR struggles to shake it - that's with my rusty driving too.

On the day there was 1 car that was significantly faster.... A Ferrari 458 race car... Even that was reeled in on the brakes and through the technical stuff.

The main thing with the Z is bang for buck - go and find something else that good for the same money. You can't. Now go and spend the value of a GTR on a z4... And find something 'better' Im not sure you can!

I really don't think the car wants for more power either, if you were to be seriously looking to break records I'm not sure id bother with much more power, the gains on power vs cost are low, especially when there are better ways to go faster.

1. Set up the suspension properly (Jamie and I were going to play with the settings.... But we were ha I g too much fun!!!!) and Learn to drive better - everyone no matter how good can do this, Lewis Hamilton, Sebastian Loeb, Alan Mcnish and Gordon Shedden all take tuition - it can be free, but even the best tuition costs a lot less than a supercharger!
2. Change the Diff for a JC racing one
3. Lose some weight, the car is heavy
4. Get bigger brakes
5. Get better tyres
6. Swap the seat and belts for proper ones and harnesses / I bet I lose 10ths at every turn by trying to keep myself in the seat!

What it doesn't need... Is a big wing or 'aero' for knockhill, the benefits would be minimal at best in a car that weighs so much and has Nanking tyres on it.

All of these would probably take away from how well rounded the car is! It's probably the best rounded at you can buy for 15k, my preference would be a coupe (sorry Jamie)

Christ I neeeeeeeed another Z4M!!

 

[Beedub]

clark came in the house with a BANG.... agrees with everything you say really bar the tyres... and of course the roadster is the car for me!!

i run those very same nankangs and have found them to be a very serious track tyre ( they need the pressure to be checked regularly, i like 29psi HOT) , HOWEVER i use my car at sprint events, so relatively short technical timed tracks that really need the balance of power, braking, grip and agility... Maybe on the longer bigger tracks they cant deal with the heat?? or maybe the Clubsports ( which lets face it is a track damper thats roadable) is just showing them up now in those bigger arenas...
However if your on a budget they are awesome ( i was at the time) but my next try will be a Cup2 or trofeo... i hope I'm not disappointed,

Either way its great to see a post from you and i actually value your opinion , the z4m is such a capable little car, I've been playing with the CS settings and getting some seriously impressive results.

i have pretty much all your list in terms of the z4m's needs and maybe TOO much power for such a small car, but what a thing it is to drive fast.

Please get another z4m and please come here more often WELCOME