Tires track pressures for CS and Michelin Pilot Super Sport

Those Pirelli Trofeo R sizes is what I would definitely use for a 360 Modena for track days. Just use them to drive to the track, enjoy the track day, and drive back. Don't waste them on the streets.

Tire compound, construction and grip is more important than printed size. A few years back I tested my GT3 RS at California Speedway on two sets of tires, brand new 265/345x19 MPSC and 4 heat cycles old Michelin S7A/S9 (slicks), the slicks were 240 and 270, a lot narrower than the Michelin Pilot Sport Cup. Same day, two sessions on each set, my lap time on slicks 1:47, my lap time on MPSC 1:52. I was 5 secs faster on the narrow tires.

The Pirelli Trofeo R on the 235/265x18 sizes will not affect or trigger any errors with the electronics in the Modena, as they are within the 5% tolerance built into these systems driven by the ABS sensors.

It is a fun fast tire, and my favorite to drive to/from the track.

 

Fantastic. Thanks F430GT.

 

360 spider with 5 spoke std wheels
Dont want stock pirelli but original tyres which are
215 / 45 / 18
275 / 40 / 18

Mostly road track once or twice but not serious tyre.

I remembered M PS2 being great, so looked at PS3... but it seems more of an all weather (more cuts in the rubber) and I think the more close descendant of PS2 is MPSS Super sport.

The problem is they dont do a 275 or 285 in the 18".

So given that the rear must be MPSS 265/40/zr18

I have the choice of the below for the fronts
MPSS 205/40/zr18
MPSS 225/45/zr18

I was worried about the front rear grip ratio and tyre wall sizes... so did a spreadsheet - attached as image

I chose 205 front on the basis that I didnt want the grip ratio to go too far forward. Would rather keep the rear planted and under steer to let me know I'm past grip rather than have the back loose grip first and step out on a country road. I hope turn in grip is ok.

The section width ratios are
Original 1.279
F430GT rec 1.213
MPSS wit 225 front 1.178
MPSS with 205 front 1.293

Remaining issue is the tyre wall differences... bit of a wait and see if the ASC light comes on! Ordering the fronts today, but rears I'm waiting till they need replacing - currently 6mm.

Takes a lot of time to find new type tyres for the 360 standard rim... doesn't help matters when Michelin decide not to do a 285 section in the 18"!!
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I installed MPSS on my starfish wheels two months ago with the following sizes:

225/40/18
285/35/18

I drive it quite often (no track use) and the ASR has not given me any problems. I like them a lot so far!

 

I think you have better size choices in US than we have in Euro. Don't think 225/40/18 is available here - 225/45/18 I had to settle for.

I also think you can get a 235/40 which we cannot get.

I'm pretty sure 265 is also the widest MPSS we can get over here too!

Nathan, I used 225/45/18 and 265/40/18 - the balance is not a problem (it's actually very good indeed) but I did need to do some slight rolling of the wings. The rolling probably would not have been necessary if I was running a more aggressive camber before I threw on the tyres. Rolling is really easy anyway, I borrowed a tool and did it myself but you can also have it done for small money.

I feel a 205 section front is not the way to go.

 

That's a bummer

 

It sure is!

This is our total choice in R18 size in Europe ......

Section Height Rim Diameter
205 40 R 18
215 40 R 18
225 45 R 18
225 40 R 18
235 45 R 18
245 45 R 18
245 40 R 18
245 35 R 18
265 45 R 18
265 40 R 18

Even as I pull the sizes off the Michelin site I notice that 225/40/18 is now on the list so Nathan that would definitely be the front to go for as it's a better match for the rear than the 225/45/18 I used and it would almost certainly not require the fenders to be rolled.

Unfortunately the 265/40/18 remains the widest rear we can use (for now) but since it gives better grip than say a 275/40/18 in the PS2 rubber the slightly less wide fitting is not a problem at all.

 

205's go on tomorrow! Will see how it goes. Too late to cancel. I'm wary of snap oversteer if I go for 225/265. I presume you drive fast though Dublin... Might be better at driving than me so I want to keep a bit of understeer.

Anyone else watch that thing with chris harris in a merc, on track, with 4 space saver tyres. He loved it!!!

I'm trying to convince myself 205 is ok.
Will let you know how it goes. N

 

You'll be fine. There's more grip in MPSS 205's than the PS2 215's anyway!

 

Well they are on! Section looks great and I like the tread pattern and sidewall design.

The sidewall is a lot smaller than on the P-zeros taken off. I envisage a harder ride and I'm going to get the front lowered a bit to make it look right... so I might be hitting more bumps...

I wish bloody Michelin would release the 285 section rear in the UK. Any of you chaps in the USA suggest who might ship them over for me? (us?)

Yes its England
Yes its Summer
Yes its Raining
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Yeah, 215/45 drop to 205/40 is a double-change and drops the sidewall by quite a considerable 15mm.

You could probably have a 285/35/18 shipped to you from a market that carries that size as it probably is EU rated but I doubt if it will prove cost effective.

 

I've written to michelin (fitter gave me a feedback form, fill it in and you get £50 fuel voucher), so I penned a note to explain the predicament and ask if they will bring more 18" sizes to the uk, or if not if I can bulk buy a batch of 285 and resell. I'd do this at profit to be clear, but in line with US prices and I think people just like me would want them. Will write back if they bite. N

 

Forgot to say, massive feel difference. Not noticbly harsher on bumps. Did get understeer but I was looking for it and release agent still on. And it was raining.

 

Not a bad idea. As you say, there's probably many UK users (ClubScud) who would be interested.

Best MPSS combo available (if one were working off the US availability chart) is probably 235/40/18 and 285/35/18. I'd certainly be number one to jump on should you be successful.

 

FWIW, in the US, TireRack is now listing Bridgestone RE-11s as available again in OEM sizes for 18" 360 wheels. The web page says, "new," but I couldn't detect what's new about them.

 

BALLS!
I'm getting hard pedal and weird ABS stuff, caused by the sidewall difference between front and back (I presume).

For the record, breaking in straight lines at speed the pedal goes hard as ABS activates. You can still break well (to the extent of squeeky tyres) but you have to push through this hard feeling with more pressure. The curve is like a step rather than a nice exponent of pressure vs effect. Once known about this can be adapted to.

The problem is breaking in turns (just on road, but roads I'd never driven before), and for example breaking after an overtake and coming back on to the right side of the road. If you are turning when the ABS senses and the pedal becomes hard you basically start going straight as ABS grip steers. At least it feels like this. Its not a good thing.

So I'm going to have to sack off keeping the front/rear section + grip ratio and go for the 225/40 or 225/45 front, and probably the 265 rears when the contis I currently have are done.

I did have the front lowered a bit, might put that back up. I've been bottoming out like a goodun.

FerrariDublin do you have a pic of your MPSS 225/45 265/40 setup from the side? I think you are on standard ride height but altered camber. I have more camber too so think its compatible. Would be good to get a visual on the front sidewall, how it looks in the wheel well, and how the front/rear pair look from the side (as stock the 360 rear wheel looks a bit bigger - its natural look)

I've updated my table. Second line is 225/40 and 265/40 which is almost the same ratio as the Pzero original. Or I can use the 225/45 front, gain a bit of side wall, bottom out less and have some extra suspension softness, with this the frount and rear wheels have almost the same rolling radius (1.44%)

When checking this out I read that rolling radius +/- 4% is OK for the 360 none CS ECUs. CS is different. I'm wondering if this is +/- 4% of equal, or if it is +/- 4% of the Pirelli original fit (where the rear has a 4.07% larger rolling radius than the front)

Image below. Anything red in the rolling radius difference % column I think will cause ABS problems.
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What tires are you running on the rear axle? Brand, model, age, tread depth?

 

continental contact sport 2
275/40/18
tread 5mm

its the line with the read text on the left in the XLS sheet.

 

That table should be expanded!

I'd be real curious how mine work - re11's 235/35/19 and 285/35/19...

 

will do tomorrow for you... anyone else interested post their tyres

 

Seriously??? Not even the insane would do that!!!

Do never combine two different tires in a sport car, people get away with that on mini-vans and SUVs because they are driving at not even 10% of those vehicles's limits.

A sport car, and one driven as intended, will reach higher dynamic limits, at which point the flaws start to show up.

Michelin Pilot Super Sport and Continental Contact Sport 2 were not designed to work together. The ABS issue is the less of your concerns, the breakaway characteristics, slip angle, deflection, absorption of bumps, rebound, lateral and longitudinal grip are all different. There is no way these two tires can work together.

...and I bet the Contis are not new either.

For sizes, on a 360 Spider, I would go 225/40R18 and 285/35R18 on the stock wheels.

If 265 is all you can find locally, you need to go with 265/40 and still go for the 225/40 front.

Bottom line, the 205 has no place in your car, and even worse when combined with mismatch tires.

 

I run/ran the following:

235/35R19 and 285/35R19 Corsa System
235/35 and 295/30 R888 (5 sets)
245/35R19 and 285/35R19 MPSS
245/35R19 and 285/35R19 RE11
255/35R19 and 285/35R19 RE11
255/650 and 305/690 x 19" Pirelli Slicks
235/315 x19" Hoosier
265/315 x19" Hoosier
265/325 x19" Hoosier
295/345 x19" Hoosier
295/315 x19" Hoosier
315/345 x19" Hoosier
295x19" 345x18" Hoosier
315x19" 345x18" Hoosier

on all these combinations, zero issues with ABS, CT, CST, E-Diff, EBD, steering or shocks.

360/F430 and all their variations use similar tolerances for tires. What works for one series works for the other.

 

F430 I will take defer to your experience!

I have just done a long euro trip on exactly this combo and it was... not terrible... I think what I am asking the tyres to do is less demanding than what you ask of them. If you were closer you could have a go and see what you think, but anyway yes 205s will be coming off, the rears I will probably leave mismatched till they are used. They were new when I got them, though I doubt that restores your opinion of me.

The Pirelli asymmetico and Direzionale were very different tyres, and they were original fit. Not sure it matters that much as the front and rear dynamic is always going to be different and after all they are doing different jobs. I had about a year with pirelli front and conti rear, again with no problems. It is my aim to end up MPSS all round.

Your advice and information is a great thing to have though, thank you for taking the time to make a reply.

N

 

Don't confuse the PZero Direzionale and Asymmetrico with what you're doing. These two Pirelli were designed as the PZero System, the logic on them is that rear tires don't steer and front tires do, so the could optimize the tread design (in reality all tires move in all directions, rear tires steer too through toe changes, it was a great idea on paper with a bad execution).

As I mentioned earlier, if you drive at 10% of the dynamic limits of a 360 Modena, even rear snow tires and front racing slicks will work nicely. It is when you get to the limits of adhesion when things go really bad. I would bet on a intermediate racetrack student stamping your car on the wall on a track day, easy bet.

Once your car is on MPSS at all corners, and you drive it for a good 1000kms, you will know what you've been missing.

By the way, tires alone are the biggest performance difference on a racetrack between cars.

For example, on the right tires, the old F430 would lap Pista di Fiorano faster than the Enzo or the 599 GTO, a plane stock F430 with just the right tires would do that.

 

Not in Europe. Even the RE12's don't come in the right size.

+1. I ended up buying MPSC and the rear tires are smaller in height than the front tires. Could only drive in sport mode, though normally I drive without abs anyway. Speedometer way off. But good grip

Anyway thanks a lot for the feedback F430GT. I'll have a look at the Trofeo R's. they're only available 235/40ZR18 & 265/40ZR18 but I guess that's ok too (surely a better size than the MPSC's I drove ). What (hot) tire pressure on the Trofeo R's for track use?