How Low Can You Go?
 

I'm putting this here, though it might be more appropriate in the Aerodynamics Section (???).

The question is, what would be the minimum ground clearance for a street-driven car?


I did some measuring the other day, and my car currently measures ~ 7" from factory side skirt/front air dam to ground. I'm planning to put together custom side skirts and a front air dam that would extend farther down, but I want to maintain a basic amount of ground clearance. Also, IF I decide to get springs/coilovers, the ride height would drop an additional ~ 1.5" overall.

Anyway, I'm just looking for a consensus of opinion on the minimum clearance I need. Here in the city, there can be somewhat steep parking garage inclines, but otherwise, it's mostly flat, paved road.

4.5 inches for stuff you don't want destroyed is about minimum.

Coincidentally, a Pepsi can works very good as a measuring tool.

Very thin UHMW makes a good front skirt which can hang lower to keep air out from under the car.

My Rabbit's oil pan is 4" off the ground (coilovers) and I've had no real issue. But it's got insane approach/departure angles. The Probe's air dam hung down about the same amount (before I changed it) and would scrape quite regularly, especially when driving straight up ramps.

My advice: buy the coilovers, lower the thing 2" or more. Get a larger air dam (and a few spares). You can get away with a lot if you learn to drive up and down ramps at an angle for more clearance.

Go on YouTube for videos of lowered cars driving around and you'll see some of the stuff you might encounter. For the dedicated it's a challenge. For the casual it's a hindrance. Under 3 or 4 inches you start getting into trouble, and less than that, you are either insanely dedicated or on air ride.

With the undercarriage/pan, I think I have about 8" of clearance right now. I'm really just looking to extend the side skirts and front dam.

The coilovers sound nice, but I'll have to be saving up for those (~ $2,000 for the ones I'd want).

The UHMW sounds like a very interesting option. It's cheap enough that I might be willing to get a section and start fooling around with it.

It's pointless to go too low because I've read from several sources (Hucho, aerohead, etc.) that IIRC 5" or so is optimal.

Interesting. So no gains after 5", or is it diminishing returns? I find that to be an intriguing number since (just with coilovers or lowering springs), I'd be at ~ 5".

I've read from NUMEROUS sources lower is better, as long as you have rake to the car.

The less air under the car, the better.

My old '94 Vette had 5.25". Stock.

If no belly pan, then go as low as you can.

Just my two cents.

When I see a race car or speed record holder holding it to 5 inches, maybe I'll be swayed.

Already answered question: Look up the word "lowrider".

Actually, search EM for "optimal ride height; there's 272 hits and I'm sure at least a couple of them spell out (from experts in the aerodynamic field) that there is an optimal height so simply going lower and lower is counterproductive as I attempted to point out before. Be my guest and test out even lower heights; another data point is always a good thing. :thumbup:

I was thinking about lowering 2 inches, then I hit a racoon.

Bent up the radiator a little (no leaks) but no other damage.
Had I been lowered I would be replacing my front bumper and possibly my radiator or more.

I may do a belly pan if I ever get the time and motivation but I'm changed my mind about lowering.

As was said earlier - depends on your approach/departure angles. My Saturn, which didn't have a super short nose, was lowered to approx 5" clearance and I never had any issues with scraping/dragging and never had to approach at an angle. If I lower this one, chances are I'll go a little lower than that, as economy would be my goal, not performance. (If you want to maintain performance, some suspension types are very sensitive to going too low)

Honestly, the most annoying thing about lowering a car a lot is that its harder to get it up on ramps. I have 2x8s that I drive cars onto first to ease the transition onto ramps now.

...back in the days of "lowered" Street and Hot Rods, the California Highway Patrol used to use a pack of cigarettes (vertical) as their "Go/No-go" criteria for TOO LOW upon which they'd issue people a "Repair Order" ticket.

I hope they were using the 100s! :p

So, it turns out that I do only have about 5" of clearance in one section of my front under paneling. So, I could put at least 2" front dam without going lower than the lowest stock clearance point. If I lowered 2", that under paneling *might* be 3.5" off the ground. :eek:

Funny thing, this is where hydraulic suspension was first used on cars. I believe it was Ron Aguirre with his X Sonic Corvette who installed it on his car so he could drive around low, and when he got pulled over, PSSHHT! The car is at legal ride height. It was a sensation.

If you love old kustoms like I do, check it out. Wild car.