Dropspeed

I want to continue this discussion as I am starting to set-up my 2011 GS for HPDE and Time Attack. (20 year instructor, former SCCA & NASA lic holder).

• What are people using for alignment specs for the Pirelli.
• Has anyone run 10" F and 11" rear on a C6 Z06/GS

The reason I ask about the 10"/11" or 11"/11" combo is I have 4, 18"x10" and 4, 18x11" wheel that I used on track on my 13 Camaro 1LE. I would prefer to not have purchase new wheels for the GS if these will "work" for at least HPDE with scrubs. (offset places them at the fender with no rubbing and they have already been on the car)

Thank you,
Matt

C6RAPTOR

I also have dropped spindles and just ordered Pirelli 325/705/18s for the rear because they are made for 13" wide wheels.
What spring rate are you using in the rear? My Hoosier R100s were 27.6" diameter and the rubbed so I increased my rear spring rate from 700# springs to 800#and the rubbing stopped.
The Pirellis have a diameter of 27.83" or .23" greater then the Hoosiers . Hope they clear.

TorontoC6

My rear springs are 800#. I have not run the 325/705's. Some folks who run them have rubbed, others not.

C6RAPTOR

My guess is that some folks may have <700 # rear springs. I should say I hope that is the case because I have two sets of tires arriving tomorrow . I will not know if they rub until the first event at The Glen.

I ordered the 705 Pirellis because they were the proper size for 13" wide wheels. The 660s are for 11.5-12.5 " wide wheels. Does Pirelli make a 325/680/18? I did not see it on the chart that I found on line.
wheel sec. width tread width diameter
325/660/18 11.5-12.5 12.75 11.81 26.30 DH
325/705/18 12.5-13.5 13.89 12.40 27.83 DH

Thanks for your reply

TorontoC6

What event are you going to at the Glen? A bunch of us are going to be there for the NASA event in April.

Poor-sha

Pirelli makes a 315/680-18 and I've run them on 13" rims without issue but they do look stretched.

C6RAPTOR

I was going to go to the Trackmasters May 22/23 event. I have not gone to a NASA event for over 8 years . I have been doing Trackmaster, BMW, PSA & CHIN. I will need to look it up to see the exact date. Late in April is best but not a guaranty that we will not have snow. I have seen snow in May.

Where did you get the canards for the front of you car?

Do you know Jim Beaton from Nepean Ontario?

TorontoC6

I have been doing the NASA spring Watkins Glen event for the last 7 years. Bill Dearborn was my first instructor with NASA and I learned a lot from him (moved from HPDE1 to HPDE4 over the years). They have always run a good event and a group of us from the Toronto area have made the trip each year. Weather can be spotty (cold, wet, sometimes a little snow) but we always have a good time and it's a great track - even better with the new pavement.

The canards were on my car when I bought it from Richard L'abbe (one of the partners who own Calabogie race track near Ottawa). The car was built by Powell Motorsports. The canards are aluminum. They did a very good job balancing that car (aero, suspension). It's got vented hood and fenders, side skirts, front splitter and rear wing (Crawford composites).

I am going to put the race car up for sale this year. I promised my wife I would sell it last year but I am procrastinating. I am picking up a new 2017 GS this weekend and will use that as an occasional track car (don't need the truck, enclosed trailer, stacks of wheels and tires....).

Sorry, have not had the pleasure of meeting Jim Beaton of Nepean.

C6RAPTOR

I will check on the canards . Are they made for the C6Z?
Where do you get your Pirelli tires ? Have you used JB Racing Tires?

TorontoC6

I believe the canards were custom. I have not seen them offered for sale anywhere.

Pirelli slicks are from GT Racing Tires.

C6RAPTOR

Have you ever had Pirelli slick shipped in the winter and had them damaged in shipping by the cold weather? I purchased 8 tires that had cracked side walls show up before mounting. JB Racing Tires said it was caused by the freezing weather and will ship me 8 more when the weather gets above freezing .
I always have kept my Hoosiers in a heated garage so I have never experienced any freezing related damage .

C6RAPTOR

Have you experienced rubbing with 705 Pirrelis in the rear of a C6Z with dropped spindels ?
I am in the process of ordering 8 tires from GT Racing Tires and I have dropped spindels but do not want to screw up.

GSpeed

I would not run the 700/705/710 rear tire. Its faster, but its a big tire, and will have clearance issues.


On the drop spindles, check your inner wheel barrel to a arm clearance. We have to modify the lower control arm to fit the 18" wheels with drop spindles.

GSpeed

Edit: If its a C6, you definatelty will not clear the 700+ rear tires, but your control arms will be fine. Just run the suspension through its travel with no shock to verify. Your mileage may vary.

C6RAPTOR

Good advice. I have had the dropped spindles for a number of years and had performed the control arm wheel clearance task after I read a post by one of the Corvette Forum members from Norway stating that he did not know about the clearance problem until he wiped out his Corvette at the Nurburgring.

GSpeed

There are several variables with the control arm clearance. The inner wheel design, the thickness of the barrel, the camber you run, the ride height you run, the shock package you have, and where it bottoms out, or doesnt bottom out.

When performing modifications such as these, you should always check and recheck all of these variables. Its like torquing your wheels, or setting tire pressures or putting gas in. We all make sure those are done, but often times forget the bigger details that are unassuming.

carefulnow

WTF is this all about???

C6RAPTOR

It is about notching the LCA
The photo was taken with my 19" OEM wheels installed . When the 13" wide 18" diameter CCW wheels are installed the wheel will hit the lower control arm when the rear suspension is compressed.

phxcobra

So I see suggestions for cars with drop spindles. But anyone have good suggestions for a C6Z with stock spindles and 18x11/18x13 CCWs? I believe with the stock spindles I'll have clearance with the lower control arm, but any suggestions on scrubs that work well with this setup (don't rub wheel wells)?

CaddyRacer

GSpeed,
What's your recommendations for track only rims and tires for my 2012 Z06 with PTM and Magna shocks...not racing, just for weekend fun? Im going to store thm at MSR garage
IE 18 or 19?
tires sizes?
scrubs or R7

...pita