Two days at Magny-Cours F1 track in France with Pirelli P Zero Corsa's

[CB72]

Honda France kindly invited me to a two day track meeting at the Formula 1 venue in Magny-Cours.
The purpose was the launch of the new Civic Type R and a few other lesser models during a "Classic Days" meeting.
The meeting was a great success as there were more than 1000 cars that came along to see prestigious cars ranging from Formula 1's to the Le Mans race winning Matra of Henri Pescarolo who was available for autographs.
The only downside was a miserable weather with almost constant rain.
As I had seen the forecast the week before, I decided to get some Pirelli P Zero Corsa's instead of my Toyo R 888's that were on the car until then.
The Pirelli's are the same size as those used on the 350 HP Lotus Exige V6 i.e. 205/45*17 and 265/40*18
I got to do three sessions with only one of them on a drying track.
The first session went well considering that I had to rediscover the track I hadn't been on for the last 7 years or so.
The tires were inflated with my "road pressures" i.e. 2.3 kg upfront and 2.5 kg at the rear.
The grip was very good as you will notice in the video when I outbraked a car before the last hairpin of the track.
Near the end of the session, I believe the ABS played a trick on me as I locked some wheels around 200 km/h and the car got a little out of shape despite me releasing the brake pedal?
The incident decided me to go back to the paddocks to understand what went wrong.
Here's the first uncut video that you need to start around the 6 minute mark.
https://www.youtube.com/watch?v=WdQEKzuFNvg

The next sessions were on a wet track that I'll comment later.

 

[mcano]

Very nice. Thank you for sharing.

I too am running with Zanardi Springs and Bilstein Shocks. I also have:
1. Zanardi rear sway bar.
2. Dali (after market) street/race front sway bar.
3. Non-compliance rear bearings and toe links (to help minimize snap over steer).
4. Front compliance clamps.
5. NSX-R upper and lower chassis braces
6. Hawk street/race break pads.
7. SS braided break lines.
8. Front break air diverter to cool the breaks.
9. Dunlop Direzza II, Star Spec tires (200 tread rating)
10. Baffled oil pan

Mario

 

[CB72]

Very nice. Thank you for sharing.

I too am running with Zanardi Springs and Bilstein Shocks. I also have:
1. Zanardi rear sway bar.
2. Dali (after market) street/race front sway bar.
3. Non-compliance rear bearings and toe links (to help minimize snap over steer).
4. Front compliance clamps.
5. NSX-R upper and lower chassis braces
6. Hawk street/race break pads.
7. SS braided break lines.
8. Front break air diverter to cool the breaks.
9. Dunlop Direzza II, Star Spec tires (200 tread rating)
10. Baffled oil pan

Mario

I need to get your option 3 ( as you will notice in my next video) and install option 4 that I bought some time ago.
How do the Dunlop's fare in the wet?

John

 

[mcano]

I need to get your option 3 ( as you will notice in my next video) and install option 4 that I bought some time ago.
How do the Dunlop's fare in the wet?

John

Hello John,

The non-compliance mods have helped reduce snap overstear, but it does not prevent spin outs. I spun out twice last weekend at the track. Both times was my fault though.

I have not run the Dunlops in the rain. On the track, they are very good. Click on the link below to see a video on the Dunlop tire compared to other leading tires, including a wet surface test.

Regards,

Mario

 

[scammy]

I need to get your option 3 ( as you will notice in my next video) and install option 4 that I bought some time ago.
How do the Dunlop's fare in the wet?

John

I have the Dunlops they do OK in the wet still good feel and no big aquaplane 215/265 and are not far off the times I do with the Nittos in the dry so a good all-round tire.

 

[CB72]

Hello John,

The non-compliance mods have helped reduce snap overstear, but it does not prevent spin outs. I spun out twice last weekend at the track. Both times was my fault though.

I have not run the Dunlops in the rain. On the track, they are very good. Click on the link below to see a video on the Dunlop tire compared to other leading tires, including a wet surface test.

Regards,

Mario

I'm surprised you managed to spin the car on a dry surface?
Was it a power oversteer or at lift off?
If it was at lift off, I would suspect that your toe-in at the rear needs some adjustment.
As Billy (@stuntman) would say it's worth my 00.2

John

- - - Updated - - -

I have the Dunlops they do OK in the wet still good feel and no big aquaplane 215/265 and are not far off the times I do with the Nittos in the dry so a good all-round tire.

Apparently the Direzza II star spec tires don't seem to be available in Europe?
They might carry a different name over here?

John

 

[mcano]

I'm surprised you managed to spin the car on a dry surface?
Was it a power oversteer or at lift off?
If it was at lift off, I would suspect that your toe-in at the rear needs some adjustment.
As Billy (@stuntman) would say it's worth my 00.2


- - - Updated - - -



Apparently the Direzza II star spec tires don't seem to be available in Europe?
They might carry a different name over here?

John

John

Hello John, I'm not sure what I did or did not do on the first spin out. Click on the link below to see a series of photos taken when I spun out. Perhaps you can see the cause of the spin.

http://www.caliphotography.com/photos/index.php?do=photocart&viewGallery=38680#page=thumbs

 

[CB72]

John

Hello John, I'm not sure what I did or did not do on the first spin out. Click on the link below to see a series of photos taken when I spun out. Perhaps you can see the cause of the spin.

http://www.caliphotography.com/photos/index.php?do=photocart&viewGallery=38680#page=thumbs

Very good pictures indeed!
My guess, not knowing the track but looking at the other guys, is that you overshot the off camber left hand turn and then had to literally throw the car to the right ( as the angle of the front wheels show) to negociate the next turn.
This action created a huge spin momentum that you were unable to catch specially as the track goes downhill at the same time.
I'm be no means an expert but less entry speed is required here.
Less entry speed usually translates in more exit speed and that's were you gain seconds.
Hope it helps?
John

PS: Make sure your have toe-out at the front and toe-in at the rear

 

[mcano]

Very good pictures indeed!
My guess, not knowing the track but looking at the other guys, is that you overshot the off camber left hand turn and then had to literally throw the car to the right ( as the angle of the front wheels show) to negociate the next turn.
This action created a huge spin momentum that you were unable to catch specially as the track goes downhill at the same time.
I'm be no means an expert but less entry speed is required here.
Less entry speed usually translates in more exit speed and that's were you gain seconds.


Hope it helps?
John

PS: Make sure your have toe-out at the front and toe-in at the rear

Thanks for the analysis Frank. From that point on I went deeper into the turn so that I was running a straighter line when I came over and down the hill. I also decreased my speed a little. Something that I did not mention before, was that I had made some suspension changes (Zanardi springs) but did not have time to get the car realigned. This may have contributed to the problem. I mentioned that I spun out twice. The second spin out occurred on an off camber medium radius turn. In this case I was just going to fast, and I'm not skilled enough to catch and correct the spin. No pics of that spin. Again, thanks for your 0.02 cents.

 

[asylum]

Near the end of the session, I believe the ABS played a trick on me as I locked some wheels around 200 km/h and the car got a little out of shape despite me releasing the brake pedal?

Check if one (or more) of the 4 solenoïd valves of the ABS are not stucked (http://www.danoland.com/nsxgarage/brakes/abs/abs.htm). I have had this problem with the right front wheel blocking and had to release nearly all the pressure on the pedal to stop the blocking.

 

[CB72]

I finally managed to load my next video on YouTube.
This time the track is full wet and there was almost no grip at all.
The ABS was disconnected after the mishap during the dry run and of course no TCS given that the car is turbocharged.
The tires were still at 2.3 and 2.5 kg pressure.
I did bring them down to 2.1 and 2.3 in the next session but the result was the same: NO GRIP.
You'll see that at the end of the video the car goes into a big spin.
The reason is unclear to me: I had to reduce my speed as I was getting close to the cars in front of me and I probably lifted off ever so slightly but I'm almost sure I didn't touch the brakes.
I'll get a non-compliance kit for the rear but I was really disappointed by the Pirelli's.
I wonder if the Lotus Exige V6 gets exactly the same rubber or not?

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

 

[CB72]

Check if one (or more) of the 4 solenoïd valves of the ABS are not stucked (http://www.danoland.com/nsxgarage/brakes/abs/abs.htm). I have had this problem with the right front wheel blocking and had to release nearly all the pressure on the pedal to stop the blocking.

I know the problem but after replacing all the seals it's still happening...

 

[stuntman]

John

Hello John, I'm not sure what I did or did not do on the first spin out. Click on the link below to see a series of photos taken when I spun out. Perhaps you can see the cause of the spin.

http://www.caliphotography.com/photos/index.php?do=photocart&viewGallery=38680#page=thumbs

Looks like you crested the left-hand corner still loaded on the right (turning left). Once the car 'landed' after the crest, you turned in for the right-hander.

Photo 3 looks like the beginning of rotation and photo 4 shows the rear starting to step out, with no steering correction in the front wheels. Photo 5 you are already sideways with very little steering correction. Photo 6 shows heavy yaw angle in the car (sideways) with still very little steering correction. Photo 7 & 8 are about the point of no return, still with about the same steering correction as photo 5.

You had a spring-energy 'flick' with the right side of the car loaded up, then the springs un-compress and throw the car to the left, as you turn-in for the right-hand corner. This upset the car and once it started rotating, you were too slow to react to the slide and did not correct for the slide soon enough or by applying enough steering. The biggest thing is LOOK WHERE YOU WANT TO GO. In Photo 8, you should be looking out your drivers side window at where you want to go. Your bad eye location was one of the leading causes of not correcting for the slide soon enough or enough steering.

I might suggest taking a car control class as well as working on picking your eyes up and look further through the corner.

I finally managed to load my next video on YouTube.
This time the track is full wet and there was almost no grip at all.
The ABS was disconnected after the mishap during the dry run and of course no TCS given that the car is turbocharged.
The tires were still at 2.3 and 2.5 kg pressure.
I did bring them down to 2.1 and 2.3 in the next session but the result was the same: NO GRIP.
You'll see that at the end of the video the car goes into a big spin.
The reason is unclear to me: I had to reduce my speed as I was getting close to the cars in front of me and I probably lifted off ever so slightly but I'm almost sure I didn't touch the brakes.
I'll get a non-compliance kit for the rear but I was really disappointed by the Pirelli's.
I wonder if the Lotus Exige V6 gets exactly the same rubber or not?

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

The brake zone at 14:30 was with no ABS?

If so, it sounds like you were managing lockup and when you released the clutch, it caused the rear to step out a little under braking. If you did a proper blip and rev-match (hard to tell), then your brake bias may be a little off.

2.5Kg is the most I would run for a HOT pressure. I would start my cold rear pressures closer to 2.3Kg.

The Trofeo R (and Michelin Pilot Sport Cup 2) are R-compound competitors to the R888. You went down quite a bit in tire performance to the Corsas.

 

[mcano]

Looks like you crested the left-hand corner still loaded on the right (turning left). Once the car 'landed' after the crest, you turned in for the right-hander.

Photo 3 looks like the beginning of rotation and photo 4 shows the rear starting to step out, with no steering correction in the front wheels. Photo 5 you are already sideways with very little steering correction. Photo 6 shows heavy yaw angle in the car (sideways) with still very little steering correction. Photo 7 & 8 are about the point of no return, still with about the same steering correction as photo 5.

You had a spring-energy 'flick' with the right side of the car loaded up, then the springs un-compress and throw the car to the left, as you turn-in for the right-hand corner. This upset the car and once it started rotating, you were too slow to react to the slide and did not correct for the slide soon enough or by applying enough steering. The biggest thing is LOOK WHERE YOU WANT TO GO. In Photo 8, you should be looking out your drivers side window at where you want to go. Your bad eye location was one of the leading causes of not correcting for the slide soon enough or enough steering.

I might suggest taking a car control class as well as working on picking your eyes up and look further through the corner.


The brake zone at 14:30 was with no ABS?

If so, it sounds like you were managing lockup and when you released the clutch, it caused the rear to step out a little under braking. If you did a proper blip and rev-match (hard to tell), then your brake bias may be a little off.

2.5Kg is the most I would run for a HOT pressure. I would start my cold rear pressures closer to 2.3Kg.

The Trofeo R (and Michelin Pilot Sport Cup 2) are R-compound competitors to the R888. You went down quite a bit in tire performance to the Corsas.

Billy, Thanks for the analysis. Yes, I'm slow to react to the slide (I had the same problem NSXPO Las Vegas when you were my instructor). I find my self kind of freezing when a slide starts in stead of making a correction. I'm still very much a novice, so I have a lot to learn. I did take the Alfa Romeo performance class in February, and I plan to go again in December. I'll remember to look in the direction that I want to next time, and try to react properly.

Thanks again for the advice.

 

[CB72]

Looks like you crested the left-hand corner still loaded on the right (turning left). Once the car 'landed' after the crest, you turned in for the right-hander.

Photo 3 looks like the beginning of rotation and photo 4 shows the rear starting to step out, with no steering correction in the front wheels. Photo 5 you are already sideways with very little steering correction. Photo 6 shows heavy yaw angle in the car (sideways) with still very little steering correction. Photo 7 & 8 are about the point of no return, still with about the same steering correction as photo 5.

You had a spring-energy 'flick' with the right side of the car loaded up, then the springs un-compress and throw the car to the left, as you turn-in for the right-hand corner. This upset the car and once it started rotating, you were too slow to react to the slide and did not correct for the slide soon enough or by applying enough steering. The biggest thing is LOOK WHERE YOU WANT TO GO. In Photo 8, you should be looking out your drivers side window at where you want to go. Your bad eye location was one of the leading causes of not correcting for the slide soon enough or enough steering.

I might suggest taking a car control class as well as working on picking your eyes up and look further through the corner.


The brake zone at 14:30 was with no ABS?

If so, it sounds like you were managing lockup and when you released the clutch, it caused the rear to step out a little under braking. If you did a proper blip and rev-match (hard to tell), then your brake bias may be a little off.

2.5Kg is the most I would run for a HOT pressure. I would start my cold rear pressures closer to 2.3Kg.

The Trofeo R (and Michelin Pilot Sport Cup 2) are R-compound competitors to the R888. You went down quite a bit in tire performance to the Corsas.

In fact the ABS should have been operational but played a trick on me and I disconnected it for the next sessions.
The video I wanted to show is the following where I had a major spin at the very end.
I believe I badly need the non-compliance kit?
https://www.youtube.com/watch?v=eKZbxxuOuhM

 

[stuntman]

So the previous video at 14:30 had ABS functional and this second video where you spun the ABS was off?

Were you off-throttle or trail-braking when you spun?

What brake setup do you have again?

From the spin, I don't think the non-compliance kit would have made much of a difference. Yes it helps keep the toe in check a little bit better, but the spin was probably due to your entry speed into that left hander on a damp track, with the front of the car loaded and rear unloaded, on the racing line (which is typically slicker than off line in the wet) causing the spin.

What wing do you have and is that an NSX-R vented hood?

 

[CB72]

Yes, on the dry track the ABS was supposed to work but after missing the hairpin, I took the fuse out.
The next session was full wet as you noticed and when I entered the fast left hander after the pit lane straight, I wanted to reduce my speed as I was getting too close for my liking to the cars in front of me.
I believe I only lifted off very gently without touching the brakes and the rear instantly moved out with no warning whatsover.
Maybe, I could have catched the car by declutching like when driving on ice but ...I didn't do it.
Apart from an error on my part, I wonder if the NSX R diff set-up I have didn't play against me?
With the kind of traction that was available that day, having both rear wheels turning at the same speed can't be good for negociating turns.
As for the brake set-up, I have Porsche 993 disks and calipers upfront with Pagid "yellow" pads while the rear is a home made set-up with 4 piston AP Racing calipers with Pagid " black" calipers.
I would say that the balance is good as I have no fear braking behind any GT3 and in the wet session I never lost the rear under braking.
Last, my rear wing is a Downforce NSX R copy and the hood also an NSX R copy.
Thanks for the feedback!
Here's the car

 

[stuntman]

What are the piston sizes for the front and rear calipers, and what's the front and rear rotor diameter?

If you disable abs and slam on the brakes, which end locks first?

I'm not quite sure that you had an "ABS issue". It's a bit hard to tell from the video, but you hear the tires chirp, and the rear wiggling could have been the downshift or too much rear bias.

As far as your spin goes, it just seems like you carried a lot of entry speed into that left hander (the two cars in front of you took the corner much slower), and on a damp track on the racing line (slickest part of a wet track is on the racing line) with a lot of entry speed, it's not too surprising that the rear end came around.

0.02

 

[CB72]

What are the piston sizes for the front and rear calipers, and what's the front and rear rotor diameter?

If you disable abs and slam on the brakes, which end locks first?

I'm not quite sure that you had an "ABS issue". It's a bit hard to tell from the video, but you hear the tires chirp, and the rear wiggling could have been the downshift or too much rear bias.

As far as your spin goes, it just seems like you carried a lot of entry speed into that left hander (the two cars in front of you took the corner much slower), and on a damp track on the racing line (slickest part of a wet track is on the racing line) with a lot of entry speed, it's not too surprising that the rear end came around.

0.02

I would have to dig up my notes on the piston diameters but as far as I remember I went for 60% braking effort on the front and 40% for the rear i.e. very close to OEM I believe.
If I try to lock the wheels without the ABS the front will go first on a dry pavement.
You are probably right that I went in too fast on the left hander as the grip level was so low.
In these conditions I suppose one would use more anti-roll bar upfront but the car was already understeering a lot in long constant radius curves.
I wonder if the Corsa Trofeo's would perform better in the wet???
Thanks
John

 

[stuntman]

Then that sounds pretty decent bias wise. Plus in the wet, it makes the fronts lock even sooner. I would still enable ABS though.

Yes a stiffer front anti-roll bar would help reduce this off-throttle oversteer, but it would make mid-corner understeer in long corners worse. From watching your previous laps, it does not look like you have an oversteering car. I think it was just the off-throttle entryspeed in the wet that caused the problem.

What swaybars are you running?

I don't think the Trofeos will be any better than the Corsas in the wet. The following tires have better dry traction and MUCH better wet traction than the P Zero Corsa:

Michelin Pilot Super Sports - MUCH better dry, ONE OF THE BEST in the wet.
Yokohama Advan AD08R - Better dry, slightly better wet
Continental ExtremeContact DW - similar dry, much better wet.
Bridgestone RE-11 - Better dry, better wet.

Overall if wet performance is important to you (since it rains a lot in Europe, I would say yes), I would go with the Pilot Super Sports hands down.

 

[CB72]

Then that sounds pretty decent bias wise. Plus in the wet, it makes the fronts lock even sooner. I would still enable ABS though.

Yes a stiffer front anti-roll bar would help reduce this off-throttle oversteer, but it would make mid-corner understeer in long corners worse. From watching your previous laps, it does not look like you have an oversteering car. I think it was just the off-throttle entryspeed in the wet that caused the problem.

What swaybars are you running?

I don't think the Trofeos will be any better than the Corsas in the wet. The following tires have better dry traction and MUCH better wet traction than the P Zero Corsa:

Michelin Pilot Super Sports - MUCH better dry, ONE OF THE BEST in the wet.
Yokohama Advan AD08R - Better dry, slightly better wet
Continental ExtremeContact DW - similar dry, much better wet.
Bridgestone RE-11 - Better dry, better wet.

Overall if wet performance is important to you (since it rains a lot in Europe, I would say yes), I would go with the Pilot Super Sports hands down.

Many thanks Billy, your advice is most appreciated.
The good news is that I know now that the 205/45*17 don't rub up front and make the car far more pleasant to ride than the 235/40*17's.
The second good news is that this dimension gives access to the Michelin PSS in 205/45*17 and 255/40*18.
By the way, I'm not surprised about the Michelin's in the wet as I use these on my motorbikes and while I was tracking the car at Magny-Cours I couldn't help thinking that I would be faster on my bike despite the wet track...
As for the ABS, I suppose I will have to upgrade to the NA2 version worth 3 set of tires!
PS: my anti-roll bars are from Dali Racing at 22 mm front and rear

 

[stuntman]

May want to try a Zanardi rear bar...

 

[CB72]

May want to try a Zanardi rear bar...

Or upgrade upfront to a 25 mm Trophy swaybar to further decrease roll...

 

[stuntman]

Your 22mm rear bar is stiffer than any OEM NSX rear bar (NSX-R, S, Zanardi, etc...). I'd still suggest a smaller rear bar.

 

[CB72]

Your 22mm rear bar is stiffer than any OEM NSX rear bar (NSX-R, S, Zanardi, etc...). I'd still suggest a smaller rear bar.

I definitely could give it a try.
Watching my video, I computed the lap times and they went from 2'39 to 2'36 and then 2'33 before the spin.
You are right, I was a little too confident when I spun...
A softer rear sway bar might have given me some warning???