mikymu

After driving my Porsche GT3 Cup car for over a year I badly needed an "easy" track day car that's fast and fun to drive. After considering all sorts of sports car from E92 M3 to another street GT3 RS (really tired of paying Porsche tax) I decided to give the 2011 Z06 carbon a try. After taking the car out on the track in all stock form I knew it's going to take alot of work to transform her into a true GT racer.

Here is a run down of what's involved and I have learns tons about this car.

To begin, here is what motivated me to get another sports car. It's just so much work to get the Cup car ready for track



First order of business is to protect the paint by covering the whole car with Xpel clear film. This took me about 1 week and alot of patience. Material cost was about $1K. So far the film held up super well and track debris and marks wash right off.











and yes, I cover the front spoiler too



Wheels and tires next. Heavy stock 19" front and crazy 20" rear won't cut it for track. Forgeline GA3R super light weight 3 piece wheels are the right choice and clear the giant Brembo ceramic rotors and calipers. GA3R with Hoosier R6 is about 10 lbs lighter per wheel compare with stock.





There is enough gap in the front to allow a wheel strap for trailer



Stock front wheel/tire vs GA3R/R6





Rear wheel/tire vs GA3R/R6





Next come one of the most important GT mods. proper racing seats and roll bar. I have seen enough roll over and crash on the track to know you can never have enough safety equipment.

I decided to use OMP HTE seat and they fit great and do not block my side vision. Seat bracket from Arizen Racing works great







There is no one better at the Sacramento area for custom roll bar than Mike at Tolle fab. I have looked at all the roll bar on the market for Z06 and they all seems to lack certain safety feature in order to make room for creature comfort. I wanted a SCCA roll bar that's bolt in and can be extended to a full cage in the future. Mike came through as always and this thing is super solid and all tig welded at around 50 lbs.

Clear out the interior for roll bar fab



Frame drilled and prepped for mounting



Weld in mounting points at bottom of B pillar





Black powder coat and looks fantastic all installed!









Now let's add OMP steering wheels with quick release and PFADT quick release adapter



Now let's address the performance issue with this Z06. My test run with the car at stock form was horrible. I did not appreciate any of the Z06 track prowess other than big power. Suspension was sloppy and the rear was wondering all over the place during braking and hard acceleration. It was unpredictable and unsettling. The engine temperature climbed all the way up to 250F and it's only 70F outside. I decided to cool her down and stabilized the Z06 with

• 160F thermostat, water wetter and reprogram fan speed
• PFADT engine and tranny mounts
• PFADT track sways
• Lower ride height
• Aeromotions active wing
• Better exhaust with LG long tube and Akrapovic mufflers
• Halltech intake
• Diablo Sport Predator flash tune
• Improve rear diffuser
• Track alignment

Cooling:

I wanted to cool down the engine without having to spend too much $$$ and decided to use 160F thermostat, replace antifreeze with water wetter and reprogram the fan speed with Diablo Sport Predator. This combo worked super nice and reduced my coolant temperature by 30F on the track compare with stock and don't go much over 220F. On the street I average 180-190F even with AC on.

PFADT sways, engine/tranny mounts:

These PFADT sways are super well made and help kept the car well planted on the track. I use the middle hole for both front and rear and the car had neutral handling



Stock engine and transmission mounts are trash. I can bend the mounts with my thumb and I can only imagine how much energy is loss with all the twisting.





Installation is no easy task. You had to drop the front and rear suspension assembly from the body and lift the engine and tranny in the same time to allow enough space for removal and install. This will be the perfect time to upgrade your exhaust. The extra vibration from the hard PFADT mounts are minimal and I don't notice it after initial install



Lower ride height:

I kept the stock suspension with leaf spring and easiest way to lower ride height was to use cable saw for PVC pipes. Wrap it around the padding on the height adjustment pads and cut the whole thing off. I was only able to reduce ride height by 1/2". You will get tons of squeal and you can use some thick grease under the pad such as the one provided by PFADT for their sway bar.



Aeromotions active wing:

Well, How do I start? This car needs more stability at the back and I don't particularly care for the extra drag. Most after market wings have upright mounts push all the way to the side and it just doesn't look right. I have always been curious about active wing - it makes sense and F1 are using it. This wing has it's own CPU and can be program to adjust wing angle at braking, cruising above and below 70 mph. It senses vehicle speed by tapping into the vehicle speed sensor.

Aeromotions offer Corvette specific wing but I felt like the upright is too tall. I decided to get a used GTR spec wing with 1.5" shorter upright since I do not have aggressive front aero. It worked out perfectly but it was an experiment that could have gone terribly wrong. First, I did not know if the rear decklid can supper the wing and stress at >150 mph. The only way to know is to cut the rear decklid open ... Thank god it has an extra upside down U shaped support and strong enough to support the wing without issue at >150 mph.



Time to mount the power pod upright after measuring out the attachment site for drilling





The other challenge I encounter with this wing is the vehicle speed sensor. GTR VSS generate 8000 pulse per mile vs Corvette's 4000 PPM. so that means I have to find ways to multiply the PPM by two. Luckily Dakoda Digital makes a PPM converter (thank god) and I was able to generate 8000 ppm for the GTR Aeromotion CPU to compute proper speed for wing adjustment



I tap into the VSS wire behind the instrument panel





Now we got drag!



It gave the Z06 a proper GT look that it badly needs



Better exhaust with LG long tube and Akrapovic mufflers:

What's a GT racer without a proper exhaust that's light, well made and sound great? After much research I decided to get the LG long tube with 200 cells catalytic converters couple with Akrapovic mufflers.

Stock exhaust removed



LG long tube with 200 cells couple with Akrapovic mufflers.





It should be snap for install right? Remove the stock exhaust and slap on the replacement ... wrong. I was thinking about the GT3 exhaust where everything is on the *** and exposed. The Z06 Carbon have the extra ZR1 style oil cooler on the driver side



Folks at LG had to custom bend the left inner bank pipes to make sure it fits around the oil cooler



Z06 exhaust was super hard to remove and install. I had to totally disconnect the front suspension assembly and control arm to create enough space to slide the LG headers in from below. The other hard part is have enough heat shield to protect the O2 wires and oil cooler which had to be fabricated for custom fit.





Finally in! Protect all the wires and plugs well away from the hot exhaust



You have to drop the rear suspension assembly to remove and install rear mufflers



Halltech intake and Diablo Sport Predator flash:

Both items are super easy to install. Slight trimming was required for the right side of the intake shield. I chose Diablo Sport handheld flash because I like the ease of install and I can play with various parameter such as adjusting fan speed and revert back to stock program any time I want.

Dyno result was very impressive. Stock this Z06 was producing 467 Hp and Tq and after LG/Akrapovic exhaust, Halltech intake and Diablo Sport flash it made 505 HP and 506 Tq at the wheel. Here is real world comparison. My street 07 Porsche GT3 RS made 365 HP at the wheel and 07 GT3 Cup car made 395 HP at the wheel with same dynopack. We are talking about over 600 HP and Tq at the flywheel for this Z06 if you consider 15% energy loss to the wheel ... WOW!





Rear diffuser:

I really dislike the disco backup light on the rear diffuser. Come on, do you really need that much light to back up? You can't see a thing anyway. I have consider several aftermarket solution but some how never like them. I decided to do the next best thing, remove the back up light and replace with wire mesh. It is fairly easy to make and both sides took me less than 30 minutes.

First you cut out a square wire mesh which can be had from several online store. Place it over the front of the backup lights and create a general shape for the opening and cut along the edge





Test fit from back of diffuser and gently shape the edge with your finger (don't press on the center) and use zip tie to attach to the backup light mounting points





It looks 1000X better than the backup light





It help let out hot air from the exhaust and reminded me of certain C6R's back end



Lastly track alignment: Stock alignment was ... pathetic. I swear it had positive camber front and rear and inner side of the Hoosier R6 never touch the track. The car was a handful to control on the track at stock alignment



I decided to dial in the camber. To do that I had to remove 2 washers from each of the front upper control arms and 1 washer from the rear upper control arm. Tire Pros at Folsom did a great job with the alignment ... you should see what it took to get my Z06 on the alignment rack (took 6 people to, lift, push and watch from all sides)



**************************************** *******************

After 3 months of hard work and research - I need to thank everyone that contributed on this forum. It made this GT transformation so much easier! - The Z06 GT is finally here. It look the part and sound like business so how does it drive on the track? My first time out on the track was nerve wrecking. I did not know how the car will behave and if the wig will rip off at high speed (>140 mph down the straight at Thunderhill). first session was painful. I kept observing the gauges and looking at the rear wing to make sure it's still there. Then I notice something odd. My Z06 at stock form did 2:07 at Thunderhill and my lap timer was registering 2:02, 2:01 in heavy traffic!? My best time in my street Porsche GT3 RS was 2:01 and the GT3 Cup car was 1:56. So I push a bit more at end of first session and broke into 1:59 with ease. Wow, took a deep breath, check tire pressure and wing and so far so good. Went out second session with much more confidence and ... holy mother of Z06, I did a 1:57 in traffic and the car was absolutely on rail!

Best of all is that this car is still streetable and has window, AC and radio. I set out a goal to make a GT car out of this Z06 and it gave back more than I ever anticipated. I feel strongly that folks at Chevy need to consider making a more track oriented car much like what Porsche did with their 911 GT3. These Z06 is capable, just need to sharpen the tool a bit and you will have one dream machine

Here are some video and pictures from the track



Standing still at Laguna Seca ALMS Corvette corall





In action at Thunderhill











Aeromotions wing at full tilt under hard braking

HC Mechanic

Nice post! Excellent driving too

mikymu

Thanks. Now I just need to get alot more seat time behind the Z06 to improve track time

camirocz

Do you mind me asking what was your total investment in modifications?

gtodoug

Great post! A fun read and very informative.

tim414

Excellent post....Is this Vette less work now to get out onto the track compared to your GT3 car?

dcsteg

Enjoyed you post very much.

Needless to say you did it right.

Stay safe and have fun.

BillY2KFRC

Very impressive build-up and great driving. Thank you for posting the details and video.

Do you think the Z06 could now beat the GT3 cup car in a race? Or would it depend on the track?

95jersey

You have learned what most on the forum have figured out. A well set up Z06 is as good or better than the best the world has to offer. It is common for decently set up Z06's to walk race prepped Cup cars.

Nice build, the only thing I would have done differently since you are using Hoosiers is switching to a coil over set up. If you think the car is fast with the OEM suspension, it still hasn't come close to what is possible with a set of 700lbs coil overs. I found the Hoosiers simply overpowered the stock suspension and create a floating effect at high speed. If you want to go to the next level, get a nice set of coil overs with a higher spring rate. In one of your pics, I see the car basically bottoming out and leaning over pretty hard, a good set of coil overs will resolve this and dramtically improve your confidence in the car, especially at high speed.

You stated the car was hairy at hight speed from the factory, just so you are aware, this is NOT normal. You must of had a bad allignment, which would make any car hairy at the track, but especially one with 500+hp.

I am also curious as to why you choose such a nice Z06 (ie. Carbon Edition). I see that as being more of a street/show car for the waxers, just too nice to beat up at the track. A base Z06 with the same mods might have been a better choice, especially with those carbon brakes and electronic suspension. Not aware of too many companies that are making after-market race pads and when you need to replace those carbon rotors, they will cost you big time. I personally would prefer the cheaper and more disposable iron set up and non-electronic suspension.

HC Mechanic

I haven't played with toe much on my car, but I have herd some toe out fr/rr can help on the track. I noticed this car is actually toed in on the rr...

widgetsupply

I think it is funny that you pick a top shelf Z06 and pour money into it because your are tired of the Porsche Tax, when so many on here complain about the Vette Tax.

95jersey

Not to defend him, but the CUP car is more than twice the cost of a Z06. So while he spent quite a bit of money, it is much less than his CUP car costs.

What is amazing is the the CUP motor probably costs 3X what the LS7 costs and makes far less HP, that is a prime example of the Porsche tax.

nhpln

Great write up! Saw this at the corral last weekend. What do you think it will run at Laguna Seca? Low 1:30s?

Pfadt Racing

Fantastic post and such a great looking car. Let us know if you would like to make the move to coilovers. Just like mentioned by 95Jersey with the amount of mechnical grip your generating you could really use an increase in spring rates.

Your turning some mean lap times out there. Keep up the pace and keep posting pics and videos! We love seeing these cars flying on track.

Antonio1988

Fantastic write up, I took the time to read everything on here and really enjoyed it!

GrillnZ

Awesome build! I commend you for calling the Z06 for what (in stock form) it really is. The Pfadt products, a new seat and MGW shifter turn the car into a COMPLETELY different beast. I too did the Diablo tune and when I swapped in a 160 stat I got check engine lights because the coolant didn't reach temp soon enough. Have you experienced this?

Treadhead

This thread is full of WIN.

EXCELLENT write-up!

GMuffley

Nice install and great photography documenting the changes.

FAsnakes

Awesome, just awesome!

mikymu

I don't have the total but .. it was alot. it's still much less than what I spend on getting my Porsche GT3 RS ready for track and beat it easily by > 3 seconds

Thanks

Much less work compare with GT3 Cup and the same compare with my previous street GT3 RS. I trailer my cars to track so that's couple hours of work

Thanks. Will do

Thanks. My Z06 is slower than the Cup. If both have the same slick tires the Z06 will be couple secinds slower and drop off dramatically after 30+ seconds of race. The Cup car is a true race car and my Z06 GT is a street car that can turn near race car speed and still drive to local in and out berger for a bite

Yes, PFADT coilover with higher spring rate will be next. This Z06 was very unstable at stock form and when I looked at the track pictures I sware the wheels had positive camber and hard braking and giving gas will swing the rear. To be fair my street GT3 RS is just as bad on the track stock form and took alot more prep to be track worthy than the Z06 ... and much more $$$ involved.

I did consider other none carbon Z06 but I like to try the ceramic rotors and I love this color combo. Nothing else spark my interest

Just the opposite. You need slight toe in esp for the rear since the wheels will toe out under hard braking and make the car wonder.

Trust me, this Z06 is basement bargain cheap to work on compare with Porsche

Yup. All true

Thanks. I am aiming low 1:30 on a set of fresh R6 at Laguna Seca. I already had more than 10 heat cycle on the R6 when I made this video. Now these R6 are just practice tires

Thanks. Your featherlite coilover will be next with higher spring rate and we spoke about this via e-mail before. I am surprised how compose the car feel with your sways and it was swinging side to side wildly on stock form. I may drive the stock shocks for a while but I have a feeling the coilover will be added soon

Thanks and glad you like the write up

Yes, I think all cars be if Ferrari, Porsche or Z06 at stock form is not fit for track and need tons of work and $$$ for the proper transformation. I do get the engine warning light and it's for catalytic insufficiency. I am not sure it's from the 160F but no big deal. I just ignore the light and it can be erased by unplug the battery for couple minutes. It does not affect how the car run


Thanks. Like you said, this Z06 got wing