I have fitted a compression strut kit to a track sierra 4WD, it has proflex suspension and runs slicks. How do i set this up and what are the correct values?

 

What settings did you carefully measure before you fitted them ?

 

To be honest none, we had a litlle accident on track and this damaged the front left side so we couldn't take measurements .

 

well worded

 

ok , then to get a baseline you will need to find a Tracking that gives you a gnats of toe in at parallel , this coupled with a wheelbase check both sides is a start .

 

OK thanks, we will try this and see how it works on the track.

 

what sort of Castor would you be looking for? I need a full front and rear set up soon, so some baseline figures would be great

 

2 deg neg camber, 2 deg toe in, 3.30 castor...ish

 

Hi
Sorry, no 2° toe in, I prefere 2 mm. toe in !!!

On my 2 wd track car, i have :
3° castor
-3° 30' camber
2 mm. toe in.

Regards.

Claude

 

2wd and 4wd have different settings

 

Be very careful adding castor , this induces "turn in only Camber" and can create instability and tyre scrub. Ive mislaid my bit of paper but iirc my Sierra is 15mm longer in the wheelbase than std , a good deal of this is Castor but after careful tesing to see what works and what i can put up with !

 

Something most people forget is also that you need to square the car up especially if you have a adjustable rear toe, taking wheel base dimensions can get each side the same distance but doen't mean they are square off the centre line of the car(suspension pick up points) Although if its an oval you race track then stagger is good but I'm sure its not for what you require.

 

Danny can you do a full geometry set up inc ride hight/corner weights etc, and could you tell me the approx costs? You could do it at the same time as fitting my frame connectors .. Also after a rear triangulated strut brace ... Pm me if you like please .

 

up for the daytime

 

morning Will, Yes we can drop me a pm or email to d_bryant@btconnect.com with full spec of your cars suspension so I know what we got to play with.

 

Yes, I know that.
I mean just 2° and 2 mm. toe in are very different.

Claude.

 

You are correct, and I think you will find that Jtech made a mistake and also meant toe-in in mm .

Between 3° and 5° of caster is considered the optimum.

On my own car, I run the following (track set-up):

Front:
Camber: 3° negative
Caster: 3° 30'
Toe-in: 2mm

Rear:
Camber: 2° 45' negative
Toe-in: 3mm

 

Why? What would most caster have a negative effect on?

 

The more caster you have, the more straight-line stability and the more negative camber you get with steering lock and the outside wheel during cornering (with the inside getting positive camber). This aids turn-in, but you can go too far, which could cause drive shaft problems with a 4wd. Also it makes the steering heavier, so the above range is considered to give good straight line stability along with reasonably weighted steering and not too much camber change .

With positive caster, you also get some self centering of the steering wheel, which is a good thing for drifting (once on full lock, you can actually let go of the wheel, and it will naturally straighten ).

 

Fair enough, I didn't think of drive shaft problems on 4wd.

I've got about 7° of positive caster on my S14 and the steering doesn't feel any heavier but that not very relatent to cosworths.

 

mike,

do these figures take into account that the escos rides on bigger diamiter rubber and so it may be different when comparing the sierra to the escos?

also, when i fitted a 2wd front arb to the 4wd estate, the stright ahead feel was very scarey, it wanted to turn all the time, but once it was going round corners it was as sure footed as it had ever been, this is what i want to regain with the compression struts and adjustable tca's, but will i get that without the front mounted arb?

 

I have a 2wd Sierra 3dr & run slicks plus road tyres as its a road & trackday car what would be the best settings. Plus how do you set the tracking I made some tracking gauges (just the wrap around type) I run 18" wheels what should be the difference between the front rim measurement & the back of the rim measurement is this what they mean 2mm toe in but that would change with wheel size

IAN