How to get more performance out of a C6 Chevrolet Corvette | Articles

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Meet Our Expert:

Sam Strano
Strano Performance parts
stranoparts.com

The great thing about these cars is that you don’t have to reinvent the wheel. Chevy made a great starting point. Most of the improvements we make to our customers’ cars are intended to get the car behaving in a certain way, rather than putting Band-Aids on shoddy engineering. Think of us as a doctor who tries to make cars handle how owners want them to.

Sixth-generation Corvettes as a whole are not bad handling-wise, but you can’t really lump them all together. For example, base-model cars are softer and tend to move around a lot. Each trim level comes with its own strengths and downfalls.

If you’re currently shopping for a car, for those looking for a good performance value I would recommend a 2008-’13 car in Z51 trim. The Z06 is still a relatively pricey purchase, and the Z51 comes with an upgraded suspension package over the base car. Additionally, 2008 was the first year for Chevy’s updated LS3 engine. You can get a few extra horses by buying a later car. The Z51 also came with gearing that is roughly 12 percent shorter than the base model, which is a plus for performance driving.

We’ve spent tons of time autocrossing these cars and we’ve found that generally the best ways to improve performance are by upgrading your shocks and front anti-roll bar. 

When it comes to shocks, we want something with adjustability. We generally choose Koni Sports or RideTech, depending on your budget.

Next we want to upgrade the front sway bar. Our most commonly installed unit is our own 15/16-inch bar. It has thick walls and is two-way adjustable. You don’t have to worry about the stock rear bar. This is a good option for a first modification if your stock shocks are still in good shape.

If you have a base-model Corvette, upgrading the anti-roll bar is a good way to firm up the suspension.

The Grand Sport is a bit of an oddball: looks like a Z06, but has softer springs from a Z51. But you can offset the handling with a much thicker front anti-roll bar.

If you plan on taking your car to an autocross or track day, you should absolutely replace the run-flat tires with your choice of performance rubber.

Overall, Chevy created a pretty robust drivetrain. One hotly debated topic is oil starvation. Some cars that are run hard tend to spin bearings and go through engines. However, based on our own experience and the experience of fellow competitors, we believe that the issue is more related to the oil used than the engine’s design. We highly recommend using Red Line oil.

Speaking of lubrication, oil temperatures can get a little too high for comfort on a base car on track. Owners should consider adding an oil cooler if the car sees much track time.

Cars that get tracked a lot should also get upgraded front brakes. The stock twin-piston calipers up front tend to cause uneven pad wear when pushed hard. The piston actually starts to angle up and you get angled wear on the pad. Wilwood makes a direct-fit, four-piston caliper, and you can even keep running the stock-size rotor. If you have money and track the car a lot, a larger AP Racing kit is a good way to go. 

Headers and a tune are a good first step for adding power. There are lots of good headers out there: American Racing, Stainless Works and Kooks are all good options.

The brake fluid in the clutch system tends to get very hot by the exhaust. Pretty much any Corvette C6’s system is now filled with black gunk if the fluid hasn’t been changed. If you don’t have a remote bleeder, you can suck out the fluid in the reservoir, refill with clean fluid, engage the clutch a few times with the pedal, and repeat a few times. As for which fluid to use, we recommend Motul RBF 600 for street cars and Castrol SRF if you’re running the car hard on track a lot.

The NPP exhaust with flaps was optional on base models, but standard on the Z51. It’s a good system, but you can take some weight out of the car and add some nice sounds by replacing it with an aftermarket exhaust. Borla makes one of the most popular replacements. 

A light flywheel and lighter damper are also a good addition for someone trying to squeeze the most out of their car. Contrary to some people’s beliefs, this doesn’t hurt the drivability of the car since it makes so much torque.

If you’re shopping for a car, there isn’t a whole lot to be scared of that won’t be immediately obvious. Keep an ear out for bearing noise from the torque tube. You may want to test drive a few different cars to give you a good idea of what is usual and unusual.

Some cars may leak water into the passenger-side footwell.

When motor mounts break, they leak fluid underneath. It looks like brown dried fluid on the subframe. Cars exhibiting a vibration that changes with the engine’s revs may need new engine mounts.

Comments

I’m using Strano’s 1-5/16″ front bar and some Konis I got from him on my C6 Z06. After that, tires and alignment and you’re good to go for AS autocrossing.

In reply to Harvey:

Nice! Yeah, Sam definitely knows his stuff.

A bunch of guys have gone to the Penskes for AS, but I’m just feeling my way through it at this point. Maybe one day I’ll be going, “Boy these Konis sure are limiting my driving!” but that day has not yet arrived.

You do have to remove a lot of shims to dial in the camber you want up front though. I have a drawer full. Once you do that though, -3 degrees is easy to get.

How did you mount your Konis on your C6?  My Koni Shocks came with no top bushings for the front shocks and I couldn’t get stock bushings separately… Also the sperical mount kit I tried only engaged a couple threads on the top studs which I didn’t want to trust going over the curbing at the bus stop at Watkins Glen.

In reply to ShiftLess :

Do you have a z06?  I understand the upper mount up front is different on them. 
 

when I got my motons, I, too, had no upper mount so I cut up my old shocks and made a mount out of the washers and bushings.  It worked quite well. 

In reply to Harvey :

Do you have stock a-arm eccentric bolts or one of the hex kits? (To adjust camber)

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