GT4 RS/ Spyder RS Experiences, Driving and Technical

[993rsr]

TDT said:

I start off at road pressures so around 2.1F and 2.3 or 2.4R

Once they start to head up and get hot I take them back down to the same level. I only did one bleed down ln Friday, once things got drier.
With the ambient and track temps - i dont want to run low pressures as they’ll be out range and you wont get them to come back up.

This is on the Dunlop Sport Race Maxx 2.

Ref camber you can see the line where the surface has warmed and melted/migrated/pushed to. Fronts look ok IME. Its not gone over the edge of the tread although it is close.
The rear has used everything available so probably could do with more if you wanted to.
Balance of the car was pretty neutral- no understeer based upon what I was doing (loads of time left on the table) and I could start to move the rear on throttle if/when i wanted to on exit to straighten.

So technically could use some more once pushing harder - which I already know, (previous 718MR ended up in the region of -3.4° Front and -2.8° Rear) but my intention is to only put on just what I need, as I need it, which then keeps the operating window as open as possible.

But I don’t think this is the excessive wear vs how some people claim the car uses tyres, considering how much tread depth you don't get at the shoulder anyway.

I’d be letting those pressures lower to start.

Maybe 1.7 front and 1.8 rear.

At the pressures you mention it won’t take long to start chewing up the outer edge. They’ll soon come up in a handful of laps.

[fridaypassion]

I always start at road pressure on a track day and just let the pressure out. Then you know you're pressures are right for the track you're on. Starting with lower pressure is a dangerous game the one time I tried it I nearly crashed at the Ring due to understeer from the too low pressure....

[jackwood]

Front end looks spot on. Looks like you were driving it on the rear a little bit at some points.. (scrubbed and rolled over the shoulder)

So then you’ll dial in the rear a bit more, and then start working the fronts a bit more….

Welcome (again) to chasing lap times

[jackwood]

And yes. Not excessive wear on either. Because you’re clearly a very sympathetic driver that has a lot of feel for the car and what it’s telling you.

You’re driving to the capability of the car and it’s set up, and not beyond it.

Much respect.

Edited by jackwood on Thursday 13th March 21:48

[993rsr]

fridaypassion said:

I always start at road pressure on a track day and just let the pressure out. Then you know you're pressures are right for the track you're on. Starting with lower pressure is a dangerous game the one time I tried it I nearly crashed at the Ring due to understeer from the too low pressure....

That’s an inaccurate statement. Too much lower yes, lower no.

From Michelin.







That’s 1.7 bar and 1.9 bar FYI

Edited by 993rsr on Thursday 13th March 22:36

[MannyLon]

Instructor at Porsche centre told me to warm the tyres prior to going onto track. Difficult on some track days I’d imagine.

[fridaypassion]

993rsr said:

fridaypassion said:

I always start at road pressure on a track day and just let the pressure out. Then you know you're pressures are right for the track you're on. Starting with lower pressure is a dangerous game the one time I tried it I nearly crashed at the Ring due to understeer from the too low pressure....

That’s an inaccurate statement. Too much lower yes, lower no.

From Michelin.







That’s 1.7 bar and 1.9 bar FYI

Edited by 993rsr on Thursday 13th March 22:36

I'll just keep doing it the way I've done it for 20 years I think.

[993rsr]

fridaypassion said:

993rsr said:

fridaypassion said:

I always start at road pressure on a track day and just let the pressure out. Then you know you're pressures are right for the track you're on. Starting with lower pressure is a dangerous game the one time I tried it I nearly crashed at the Ring due to understeer from the too low pressure....

That’s an inaccurate statement. Too much lower yes, lower no.

From Michelin.







That’s 1.7 bar and 1.9 bar FYI

Edited by 993rsr on Thursday 13th March 22:36

I'll just keep doing it the way I've done it for 20 years I think.

Fair enough doesn’t mean you are right, or lower pressures
From cold as comfirmed by Michelin will cause you to under steer
Off at the ‘ring.

[LiamH66]

TDT said:

Tyre wear still quite normal.
Front Left (VL) and Rear Left (HL)

2400mls in total.
2 light track days (Goodwood & Castle Combe) at c -2.4° front & -2.0° rear
Then Oulton Park with c-2.7° front and -2.2° rear.

I guess it’s to do with track temps, driving style - how you load the tyres? or I’m just not going fast enough…

I start off at road pressures so around 2.1F and 2.3 or 2.4R

Once they start to head up and get hot I take them back down to the same level. I only did one bleed down ln Friday, once things got drier.
With the ambient and track temps - i dont want to run low pressures as they’ll be out range and you wont get them to come back up.

Tyre wear looks pretty good to me, especially since the first 2 outings were on standard camber (and I guess ride height?). Would need to look at tread blocks across full tyre widths to consider whether camber is enough in my mind, but gut feel from many 981 GT4 track days, and a couple in the GT4 RS now, is I'd be happy enough with that.

This time of year, I'm similar to you, just bleed them down as the pressures come up. On a warm dry day, I'll generally dump quite a bit of pressure before the first outing if it's good and dry, otherwise I'm coming in too often to bring the pressures down. 2.1F 2.3R is exactly what I aim for on a cool dry track, a little higher if it's damp or wet. On a hot day I found at 1.9F 2.1-2.2R hot, I could allow tyres to get up to temperature over a couple or 3 laps and then sustain for as long as I wanted to stay out. TPM threw an absolute hissy fit when going back out after lunch break, with left front at 1.6, maybe even lower. It was a useful reminder to stay away from the kerbs while getting them back up to temperature.

Suspension Secrets say they lowered the front of my one (also has FAL) by 15mm, but that's all there is to play with. I haven't been on track with it yet, but my gut feel is I'd like it a bit lower. Agree entirely that they are quite a "pointy" handling car that appreciates subtlety of driving, and rewards it well. However on standard ride height, if I was on the brakes too early, so wasn't really trail braking at turn-in, the front would pick back up to ride height, and it was difficult to get it to bite with confidence. At Oulton, it was very specifically at Island and Druids, where I wasn' t finding braking points consistently. Driver error, obviously, but I'm expecting it being lower now will help. Shorter front springs might help even more.

ChrisW. said:

The saving of ST's is a two-off saving ... because they run so much cooler than PCCB's or steels that the pads last far longer. They are also cheaper to refurbish (come the time) than PCCB's though there is some uncertainty surrounding Surface Transform as a company. Should the worst happen I would be very surprised if there wasn't some pre-pack liquidation to escape the debt and give their technology a second chance ...

I think you were one of the first to make me aware of just how good the technology is. I've since had a good chat with Suspension Secrets about ST, and I'm definitely sold on how good they are. Agree entirely, they are above mag wheels in my priority list. Mag wheel have an upside in unsprung mass, and a downside in potential fragility. ST brakes give me lower unsprung mass, consistent performance at almost any temperature, reduced brake temperature in general, hopefully some longevity and lower maintenance costs, and less wheel cleaning. It's kind of a no-brainer, but a £15.5k no-brainer nevertheless. I get on pretty well with the standard "steel" brakes that my 4RS came with (usefully better than 981 GT4 standard brakes IMO), so it's probably less of a priority than a better suited set of road springs for now. Helpful advice though. Thank you!

Liam

[Throttlebody]

993rsr said:

fridaypassion said:

993rsr said:

fridaypassion said:

I always start at road pressure on a track day and just let the pressure out. Then you know you're pressures are right for the track you're on. Starting with lower pressure is a dangerous game the one time I tried it I nearly crashed at the Ring due to understeer from the too low pressure....

That’s an inaccurate statement. Too much lower yes, lower no.

From Michelin.







That’s 1.7 bar and 1.9 bar FYI

Edited by 993rsr on Thursday 13th March 22:36

I'll just keep doing it the way I've done it for 20 years I think.

Fair enough doesn’t mean you are right, or lower pressures
From cold as comfirmed by Michelin will cause you to under steer
Off at the ‘ring.

Track days, not racing, gives you the luxury of working your own strategy. Slowly work the pressures into a sweet spot with multiple sessions or take an initial setting based on experience and hope all 4 tyres come into range.

[GT_cars]

993rsr said:

Fair enough doesn’t mean you are right, or lower pressures
From cold as comfirmed by Michelin will cause you to under steer
Off at the ‘ring.

I agree with RSR, that's a 1st

I Always let some out, I always do the sighting laps which brings them up a bit or i;ll stay oem and do it after slighting laps if it's cold, then it's a few faster laps and on a Cup normally only one bleed down, NO one is running off the road with a softer tyre unless stupid !
And I am not sure why people skip slighting laps, it's ideal way to get the heat in a tyre after 1.5 hours sitting in the pits on arrival.

When I ran Dunlops I was messing with Pressure too much all day they are crap at holding a pressure imho.

It's not hard, I tend to not offer advice these days as every one on forums bites your head off, or just does what they want to do and I let people get on with it.

issue is todays cars and high spring rates really demand a better R spec tyre, and much better pads, and proper track geo's so it's a never ending chase which then makes the car pointless as a road car. (A cup 2 is a basic biginner tyre which is a great summer road tyre, at 30oc you get 3 fast laps that's it) It's why I gave them up, I got the 4RS for a laugh to do a few and it brought it all back to me, car needs a £20k spend on it and it's really £3k a track day all in. 2 mates also bought GT4's and both sold them just after 3 or 4 track days and have gone back to Caterhams, £80 geo, pads and tyres last a season. Track a 4RS in any serious way you need £50k year one and £30k PA after. Got to pay to play. £65k 1st year if you go ST also !!

[Snowy999]

GT cars - I literally live on a different planet to you!

Lockton track day insurance, OEM pads and steel discs plus Dunlops, had a great day at Spa and now Oulton and another one in the tyres and pads still have a massive way to go?

How is that a £65k to set up and £5k per track day?

I ran a GT4 for 7.5 years - nothing like that cost.

[ChrisW.]

The standard tyre pressures on my RS are 2.1 front and 2.3 rear ... with 1.9 / 2.1 for track days ... to start which is what I do.

I was on PS4S and having taken a little more air after lunchtime the tyres were 1.7 / 1.8 and the TPS was complaining bitterly about the 1.7 ... it likes 1.8 minimum.

To give a benchmark on a hot day on Cup2's I used to put 10psi back into each tyre and generally speaking once home they would be about right.

Yes the PS4S in the dry started to run-out after around six laps and I didn't think there was much point in taking more pressure out of the tyres which were showing 2.1 / 2.4 ... but maybe if I had stayed longer that's what I should have done ?

Tyre wear was very even and they've worn well ... Cup2's on later this month.

[n12maser]

Snowy999 said:

GT cars - I literally live on a different planet to you!

Lockton track day insurance, OEM pads and steel discs plus Dunlops, had a great day at Spa and now Oulton and another one in the tyres and pads still have a massive way to go?

How is that a £65k to set up and £5k per track day?

I ran a GT4 for 7.5 years - nothing like that cost.

Demon's been spouting this b#ollox for years on the forum, ignore.

[TDT]

For last Friday, I took the bleed down approach due to the conditions at the start of the day.. which was a fully wet and cold circuit.

In the summer when we’ve had dry and warm days… then starting pressures would be lower knowing that they can come up.

So you just have to adapt to what is going on, on the day.
Bit of common sense.

[MannyLon]

n12maser said:

Demon's been spouting this b#ollox for years on the forum, ignore.

It’s no 997 GTS though

[Mutton]

Lot' of interesting talk regarding set up etc. Out of interest, what are people setting their front and rear anti roll bars to on the 4RS?

Looking at TDT's laps vs last year in the GT4 MR there seems to be around a 2 second improvement in lap time comparing the very fastest laps in both vids, I guess mainly down to power / quicker gear shifts rather than any gains in the corners as the MR looked just as capable with its more focused set up.

[TDT]

Mutton said:

Lot' of interesting talk regarding set up etc. Out of interest, what are people setting their front and rear anti roll bars to on the 4RS?

Looking at TDT's laps vs last year in the GT4 MR there seems to be around a 2 second improvement in lap time comparing the very fastest laps in both vids, I guess mainly down to power / quicker gear shifts rather than any gains in the corners as the MR looked just as capable with its more focused set up.

Some pretty sharp observations, and without me publishing the data!
As you say, I haven’t even leaned on the chassis in the cornering and braking yet.
Tbf I have gone quicker the GT4MR but I hadn't published that video yet. But 4RS is faster still as is. I guess this speaks to the performance of the car and also my own personal development continuing.
The cool thing was that I can do that pace so easily even with backing off and traffic management. So will be really fun later in the season once the car is fully dialled and I’m back up to driving speed.

As for ARBs. i’ve left in factory positions Middle, front and rear.

Edited by TDT on Friday 14th March 10:23

[MannyLon]

Mutton said:

Lot' of interesting talk regarding set up etc. Out of interest, what are people setting their front and rear anti roll bars to on the 4RS?

Manthey set it a middle for both on their standard car setup.

[jcosh]

Chaps

Can I hijack this thread momentarily RE centre locks?

Does anybody experience creaking / ticking centre locks once a little bit of heat is in them? I had noted this a few years ago, but after some recent work where the centre locks were thoroughly cleaned and re-greased, they are creaking / ticking loads. It was very apparent at Oulton Park last week and also the same at Donnington the following day. Once cooled they go quiet again, but just a little bit of heat form the brakes and they creak / tick again.

Any ideas?