Lowering a Fiesta Mk 4

[SAMD]

Rightho, the rear appears straightforward enough. Cut the top off the rear turrets and extend them to whatever length is required.
But the front shocks? Has anyone been here before?
The options as I see it are,
1, buy new shorter shocks (if they exist)
2, Machine the shaft of the shock down to the required length and rethread it.

Any others?

 

[davecoupe]

Buy coilovers.

 

[Steve]

Out with the standard stuff, in with a Spax/Gmax kit or the likes for around £250-£300

The shocks wont last very long like that. In my old Zetec-S with 60mm springs in, the shocks lasted 1 year before starting to leak. I wouldnt waste your time.

 

[SAMD]

Hmmm, The coilovers are probably the right way to go, however the whole point of this exercise is to stay as cheap as possible and I would think that worthwhile coilovers will be £100 per corner. This would bump the cost of the cars quite a bit.
Although, if it has to be done...

 

[garyhoker]

dont start cutting anything the hospitals are full already get a lowering kit including shocks search websites be safe not sorry ..........

 

[davecoupe]

You want a cheap race class but are going to allow competors to manipulate suspension mounting points?

 

[corsacj]

springs and shocks changed, why make it so complicated?

 

[SAMD]

Rightho, there seems to be an issue here over the cut springs thing, both on this and another forum so lets look at it. Maybe I am failing to see something obvious. (always a possibility) But to my mind there is no reason to buy springs that are cut to a particular length from Ford or suchlike when the original spring can be cut to that length. Spring rates of course are important and the uprated (by cutting) original spring may not be the ideal spring rate. But as know one has any idea what the rate should be it doesn’t matter anyway.
So, the original spring is a coiled piece of spring steel . It has probably been cut by the manufacturer to be a given length and the spring seat on the shock absorber is shaped so that the coil can be fitted down into it.
What is/are the reason/s not to cut the spring to the required length and use it in the car?
I am talking about legitimate reasons here. The ones a Scrutineer would use. Not the implode/explode/spontaneously combust/miraculously unwind itself from around the shock absorber and shoot out the back of the car type reasons.

 

[mthompo]

please dont start this argument again.....

 

[Steve]

It has probably been cut by the manufacturer to be a given length .

No, the spring is not cut by the manufacturer. Its has been made exactly to a specific length and strength. Springs are not just cut from a big length of coil.

If you want to cut your springs, go ahead. But you wont get any advise on the subject about doin so on this forum im afraid.

At the end of the day, when you car is checked before it goes onto the track, you will more than likely be disqualified, if its noticed that is. And if its not and you have a major accident(even if its not the fault of the cut springs) you will be held accountable, as your track insurance wont go near you.

Will you tell your insurers that the springs will be cut before going onto the track?

 

[SAMD]

But surely that is the whole point of a forum Steve. If it is wrong then I dont want to do it. But so far knowbody has been able to explain why it is wrong.

 

[mthompo]

it WILL NOT get through scrutineering, go ask the like of big gavin, or mike it wil be a no.

 

[Steve]

But surely that is the whole point of a forum Steve. If it is wrong then I dont want to do it. But so far knowbody has been able to explain why it is wrong.

Surely the fact that cut springs dont even pass MOT is answer enough.

 

[düb]

But so far knowbody has been able to explain why it is wrong.

Surely there are reasons above?

 

[mthompo]

listen i work in bangor autoparts i can do ya a set of 40mm lowering springs for fiesta 82.50 all in! buy them job done!

 

[Gambit]

if your trying to make a 1 make car series then just set a height that ALL cars must not be lowered below using a spring & shock combo

same way as i assume you have control/set wheel size, tyre profile & brake setup

then its up to entrants to make their cars pass scruinteering.

 

[SAMD]

Surely the fact that cut springs dont even pass MOT is answer enough.

Hmmm that is a good point, isn't there some of the MOT testers on here? Perhaps they could give a reason? I know it may not be all that relevant. I mean, slicks wouldn't pass an MOT either, in fact not one car on an F1 grid would pass an MOT lol

 

[SAMD]

if your trying to make a 1 make car series then just set a height that ALL cars must not be lowered below using a spring & shock combo

same way as i assume you have control/set wheel size, tyre profile & brake setup

then its up to entrants to make their cars pass scruinteering.

Spot on Gambit, I am just trying to make the cars go as well as possible as cheaply as possible. I also think the standard height springs could cause a roll over more easily.

 

[Steve]

The car will not roll over on the standard spring. If it did the car would be recalled by Ford. The anti roll bar takes care of that.

 

[Gambit]

yep well its not up to you to make them go as well as possible you just set the parameters/rules that they must adhere to:-

cars must use ONLY 14" 5j wheels
cars must use ONLY spring/shock suspension
cars must not be lower than <insert height> when measured from <insert measure point> to ground
etc etc

 

[SAMD]

The car will not roll over on the standard spring. If it did the car would be recalled by Ford. The anti roll bar takes care of that.

Yes I know, but the higher the CoG the more easily the car could tip in the event of a nudge say from the car behind or at the chicane.

 

[SAMD]

yep well its not up to you to make them go as well as possible you just set the parameters/rules that they must adhere to:-

cars must use ONLY 14" 5j wheels
cars must use ONLY spring/shock suspension
cars must not be lower than <insert height> when measured from <insert measure point> to ground
etc etc

That is what will happen, I just want to have the right spec. before it is put into print.

 

[purplea4T]

In effect a cut spring in a standard damper will be much the same as a broken spring, ie, ready to fall out if the load is not maintained on it. There are many different aftermarket set ups available for the mk4 fiesta and this is the road I would be going down if I were you rather than complex over thought engineering ideas. Companies such as spax, koni and eibach spend a fortune to develop their products to ensure performance and safety, so I'd rather give them the money than bugger about trying the above methods. Indeed if this is for a race series, do as gambit suggests, make as much as you can a control part, using the same shocks and springs from the one and only manufacturer

 

[SAMD]

That is a fair enough argument purplea4T. But we are now at the stage of trying to find out why a spring should not be cut.

 

[SAMD]

I am aware of some metallurgical reasons why it can be unwise to cut a spring. However, if the right precautions are taken these can be overcome.