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She is ready for lowering now. Have 15" x 7" Rota RB alloys and new 195 tyres. So how low do I go? Also what springs and what shocks? My driving is mainly all street with the odd race day thrown in.

How much do you care about smashing things with the bottom of your car?

Do you want to have to slow down for speedbumps and railway crossings?

Do you want to be legal?

Minimum clearance = 100mm I believe...or be prepared to be defected.

According to ncop, you are allowed to change suspension height by +/- 50mm as long as you keep at least 2/3 of the standard suspension travel distance. There is no minimum ride height specified as there are many cars with a standard ground clearance less than 100mm. How you go on the side of the road is anyone's guess.

I am waiting on confirmation of this and other issues from can do's office as the new legislation up here affects pretty much all my cars.

i like to keep it at 100-110 mm.

its honestly not worth the headaches of driving and ruining a perfectly good car let alone the police & insurance woes.

MattR wrote:According to ncop, you are allowed to change suspension height by +/- 50mm as long as you keep at least 2/3 of the standard suspension travel distance. There is no minimum ride height specified as there are many cars with a standard ground clearance less than 100mm. How you go on the side of the road is anyone's guess.

I am waiting on confirmation of this and other issues from can do's office as the new legislation up here affects pretty much all my cars.

Yes there is a minimum ride height in the NCOP. Car must be measured 100mm off ground at halfway point between front and rear axles.

Section 2.1.4 Ground Clearance and Running Clearance, you just quoted section 1.1 BASIC MODIFICATIONS NOT REQUIRING CERTIFICATION. Go down the page a few scrolls.

No worries on being found to be wrong but, then how does that work for a car with a standard height <100mm?

And it's not just euro super cars, what about all the lotus seven copies, or cars that are pre adr. My charger was built in 71, so I have about 3 go worry about, but my earlier Val's were lucky to have a seat belt mount point let alone a seat belt. And the valiant front suspension can be wound up and down to adjust height quite easily in standard form.

You just answered your own questions with the info in your questions.

1. Pre ADR vehicles follow different set of rules. Wont go into legalities.
2. NCOP for modifying light vehicle covers modifying from oem setup. If the car suspension is not modified and height is oem, then it is legal as it has been complienced that way.

MattR wrote: And the valiant front suspension can be wound up and down to adjust height quite easily in standard form.

...ah man, I wish I still had my old yellow VF Pacer ....

It seems that 100mm is the legal limit. so what that does that represent in lowering height? Also who has done this for a street car and what problems with speed bumps etc are incurred?

jackmack wrote:It seems that 100mm is the legal limit. so what that does that represent in lowering height? Also who has done this for a street car and what problems with speed bumps etc are incurred?

Measure your car first, but on an NB8A it's about 40mm drop from stock.

Every car is different though, some it might only be a 30mm drop, some a 50.

Measure first.

I set my tiens to their recommended height then decided to check it against this:
http://www.specmiata.com/download/SM_Setup_Guide_V2.pdf

Mine
Front Arch 585mm Pinch 118mm
Rear Arch 600mm Pinch 116mm

Jim's Pinch front and rear 117.475mm so i'm pretty close.

jackmack wrote:It seems that 100mm is the legal limit. so what that does that represent in lowering height? Also who has done this for a street car and what problems with speed bumps etc are incurred?

At 100mm off the ground, you should have no issues with speedbumps.

project.r.racing wrote:

jackmack wrote:It seems that 100mm is the legal limit. so what that does that represent in lowering height? Also who has done this for a street car and what problems with speed bumps etc are incurred?

At 100mm off the ground, you should have no issues with speedbumps.

"should".
My clearance was about 110mm last I checked; I can clear every speed bump I've come across but I do sometimes have to attack them at an angle. Wouldn't have it any other way - the car looks and feels great at the current height - but personally I wouldn't go any lower.

I ran it at 95mm for a while and speed bumps were death. I have no idea how Aussie staynce folk daily their slammed cars.

hence why i said 'should' and not 'would.' when i was younger i use to run at 90mm, there is no sound deadening on the chassis rails.