Suspension modifications

Archives of Posts to the NZ MX5 List back in 2000
Locked
Sam Parker

Suspension modifications

Post by Sam Parker » Thu Dec 21, 2000 8:49 pm

Following on from a discussion on the list a few weeks back about lowering
vehicles and cutting springs I promised to give an update of the regulations,
the following is an extract from an LTSA infosheet - whilst it is not
specifically a regulation it is the advice LTSA have provided to those issuing
WOF's

Clarification:

The following suspension modifications are acceptable for Warrant of Fitness
purposes and do not have to be certified by a LVV certifier:

1. After-market shock absorbers (including air adjustable units) may be used
provided they are fitted to the vehicle manufacturers mounting points.

2. After-market road springs, including those that raise or lower the vehicle,
may be substituted for the originals provided that:

7 The springs are fitted correctly in the original manufacturers mounting
position.

7 There is no evidence of heating or cutting of the springs.

7 The springs remain in contact with their seats when the vehicle suspension
is fully extended.

7 No wire ties, external spring locators or other non-standard methods of
retaining the springs have been used.

7 The road clearance of the unloaded vehicle is not less than 100mm measured
at any part of the vehicle other than the wheel rim, brake backing plate and
the outer knuckle of the suspension joint. A lower road clearance is permitted
if specified by the vehicle manufacturer. Body kits such as front spoiler and
side skirts may be below this level provided they are of a lightweight
construction.

7 The normal relationship between the front and rear suspension height is not
unduly affected.

7 There is sufficient travel in the suspension to ensure that contact is not
made with the vehicle manufacturers unmodified bump stops when the vehicle is
fully loaded and operated under normal conditions.

3. If blocks are used in leaf springs to adjust their ride height they must be
securely fitted, have the same or more seating area as the original fitment,
be no more than 50mm high, be made of metal and be designed for the purpose.

4. After-market suspension bushes may be substituted for the originals,
provided they are made from an appropriate material such as polyurethane and
there has been no cutting or machining of the suspension arms to fit them.

5. After-market stabiliser bars may be fitted provided they use the original
mounting points.

Action:

Vehicles with suspension modifications that do not comply with the guidelines
above must be referred to a LVV certifier unless the modification has been
certified previously.


Regards

Sam & Denise Parker
340 Beach Road
Mairangi Bay
Auckland
NEW ZEALAND

Ph/fax 64 9 478 4761
Mobile sam 021 909 140, Denise 025 774 917
email samparker@clear.net.nz

Gary Morrison
Need, more, 5-ing, time....
Need, more, 5-ing, time....
Posts: 100
Joined: Sun Jun 04, 2006 3:24 pm
Location: Wellington

Suspension modifications

Post by Gary Morrison » Thu Dec 21, 2000 10:34 pm

The bump stop one is interesting. There seems to be a growing consensus that
our cars, when fitted with lowering springs, end up with too little remaining
suspension travel, and are essentially running on the bump stops... In
addition it seems that the suspension geometry that Mazda designed into the
vehicle is spoilt when the car is lowered...

zorruno
Black is the new black.
Black is the new black.
Posts: 601
Joined: Thu Apr 13, 2006 11:20 pm
Location: An Eastern Beach

Suspension modifications

Post by zorruno » Fri Dec 22, 2000 9:12 am

This is excellent information Sam. Thanks!
(z)

Locked

Return to “2000”

Who is online

Users browsing this forum: No registered users and 11 guests