bump stop clearance

[waynos]

does anyone know how much  travel do ya need in  the front ?
gonna cut down my bumpstops cause i haven't been able to locate shorter ones anywhere.
i know ya not meant to do it but i have half an inch at the moment
i want it low as possible but engineering wise it is not good.
iwas wondering why it handled so good .
guess the chassis is taking all the strain
can't afford drop stubs yet so i just wanna take the cheap option for the moment
any advice is much appreciated
thanks waynos

[CraigA]

My XU1 has factory shortened bump stops at the rear.

Cut them to suit but leave enough so if the suspension does bottom out it hits rubber, not metal to metal.

[mcl1959]

The main point of suspension travel is to accomodate all sorts of driving environments. On a perfectly flat straight road you don't need any suspension at all.
Your car handles quite well with very little travel on smooth roads. Take your car down a potholed gravel road at any speed and tell me again how your car handles, especially if you try to go around corners.
Your engineer will tell you what the suspension travel requirements are to suit ALL road conditions. Basically a small reduction is fine but if over half the travel is removed, you wont pass.

Ken

[waynos]

as always yhanks again ,
i have had it engineered already my engineer was so impressed i had two thinigs wrpng (brake line needed mounting  and wheel bearing needed tightening) only because i didnt have time,
didn't even have to take it back to him,my dad went and picked the papers up for me
i just want my car to drive as good as possible
it's always a compromise between having aslow car and having drivability
l

[FC427]

Have been told by an Engineer that 50mm is the minimum suspension travel allowed ......FC427........

[waynos]

cool thanks fc427 that gives me something to work with

[Glenn 'Stinky' Stankevicius]

Legal minimum front bump stop clearance is 52mm (from memory) in SA, but you are not allowed to cut the bump stops as they specify the minimum height for these too.

[FB_MAD]

I found the following from the DOTARS site about a year ago under VSB 14 National Code of Practice for Light Vehicle Modifications and wrote it down in my work diary at the time.

This is for FB and EK Holden but would probably be the same for FE/FC I guess.

Maximum allowable wheel track 1410 mm.

Minimum bump stop clearance is

Front 25 mm

Rear 67 mm.

I'd say the bump stop clearance specs would be for factory length bump stops ( not shortened ).

I've lowered my FB 3 inches at the front,standard kingpin front end,  and shortened the bump stop approx 1 inch and have kept it in as much of a cone shape as possible when shortening so as to maintain an amount of progressive bump..I still have about 1 inch clearance which is fine untill I hit a pot hole ( as Ken says ) than all the spiders and dirt and crap get knocked out of the car with the BANG.

I doubt very much that I'd get an engineer to pass it as it is but it's running a 149 so only need normal rego checks and my rego inspection bloke says as long as its no lower than 4 inches at any point he's happy with that and so am I

Hope that bit of info is of help.

[FB_MAD]

Waynos,

If your running a HR front end you can get some polyurethane shortened bump stops from fulcrum suspensions.They are made for HR front ends but won't fit kingpin front ends.

I bought a set of four for a project a few months back from one of fulcrums dealers namely "Carline ",Raymond Terrace ph 02 4987 4248 ask for Bernie.

Or you could go direct to fulcrums website http://www.fulcrumsuspensions.com.au  and find a dealer near you.

They were doing a fresh batch of them when I bought mine about 4 months ago and from memory they were $54 for the four of them.They are approx 1 inch tall as opposed to the factory ones which from memory are about 2 inch tall or so.

And they are a very pretty purple colour too

I'd give you the part number but my misses has put the bloody things somewhere and I can't bloody find them.

If you give Bernie a call at Carline Raymond Terrace on ph number above he will probably remember where to find the number to order in his catalogue.

[waynos]

thanks fb mad,
been lookin everywhere i'll give them an oi.
and also thanks all for the input.
i purposely drove down one of those gravel potholed roads to test her out when i first got it regoed,
it scared the hell outta me .
guess all the dirt and spiders are gone now

[ratbox]

if you want it to look kool and handle round corners there has to be sacrafices  

a shitty rough road is a shitty rough road weather yor in a fc holden or a late model shopping car

[waynos]

too right ratbox,
but she drives way better than a stocky,i gotta be happy,
so the next question is, are the dropped stubs really worth it?

[FB_MAD]

I bought some for my UC Torana years ago from CRS.Dropped the front 2 inches plus bought 1 inch lowered heavy duty front springs to get 3 inch drop.Used all standard torana brake/steering components except I had to use LH/LX steering arms which are different to UC ones.

Don't know how well the lowered stubs  work on HR front end though.Others might add to this.

They don't make kingpin lowered stub axles but I've heard that one of the mid '50s ?? chev kingpin stubs will fit and can be used to obtain some lowering of the front end.Don't have any further info on that one or whether its right.

Are the lowered stubs worth it ?,

In  my mind yes they are as you still obtain a lot of suspension travel which to me is better and safer than the old bang you get from lowered springs only and minimal bump rubber clearance.

An engineer would probably be more happier with passing lowered stubs than suspension sitting on the bump rubbers at normal ride height/weight.

Your car may hit the road a lot easier on full suspension bump with lowered stubs however.

[waynos]

i keep hearing this chevy stub axle thing but dont believe it
done lotsa research and found nothing but holden stole alot from chev so ?
i'm gonna start measuring
get back to you

[FB_MAD]

Thought I'd add a bit more to this  as I've just found my shortened HR front end bump stops that have been "missing" for a while ( ie:- the missus put 'em where I couldn't find 'em ).

Shortened Polyurethane HR Front end bump stops are available from http://www.fulcrumsuspensions.com.au under part number SPF0147K "Super Pro" shortened bump stop.

They are 1 inch shorter than original Holden rubber ones.