Suspension Set Up

[DickieB]

Had no luck on "Techie Talk" (except Al Y - thanks) so thought I'd try the motorsport bit as well for this topic:

I need to do better. I've read Alan Staniforth's book and the introduction lost me, let alone the rest of the book.

What I need is a "Janet and John" guide to suspension setup. To be honest we're only talking tyre pressures, camber, toe-in/out and fiddling with the single adjustable Ledas, but I haven't got a clue what to do, how to measure it etc.

There must be a simple book/video/etc......

Thanks

Dickie B

[Arm]

If you want an idiots guide to suspension setup please try Steve D on 01606 836354 !

Ash

[Rob Navin]

Dickie

I use Trev at TranZpower to set all the suspension up on mine.  He sets the car up whilst you are in it all the way through to make sure its all 100%.  Trev runs a selection of Radicals in their endurance races and some R500's Cateringvans for similar events to great effect.

I would recomend taking it to Trev and listening to his explanation on the set up and alternatives over just reading the books.  It makes things a lot easier to take in when you have it pointed out on your own car rater than drawings.

If you want any other info ring me.

BTY will done on the heat win mate.

HTH

Rob

[Kev Bamber]

Hi Rob, where is TranZpower? - I've got chronic understeer since putting the K in. Was gonna try reducing the neggy cos of the weight loss, was at 2 1/2 degrees and gonna try 1 1/2 degrees.

Kev.

[barney]

must agree with rob,

trev`s a top bloke and knows his game,we have also had our works cars for the rgb series set up there ,with good results

well done to richard on the heat win as well,    

ps also found Trev very reasonable cost wise VGVFM  

[Blatman]

Like I said on Techie Talk...........you should have mentioned this earlier on Saturday (or did you? )

We can set the LoCost up anyway you want with some string, and my tracking bars.......you just need to know what you want, or if you have a handling issue that you don't like, tell me how you would like it.......then I'll get my brother to throw some spanners at it! ! ! ! ! !

[SteveD]

yes mr mason the only idiots car i have set up is yours and that seems to work ok does it not  

[Richard M Green]

Kev,

Having just gone through the Crossflow to K-Series transformation I too suffered major understeer problems, also less effective braking.

We concluded that it is due to less weight transfer onto the front tyres under cornering and braking.

Fitting 200lb/inch springs instead of the previously fitted 225lb/inch made a huge difference, and that was just to the old Spax units. Now I've replaced them with rose jointed AVos the improvement is even more pronounced.

Now all I've got to do is learn to exploit it.........

[Rob Navin]

Kev.

Trev is based in Chesterfield.  If you did want to take it to him you are more than welcome to break the journey at mine.  His number if you do want to want to get in touch is 01246 456277.  Running the cateringvans he has got quite a bit of info on 7's with K's in and would talk you through your options even if you were not booking it in.

If you are going reduce the spring rate as Richard suggests do that before you get the rest of the car set up.

Barny, are you feeling OK ??  You do realise you have just agreed with me       You best have a little sit down for a while.  

[barney]

Barny, are you feeling OK ??  You do realise you have just agreed with me       You best have a little sit down for a while.  

Mmmm

Nurse the screens..its time for my medication...                

[John Loudon - Sponsorship Liaison]

Richard,

If you have Stanniforth's book, look on pages 238 and 239 - everything that you might need to know in a nutshell.

HTH

Regards,

JL

[machin]

I was under the impression that having more weight transfered to the front would also increase understeer (because the front tyres will be working harder....)

I can only think that the reduction in weight (assuming a K is lighter than a crossflow......) is messing up the geometry (wheels being pushed into less negative camber) and therefore the tyre contact patch is compromised, hence a change to the camber as suggested above (although changing to softer springs would bring the nose back down and hopefully give the original geometry....)

Just set me thinking,

Machin

[Kev Bamber]

Yes, that kinda was my thinking, I've always thought that the more weight at the front, the greater the understeer, and that fitting the K as you put it "messed up the geometry" rather than inducing understeer simply cos of the weight loss.

I was reducing the neggy because for a lighter front the optimium would be less of a camber angle for a flat tyre contact patch - if you know what I mean!

[SteveD]

and less weight at the front = understeer  

[machin]

No, less weight at the front is less understeer, -see original 911 for an example of this.  Don't confuse extra downforce (from aero in F1) as being the same as getting more weight over the tyres.  For example a car with 300kg over the front wheels will say produce 2600N of grip with which it can turn that 300kg, a car which produces an extra 200 kg in downforce will have something in the region of 4300N of grip with which to turn the same 300kg (i.e much more grip per kg mass turned =less understeer).  Now you want less weight over the front wheels to reduce understeer because the grip(N) produced per kg download decreases as mass goes up, i.e 300kg may produce 2600N grip, but 600kg won't produce 5200 (2 x 2600), but more like 4900N, -i.e less grip per kg mass being turned, and hence more understeer (if we're talking about the front wheels)

The other reason that the softer springs could induce understeer themselves is that now the front end weight has gone down the original springs are effectively too stiff and now you have a car with too stiff a front roll resistance (more weight on outside front tyre when cornering), so the outside front tyre is being overworked =understeer.  The best way to see if this is true is to see if the car is rolling in the corners (? -shouldn't be if it wasn't before the engine change, -unless the new engine has a highercentre of gravity) if it is then conversely you should either up the spring rate or add an anti-roll bar, if roll is neither excessive or too stiff, then it must just be the front geometry gone out because of the change in weight  over the wheels, i.e as said in a previous post, the wheels are being pushed into less negative camber.

I think!

Machin

N.B -Kev the new lower weight will cause the car to rasie up on its suspension, kicking the top of the tyres outwards (or less inwards...), i.e less negative camber, so you'd have to add negative camber (move the top of the wheels more inwards) to bring the car back to a 'flat' tyre contact patch.  And remember , this will change when you sit in the car (pushing the car back down slightly), plus you may want more negative than 'flat' to give you more grip when the car rolls in corners, but basically to get the car back to how it was before the weight reduction you will have to add negative camber.