Help On Tarmac Rally Suspension Setup - Used On Road And Track Too

[boombang 2]

As coming towards end of my 205 build, I'm just reviewing the suspension setup.

 

Have Gaz gold kit on there, currently with 9" 225lb springs.

Rear beam is a rebuilt 309 item on standard torsion bars (have 21.5mm to go in there).

 

A bit of research to what old Pug Sport specs were makes what I have way off, rear more of fast road setup than anything.

 

Thinking of ditching the 309 beam and going to 205 with uprated torsion bars.

 

Also the front sits very high on the 9" springs with the pans wound down, sure there is nobody in the car but think an 8" spring might be worth looking at. Others I spoke to who have fitted the Gaz have said simlar. Plenty of travel left on shocks, has been measured by a mate and looks to be no worries at all going down that far.

 

Have 205 and 309 front ARB available, but thinking of not using on at all with the stiffness of the setup.

 

Possible spec would be as follows:

 

8" 225lb fronts, adjustable damping with eccentric topmounts (set at middle for balance between castor / camber, obviously to be played with in future)

309 arms

no front ARB

 

205 beam with 23mm torsion bars and standard ARB.

 

 

Any more thoughts?

 

Will always be a compromise as I want to use it on rally, road and track, but ideally want it to ride well and compliant enough for rally and weekends out on the road.

[tom_m 0]

sounds good to me. with the gaz being adjustable you'll be able to wind out most of the on road harshness of a tarmac rally biased setup, and then turn up the damping when you take it on track/on a rally.

 

mine is on 185lb front and 21mm rear with bilstein tarmac dampers all round, is very stiff, but its all in the damping; having run the rear beam with oe dampers and found it nowhere near as stiff as it is now.

 

i've got a 23mm arb in my rear beam with the oe front, gives sharp turn in and hangs on harder in the corners, but easily provokeable to controlable LOO.

Edited January 25, 2009 by tom_m

[boombang 2]

Interesting to hear that Tom. A lot of people I know run standard torsion bars on rally / track 205s and IMHO feels way too soft but heavy on the rear & won't move around in controlled way.

 

I do like a car where you can make the rear move around on the throttle, maybe just more proof I am lazy?

 

In fact the best time ever on track was in a 309 with seized beam, talk about the car being super-responsive and tail happy!

[welshpug 1,626]

Do you remember what Mark's car handled like last time at Longcross on standard bars and 225 springs? lol...

 

I find it amusing all those cheaply put together 205's (and often not that cheaply...) out there that seem to understeer like buggery due to a standard rear end, and the properly setup cars are going everywhere sideways, Andy corner a case in point, no front ARB and sideways everywhere...

[bensonmi 4 2 Cars]

sorry to but in but i find this one interesting,so what is the best way to prevent understeer? softer front and stiffer rear or stiffer front and softer rear??? simplifieing a bit here!

[Slippy 0]

On my Clio tarmac raly car stiffening up the rear helped turn in i.e made the rear step out more

[philfingers 5]

Mines (ex tarmac car) has been running gravel setup (PTS coilovers with 10" 185lb) on the front with std bars on the back with PTS gravel dampers. This is great for road rallies, though the fronts are a little soft and I'm going to run my tar ones on the front. I have fitted a 309 ARB on the front. I did have 21mm TBs and 23mm ARB on the car when I got it but found it too harsh on the back. Then you need to realise that road rallies on blind roads in s*itty conditions requre a more progressive setup than an out and out fully committed approach such as tarmac single venues or track work. I prefer the more progressive rear, where if you come into something which rough, slippy and tightening it won't catch you out.

I have run eccentric top mounts previously and will again (this car came with concentric R/J'd PTS units on the tar setup but the gravel ones were std with HD runners), on my 309 I ran them at 1:30 on the offside (viewed from the front) and 10:30 on the near side. With std bottom arms on the 309 this gave a front camber of 1º40”, which was perfect. Can't remember the castor (will be on an invoice somewhere!) but it felt 'right'

Edited January 25, 2009 by philfingers

[Henry 1.9GTi 36]

If possible I would use a front arb and softer springs over no arb and harder springs. Just make sure total roll stiffness is what you want it. If you go 309 track at the rear I assume it would need to be alot stiffer, but perhaps good for road rallies as it wont oversteer as much. Would be more planted and understeer on the limit, probably good for a road rally.

 

good luck.

[chownr 0]

Just my two pence worth but I think most people go too hard and too short on a front spring for rallying. 185lb is fine and on smooth tar 200lb is also usable. But 8 inch springs are just too short for everything except circuit racing - they simply go coil bound which results in some interesting handling. Id use 9 inch for relatively smooth tar/broken tarmac and 10 inch is worth atry also. Dont be fooled into running the lowest ride height you can get away with. In my experience you dont need to slam the ride height

 

Ive always struggled with understeer and the best way to cure for me is an uprated rear ARB but it can make the car twitchy on occasion. Other options are to run the car slightly nose down or without front ARB but this can make the car roll excessively.

 

You can fine tune your car to suit your style but its essential that you get the basics right - spring rate, damper rate and ride height. The rest is fine tuning. What you want to aim for is a compliant car that is easy to control on the limit - which by definition is generally a softly sprung car. Something that is hard and low will have a very narrow and focused limit - good for circuit racing - not so for rallying.

 

Hope this helps

 

Rich

[bren_1.3 1]

205 beam with 23mm torsion bars and standard ARB.

 

 

going back to the 205 beam would give you some options on ARB choice either using the 205 19mm or the 106 24mm and 22mm items.

[boombang 2]

Thanks for the opinions, think for now going to work towards getting a 205 beam on there and trying to work out my options for torsion bars.

 

IMHO every 205 rallycar I've driven has been too soft on the back, including one running 21mm torsion bars. Front on it felt planted and good though (225lb 9" on tarmac billies).

[meggy6620 0]

heres a thort try useing a 306 std damper on the rear as it is very cloes damp rate to a 205 gravel set up as this would give you a sligtly harder ride on the road,

also you could drop the rear end and have nearly no travle when you go to the track,

but the rallying needs differnt set ups depending on the event you do as england dont exactly have smooth roads so you need travel but enough stiffnes to get it sliding.

[welshpug 1,626]

that wouldn't work, the 306 standard sport damper is the same part number as the 1.9 gti, far too soft a damper for a 21mm torsion bar!

[Craigb 2]

306 gravel billys work on the back ..

[meggy6620 0]

Or just put gravel 205 dampers on they work well enough on both rough and smooth just change the ride hight to suit conditions

[boombang 2]

OR could just stick with the adjustable Gaz stuff I have already got???

 

Also worth noting that putting on "uprated" dampers won't stiffen the rear, only mute the actual suspension response. It's a bodge...

 

I do wonder if people even bother reading a thread before posting (punctuation and spelling words correctly so you can actually read them helps too).

 

 

 

On topic though, currently debating the 309 vs 205 beam thing.

 

Having a look about to see what torsion bars are available used, then work out what beam to use - think would rather go to 205 beam for extra clearance on the arches.

 

 

Does seem that there aren't all that many people about who've gone for uprated torsion bars for anything other than track / race cars.

 

From reading the above, I might try to blag a drive of a mate's rally car with 21mm rear bars (225lb PTS tarmac setup on front). Having been in it as a passenger it still feels a touch too hard on front compared to the rear - makes sense though that going down to 200lb on front could regain the balance.

[tom_m 0]

Does seem that there aren't all that many people about who've gone for uprated torsion bars for anything other than track / race cars.

 

From reading the above, I might try to blag a drive of a mate's rally car with 21mm rear bars (225lb PTS tarmac setup on front). Having been in it as a passenger it still feels a touch too hard on front compared to the rear - makes sense though that going down to 200lb on front could regain the balance.

 

i think most people don't change the torsion bars because of the cost and effort required compared with swapping a set of springs.

 

and i'm sure i'm only telling you something you know already, but the Peugeot sport specs were for 23mm bars with the 225lb springs, so it will probably feel like a stiffer version of the type of handling you don't like. i'd offer you a drive in mine, but its not exactly road worth at the moment

[meggy6620 0]

Sorry about the pelling and stuff as im dyslexic.

[welshpug 1,626]

so am I, its no excuse.

[Spiky 37]

well with suspension setups, i do the try/test and see what i think

 

i did have 185 srings (advice from this site) and found them soft for tarmac track days, so changed to 300, now it's much better

 

i now have a 309 front arb ( against peoples views on here saying my car wont handle) and guess what it handles great, even pushed hard at oulton park

 

so my advice is try and if you dont like change

[meggy6620 0]

Ye i no its no excuse lol, but as set up gose just start with what you'v got try it and sea what happend.

 

At the end of the day its personal choise as every one drives different.

 

My set up is 205 beam std 1900 bars and ARB (or some times no ARB) with billys and just change the ride hight around for oversteer (High) and understeer(Low) and use some slightly softer and narrower tyres to keep the heat in em.

[James_R 3]

Having a track set up rather than rally I'll say mines on the stiffer end of set ups, but what I've found most important is matching the spring rates so you end up with neutral/oversteer balance, at least with oversteer and a plate diff you can adjust the line of the car on exit.

 

Having driven toms set up gravel springs rates tarmac damping, I'll agree its very firm, but has also felt less composed than my car with much stiffer spring rates, but damping more suited to spring rates.

 

As for beam widths, I've been using a 205 beam, and considered a 309 beam width for higher speed stability at the ring, but then decided back on a 205 beam as you can add spacers to a 205 beam to give you 309 width but not the reverse is not true, you loose a lot of turn in sharpness with a 309 rear beam, and more understeer potential.

 

Also I'd aim to have the rear TB's stiff to the point that in the wet you need no ARB, then adjust the rear stiffness with ARB size for dry conditions.

 

Sorry if these are all really obvious things, but its how I'd aimed to set up my car, albeit for track use, but the end result is similar. I'd also say PTS probably had it pretty right, they seem pretty hot on sus, shame they can't make 16v engine which hold together

 

 

 

 

As for dyslexia being an excuse.... agree with WP, type it in Word and click spell check.

[boombang 2]

well with suspension setups, i do the try/test and see what i think

 

i did have 185 srings (advice from this site) and found them soft for tarmac track days, so changed to 300, now it's much better

 

i now have a 309 front arb ( against peoples views on here saying my car wont handle) and guess what it handles great, even pushed hard at oulton park

 

so my advice is try and if you dont like change

 

Ta Spikey, agree that with the 2.25inch spring setup and adjustable damping on the front I got loads to play with, and another set of springs won't break the bank.

 

Only issue really is the torsion bars, whatever I get it'll cost a fair bit.

 

You're not wrong about the 309 front ARB. A mate at a well known Pug tuners insisted on a customer trying it out and it worked very well at Brands and Combe. Seemed to help sharpen up turn in and mid corner stability.

 

Having driven toms set up gravel springs rates tarmac damping, I'll agree its very firm, but has also felt less composed than my car with much stiffer spring rates, but damping more suited to spring rates.

 

As for beam widths, I've been using a 205 beam, and considered a 309 beam width for higher speed stability at the ring, but then decided back on a 205 beam as you can add spacers to a 205 beam to give you 309 width but not the reverse is not true, you loose a lot of turn in sharpness with a 309 rear beam, and more understeer potential.

 

I'd also say PTS probably had it pretty right, they seem pretty hot on sus, shame they can't make 16v engine which hold together

 

With the Gaz I should be able to fine tune the damping to whatever I am running, and if needed back off a touch in the wet.

 

I'm personally in preferance of as little damping as you can get away with, as you said it helps composure and lets the spring do it's job.

 

The car I know with 21mm bars is still a touch neutral for me, be handy to try out a car fitted with 22/23 bars.

 

At the moment thinking of seeing what (if any) torsion bars are around 2nd hand, then if I were to find a 205 one swap over to that setup rather than 309.

If unable to find anything, to keep things simple I might go for something like a 23/24mm bar on the 309 beam (got to find the calculations and work out what equivalence is on 205 setup).

[welshpug 1,626]

I did some searching

 

 

Excellent, I'll try that - I take it bar diameter is also in inches?

 

For 21.5mm (0.846 inch) 309 bars, using the above arm and bar lengths you get:

 

148lb/in

 

Makes 19.5 standard 309 bars 110lb/in

Also 22mm 309 bars 162lb/in

 

Sound about right? to me sounds a little low but then I've never looked into t-bar spring rates before.

 

http://forum.205gtidrivers.com/index.php?s...69924&st=10

 

 

going from what I found that 205 bars are 36mm shorter, and basing the quick calculations on sandy's measurements of 10" trailing arms and 39" torsion bar (309) a 23mm bar is 194 LB" in 309 length, and 201 LB" in 205 length.

 

 

bar dia 205--309

 

19mm: 95 lb"

 

std 309 20mm: 111 lb"

 

21mm: 139 lb"--134 lb"

 

22mm: 168lb"--162lb"

 

23mm: 201 lb"--194 lb"

 

24mm: 234 lb"--229 lb"

 

 

 

21.5mm partner torsion bars (fit a 309/405) ; 148 lb"

 

vaguely only 5-6 lb" difference over that 36mm.

Edited February 3, 2009 by welshpug