[race_prep] Guernsey Hillclimb 205 Build

[Anthony 1,003]

Is there not a garage with some proper 4 wheel alignment equipment on the island somewhere, something like a Hunter?

 

It would be much quicker and easier to check and setup on that, as not only will you see each wheel measurement individually, but you can also see the results of adjusting the stub axles "live" assuming that you can see get on the hub nut with the sensor/plates attached to the wheels.

[wardy18 33 1 Cars]

Yes only one that i know of but they would be ridiculously expensive and wouldn't let me loose on it!!

 

I only found out monday that there;s a guy with some digital floating corner weight apparatus stuff and knows a lot about balancing the car so thats definitely on the list, hopefully before the end of the season but with my last few events now being all a week apart time is very tight

[Miles 331 1 Cars]

They should be able to adjust it, Very easy and without knowing what the backs set to I wouldn't want to drive it in, Even if a few quid it's well worth the spend

[wardy18 33 1 Cars]

and without knowing what the backs set to I wouldn't want to drive it in

 

Lost me on that one Miles?? You wouldnt want to drive/race it not knowing what the back camber/caster is or you wouldnt want to drive it in to the corner weights scales not knowing this??

 

I've been told its about a £100 for the use of the corner weight stuff and the guy so thats a bargain in my eyes but as for anyone to do the camber/toe that would cost a lot at teh only place i know off so will have to have a play manually myself.

[Cameron 16]

What I'd do is get it on the corner weights, then check the camber & toe while it's up there. Since corner weights are set up effectively as a flat floor they're the best place to check geometry.

 

Ask your corner weight guy whether he knows how to use a string box to track a car, and definitely consider using the technique yourself as it's very useful! I can write you a brief how-to if you want, but I'm sure there are places on the 'net that will show you how with pictures. It's very simple once you know how and more accurate than most "specialist" alignment equipment.

Edited August 29, 2012 by Cameron

[wardy18 33 1 Cars]

This is what i use for checking and adjusting the Toe angle, seems to work pretty well as long as you know you are starting from equal each side

 

[Cameron 16]

Yeah Dunlop Gauges are alright, but not as accurate as string and only show total toe, they won't tell you if it's uneven side-side. When you've changed any parts you should set the tracking with all 4 wheels, Dunlops can be used for quick changes, but personally I'd always use a string box; once you get the hang of it it's so quick that it's always worth it.

Edited August 29, 2012 by Cameron

[wardy18 33 1 Cars]

String box looks like a good idea from what I have seen on a quick google search, what's the best way to ensure you are parallel with the centre line of the 205? I have a couple of ideas but I you can draft up a quick DIY guide that would be much appreciated Cameron, thanks

[Cameron 16]

It's dead easy, I'll write you a quick how-to tomorrow on one of my many internet breaks.

[johnnyboy666 195 1 Cars]

id be interested to read that too

out of interest, does the string method only work on completely level ground?

and can you adjust it so it works for cars with wider track on the front than the back and vice versa?

[welshpug 1,661]

and can you adjust it so it works for cars with wider track on the front than the back

 

AKA standard 205's you mean?

[johnnyboy666 195 1 Cars]

pricisely and as Im sure you know my track width isnt exactly standard! And that seems to pose a problem for most spanner monkeys!

[wardy18 33 1 Cars]

From what I have seen of them doing some searches it can work with any track widths, simply run a string down each side of the car which is parallel to the cars centre line then measure of that string to the front and back of each wheel!!

 

It's the finding the cars centre line that I want to know the best method of.

 

Thanks Cameron, whenever you get a minute!!

Edited August 30, 2012 by wardy18

[tri_longer 25]

Sorry to jump on board (again) but I would also be very interested in seeing the guide for sring boxing. I saw it not long ago being done on a Clio at the BTCC round of Oulton Park. Have to say at the time I had no idea what they were doing but kind of makes sense now, so would like to have a look at doing this on my car also.

[alexcrosse 124]

2 strings parallel to each other either side of the car (say 1.6m appart or so) level with the centre of the wheels.

 

Ensure they are parallel to the centreline of the car by measuring the distance from the centre of each wheel to the string on that side and making this measurement equal by moving whatever you have tied the string to, make sure to keep the strings parallel whilst doing this... do this front at back and you strings and car will all be parallel.

 

to measure the tow you measure from the front of a wheel rim to the string, and the back of the rim to the string. Then you do your trig (Tan-1((front-back)/wheeldiameter)) and that's your tow. Do it for each wheel and as cameron said your then measuring the car as a whole, rather than front and back.

 

If you want a spreadsheet where you just put the numbers in and it tells you tow give me a PM.

 

The clios and most race cars do it by having poles that clip/bolt onto the actual car, so no string set up is required, just straight to the measuring.

[wardy18 33 1 Cars]

Ah ok yeh i know what you mean, so see this pic below, both measurements "a" must match each other and "b" match each other and "c" match each other then you know you are parallel to the centre of the car

 

Red lines are the string btw and that is meant to be 205 in the middle hahah

 

 

Edited August 30, 2012 by wardy18

[Cameron 16]

Ok, so as promised, a how-to on the string box technique!

 

While Alex's method is fine if you're very careful, this method is much more accurate and a lot more fool-proof.

 

What you will need:

• A flat and level area to work on; for tracking this isn't so crucial, but find the best place you can - a garage floor is fine.
  
• 2 poles of either metal or wood, roughly 200mm wider than the car.
  
• 4 axle stands, / oil cans / piles of bricks
  
• Some string - the thinner the better, straight fishing line is perfect.
  
• Some small weights - old coke bottles work pretty well if you half fill them, but use whatever you have knocking around.
  
• A small steel ruler and a tape measure.
  

Setting up:

1. Park your car with the handbrake off and out of gear, centre the steering rack by turning lock to lock and finding the centre, and either lock the steering wheel in place or make a note of the centre point.
   
2. Roll the car back and forth a small amount (6-12 inches) to take any tension out of the tyres and check that the steering wheel is still central.
   
3. Measure the width of your car then add 100mm, this will be the width of your string box. You will need to cut some small notches in your poles that are EXACTLY this distance apart - the more accurate the better! So if your car is 1350mm wide, cut your notches 1450mm apart on the poles. The string will sit in these notches and this will ensure your box is parallel.
   
4. Set 2 axle stands (or bricks / oil cans.. whatever you have) about a foot in front of the car and rest one pole on top, then measure from the pole back to the wheel centres on either side and adjust until they are the same distance - this will ensure the front pole is parallel to the front axle.
   
5. Set 2 axle stands about a foot behind the rear of the car and rest the other pole on top. Measure from the front pole to the rear pole on either side of the car and adjust until they are parallel.
   
6. Tie your string / fishing line around the front pole (in the notches) then run it down the car to the rear pole. Tie the end to a small weight and hang it over the pole (in the notch).
   

The box is now set around your car, but you'll need to adjust it so that the string lines are parallel and symmetrical to your car's centre line.

 

Squaring the box:

1. Remove the hub centre caps, and ensure that the string lines run level with the centre of the wheel - carefully raise or lower your stands until they're right.
   
2. Starting at the front left, measure from the string line to the hub centre, or to the end of the driveshaft stub. Whichever point you choose, it needs to be the same on either side of the car. Do the same measurement for the front right.
   
3. If the distances are different, move the front pole side-to-side until the measurements are the same on either side.
   
4. Repeat for the rear, measuring to the end of the stub axles, then adjusting the rear pole until the measurements are the same.
   
5. You will most likely need to repeat steps 2-4 at least once, as moving one end will slightly change the other. Once you get fluent at this tracking technique it will take you much less time to adjust!
   

So if all that went well, you now have a perfectly square box around the car, parallel to the car's centreline. It doesn't matter what your front & rear track widths are, as you measured to each axle's datum (hub / stub axle centre) separately. It's probably a good idea to rest some weights on top of the poles where they rest on the stands, or clamp them in place, just to make sure you don't knock them when measuring.

 

Measuring the tracking:

1. Get a sheet of paper to write your measurements down on!
   
2. Start at the front left and measure from the rear edge of the wheel rim (level with the string line) out to the string line - make a note of the measurement.
   
3. Now measure to the front edge of the wheel rim out to the string line and make a note.
   
4. Subtract your front edge measurement from your rear edge and then half the result. This will show you the toe setting for that wheel in mm. For example if your front measurement is 110mm and the rear is 106mm, you get -4mm showing 2mm of toe-in. Write this number down.
   
5. Repeat steps 2-4 for each wheel.
   

Now you can go about adjusting the toe - leave the box in place and carefully(!) adjust the tie rods to set the toe in or out as necessary until the wheel rim measurements come out at the value you want. Once you have this, check the steering is still centred and roll the car forwards and backwards to take the tension out the tyres, check the measurements one more time and adjust it until you're happy.

 

If you want the measurements to be in degrees then you'll need to grab a calculator and do some trig.

Edited August 30, 2012 by Cameron

[johnnyboy666 195 1 Cars]

sounds a bit fiddly!

I've been thinking about getting one of these:

http://www.ebay.co.uk/itm/Laser-Wheel-Alignment-Gauge-Tracker-Tracking-At-Home-Trackrite-/251121231343?pt=UK_Diagnostic_Tools_Equipment&hash=item3a77fde5ef

 

looks quite simple to use

[alexcrosse 124]

again... only does 2 wheels.

[wardy18 33 1 Cars]

Looks good Cameron, many thanks, the only main variable is if you dont get those notches on the poles that the string sits in spot on, but once the string is in place a quick double check that they are exactly 1450mm (using your eg) would sort this out!!

[Cameron 16]

Just cut your notches with a junior hacksaw and they'll be the perfect width for some thin string to slip in to. You want to use the thinnest stuff you can get your hands on, like a 0.5mm black cotton thread or fishing line something like that.

[petert 588]

I run 350lb front & 23mm tb and 25mm arb. It's a well proven formula. What I don't get however is your rear tyre pressures. Are you saying you start with 26? What tyres?

[wardy18 33 1 Cars]

I used to run very low pressures but this year so far have run circa 26psi all round, normally a couple psi lower in the front than the backs due to being able to warm up the front tires and so increasing pressure

 

After a lot of reading different set up websites etc it appears i have had this all wrong, it seems more psi is required in the front than the back to counteract understeer and attempt to induce some oversteer so pressure i have seen are circa 28psi front, 24psi rear

 

Im running A15 Soft Compound Hillclimb Avon Slicks

 

However it all depends of tire roll to be honest so once the suspension set up fixed and camber/caster set then i can find what pressure suits the tires best

[tri_longer 25]

I have to say Simon that is a lot higher than I am running, currently at 20 front and 15 rear.

[wardy18 33 1 Cars]

I have to say Simon that is a lot higher than I am running, currently at 20 front and 15 rear.

 

Im hoping the uprated spring rates will allow me to come back down to those pressures as i used to run 20-22 but at the moment i would more than likely roll the tire off the rim!!

 

atm any lower than 24 and you can see the whole tire side wall is being scrubbed!!