I just got a 2003 zo6 and am planning on autocrossing it this summer at Blackhawk Farms Raceway in IL. I wanna stay in the class I am in so I only have so many mods i can work with. I am going with super sticky tires which will bring me to the middle of my point range so the following are about the only other mods I can go with:

1. I want to put in an aftermarket air filter (so many options) but dont want to have to retune, which would cost me too many points. I was looking at Halltech. Any ideas on which filter and is their air straightener a good idea?

2. Ideas on exhaust modifications. This will mainly be a track car so I am not worried about how loud and how legal.

 

Exhaust is going to offer you very little benefits on a mostly stock car. You probably want to spend your points elsewhere.

I would be spending my points more in the suspension areas. I would look at shocks (possibly coil-overs depending on points) and sway bars. The Z06 should have plenty of power bone stock for most autocross courses, unless the group you are running with prefers a more open track layout. SCCA in my area runs VERY tight course, while the Vette clubs are far more open.

 

I am running road course autocross. The track at Blackhawk is 2 miles, so im hitting high speed.

Whats your opinion on air filter and a tune instead of the exhaust? Or do you still think suspension is the way to go?

My main competition is a 2011 GT 500 which wiped the track with me in my Roush 427 last year.

 

I would think a tune a CAI are going to offer you maybe 15 HP. Replacement shocks should cost you zero points. You could go with the '04 Z06 units which are somewhat expensive, but offer very good performance. They should qualify as bone stock.

Definitely get a good set of tires. I assume you are going with a set of R-compound.

From there, I am not sure what the best bang-for-the-buck is going to be point-wise since I am not familiar with you point system or the track you run. Since it sounds like you think you need more power, your best bet might be going with a cam and tune or heads/cam/tune.

Headers can offer some big gains as well, but those will require a tune.

 

I'm going to run Hankook z214 tires.

I'll look into the shocks and see what the points say.

Besides the tires and some race pads im gonna run a race and see how i stack up.

Thank you for your help!!!

 

Unless the '04 Z06 is in another class, you should be able to use them as a stock item. Coil overs will definitely be a point item.

 

I looked at the point rules and it's points if there is a change in spring rate. Would that apply. I'm new to car tech.

 

No it would not. So you can look at replacing the shocks, lower the car on the stock bolts, and corner balance the car...and get an aggressive autocross alignment.

 

Here is my Point Sheet. Would any of that affect points. Again thank you for your help.

The point assessment schedule will be used to place a vehicle into the proper category when any modifications
are made to the vehicle. Any addition of a kit/system will be assessed an SPA for each individual
component/part added. "Bumping" of a vehicle will occur when certain modifications are judged to offer a
competitive advantage to other vehicles in the prescribed category. Points are assessed at technical inspection
for such modifications. The addition of modification points, including Stock Assessment Points (SPA) within the
Midwestern Council High Speed Autocross Classification List, if any, is used to determine when a vehicle is to
be bumped to a higher category:
Point Assessment Schedule
Total Points Category
0-2 Stays in Stock Category
3-9 Bump to Prepared Category
10-22 Bump to Modified Category
23 and over Move to Race or Street Tire Class
Dealer-installed options that are not available from the factory are considered vehicle modifications from the
base model. The modifications should be assessed appropriate points as listed in Section 6.3.
Points will be assessed at tech as follows:
Tires, Wheels and Suspension
Adjustable non-factory air spring 4
Coil-over addition 4
Tires with a wear rating less than 140 3
Change of rim width, per full inch increment of increase over stock 1
Change of rim diameter, per full inch increment (up to 16" = 0; greater than 16" = 1 point per inch from
stock)
Decrease in rim diameter from stock = 1 point per inch)
Suspension bushing replacement, excluding sway bars and shock absorbers 1
Sway bar revision or addition: Front=1; Rear=1 1,1
Change of spring rate 2
Other/additional suspension modification, including panhard or track bar 2
Camber plates or other alignment hardware enhancement or changes 1
Chassis stiffening (per each system) 1
Brake conversion, including LB1 option 2
Engine
Engine displacement change (per each 3% increase) 1
Engine swap, all engine swaps will be classed in the appropriate Race or Street Tire Class.
Removal or tampering with emission control device, per device 1
Removal of catalytic converter(s) 1
Intake manifold change or adaptor without carb or fuel injection change 1
Carburetor or fuel injection revision on stock manifold 2
Carburetor or fuel injection revision with non-stock manifold 3
Air intake modification (air box) excluding filter element change 1
Camshaft change 2
Valve size change and/or head modifications 2
Port Modification (rotary engine) 4
Ignition and/or computer module change (normally aspirated engine) 2
Ignition and/or computer module change (turbo or supercharged engine) 4
Exhaust manifold change 1
Open exhaust and/or muffler removal 2
Exhaust system enhancement (beyond manifold and converter changes) 1
Accessory drive revisions, including underdrive pulleys 1
Turbo/supercharger system modification or replacement: includes any non- “computer” based
mod related to boost control; does NOT include engine computer module points 3
Turbocharger or supercharger addition, not including Intercooler 4
Intercooler change or replacement 3
Intercooler addition 4
Other
Final gear ratio change less than or equal to 20% (from stock or factory-delivered option) 2
Gear ratio change greater than 20% (from stock or factory-delivered option) 3
8
Limited Slip differential, except exact replacement of stock OEM equipment 2
Replacement of driver’s seat with racing seat (Only for vehicles which do not require a lap
and shoulder harness) 1
Obvious attempt of weight reduction or weight transfer, i.e., removal of each bumper, removal of or
replacement of each body panel, each Plexiglas window panel, battery relocation, etc., per
modification (first modification = 2; subsequent modifications = 1; maximum = 4) 2,1,4
Other points may be assessed for modifications not stated here by the Chief Technical Inspection (1
point maximum, per modification)
9

 

No, the items I listed are "Free". It should also be noted that you can look at other shocks. The C6Z shock is popular and cheap. But you best bet might be to find an aftermarket unit Koni or Bilstein that offers some adjustments. I haven't looked into these shocks enough to know if there is an adjustable (non-coil over) shock.

I would also add a racing seat and harness bar. This will really help your times, but costs 1 point. This will gain you more than a CAI change that you were planning and costs the same 1 point.

 

Ok. Thanks for your help Grimlock!!!

 

2013 GT500 is putting down nearly the same Nurburgring time as the 2001 Z06...just sayin. Handle that...lol.

 

Are you in prepared class? 3-9 points? Your tires put you at 3 points. I agree with the seat and harness. I would recommend suspension components. Coilovers will be 4 points but might be worth it. Sway bars is another option. I run blackhawk all the time in scca and that track is a handling track, not a horsepower track.

 

This is the guy I would listen to. If he knows the track, he can give you much better advice than I can.

 

The 2013 GT500 they tested on the Nurburgring was beating the 2001 Z06 by a TON. It was beating the Lamborghini LP670. Of course that time is from a prototype GT500, so who knows what it will really run.

Or did you mean the GT500 is running with the C6Z?

 

I have a spa of 3 so im in prepared. Im going too look into a seat and the belt bar. Got to do some research on different springs. If i went with coil overs I would get bumped a class.

 

The guy with the 2011 gt500 has been on my mind all winter. I want a piece of him

 

Anybody have an opinion on a short throw shifter?

 

the guy with the GT500 is very experienced and very fast.

how about SM ( Street Mod ) ?

must be on street tires ( 140 or over ), mod.'s more open.
you'll be running against another black '02 Z06

 

Driver mod is always the best mod.