I had my 911 lowered. Looks good, but.....?

I've just had my car lowered. Ever since I had Bilstein sports installed the car looked quite tall for a 911. Now it looks stunning, but:

1. I measured the distance from the garage floor to the fenders and got the following results:

Right front: 62 cm.
Left front: 63 cm.
Right rear: 61 cm.
Left rear: 61,5 cm.

What do you think about that? Did my mechanic do a bad job or is this acceptable? Of course my measurements aren't the most precise in the world. I simply held a rule up to the side of the car.

2. I haven't had a 4 wheel alignment carried out yet, but I now notice an increased tendensy for the car to follow irregularities in the road. I can feel how the steering wheel moves in my hands when driving on roads that aren't perfect. Is that normal for lowered 911s? It's worst at about 120 km/h (75 mph) where the steering wheel is almost shaking as if wheel balancing was not ok?

[boyo]

Try measuring with someone sitting in the drivers seat!

There's a reason the left is higher than the right...unless you're in the UK or Australia.

What you may be feeling is "bump steer". There is a simple fix involving lowering the steering rack too. This is a job you can do yourself, and the parts are pretty cheap thru Pelican. Search their catalog for "bump".

-Boyo

[Planter91C2]

if you are measuring from the floor to your fender, maybe you should check for uneven tire pressure.

Yes "bump steer". That was the expression I couldn't remember That's it. It looks and feels a bit like wheels out of balance, but still there's no doubt that it's a different problem somehow. It feels as if the road surface is to blame for the movements in the steering wheel.

Regarding the car's height I just found this:

vorne: rechts 625mm (625mm) / links 625mm (630mm)
hinten: rechts 615mm (595mm) / links 620mm (595mm)

These are measurements from 2 German Carrera 3,2 owners cars. They seem to have small differences on their cars too. Maybe it's not unusual?

Hadn't considered the thing with a person in the drivers seat. Maybe that's the reason. I checked tire preassure last week. Should be ok.

But daaahm the car looks good

[Glasgow 911SC]

Pics?????????

Sorry no digital camera. Did take a pic today, but that was with a normal stone age camera

[hobieboy]

Definitely save your final judgement till you have alignment done!
The difference in left to right might be the effect of your last corner balance?

[gr8fl4porsche]

When you lower the car you definitely need an alignment.

If the rear torsion bars were adjusted than the rear alignment is
gone. You have to remove the bolts responsible for proper alignment to pull out the t-bars. Also when you lower the front the geometry changes. Great time to install turbo tie rods and bump steer spacers prior to paying out big bucks for a proper 4-wheel alignment. Until the alignment, the car will not handle properly.

The 1cm difference in the front may go away when you sit in the car.

[chrisp]

You should try to use chassis points to the ground instead of fenders. Fenders are rarely consistent. Guys who have tried wider tires know this first hand. The differences you are seeing may be the fender inconsistency or it may be true height irregularity.

I use the center of the front torsion bar (measured at the cap) to the ground and center of the rear torsion bar (measured at the spring plate cap) to the ground.

I don't recall the numbers off hand but this is how Porsche measures and they have a spec for this. It's in the shop manuals.