205 Road - Suspension Balance/set-Up Questions

[Mac Crash 78 1 Cars]

I’m looking for some experienced advice on suspension set-up and suitability of componentry. The car is for fast road use only at the moment.

 

I’m about to fit PTS Bilstein coilovers, currently they are fitted with long spindle forest inserts, 185lb forest springs & AB motorsport offset/eccentric rose jointed top mounts.

 

Rear is standard 205 GTi beam with Bilstein dampers (1038 Group N type)

Car height is standard.

 

Q1. Will the balance between front & rear be too unmatched? If so, will I need to buy

Tarmac inserts & springs? I’d prefer compliant suspension rather than stiff for British roads.

 

Q2. If optimising the front negative camber settings will the standard 205 driveshafts manage? If not then I have 309 wishbones and shafts, would these be sufficient and would it be best to just use the shafts? Or the shafts and wishbones together?

 

Q3. Are the values between forest and gravel the same? as I here conflicting information, i.e. are forest and gravel spec just the same with different names or are they completely separate things?

 

Q4. As soon as I can I’m going to solid mount the 205 beam, I also have a 309 GTi beam in standard form, if using 309 GTi wishbones, should I also use the 309 beam or would the 205 be better with it’s own beam? I’m not worried about wider track dimensions as I’ve read the 205 is a better car with it’s own geometry.

[welshpug 1,646]

q1, yes it will be unbalanced, the rear is far too soft, tarmac spec up front will make it worse.

 

q2, depends what you mean by "optimising"

 

q3, gravel was 185 lb front springs, 250/120 inserts, tarmac was 225 with higher 300/200 inserts , IIRC gravel rear was 20mm bars and 360/ 250 damper, tarmac 21mm bars and 460/250 dampers.

 

q4, totally different debate, but personally I find 309 or 205 front with 205 rear brilliant, 309 rear is said to induce more understeer.

[Mac Crash 78 1 Cars]

WP > Thanks...

 

Q1. So I'm looking at bigger torsion bars? and I'm right in thinking standard they are 17mm? I for sure did not expect the front and rear to be balanced, that would be too lucky but I'm surprised it is so way off... which would mean that the 205 standard front dampers are significantly softer than a forest/gravel damper? but that's okay as long as I know what I need.... any idea who to buy torsion bars from?

 

Q2. I'm not sure how much NC will be achievable, I'm hoping for 1.5 degrees?

 

Q3. Right!, so gravel and forest are the same thing, thanks.

 

Q4. I'll stay with the 205 depending on if I can still use 205 shafts after the front camber is set?

[welshpug 1,646]

standard is 18.9mm torsion bars, front springs are about 100 lb/in.

 

uprated bars from here - http://www.torsionperformance.com/

 

 

 

 

Q3. Right!, so gravel and forest are the same thing, thanks.

 

 

 

 

not sure where you read that

[Mac Crash 78 1 Cars]

standard is 18.9mm torsion bars, front springs are about 100 lb/in.

 

uprated bars from here - http://www.torsionperformance.com/

 

 

 

 

not sure where you read that

 

Ah so... regarding OE springs, that explains things... and thanks for link, will try them for prices...

 

http://www.specialtuninguk.co.uk/acatalog/20mm_Torsion_Bars__Pair_.html

that's without VAT

 

Well, if gravel and forest springs are both 185lb would you say they are the same?

when looking for PTS inserts I can find only gravel or tarmac, no mention of forest?

[allanallen 528 2 Cars]

I think people often refer to gravel stuff as forest as well, I wouldn't get too hung up on it.

 

For fast road use I'd stick with your front inserts and maybe go a little softer on the springs. Rear end I'd be looking at 21mm bars and preferably the grpA rear billies to complement them.

I personally wouldn't bother with the 309 rear end.

 

-1.5 neg camber and a little castor increase is easily obtainable with your top mounts and 309 wishbones.

 

Reading your other posts, Is the car destined to be a road rally car?

[Tom Fenton 1,536]

Regarding driveshaft length, it's a very fine line. Adjust eccentric top mounts fully "in" on otherwise standard bits and you may find your driveshafts bottoming out and knocking. Conversely use 309 arm with 205 shafts and you may find the inner joints pop out on full lock. It's no exact science but be aware you may have some adjustments to make.

[Mac Crash 78 1 Cars]

aa > from everything I've researched I'm at the same conclusion regarding the gravel/forest tags... just really wanted to confirm this.

I can sell on the 1038's and buy the Group A dampers, I've no issue with that as you get what you pay for. The bar prices have surprised

me though to be honest but will shop around for best prices... definitely sticking with the 205 beam now, but the existing beam isn't right

as the n/s wheel is visibly toed in as opposed the o/s wheel and the car steers to the left, hoping it's no more than a bent stub axle off the

hub, will investigate this when the beam comes off.

 

Still not sure where this car is going, atm for fast road use, testing, finding stuff out etc and of course enjoyment... it's a road going 1.9 8v

with almost a full service history, there is no rot that I can find and the car has never really wanted for anything, the only real bad thing

about the car is the paint... it's fine in most places, has the usual laquer peel in patches around the roof and has had the rear quarter

resprayed as temporary measure as it was in primer when I bought the car, needless to say 2013 cherry red doesn't quite match the

1990 cherry red))) that's the only real bad point, the interior is mint apart from the drivers seat which is generally the norm. With the

paint fixed I'm sure it would be classed as a decent example which are climbing in value. Mechanically the car is good, everything

works and the engine is still really keen, we also have a very good stage III head for the 8v which belongs to a friend who's offering it

up for free.

 

But, I don't need 2 GTi's, not right now anyway... but that's what I've ended up with, impulse and lack of willpower... the plan is to build

a road rally car to begin with then develop it into a stage rally car when experience and budget allows, the track car is a solid 89

non sunroof shell in white, its fitted with an SD C44 cage, light weight race seats with proper alloy brackets, there's a spare Quaiffe

with it too and other parts, spare coilovers, spoox top mounts, GTi 6 tarox brakes which can all be sold to fund the parts we need,

for me there is no doubt that this car should be the basis for the rally car as a good deal of the work has already been done... however

there is no engine... but lot's of options... I know the 16v is the way to go, but still we are keen to go with the 8v... so there are decisions

to be made and in the meantime we can start preparing the white car.... it's what to do with the red car in the long term? still not sure.

 

TF > Acknowledged, this is what I'm unsure about, I'm not going to set the struts fully in and standback and say, yip, that looks fine,

1.5 deg will be fine for road use... I have 309 driveshafts and wishbones available, will these address any issues regarding correct lengths?

What would you do?

[welshpug 1,646]

I use the softer gravel stuff and 21mm bars on my roadgoaing 205, 22mm arb, 309 wishbones, ZX1 6v 2.4 turn steering rack.

 

309 wishbones and 205 shafts, the wishbones sit pretty level and I haven't had any issues with them.

[allanallen 528 2 Cars]

309 wishbones, 205 shafts and half a degree neg on the top mounts you may well be fine. With today's reproduction driveshaft tolerances being what they are they may not be though.

[Mac Crash 78 1 Cars]

Will 309 driveshafts help in this respect?

[allanallen 528 2 Cars]

In an ideal world yes 309 wishbones and 309 shafts are the way to go. Got a bit muddled reading your posts as to what you actually had and wanted to do.

[Mac Crash 78 1 Cars]

No worries, have that covered, thanks, I'll be back no doubt with more questions later)))