Lowered SC - How Low

[Jcon]

I have an 81 SC. It was lowered by the PO. At what point do I measure to describe the ride height.

I'm also looking for reccomendations on ride height when installing a chin spoiler - I just bought one from Moses ( Great Guy) along with a new valence thats in the paint shop right now.

Thanks

Jeff C

[tsuter]

I've lowered mine to "euro spec'. That is 24 3/4 at the rear fender lip and 25 at the front. The result is about a 1 degee nose down. Even though the front measurement is higher. Measure ground to lip at the wheel center line. Be on a good surface and jounce the corners around a bit before measuring to get it right.
Camber, caster, and toe then will likely get reset if you do lower the car.

[addictionMS]

how low you can go is dictated by where you live. Here in CA there are not many steep curbs or many harsh speed bumps so we can go vrey low. When I was in Texas, the curbs were much steeper because of the heavy rain, so you could not lower your car as much.

Spend some time looking at wehre you drive and you will get a sense of how low you should go.

Jim

[masraum]

The most commonly quoted Euro height is 25.5 inches at the topmost part of the Front wheel arch and 25 inches at the topmost spot of the rear wheel arch. That is suppose to give the car a 1 degree downslope. If you are wondering how what measures higher in the front could result in the front being lower than the back it is because the wheel arches are cut differently.

[RANDY P]

23.75" R and 24.25" F on a full tank of gas..I haven't touched my chin spoiler yet. Pretty much a no brainer to drive...





rjp

[Eric Mckenna]

I'll have to go out and measure it.. you'll want to measure it fronthe ground to the bottom of the fender lip.. it will give you the ride height... mine is hte gray SC in the back behind hte orange VW,, ugh .. i mean 914! hahahaha just screwing around..



Eric McKenna

[rcm]

Mine also has been lowered a few inches. Does anyone have the correct caster/camber numbers for the rear.

I will take it in for a four wheel alignment after the 4th but, I can do a rough with the snap-on align tool.

Thanks

[ted]

Too low in regards to ground clearance is one issue.

Too low can change the roll center and make the car too easy to slide. This symptom would most likely only be experienced in AX and big track events.

When it gets that low what is the negatative impact on roll center?

I've heard the front A arms should be close to parallel with the ground and not pointing up to the outside (thanks Wil ) of the car.

What’s the best ride right with respect to roll center/handling?

[nostatic]

Randy, yours looks about the same as mine. How do you not scrape your front spoiler? I don't have one and end up scraping the tow hooks a fair amount (even going slow and angled).

[RANDY P]

How you doin' Todd?

I'm just real careful where I drive - Both my driveway and work parking lots are as flat as boards - I really don't take the car too many places I don't know what to expect. Been driving these roads here forever - so I know where not to go.

I've owned more than a few cars that have literally sat on the ground. Lots of experience driving low....

[tsuter]

Fr:
Camber -0deg +-10min
Caster 6 deg 5 min +-15min left and right
Toe in +15min +-5min
Rr:
Camber -1deg +-10min
Toe in +10min +-10min

With Turbo and 8s or 9s on the rear set rear Camber to -30min +-10min

[Wil Ferch]

Wrong....
Too low would have the lower A-arms pointing DOWN toward the inner pivots on the car. A-arms should be parallel to ground or a slight slant DOWN TOWARD the BALL-JOINTS. Correct...too low will really screw up camber curve characterisitcs and will make the car a diabolical handler.
Lowering also messes up the bump steer characteristics. The steering rack spacers are only 12 mm ( say...1/2 inch) thick, so if you lower your car that amount and use spacers, you didn't change bump steer very much. However, most people go about 1" lower than Euro setting ( 25.5" fr / 25" rr), and therein lies the rub...can't control bump steer very well unless you reshape and rebend the steering arms to compensate...a tricky and expensive proposition that requires a great deal of skill and knowledge. Or..use the expensive ERP bumpsteer kit which alters the attachment height of the steering arm at the tie-rod end. About $350 last time I looked.

Oh... and if your shock rod isn't shortened for the amount you're lowered, then you might lock the shock solid because you took away that much of suspension travel....

So....it's all pretty simple.....right ? Just slam 'er down !! No worries...

---Wil Ferch

[bsaffin]

Anyone know what the stock ride height would have been on an '88 Carrera? I just did a quick measurement and mine is ~26.5 at the back and ~26 in front. Not only does it seem high, but backwards as well.

...Bruce

[Wil Ferch]

Late 80's USA cars were pretty much delivered to Euro spec....25.5" fr/ 25" rear, although a tad higher ( less than 1/2" on either end) may have been delivered too.
---Wil Ferch

[tsuter]

I "slammed em down" 21 years ago and haven't looked back. Did install the bump steer kit. Also have had to reweld a couple broken tow hooks on the front. Even the little bolt on skid protector doesn't always save em or the front valence.

[Jcon]

I just measured ..and I'm dead on euro spec. Next dumb question, What is the standard U.S. height for an SC?


Thanks again

Jeff C

[masraum]

Bruce, Us Carreras sit about like yours when at stock height. The rear of the car gets jacked up more than the front because of the bumper laws. Mine sits maybe just a tad lower than yours front and rear.

tsuter, those are the stock alignment specs, very few people go with those specs unless they are more interested in tire wear than handling performance.

The "performance" alignment specs while usually different from person to person are usually more like this.

Front
Camber -1 deg
Caster 5-6 degrees depending upon what you can get
toe 1/32 - 1/16" toe in

Rear
Camber -1.5 deg
toe 0-1/32" toe in

I usually see about a half a degree less camber in the front than the rear, but I have seen listed anything from equal camber front and rear to 1 degree less in the front. Personally I think the camber should be somewhere between a half a degree different to equal to help with understeer, but what do I know.

This is for cars that also do street time, I think most of this goes out the door if it is a track only car with really sticky tires.

[tsuter]

Masraum Steve - Excellent mention with the alignment specs- yes mine are stock and you are right I don't like tire wear and I don't track my car - at least not anymore. So I avoid the negative camber. I also use a front strut top tie rod that is adjustable.
I believe the US 5 MPH bumper height laws were revised efffective for model year 1983. So 911s prior to 83 had much higher rides and really needed lowering. After 83 I believe they came much closer to the 25/25.5 height mentioned in this post.
Porsche was pretty lazy at the advent of the high 5 MPH rules and added a bit fat washer on top of the front shock absorber to get the additional height. Really fat like 10mm. These washers should be removed when lowering the pre 83s.

[Wil Ferch]

RandyP:
At your ride height numbers.....how is your lower A-arm? Parallel to ground?
---Wil Ferch

[jase007]

These are interesting F and R numbers being thrown around. What if the PO rolled the fenders b/c they wanted to stick larger wheels / tires in there? That is my case. Lowered to Euro height and removed washer ('76 Targa) and had alignment done (also added Koni adjustables and set rebound second from full soft - stock bars). The ride was awful for metro area and crappy roads (shocks bottomed out occasionally). Installed S.A.W. spring plates and raised to a height just under some of the standard numbers mentioned here. OK compromise.

I think this really depends on car, year, T-bar stiffness, having straight "unrolled" fenders, driving area, etc...

Jason