250lbs Front Springs On Coilovers

[Cameron 16]

Probably down to the front IR being a total guess!

[taylorspug 7]

Take the piss all you want, wheel rates are a very important thing to know.

 

Lighten up, t'was but a joke. Plus it wasnt even made in reference to your post, i quoted Als? Im not even remotely saying theory doesnt matter, im partial to the odd bout of maths based theory to work certain things out, especially with static suspension setups (I rarely bother once the car is up and running though). However i dont bang on about it, as suspension calcs seems to be one of those things people either 'get' and use, or ignore and just go off of recommendations (which is no bad thing as long as the advice is good).

 

It was nice to see a comment based on personal experience of a stiffer front and rear setup ignoring the calculator, thats all.

[Henry 1.9GTi 36]

because the damper sits inboard of the wheel the radius it is rotating about is shorter. So would make sense for the IR to be more than 0.8 i.e >1

 

and I obviously can't read..

Edited February 25, 2010 by Henry 1.9GTi

[Rob Thomson 6]

The IR for the 205 front suspension is something like 4:5

With a McPherson strut how can the discrepancy between wheel and spring movement be so great? The strut's mounted directly to the hub. The strut isn't vertical so there'll be a slight difference, but surely not 25%.

 

Or am I being thick?

[Rippthrough 98]

Like you say it's just from it not being mounted vertical, the camber and castor on the strut, it's probably closer to .97-ish, so your 250lb springs are around ~235lb wheel rate.

Edited February 25, 2010 by Rippthrough

[Cameron 16]

That sounds a bit more realistic. I only worked that out from what I could make out from a pretty obscure pic as a rough guess. I'm pretty sure the point where the axis of the strut crosses the lower wishbone falls short of the balljoint, so you'll get a small leverage ratio there, but also as Ripthrough said the angle of the strut will also play a part in reducing the spring rate.

 

Dan - must just be my time of the month then, sorry.

[Batfink 201]

so how useful is that chart now?

[Tom Fenton 1,542]

That 0.97 of Phils sounds more like it as opposed to the 0.8.

 

It also makes my 225 lb front springs have a wheel rate of approx 218lb, and my 23mm bars a wheel rate of 219lb.

[Cameron 16]

Yeah it does sound a lot better.

 

Kev - still pretty useful, whoever created it obviously knew the 205 rear geometry. It's only the front that's being debated.

[Daviewonder 533 3 Cars]

I know that's going to make no sense to 99% of people.

 

 

Thank god for that, I was worried I was the ony one

 

I know this thread would be useful when working out what rear suspension setup I need, If only I understood a word of it

[dino20vt 3]

So 23/24 according to the chart, from people experience does that sound about right with 250lbs front springs?

 

Before I look into the possibility Of buying some of those eBay TB's, anyone got a secondhand set they don't need anymore, perhaps gone bigger?

[Cameron 16]

23 IMO.. 24 might be a bit stiff.

[welshpug 1,658]

just hope the dampers are man enough to control them

[joe1joe 3]

so could some one change the table!?

[Cameron 16]

Why? There's nothing wrong with it, the rear spring rates were fine.

[Anthony 1,003]

... and after a few waves of the mod stick, we're back on topic.

[Sam 4]

The last version of my setup was 23mm bars and 300lb (?) springs and the car felt very planted and yet wasn't too harsh. I ran no front ARB also.