Jun 16, 2018 update to the Chevrolet Corvette Z06 project car

Project Z06: Rebuilding and Recovering Our Stock Seats

There’s a lot to like about C5 Corvettes, especially our 405-horsepower Z06. But they’re not without flaws, and some of those flaws are downright disappointing.

Not to use this forum to namedrop our famous friends, but when we had the chance to ask C5 founding father John Heinricy if he has any regrets about the car, he readily admitted that the seats were not ready for primetime. Their design isn’t really a match for the car’s capabilities, and even more depressing is their lack of durability. When we did a project with a 35,000-mile, then-8-year-old 1999 C5 a decade ago, the driver’s seat was already beginning to show serious signs of wear.

So it’s no surprise that our 95,000-mile Z06 needed some help in this department. The passenger side was actually in surprisingly good shape, but the driver’s side was basically done for. The outside bolster showed the very typical wear patterns from repeated entries and exits, the foam had deteriorated, and the leather had started to rip. It was time to pay some attention to our command surfaces.

Nowhere to Hide

The solution to our seat dilemma came from the definitive source for owners of ailing Corvettes: Mid America Motorworks. It’s basically a one-stop restoration parts shop for any generation of Corvette, and C5s have definitely aged to the point where they could use some restorative therapy.

Not surprisingly, one of the more popular products that Mid America sells is a seat restoration kit. Customers can customize the kit to create a variety of looks, ranging from completely stock to totally bespoke, show car-type stuff.

The complete rebuild kit includes all-new leather for both the upper and lower seat cushions as well as new foam for the entire bucket. Installation isn’t complicated, but making everything fit properly requires a little patience and a willingness to improvise. Here’s how we did it.

Step 1:

Installation begins with taking out the stock seats. This means removing the plastic beauty covers and the four bolts holding each seat to the car. Depending on your car’s trim level, you’ll also have to remove an electrical connector or two for the power adjust and safety features.

Step 2:

Once the seats are out, start the disassembly by removing the seatbelt attachment points. If the seat has any power adjustment features, take off the trim panel for those switches as well. Ours was snapped into place and secured with a couple of Phillips screws, one of which was hiding behind the recline lever; unscrew that one first. Remove the lever, too, by releasing the spring C-clip that holds it on. (The clip will shoot either into the darkest corner of your garage or directly into your eye. Consider this your warning.)

Step 3:

If you’ve followed our instructions so far, you’re now holding pieces of leather-wrapped foam. The leather covering the back cushion is easy to remove. Just undo the zipper and release the hog rings–essentially big manual staples–found at the bottom edge of the assembly. Then, simply slip off the back cover like a tight leather vest–think Rob Halford after a Judas Priest concert.

Step 4:

Removing the bottom cover is a little more complicated. First, undo the drawstring. This will reveal several hog rings that secure the various flaps of leather and hold it taut. Once you snip off the hog rings–a small bolt cutter or a large pair of diagonal cutters will do the trick–the bottom cover will come off and the foam will be exposed. Remember that these seats were upholstered by hand, and although the factory had standard assembly procedures, they still allowed for small variations in technique. In other words, don’t freak out if your upholstery doesn’t resemble ours exactly.

Step 5:

If you’d rather avoid buying all-new inserts but still want to address some shabby areas in your cushions, you can try repairing them. Stuff any holes or gaps with small pieces of foam from an upholstery supply shop, craft store or sewing center, attaching them with contact adhesive.

Of course, we’ll always recommend refoaming the seats if you’re removing the covers anyway. Replacement inserts cost little, and the stock foam is notoriously weak. Even if the old foam appears to be in good shape, it has still absorbed years of atmospheric moisture and butt sweat (which is the third worst kind of sweat).

Step 6:

The foam inserts that make up the meat of the seats simply slide onto the fiberglass frame and stay in place via tension and the leather covers. You’ll find that the foam supplied by Mid America Motorworks feels a bit stiffer and denser than the stock stuff–because it is. Mid America’s inserts are built to somewhat tougher specs, so expect them to cradle your butt for a bit longer than the OE pieces.

At this point, you have the option of upgrading your base-model seats to sport seats. The frames are the same; the only difference is the foam and the leather.

A note to competitors: Changing your seats might conflict with your car’s class rules. Oddly enough, Chevy didn’t offer a sport seat option for the Z06, so making the upgrade can amount to creating a model that never existed. While this is an acceptable modification in the NCCC’s least prepared classes, for example, it wouldn’t fly in the SCCA’s Street autocross classes. Check your rulebook.

Step 7: 

New foam inserts sometimes come out of the mold with a little extra material attached, so yours might need a trim to fit properly on the seat frames. Use your old foam as a pattern and cut gently. The ideal tool for the job is an electric knife, but a long razor blade (the kind you might find in a wide scraper) also works.

Step 8: 

Time to pull on the new seat covers. The covers and the foam have some heavy-duty, hook-and-loop closures in key spots that will help you line up everything properly. At first, though, we find it handy to leave them unfastened as we tug the skins into position. A quick shot from a heat gun on tight spots will help the leather stretch over the new foam. Once everything is assembled and hog-ringed, you can then work the hook-and-loop tabs together with your hands.

Now, to bolt the seats back in, just reverse the process of taking them out. Yeah, that’s a copout, but it really is that simple.

Step 9:

To help the covers settle properly into place, try sitting in the seats and wiggling around a little.

By the way, notice how the new leather feels waaaay more luxe than the stock stuff? We don’t know any fancy leather-working terms, but the replacement material feels flat-out better, thicker and more durable than the original rat hide.

Plus, Mid America allows customers to personalize their seat covers with some cool touches, like contrasting color panels and custom embroidery. Ours have insets that match our Le Mans Blue exterior. We also had them add a Mid America logo and a Grassroots Motorsports script, ‘cause that’s how we roll.

You’ll spend about $1300 to completely recover and refoam both seats in OEM-grade leather. Throw in another couple hundred bucks for the higher-quality leather we got, or for two-tone or contrasting stitch options. It’s a worthwhile expenditure considering the seat is something you constantly touch every time you’re in the car.

Coming Up: Making It Faster

Yes, we love our revitalized seats, but they’re still essentially stock–not really up to the task of serious racing. As we modify our Corvette extensively in the search for more speed, we’ll be on the lookout for more trackworthy options. Since C5 seats are fairly easy to remove and replace, we might just have one for weekdays and another for weekends.

Other project plans? Our Corvette has some serious suspension surgery coming up, and later we’ll be adding some fancy aero bits that will press our revised suspension even harder into the pavement.

HANDY TOOLS FOR REASSEMBLY

Electric knife or long razor blade: Even a good, sharp chef’s knife will do the trick for trimming excess seat foam. Scissors, however, work like crap. We found that out the hard way.

Hog ring pliers: Do yourself a favor and actually invest in a pair of hog ring pliers. Their jaws have notches that hold the ring and squeeze it properly. Don’t try to use regular pliers as you’ll only frustrate yourself. Hog ring pliers are available from any specialty tool vendor, upholstery shop or farm supply store. If you paid more than $15 for a pair, you got screwed.

Heat gun: A heat gun allows you to soften and stretch targeted areas of your seat cover. Just be careful and judicious when using it around any fabric, especially your fancy new leather. Leaving the covers in the sun before installation will give you more wiggle room, too.

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