Track control arms

[capri71]

I'm wondering if any OSFs have longer TCAs than those on the mk3 capri 2.8, but are otherwise similar/interchangable? Reason is to add some camber to the front wheels and widen the track without spending much:mrgreen: any ideas?

[Vista]

Use adjustable track control arms, you can get them for escorts so I assume you can also get them for capris?

[JP.]

Use adjustable track control arms, you can get them for escorts so I assume you can also get them for capris?

I assume they are the same

[livewire7116]

escort and capri are the same bottom arms

[Retromotorsport]

5ierra ?

[capri71]

i know about the adjustable TCAs - over a £100 a pair so not doing that at the moment

will look at sierra ones but my next idea is to "move" the mountings out a bit on the crossmember

[Retromotorsport]

i know about the adjustable TCAs - over a £100 a pair so not doing that at the moment

will look at jelly mould ones but my next idea is to "move" the mountings out a bit on the crossmember

 

And cause yourself loads of bumpsteer ..

 

 

And how much camber are you hoping to get.. most capris that are slightly lowered run too much camber anyway ...

 

If you see a car with loads of camber its masking another problem, its a fix, not the right way.

[capri71]

Bumpsteer? I will be using a different rack, and making track rods to a custom length to suit... but you reckon if lowered they run too much camber anyway? I have 2" lower springs to go on so maybe I'll leave it for now

 

btw - I'd have the same issues if using pricey adjustable TCAs anyway

[Retromotorsport]

And what rack was you going to use ???

 

Its just a bit crucial getting rack height/ rack length/ tca lenght and inner/outer pick ups all in the correct ratios .... and i've seen some major feck ups ... even done some myself when not using the string computer and trusting measurements

 

Also what worrying me is you didnt say ' well at the moment i have 0.5 degress neg camber..or whatever.. if you dont know where your starting from ..dont start.

 

so whats the reason for this extra camber and track width your after

 

The reason i never mentioned adj tca's was because i assumed you was designing a front end and wanted a standard TCA that was longer.. not trying to just gain camber and track without going into it properly.

[capri71]

And what rack was you going to use ???

 

the new looking one of the 2. my plan is to make new mounting points in the crossmember. The track rod ends will be new capri items, which I'll fit once ive sussed the required rod length/overal width and rethreaded the ends.

 

I'm going to think about camber once Ive seen it with the lower springs on.

 

and for the record, I do things properly... YES I look for the simple solution first and I ask a lot of questions which probably make me look ignorant, but I get there in the end, always.

[Retromotorsport]

well if your using that rack, then your inner TCA points are allready fixed. .. old fords dont apply ackerman to the steering arms, they space the rack to produce ackerman, so you have your TCA inners pick ups, and your track rods should be the same as your TCA's ..

 

place the wheel in position and measure from the outer pick-up ball centers to the inner and thats your TCA length

[capri71]

so you have your TCA inners pick ups, and your track rods should be the same as your TCA's ..

 

 

What do mean by "should be the same"???

[Retromotorsport]

If your TCA length and Track rods are different lengths on a that set up you will have bumpsteer.

The only time they are different is when your using wishbones.

[BIGKEV]

I'm trying to follow this ithread but your losing me with all the technical jargon - interesting though

[JP.]

A bulb starts to glow here...........

Have a Siera powersteering rack on our V8 Capri mk1. It has shortened arms to the Capri length.

Why Siera ??? well previous owner did convert it cause he probably couln't find a Capri ps system.

 

That Ackerman thing with spacing the rack to produce Ackerman makes me think.

So if I understand it correctly, If the previous owner did not space this to standard specs than this could cause my bumbsteer??????

 

At the picture you'll see a standard Capri X member with welded brackets that hold the Siera PS rack.

[capri71]

If your TCA length and Track rods are different lengths on a that set up you will have bumpsteer.

The only time they are different is when your using wishbones.

 

O.k, so the track rod and control arm start at the hub, more or less inline but the inner points are nearer than standard as this rack is slightly wider (distance between inner points and longer track rods)

so the only way to do this is to remount the tca further out, to widen the track by about an inch each side. Question is, how much of the conciderable extra camber do i want to keep? the rest can be eliminated by remounting the strut tops?

[Retromotorsport]

Ackerman wont cause bumpsteer.. but if the TCA's are different overall length to the track rods overall length then you will ..

 

Lay a 6" rule down ..

2" below this lay a 12" rule down so that one end is square ...

 

On the un-square end place you finger on one and your thumb on the other...this is the inner pic ups ..

 

Now place 2 fingers on the other end and move the rules either way .. your see the shorter one swings in a smaller arc ... and your previously striaght fingers are twisting .. now if you lay 2 12" rules and repeat you will see that the fingers dont twist ..

 

 

Or... taken further..

 

2 rule and 36 inch rule

 

lift both rules up at one end by 2" and the 36 harldly moves a couple of dergess yet the 2" goes through 90degrees.. so allthough the wheel thats mounted at the end of teh 36" rule staye where it was the steering has been pulled in by 2" ..

 

get me..

 

Wish it was easy to upload pics..be far quicker than trying to explain

[Retromotorsport]

Personally..i'd buy a 2.8i power rack ...

 

£139

http://www.carparts-direct.co.uk/cart.c ... y=1&submit

[capri71]

I know where I can get one even cheaper, free infact... 4 inches away from the rack I intend to fit, in the picture

I'll exsplain - I'm REPLACING the standard 2.8 powersterring setup for the vauxhall EPAS column and related rack. The corsa rack weighs 10KG less than the rusty 2.8 rack and the electric column weighs less than the 2.8 column and pas pump. It also elimates the pump from the engine and a load of hydraulic mess. AND reduces load on the engine.

 

Another reason I'm using the corsa rack is that it has the correct rate, suited to the power column.

 

I do understand Ackermann geometry fine I just don't understand what bearing it has on track rod length surely if the rack is correct width overal, it will not upset the geometry? look at the diagram here and tell me what bearing the inner ends of the track rods have to do with ackermann.

As for the bumpsteer, why would having LONGER track rods upset anything if the overal width of the rack is standard and the TCAs are standard???

[Retromotorsport]

The only reason i mentioned ackerman was because i was saying that ford dont angle the steering arms like in that diagram to get ackerman.. so your two outer points are fixed ... ie they are inline and equal distance from the cars centerline ..

 

And now that your saying your fitting the corsa PS stystem .. why the f**K are we having this conversation.. just fit a manual rack from any capri ..jobs down apart from mountting the EPA to the coloumn..

 

You say that the Corsa rack has the right ratio for the EPAS... it dosnt, the EPAS is torque sensing .. you could have a rack of 1:1 ratio and the Epas would provide the same assitance for a given input as it would for a 3:1 rack

 

So basicly .. your doing what we do to countless racecars but overcomplicating it .. we use standard escort QR's and with over 40 cars out there using the system i fit.. think we know how it works.

 

And again.. your final question ..you asking about 1 part when i have repeatably said .. the track rods need to be the same length as the TCA's ..

or

 

all dimensions taken from the centerline of the car

 

tre pick up .. 510mm

TCA outer..... 500

TR inner (ball joint on rack) 260

TCA inner ... 250

 

TCA length 250

TR inner to TRE 250

 

That works ...

 

if the outer TCA pick up is inline with the TRE, (both 560 from CL)and teh rack inners are still 260 then the inner TCA need to be 260 from the centerline ...

 

 

I dunno.. i cant explain the fact that you need the TCA to be the same Length as the TRE to inner TR ball joint to be the same any easier

[capri71]

I said the corsa rack was suited to the column because I guessed that the ratio is quicker than a manual capri rack. Manual racks are generaly higher ratio afaik.

As for torque and assist, I have no issues or questions with that - my priority is to acheive a low steering ratio ie fewer turns of the steering wheel lock to lock.

You use the abreviation QR. Does this mean quick rack? is that what you use to acheive the same thing? ... less turns lock to lock than a standard manual rack?

 

Anyway, the point is that I MUST keep the TCA and TR the same length to avoid bump steer yes?

The corsa rack has longer track rods and the inner joints are closer to the centreline, meaning that if I shorten the track rods to match the TCA, they won't reach the pickups on the steering arms.

 

Could I solve the problem by spacing the steering arms off the strut so the track rod pickups move in (toward centreline) to suit the lower overal rack width?

And as for why we are having this conversation, its cos I'm determined to use the corsa rack, because its so light mainly but also cos i see no problem modding the xmember to take it, its new not remanufactured and designed for the column.

This began with questions about TCAs and camber but weve moved on - you convinced me to leave that alone seeing as I'm dropping it 2" which you say will add neg camber anyway. SO, the questions are about making the corsa rack fit without causing bumpsteer.

[Retromotorsport]

If you space the steering arms in you would get Negitive Ackerman.. like i've said, your outer pickups are fixed.. you cant move them.. fixed.. 100%

 

You need to get the TCAS the same length as the measurement from the inner ball joint on the rack to the outer ball joint on the TRE .

 

The only way if the ball joints are closer to the centerline of the car is to move the inner TCA pick up in.

 

Its a lot of work and you would need to have custom TCAS made.. as the chances of finding something that will fit is next to impossible hence why i would use a QR (quick rack) capri steering rack..

[capri71]

The only way if the ball joints are closer to the centerline of the car is to move the inner TCA pick up in.

 

Righto just spoke to rally design and their adjustable TCAs should be o.k.

 

Retromotorsport - I realy appreciate the help youve given me cos sadly, I'm not well off enough financialy to have things like this done by people like yourself - if I was, I would be coming to you though, for sure - MANY thanks

[Anglia68]

Surely if you use the Corsa rack in place of the original Capri one it will turn the wrong way.

The steering shaft on the Capri rack is at the rear but on the Corsa one it's at the front so if you connect it up to your column when you turn the steering wheel to the right the road wheels will turn to the left.

 

[Retromotorsport]

Ahh a good point made by the above poster... just get a capri QR on

 

And thankyou for the thanks..but please..its Gary or Retromotorsport .. not retrosport.. as some company in scotland get the thanks in ggogle searches

 

Bad enough being called Dave all the time