I took my '07 Z51 to the track for the first time. I ran it at the Thunderhill on the new full 5 mile configuration. I was surprised about a couple of things. I knew the seats would be horrible and they were. I new the run-flat tires would be like rocks and they actually weren't as bad as I had anticipated. The brake we beyond pathetic. On my third hot lap of the morning I had brake fade so bad I had to park it. I luckily found a Hawk dealer in the paddock (it was a Friday before a NASA weekend so it was busy) and he had some DTC-30s for the front. Braking was much improved. On Saturday, in 97 degree temps the coolant temp got up to 230 and the oil temp hit 290, so the stock cooling isn't sufficient either. I make notes of all of these because I have been the chief driving instructor for a large Nor Cal HPDE club for 11 years and have driven dozens of cars right off the show room floor that are have been well balanced given their HP and handling capabilities so I was a bit surprised and disappointed at the short comings of the Z51.

I have several upgrades planned but I was very interested to see what the was like "out of the box" so I could compare it to the other stock cars I have driven.

And then there was the issue with the Active Handling, I thought that when I disabled traction control it would also disable Active Handling, not so, it was very annoying. I like to drive the car instead of having those pesky electronics interfering. How to I disable it?

 

Hold the traction control button down until you see TC and AH off on the dic. It takes about 5 seconds or so.
BTW, you have the Z51 option, the car isn't a Z51. (Z51 police ).

 

Thanks for the How-to and the clarification... yes the Z51 option!!

 

ok that works sort of
to shut it off you can unplug the steering position sensor on the column under the dash

 

An '07 C6? That means it's at least 7 years old.

Not new, not "right off the showroom floor".

 

A chief driving instructor will find the limits of a C6 pretty quickly, your numbers are about right for someone just starting to push the car hard. Starting list:

• Tires
• Brakes+ fluid + cooling ducts
• Radiator/cooling
• Harness/safety
• Accusump or better Dry sump (required if running R compound)
• Camber Kit/Alignment
• Spindles
• Suspension
• ...

Blown motors are a risk, short shift especially in long high speed turns.

Read this thread Active Handling Defeated


Upgrading to a Z06 may be a less expensive way to go, especially if R compound tires are in your future

 

Calipers can be made to work. SCCA T1 drivers made do with them all through the C5 period. They do have a bunch of weaknesses though. Long pedal is caused by pad taper and can be counteracted to some degree by flipping pads from one side of the car to the other in the same relationship to each other. Add some brake cooling to keep from boiling brake fluid. You have the answer on the TC/AH. To get rid of AH you can disconnect the steering sensor and that will ABS and TC still working.

The 07 Z51 is still a pretty good track car. When C&D did their fastest track cars at VIR in 07 it was only beat by a Z06 on EMTs, a GT3 on R compound tires. The Z06 stomped both of those pretty bad but the Z51 was only fractions slower than the GT3 and it didn't have R compound tires.

Bill

 

All good feedback. I guess I should have said that I have raced many seasons in BMWCCA, SCCA and NASA as well as running in 3 - 25 Hour of Thunderhill Endurance races. So I can find the limits of most cars pretty quickly.

As for using the term "showroom" I meant an unmolested example. I have driven Porsches, BMWs, Aston Martins, Miatas, Vipers, STi's etc. so I have a lot of different marques to compare against.

I believe the C6 is a good foundation, it has great balance, very flat torque curve and crisp steering input and I have suspension, seats, harnesses, radiator, oil cooler, upgraded brakes, brake lines, alignment, track rubber all planned for the car but I was very interested in seeing what the car would do in "stock" condition.

For reference I was able to turn 3:48's on the 5 miles of Thunderhill and the Spec Miata Pole by 20 year hot shoe Joey Jordon was a 3:40. I am sure I would have been able to turn at least a 3:40 with R-compound tires.

What is the reason for going to different spindles? Different geometry?

 

exactly opposite it allows you to lower the car and keep the geometry the same.
The sweet spot is lowered one inch. if you want more (lower) then you need the drop spindles to do it (pricy though)

 

Sorry, I meant to type hubs. They tend to have a short life run near the limit on track getting loose and/or the speed sensor failing. More robust hubs are available.

I wasn't aware of the spindle trick above.

Enjoy your C6, I came from a MX5, the bank account is smaller but the right foot is much happier

 

Okay, I can relate to that and good to know they are a weak spot on the C6. Front hubs are a weak point on the MX-5s as well. First thing we do is tear down the new ones, clean out all that crappy lithium grease and repack with good molly bearing grease.

And yes, it is quite a sensation actually 'accelerating' out of a corner! :p

 

One more note on the SWPS, the wiring is tight, the connector is not easy to access, and I recall a post the connector is designed for only 3 insertion cycles. I haven't seen any one wire in a switch but it should be possible.

A intermittent SWPS can result is a brake locking up at not so appropriate times. Many of posts on this in the same vein as the bad GM ignition switch issue.
Service Active Handling Consumer Action

For other Corvette info, David Farmer has a really useful collection.

 

Nice article!

 

Here's a copy of the article courtesy of VIR:

http://virnow.com/files/2012/09/Car-...ning-Lap-2.pdf

 

Were you running Trac off or Competitive driving mode? Perhaps you should try Competitive mode first? It disables traction control and halves active handling.

From what I remember seeing, pro drivers weren't gaining anything with active handling completely disabled vs comp mode.

 

AH holding you back is noticeable for me on long or negative camber sweepers, seems worse on rough pavement or when using gators.

The risk is if AH glitches and thinks the wheel is pointed a different direction than reality, it try's to correct. Not cool if threshold trail braking during turn in at the end of a long straight.

 

Thanks for the thread, my AH glitched today and pulled me over the solid yellow on a windy road. Wasn't going fast and no traffic but crazy experience

 

They work better, if you get yourself properly "strapped in". There is a way of locking the belt. I'm surprised, that almost nobody knows this!

First adjust the seat to the position you want to have it on the track. Lock the belt on (as you would normally do). Then draw/extend the seat belt all the way out. Then slowly let it wind itself back in and you'll hear small clicks during the belt is retracted. If you try, it won't come back out, it's locked. Now you move the seat a little bit backwards and let the seatbelt retract in a little, so that it's locked a little tighter. Now move your seat back to the driving position. Test, if the belt is tight enough to hold you in place. If not, move the seat a little back and pull the lower belt a couple clicks more in. Check again, if it's tight enough. Repeat, if necessary.

This helps tremendeously keeping your body in place.

If you got the belt too tight or you are just done with driving, release the seat belt and let it retract itself completely. Now it works normally again. And if you got it too tight, draw the whole belt out again and listen those locking clicks... etc.

 

Doubt he's looking for response to an 11 year old thread. And all seat belts do that.

 

Oops. Didn't notice the dates...

No, they don't. Not even Corvettes. C5 doesn't do that. In C4 you have to push the "CINCH" -button to have that locking activated.