Wilson's Slammed C5 Corvette Page

Lowering the C5?

The goal is to lower the car as much as possible. This should be easy to attain from either the $50 RKSport Lowering Kit or the $1,750 Mallett Lowering Kit. The Mallett kit cost more because it includes Penske Shocks which Mallett claims are needed because:
"The stock shocks in the Corvette are too long after lowering the vehicle more than about 3/4". They will bottom and eventually break the internal valving."

These kits include longer bolts to lower the rear spring. In the front they rely on the factory adjustable jounce bumper bolts which are between the spring and A-arms. It should be possible to lower the front more by putting in thin plastic shims in place of the bolts .

One issue to consider with lowering the C5 was how it will look lowered. Some people consider the wheel well to not fill out correctly when the car is completely lowered. I created a mockup image to see how it looks.

Stock

Mockup lowered C5

I think it looks great! I completely removed the bolt to see how low the rear would go.

As Low As Lift Goes - Lower Than The Lift Goes

I removed the rubber jounce bumper in front to see how low it would go. (the metal front adjuster was still in at this point, so it may go lower. also, maybe the spring could be raised which would lower the car even more. to do this the insulators would probably have to be altered.)

So it can be lowered, but there is also the issue of how it will ride when lowered. Some people say it will cause:

poor tire wear

inconsistent steering effort induced by trough wander

less handling performance on wet roads
-- i think these can be fixed with an alignment

uncomfortable head-toss because of high roll stiffness
-- shorter shocks would reduce the distance between the bump stops so they dont hit. True that removing the jounce bumper will increase stiffness, but isnt this why we have a sports car?

Raising the C5?

More details about how to lower the car will follow, but first I spent a lot of time trying to figure out if the car could be raised when it comes to speed bumps or steep driveways. There are four main ways to raise a vehicle: hydraulics, air bags, air shocks and air cylinders. Some initial concerns i had were:

As little trunk space can be used as possible. I wanted to avoid using extra batteries. The CD player could be relocated to make more room.

What will the damping characteristics be like if i replace the stock shocks? The suspension needs to remain firm and respond like a sports car.

The suspension should not be hacked up. It should be able to return to the stock state. I could relocate the brake lines or buy new lower A-arms.

Hydraulics were out of the question because CCE told me that i need at least 2 batteries per pump. That would take up too much trunk space. I wanted to be able to run the system off the car's existing electricity.

Air is easier to work with and needs less maintenance than hydraulics, but air bags are way too big for the C5 suspension and not suited to a sports car. I investigated air cylinders which i also found to be too wide. The C5 shocks are only 2" wide and there isn't much more room than that. CCE's cylinders are 3" and may fit, but their style does not have shocks built in. If there was a tubular upper A-arm available for the C5 then it might allow more room for air cylinders. Detroit Speed does not plan to make one. Global West has one for the 2000 Camaro, but i don't know if it would fit the C5. Pratt-Miller has an A-arm but i don't know if it's tubular.

Air Shocks?

Air shocks could go right in place of the stock shocks, so i looked then at using air shocks. I was told by AIM as well as other people that air shocks will not be able to lift the 3,000 lb C5 even though the weight distribution is 50/50.

I tried air shocks anyway, because i read about people using them, and i found Monroe air shocks which fit the front for $80. For the rear i found discontinued Delco shocks that were short enough after the car was lowered. Shock Shop sold them to me for $100. C5 shocks have stud tops, a tab mount bottom in the front and a clevis bottom in the rear. The Monroe shocks have a loop bottom in the front so i needed to find a tab mount (from Penske) to convert the mounting type. In the rear i used a stem bottom and added a clevis (from Penske). The Penske hardware is expensive ($300) but i found no other suitable mounting hardware. I considered using mounts off a cheap shock for another car, but couldnt find which car's to use.

The front shocks did fit, but they hit the upper control arm when the car was on the lift because the air shocks are wider. This didn't appear to be too big of a problem. I had to use a die to cut threads into the lower stem of the rear air shocks. The stem is threaded by Delco, but not all the way down to the base. I needed the clevis installed at the base, so i needed to thread the stem.

The shocks did raise the car about 3" from its lowered height and they did it in just seconds. The ride quality seemed okay, but i finally decided not to use air shocks because the valving (damping characteristcs) would not be as good as C5 shocks. If anybody wants these shocks to try this they are for sale from me.

I was going to get the air lift setup from Easy Street because their website is very informative. Their 2-path system drawing helped me a lot. The Air Setup costs $600. The compressor would fit in the trunk in one of the side wells and the tank would fit in the center well (The CD player would be moved to the other side well). Air Ride Tech sells a digital air gauge for $175. This would be easier to install in the cockpit because wires are easier to route than hose.

Keep Reading to see how i finally lowered my C5.

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