Front/rear Balance Bilstein Gpn Eibach Combo

[Castorkid 11 1 Cars]

Dear Forum,

I'd really appreciate some advice on my current 205 gti set up which is as follows:

Standard 1.9 engine

Standard interior apart from race seat (no cage)

Solid mounted rear beam with 306 negative camber radius arms

22mm torsion bars

25mm rear arb

Bilstein group N dampers

Eibach prokit springs (30mm lower)

Group N top mount rubbers

309 front wishbones

283mm brake conversion (Gti-6 calipers, Ferodo DS3000 pads, Tarox discs, SRF fluid)

Group N engine mount kit

Yokohama Advan AD08's 195/55/15

 

I find the current set up quite oversteery. I was planning to turn it into more of a track car so was sensibly advised to go stiffer at the front on coilovers. However, work has got in the way of track time and so I can enjoy using it, I am now planning a fast road spec which I guess means going softer at the rear.

 

Question: Do I need to reduce my torsion bar rating or ARB rating or both, to get a better balance with the current front end? What would you all recommend in terms of bar thickness mms? I know suspension feel is a very individual thing, but would appreciate all your experiences.

 

Kind regards

 

Nick

Edited September 17, 2012 by Castorkid

[Tom Fenton 1,536]

By far the cheapest solution would be to go back to standard GTI torsion bars at 18.9mm and then see how the car feels. The anti roll bar is somewhat of a subjective thing, and easily altered, so I would leave the 25mm bar in for now and see how you like the car with the softer rear bars in. At the moment the rear end is very hard compared to the front.

[allanallen 528 2 Cars]

I agree with Tom, either drop some standard bars in or you could go for some standard dia firmer springs?

[Cameron 16]

Firmer front springs if you can get them, otherwise revert back on either the TB's or rear ARB.. that setup probably has a pretty high rear stiffness bias, assuming the Eibach are a fairly low (sub 200lb/in) rate.

[Castorkid 11 1 Cars]

Thanks for your replies. Not sure my front dampers would be suited to the higher rated springs. I dont mind throwing a bit of money at it, if you think that theres a better balance to be had with both new torsion bars and an ARB.

[allanallen 528 2 Cars]

Thanks for your replies. Not sure my front dampers would be suited to the higher rated springs. I dont mind throwing a bit of money at it, if you think that theres a better balance to be had with both new torsion bars and an ARB.

 

If they're GRP n billies on the front they'll stand firmer springs, I run 180lb springs on a set and they work really well.

[Henry 1.9GTi 36]

use more throttle is the cheapest option and most fun!

[Castorkid 11 1 Cars]

Thanks Allan. Yes they are Group N Bilsteins. Have you got the Peter Lloyd Rallying 180lb tarmac springs? Whats the spec of the rear of your car?

[pug_ham 243 3 Cars]

Yes they are Group N Bilsteins. Have you got the Peter Lloyd Rallying 180lb tarmac springs?

Like Allan says, these are perfectly suited to higher rated springs such as the Peter Lloyd Rallying 180lb tarmac springs ones.

 

I have a set spare if you wanted to try them.

 

pm sent.

 

g

[allanallen 528 2 Cars]

Yes I've got PLR springs on bilstien GRP N at the front with 21mm bars/19mm arb and GRP A billies at the rear. I find the car very neutral to be honest certainly not oversteery. I think I'd prefer it with the 22mm bars if it was purely a road car.

 

Only issues you may have with the PLR springs is the ride height, they're supposedly -25mm but they're more like standard ride height in reality. I can get you a arch to wheel centre measurement if youre interested.

 

Al

Edited September 18, 2012 by allanallen

[stu8v 68 1 Cars]

I thought Gravel spec was 180lb and Tarmac was 225lb ?

[welshpug 1,646]

That's group A.

[stu8v 68 1 Cars]

Oh right. Just assumed they used the same on both

[Castorkid 11 1 Cars]

Allan

Thanks for your input. I'd really appreciate that arch to wheel centre measurement you mentioned. I'd like to keep the ride height the same at the Eibach's if possible.

Cheers

Nick

[allanallen 528 2 Cars]

Allan

Thanks for your input. I'd really appreciate that arch to wheel centre measurement you mentioned. I'd like to keep the ride height the same at the Eibach's if possible.

Cheers

Nick

 

I'll get you a measurement next time I'm with the car buddy, they'll sit some 30-40mm higher than your eibachs though. PLR or faulkners will custom wind springs for you, obviously at a price though!

 

[matt.f 16]

I can get a measurement tonight if you want.

I too run GP-N with 180lb springs and its spot on,never changed the rear from std 1.6 beam(rebuilt ,gp-a mounts)and it seems fine to me.No doubt could probably get it better on the rear but seems to work ok

[welshpug 1,646]

It would work sooo much better on 21's imo.

 

Ive been in gpA billies for 6k miles, bit jittery on small unduations but very good at speed and bigger bump and wonderfully balanced turn in, not what it was on std bars.

[Castorkid 11 1 Cars]

The more I read this topic, the more I think I should keep the back end as it is and invest in some adjustable coilovers, here's why...

 

Originally, I bought my 205 as a standard but tired example with the aim of using it as a fast road/track car. As I have little time or practical skill I thought it best and safer to take it to a specialist garage for set up advice and work. The spec you read at the start of this topic is the fruit of their labours. In the suspension department, I went for the Group N Bilsteins and Eibachs on the front as, a] they are a very popular choice - safety in numbers, b] were recommended by the garage to go with their rear end spec as a fast road/track car and c] I knew less then about front/rear balance then.

 

A couple of Donington track days, a trip to the Ring and some general blattery convinced me that all was not quite right and that I needed to improve things (especially in the over steery/high speed stability department). A year or so later and after investing some time in learning about suspension set ups and asking for advice on here I have come to the conclusion that for the road, Peugeot probably new best and that so far all I have succeeded in doing is buggering up all their hard work.

 

My ideal, would be to have it set up for a fast lap of the Ring/Cadwell so after considering all your advice so far, I have decided to go stiffer on the front. Interestingly, I came to this decision previously about a year ago and ordered some ASTs with 225lb springs. However, 2-3 months later I got bored of waiting and with no sign of their arrival, I cancelled the order.

 

So next question...do 225lb springs coilovers still seem a good balance with the rear (22mm TBs and 25mm ARB) for a Ring set up and if so which manufacturer? I'm happy to spend approx £2K. Once I've got this sorted its cage and Gti6 time....

 

Thanks for all your help so far.

 

 

Nick

Edited September 19, 2012 by Castorkid

[allanallen 528 2 Cars]

You're certainly in the right ball park with 225lb springs although personally I'd start around 200lb. 2k is a fair budget for front dampers, I can't recommend any at that price as I've never spent that kind of money on any!!

I'd be looking elsewhere though as AST seem to have terrible after sales/customer service, I'm sure welshpug will tell us different but I've first hand experience of a few dissatisfied customers.

 

I'd try and budget in a plated diff aswell

[welshpug 1,646]

Not at all Al great product, but poor old Curtis is run off his feet! I'd still buy them, as in my experience you wont need to rely on the backup too often at all

 

£1200 will get you either a full bilstein non adjustable (damping that is, not ride height) rally damper setup, though tbh you shouldn't need to adjust them, or AST's sportline 1's which are adjustable damping, sportline 2's are near 2k afaik, depends largely if you need rears as well as they take a fair chunk of the budget the higher spec you go.

Edited September 19, 2012 by welshpug

[matt.f 16]

LSD ftw,one of the best mods imo.

Plated the one to have

[Henry 1.9GTi 36]

I dont think sport line 2s are much more expensive, But the design should go someway to combatting side load induced stiction, atleast over the 1's anyway. I have yet to try out my sportline 2s but am definitely looking forward to it. The quailty looks second to none. I had the same experience with AST, although have met curtis and he is a really good chap. Just swapmed. You could try going to AST direct. I e-mailed them and got a very good response with prices for their entire range on a 205 including top mount and spring costs. They also sent me a .pdf on some of the technical specs of the range. Definitely worth a shot. I dont think you will get much better for the money. Unfortunately the next step up is some of the KW race stuff (quotes £4-7k from a very nice man in germany) ,ohlins who are supplied by Aurok in the UK, again they will be quite pricey but maybe within your 2k budget. They will use a standard bilstein strut body and fill it with nice ohlins internals to your spec, but you would have to sort out the drop link mount and top mounts. And then penske will supply a linear roller bearing damper for around £7k as per the 306 production touring car. Let me know if you want any info or contacts for the above. Personally I would keep your bilstein grpNs and maybe think about gaining rear end grip / loosing front end grip in other ways. Weight distribution, cambers etc.. Allan does some very nice -3deg rear trailing arms for example! Also double check your bumpstop clearence at the rear, caught me out a few times!

 

Good mention on the LSD as well, they will promote understeer so you could use that to change the balance as well.

Edited September 19, 2012 by Henry 1.9GTi

[feb 47]

Not at all Al great product, but poor old Curtis is run off his feet! I'd still buy them, as in my experience you wont need to rely on the backup too often at all

 

How long (in terms of miles) have you been running ASTs Mei?

 

In my Forester one of them started leaking after around 22k miles and I am not the only one having had this problem.

 

Ditto, a different car and x1.5 times heavier than a 205 but I am interested to know how they do on a lighter car reliability/mileage wise.

Edited September 19, 2012 by feb

[EdCherry 34 1 Cars]

22k miles isn't exactly bad, after all they are rebuildable for a reason.

[matt.f 16]

Proflex are very good too