Parts Advice For Fast Road Suspension Setup.

[Ams 23 1 Cars]

I've been reading so many searched threads these past 2 weeks as to what combination of bits to get that my head is going to burst! The info has helped greatly but I need some direction before I start spending what little I have. There's so many but with different wants and setups hence why I feel it's necessary to post up for advice for my own car and hopefully someone can steer (ho-ho!) me in the right direction.

 

My intention for the car is primarily fast road and perhaps the odd track day, I don't mind comfort as it isn't a daily and is mainly going to see use during dry weather conditions. A firm but stable ride with minimal bumpsteer at speed is what I ideally want, somewhat similar characteristics of my previous factory 197 Cup which was great fun on country roads (such a fatty though!). Currently I have -

 

Front:

Standard 17mm ARB.

309 Wishbones.

Bilstein Group N Dampers.

Eibach Pro S -35mm.

 

Rear:

Bilstein Group N Dampers.

Standard 1.6 GTi Drum setup i.e. standard 19mm ARB and 18.9 Torsion Bars.

Rear beam may need a refurb.

 

I'm considering replacing the front Eibach springs with PLR Tarmac 180lb/190lb items seeing as I have the heavier XU10J4RS installed. The PLRs raise the ride height thus the CoG but the lower arms are currently horizontal on -35mm Eibachs so presumably it's a worthy tradeoff for reducing bumpsteer and getting the arm travel arcs back in line. Also the engine is tilted so I'd gain more sump clearance and the Group N dampers are a decent match. I'm also looking into eccentric topmounts for a little added control over the front geometry setup.

 

However increasing the front spring rates means I need to think carefully about the rear suspension setup as I don't want to end up with a mismatched front/rear leading to an unstable rear/excessively understeery front for the twisty country roads I drive on.

Would a rear setup match the above if it consisted of:

 

309 Beam (wider track to match the front 309 bones? More road friendly in regards to rear stability?)

21mm Torsion Bars (from a Partner/Berlingo van?)

No idea on ARB!

 

Since I plan to refurb the rear axle it's my chance to get the above sorted but I'm not sure if it's along the right lines, I'm sure I'm cocking something up in my thinking. Any help is appreciated really!

 

 

 

 

 

[allanallen 528 2 Cars]

180lb springs and a 309 axle will balls it up completely IMO. What don't you like about your current set up? It looks ok really although I'd be stiffening the rear up.

PLR springs IMO will make it sit too high for a road car, I run them on my road rally car that goes down rough green lanes etc, if you see what I'm saying?

You'll gain little to bugger all running eccentric top mounts with standard size springs, there's very little room to adjust them plus you'd need to use sleeved nuts on the short spindle dampers which isn't ideal.

[welshpug 1,655]

Stick some 21mm bars from anthony in a 205 beam, thats a decent starting point for a road car imo, those and eibach or similar up front and a 22 or 24mm arb work well.

 

Making a fwd car handle does not include making the rear wider, unless the front is significantly wider, and even then, the best 205's still run 205 width.

[Ams 23 1 Cars]

180lb springs and a 309 axle will balls it up completely IMO. What don't you like about your current set up? It looks ok really although I'd be stiffening the rear up.

PLR springs IMO will make it sit too high for a road car, I run them on my road rally car that goes down rough green lanes etc, if you see what I'm saying?

You'll gain little to bugger all running eccentric top mounts with standard size springs, there's very little room to adjust them plus you'd need to use sleeved nuts on the short spindle dampers which isn't ideal.

 

I thought PLR springs were very slightly lower than or equal to standard height, are they even higher than standard? I read a number of threads where people (with different setups) found raising the ride height back to near standard significantly improved handling, I thought it would be a better starting point but if the Eibachs are good enough then I'll keep them in. The real problem with the handling is actually the rear axle because the rear ride height has always sat much higher than the front, the car was like this when I bought it so the setup has always been undesirable. I haven't been able to drive the car with any confidence, due to the peculiar rear ride height, since buying it.

 

Stick some 21mm bars from anthony in a 205 beam, thats a decent starting point for a road car imo, those and eibach or similar up front and a 22 or 24mm arb work well.

 

Making a fwd car handle does not include making the rear wider, unless the front is significantly wider, and even then, the best 205's still run 205 width.

 

So just to make sure of this - get 21mm torsion bars and a 22-24mm ARB, keep the 205 beam on and leave the front end as it is. Is there a significant difference between the 22mm and 24mm ARBs? I presumed the 309 beam would help even the front-rear track width discrepancy created by the 309 wishbones, is it not worth it hence why I should stay with the 205 beam?

[allanallen 528 2 Cars]

My car on PLR springs sits somewhere around standard ride height maybe a bit higher and with the sump gaurd etc it's gonna be heavier than a gti6 engined 205. IMO the 180lb springs are a bit firm for a road car, I prefer the eibachs, much more forgiving/comfortable on the road.

The rear ends too soft as it is really so upping just the front spring rate will really upset the car and make it 'understeery', as does widening the rear track. I really see a 309 beam as an aesthetics mod rather than a handling mod, I'm sure some folk will argue otherwise!

[starky5 18]

I've just taken the 21mm bars out of my 309 axel and put standard one back in and it feels much nicer on the road to me

[Anthony 1,002]

The PLR Tarmac springs sit about standardish height on a 205 GTi-6. They're certainly not the 1" lower PLR claim!

 

With some reasonable dampers they actually work quite well on the road in my opinion, nicely poised but not bone jarringly stiff, but crucially, with such an increase in spring rate on the front, you're going to need to uprate the rear accordingly to match and keep it balanced - it will be too keen to wash out and understeer otherwise IMO.

 

Have a look for some recentish pictures of Paul_13's car and you'll see the height they sit at. He's very happy with the way the car drives with them fitted, matched from memory with 22mm torsion bars and a 25mm ARB, although I would personally say that you wouldn't need to run quite that stiff at the back for satisfactory results - I'd say a 21/23 combo would work.

[Paul_13 212 1 Cars]

24mm arb ;P

 

I'll post some pics up shortly

[Paul_13 212 1 Cars]

[allanallen 528 2 Cars]

mine sits higher than that on PLR tarmacs??

[Anthony 1,002]

What engine is in yours Allan? I'd imagine that they would sit quite high on an alloy block 8v for example, judging by how much lower Eibach's sit with a GTi-6 boat anchor compared to an comparitively featherlight 8v.

 

Also, are you sure you've got tarmac and not forest PLR springs? The forest ones are similar spring rate (160lb) but stated as being an inch higher than standard from memory

Edited July 26, 2013 by Anthony

[Ams 23 1 Cars]

When I called PLR they said the Forest springs sit higher but Tarmac is pretty much standard if you have an XU10. Pauls car sits really nicely I think! Here's how mines is since picking it up:

 

My current "drag racer" stance.

 

In the pic below you can just make out the angle of the wishbone to the left on Eibachs Pro S, both sides are practically are horizontal. The car is ever so slightly lower on the drivers side too, maybe due to an uneven rear ride height? The E-Cig pack on the right (same dimensions of fag box) shows how much clearance I currently have, it's touching the casing. Damn you engine tilters!

 

 

 

I cannot verify the condition of the factory spec 1.6 drum rear axle which is why it's probably not wise for me to lower it to match the front as I fear the beam will poo itself, it's probably shagged anyway. This above is why I haven't be able to capture a baseline experience of how the car responds anywhere near the limit thus I have no reference point. I'm basically doing this blind and narrowing down the correct parts to install based from advice from you guys. Ideal outcome is I get it right off the bat. The roads I take up here in Scotland tend to consist of decent surface quality, full of crests and compressions on bends, lots of undulations on gentle 4th gear bends, the usual 2nd-4th gear stuff. It's well suited to a small car like the Pug if setup correctly. I plan to fit a locker diff/LSD when I receive PugPete1108's VTS 5 speed box (I currently have the 6 speed installed) but really really need to make sure I have the correct suspension component combination sorted before it's fitted.

 

So just to verify the input I've received thus far (appreciate it by the way!) my options are:

For the front switch to PLR Tarmacs due to the added XU10 weight/reset arm angle/improve ground clearance/minimise bumpsteer.

For the rear stay with a 205 beam albeit reconditioned, install 21mm TB's and a 23mm ARB.

 

Or

 

Keep the front as it is with Eibach Pro S springs- see how it goes.

For the rear stay with a 205 beam albeit reconditioned, install 21mm TB's and a 23mm ARB? (same as above but still compatible with the easily changeable Eibach springs?)

 

Could I ask what difference there is between a 21mm to 24mm rear ARB is because I've noticed the replies are mentioning one or the other?

 

I'm hoping one of the above options will provide a balanced combination when driving briskly and provide a good platform for testing on fast road which I can tweak further myself via tyre choice and geometry settings etc (in other words, the fun part ).

Edited July 26, 2013 by Ams

[allanallen 528 2 Cars]

It's an 8 valve yes, it's a heavy bus though with a very industrial sump guard, strengthening plates, full interior and cage etc. I'll measure the wheel centre to arch later as I'm curious now. It may be a slight optical illusion as it is on quite high profile tyres.

I ordered 180lb Tarmacs off PLR so I can only assume that's what they are

[allanallen 528 2 Cars]

I'd personally try sorting the rear end first and see what you think, the rake your running at the minute will make it drive like a dog so I don't think you're giving the front springs a fair chance.

If you don't like it still try the PLR springs and raise the rear to suit.

 

Arbs are a personal preference thing, Anthonys recommendation of a 23mm arb Is probably based on the skip brown road speed setup, I believe that's 21tb/23arb? it's a fantastic fast road set up either way.

I say 24mm as a recommendation on what I use and like for the road.

 

Al

[Anthony 1,002]

SBC was 20mm torsion and 23mm anti-roll bars (although later ones might have had 21mm TB's)

 

As Allan says, ARB's in particular are a subjective thing and different people will recommend vastly different thicknesses.

 

I personally don't like mega-stiff rear ARB's on primarily road going cars as it can make them very skittish and nervous feeling, particularly on fast bumpy corners and in wet conditions, which just doesn't inspire confidence to press on. My previous 205 had a 22mm ARB on the back and that was pretty good for road use I found, and the current one has a 23mm as part of the Skip Brown setup.

 

I also agree with his suggestion of sorting out the beam as it stands (as it's probably in desperate need of a rebuild if it's an unknown) and to set the ride height to match the front - you'll want something in the region of 310-312mm between shock centers with the standard 18.9mm GTi torsion bars to match the current front. If nothing else, that will give you a good beam and a known good starting place to develop from

[Willem_Jacobs 6 1 Cars]

Stick some 21mm bars from anthony in a 205 beam, thats a decent starting point for a road car imo, those and eibach or similar up front and a 22 or 24mm arb work well.

 

Making a fwd car handle does not include making the rear wider, unless the front is significantly wider, and even then, the best 205's still run 205 width.

 

I would not go with a wider rear... My CTi is runningthe later GTi 19mm torsionbars, combined with a 'made to fit' 24mm citroen saxo rear ARB...

I am however using 306 GTi trailing arms fitted with MI16 alloys (ET 28) Wich makes the rear quite a bit wider....

 

At first i ran it with the wheels fitted straight to the hubs.. later on i decided to make the front wider as it was unpredictable in fast corners (lift off oversteer was a real danger) After fitting som 10mm spacers tot the front hubs (in effect going back to standard dimensions)

 

Be careful not to make the car 'square' the driven axle (front) is supposed to be a little wider, to make the car more stable...

[Batfink 201]

A wider rear track will generally make a car understeer more. The 309 gti had 1mm thicker torsion bars though I think but I've never felt the conversion changes the characteristics so drastically other than to look nice. The car looses its edginess at the rear

Edited July 26, 2013 by Batfink

[Ams 23 1 Cars]

Cheers for the pointers it's helped immensely. I'll stay with a 205 beam (obtain a reconditioned one) complete with 21mm TB's and 22/23mm ARB then get the rear height adjusted to match the current front suspension ride height. I'm currently waiting to grab some 1.9 hubs from Miles as my current ones are goosed. Once they're fitted next week I'll begin inquiring for a reconditioned rear axle with the recommended bits I know I'll have to travel to England as there's nobody in Scotland that is renown for such work off these boards.