How do I measure the \"optimum\" height?

Quark · Postby **Quark** » Wed Nov 01, 2006 2:31 pm

I have all different suspensions parts going together, new shock mounts, bilsteins and adjustable perches.
Was just wondering what the height of the actual car should be, and how I should measure it?
If i want it about 30mm lower than stock, which I've heard it about perfect, can i measure it from the front lip to the ground?

Thanks for your help,
Matt

Garry · Postby **Garry** » Wed Nov 01, 2006 3:05 pm

I usually measure from the bottom of the wheel rim to the lip of the guard. That removes any error caused from tyre wear/underinflation and it's easier than trying to find the centre of the wheel.

Matty · Postby **Matty** » Wed Nov 01, 2006 3:10 pm

but it depends on wheel size!

Hub centre to fender lip is the adopted standard aproach.

Nominally, horizontal lower control arms should optimise handling. That equates to fender heights of ~315mm in the front and 325mm in the rear.

Garry · Postby **Garry** » Wed Nov 01, 2006 3:22 pm

but it depends on wheel size!

Yes, but its still an accurate, repeatable way to measure the change in height.

StanTheMan · Postby **StanTheMan** » Wed Nov 01, 2006 3:24 pm

but it depends on wheel size!

Yes, but its still an accurate, repeatable way to measure the change in height.

but its not comparable from car to car once the rim size has been changed.

Garry · Postby **Garry** » Wed Nov 01, 2006 3:33 pm

but its not comparable from car to car once the rim size has been changed.

Indeed, unless you add on the radius of the wheel

StanTheMan · Postby **StanTheMan** » Wed Nov 01, 2006 3:37 pm

IMMX5 · Postby **IMMX5** » Wed Nov 01, 2006 11:38 pm

Just had this discussion with a helpful chap in Mazda today (I believe this was the exception though it should be the norm). Herewith the extract from the manual relevant to the subject.

I have just measured up my (stock - 3700km) NC which had to have some work done to the underbody/suspension. I now have the ammo to get a fix w/o argument hopefully...
LF - H = 399mm; RF - H = 396.5mm
LR - H = 378mm; RR - H = 370mm

So it just meets the 10mm Left/Right and 10 ->30 mm Front/Rear tolerance - BUT it is \"nose-up\".

I rest my case..

[img][img]http://img241.imageshack.us/img241/3089/manualextract0oj8.jpg[/img][/img]

Garry · Postby **Garry** » Thu Nov 02, 2006 8:59 am

But all NC's seem to run nose up, except for the guys that have lowered their cars

Charlie Brown · Postby **Charlie Brown** » Fri Nov 03, 2006 9:36 pm

IMMX5 wrote:Just had this discussion with a helpful chap in Mazda today (I believe this was the exception though it should be the norm). Herewith the extract from the manual relevant to the subject.

I have just measured up my (stock - 3700km) NC which had to have some work done to the underbody/suspension. I now have the ammo to get a fix w/o argument hopefully...
LF - H = 399mm; RF - H = 396.5mm
LR - H = 378mm; RR - H = 370mm

So it just meets the 10mm Left/Right and 10 ->30 mm Front/Rear tolerance - BUT it is "nose-up".

396F & 370R, mine was 380F, 370R standard.
That's way too high in the front.

Now mine is 340F, 330R. Within 1mm left to right.

The speel from Mazda says the rear is higher than the front. How is this possible when both cars were the other way around standard?
Currently the sill line of my NC is parallel to the ground with 10mm larger dimension to the wheel arch on the front compared to the rear.