Second Track day: Things I am going to change

[Leman]

So here I am sitting in my garden on Friday, not a holiday, but as everybody has taken the day off from Thursday (Faire le Pont: Bridged the weekend) most of my team have upped and off. Including wife and children to Europarc!

I hope this answers (and thanks) questions and suggestions from my last post.

The second planned track day was at the old formula one track of Dijon-Prenois

http://www.circuit-dijon-prenois.com..._nvo_modif.jpg

The started cold and warmed up fast with a dry track.(6C to 14C). I ran the stock run flats, and the last modifications of brake fluid, and larger duct cooling. I have not changed the pads nor rotors from the last time.

I am new to this track, which was scary as there was also the some Porsche GT3s and Porsche CUP plus a Ferrari (Ceramic breaks) and a Ferrari Challenge, amongst other things, so this was going to be a quick day.

I set off with a co driver, who knew the track and quickly found my weak spot. (On the photo, it it the bend leading into the big bit sticking out on the left.) It starts with a fast left, up to a bling crest, down into a tightening (width) right followed by a tight and step right, and then back into the fast section - double left, taking you out of the "horse shoe" into the fast right hand curve into and past the stands. That is the most dangerous corner on the track. (Three spins and one lotus into the sand!).

Fist off, braking - yep, back with the shuddering disks (apparently lightly glazed) and on stock tyres not exactly confidence building, as the straight line braking feel on the pedal makes you think you are hitting the ABS, when in fact you are not, which makes for some hairy entry speeds!

Second point, the tyres are not up to the braking and turn in precision needed, they work, very well, but again not enough late braking opportunities.

To put the speeds into perspective (Kilometers per hour and Miles Per hour conversion). At the end of the day, (I was attacking a slick shod GT3) I hit the 280 KM/H (173 Miles per hour) mark at braking (150 Metres) at the end of the straight in front of the stands! A personnel best. Only two cars did better, the Porsche CUP and the Ferrari Challenge!

With better brake and tyre feel, I think I could brake much later; about 75 Metres out, and hit 285 KM/H (177 MPH)

The entry in the "Horse shoe" was my slowest, about 90 KM/H depending on traffic! (55 Miles per hour).

Where I lost the most time, roughly 5-10 seconds, was the lack of late braking and turn in. Although on the fastest corner into the stands I hit 1g lateral force.

The HUD in track mode is a must, as it also flashes change up stages, for those who have not tried!

So at the end of this day, back to the drawing board, my next outing will be the Bugatti track of Le Mans, as I am missing Monza due to holidays.

LoT - Circuit Guides

Therefore I have decided to change the front rotors, as I cannot determine the cause of the, albeit slight on road, judder, as I am not going to spend cash on OE rotors to have the same thing happen. Question now is what and how to source them! I will also slightly lower the suspension to account for the semi slicks. I need to source some OE wheels (Frankly the prices of the some makes are crazy, CCW with Pirelli P0, $8900) for the road tyres, and hence need to buy a sensor programmer. (Thanks Bob)

Also I have ordered some Yokohama Advan semi slicks, as these are just about the only model price/quality I would go for, I saw a GT3 blow a Pirelli and rip off its back bumper off at Dijon.

So another hit on my budget; tyres 3K, Rotors around 1.8K fitted, Suspension 1.8K, wheels around 1.5K

But I can guarantee, the car got a lot of attention, in fact it does every where, most people are really nice about it too. (unlike when they see a Porsche LOL) and every one expected the car to be modified, and simply could not believe the pace of her on the track in near stock mode!

At the end of the day, the "wounded" counted one offed Lotus, two sets of split break rotors on the S2000 Mugen (!), a torn off rear bumper and some accelerated heart beats

Al in all a great day, and I will post a link to the photos when they are posted.

[6speeder]

Sounds like fun had by all. You might want to investigate the Hoosier R6's. Great road race tires.

[DennyM]

Thanks for posting up ... and for representing well "over there"
Couple of guys with similar brake issues:
C6Z OE Track Rotor Options

I need better brakes for my C6 ZO6
Releated discussion on rotor options:
C6Z Brake upgrade... - Corvette Forum

[Leman]

Originally Posted by DennyM

Thanks for posting up ... and for representing well "over there"
Couple of guys with similar brake issues:
C6Z OE Track Rotor Options

I need better brakes for my C6 ZO6
Releated discussion on rotor options:
C6Z Brake upgrade... - Corvette Forum

Yep doing what I can! and loving it. Gave my Z the present of a full wash and wax to get rid of the rubber marks... looks great.

Thanks for the links. Definitly going for something written up on this forum. I hope the photos will be up for Monday,

[BEZ06]

That sounds like great fun - and thanks for the excellent report!!! I'm looking forward to some photos.

How long is that straight? It looks to be about 1 KM, is that about right?

I'm not scheduled for a track event until the end of June, but you've got me craving some track time and I think I need to see what events are going on this month somewhere near me!

The C6 Z06 is a beast on the track, and I'm glad to hear that you are representing us well over in Europe, and it's good to hear the other drivers seem to appreciate its capabilities.

I've got a TPMS reset tool ready for you and I'll be in touch to confirm which one you would like and get it sent over right away.

Bob

[Leman]

Originally Posted by BEZ06

That sounds like great fun - and thanks for the excellent report!!! I'm looking forward to some photos.

How long is that straight? It looks to be about 1 KM, is that about right?

I'm not scheduled for a track event until the end of June, but you've got me craving some track time and I think I need to see what events are going on this month somewhere near me!

The C6 Z06 is a beast on the track, and I'm glad to hear that you are representing us well over in Europe, and it's good to hear the other drivers seem to appreciate its capabilities.

I've got a TPMS reset tool ready for you and I'll be in touch to confirm which one you would like and get it sent over right away.
Bob

Thanks Bob, looks ok.

Here is the link to the day's photos. Frankly not sure how long the straight is, but about 1500 Metres sounds right.

Honda NSX Club photos galleries :: 2008 / H0501 Dijon

http://v-images.com/HondaNSXClub/gal...H0501_c037.jpg

[kiwi ZO6er]

I've had my right hand drive converted 06 ZO on the track twice, once at Pukekohe, Auckland, New Zealand and the other at Rotorua NZ. I had the same shudder in the LH front brake as you but fixed it by changing the front discs from side to side. I did blow oil out the air filter both times but now know to lower the level of oil in the dry sump before my next track day. I was not able to reach speeds above 245 K,s per hour so am very envious of you 280kph speeds. It started missing badly after reaching about 242 kph climbing slowly in speed to about 245kph over about 8 or 10 seconds before brakeing so I can only assume it has some kind of govenor fitted. I tried both 5th and 6th gear and the same thing happened at the same speed. Have you had to do anything to allow your baby over this speed, if so what did you do. I am sure I could have got another 20 or 25 kph out of my baby before braking. If Leman or anybody can help me that would be great. Cheers from down under here in New Zealand. Ken

[Leman]

Originally Posted by kiwi ZO6er

...... It started missing badly after reaching about 242 kph climbing slowly in speed to about 245kph over about 8 or 10 seconds before brakeing so I can only assume it has some kind of govenor fitted. I tried both 5th and 6th gear and the same thing happened at the same speed. Have you had to do anything to allow your baby over this speed, if so what did you do. I am sure I could have got another 20 or 25 kph out of my baby before braking. If Leman or anybody can help me that would be great. Cheers from down under here in New Zealand. Ken

Hello "Kiwi"

From what you describe it sounds like you are correct about the speed limiter. Although I did hit the limiter, over rev. once, the engine did the same old limiter judder as per normal in any car.

From the description, the speed limiter is a possible, As standard, I have not seen anything stating the Z06 has a limiter, so I would assume that this would be a New Zealand homologation requirement.

Here in Switzerland, we are allowed to junk a lot of the emission stuff the car comes with, so I actually have 515 HP, not 505HP and run on 100 Octance petrol (gas) mainly from Shell. But that difference is frankly not the reason I get good speeds, as all members who have tracked get up to and beyond, depending on the track.

I can only think of a couple of other reasons, not being a wrench wielding mechanic but a seat of the pants diagnostic person :-)

Starting at the simplest:

1. Test the fuel air mix (and just about everything else) via the electronic connector. OBD11. I would think that any limiter settings would be found here.
2. Check the sparking cable spark. This is an old one, but a damaged cable can do a lot to increase the resistance and produce a poor spark. You would see an excessive carbon deposit on the out rear exhaust, as the fuel would not be properly ignited.
3. Check or change the spark plugs for OEM or better. Check the gaps as well. The colour of the end of the plug will tell you a lot about the actual engine conditions, ie Pink, black etc.

And probably the one that will work best:

4. Getting an ECU tune might be the only solution at the end, to get rid of any permenant eprom settings you may be stuck with for New Zealand homologation.

Maybe some more knowledgeable members might have come across this.