Suspension Overhaul

[Doof 11]

I think it might be time to overhaul my suspension a little. I've not done anything for about 5 years and while it's only done about 7k miles in that time, it's sat for long periods which probably haven't been kind and the knocking from the front brakes is worrying me.

 

Current spec:

 

Front - Bilstein Sprintline shocks with SBC Roadspeed springs. 309 Wishbones / driveshafts. 307 HDi calipers and standard pads.

Rear - 309 rear beam, otherwise standard with Bilstein sprintline shocks. The beam is lowered slightly and was bought rebuilt about 4 years ago. It feels ok but I can easily push the trailing arms up when it's on axle stands. I'm wondering if it could really do with a stiffer torsion bar. Also, as it's lowered slightly (and missing bumpstops) it scrapes the arches when i've got too much stuff in the boot. Obviously i need bumpstops but it worrys me that it scrapes so easily, even with just me in the car I've had a scrape. It's surely far too soft?

 

 

What to aim for to get it handling / braking superbly once again...

 

Front springs - I think they're probably ok. Some Eibachs might be nice.

Rear suspension - updated torsion bars, roll bars. I've absolutely no idea what thickness i should go for. Any thoughts?

Shocks - would it be wise to get them overhauled. Anyone know where it can be done and how much?

Brakes. Should I ditch the heavy 307 HDi calipers in favour of something lighter? Standard 205 calipers with good pads are ok on track days aren't they? (it's been ages since i did one but once i'm happy with the brakes I'd like to do another. I'm even wondering about hi spec 4 pots, though i'm not sure they're needed / any good...

 

Where would you spend the money with the given current spec?

 

Thanks for any help,

 

Lewis

Edited July 2, 2012 by Doof

[kyepan 291]

if the dampers have not gone, keep them.

 

21mm rear torsion bars, 24mm rear arb, zx arms, and solid beam mounts make for a stable solid and predictable rear end. Would say you need about 190-200lbs up front for it to feel reasonably even, I think that the eibachs progressive rate fronts are great for standard rear bars but perhaps a touch soft for uprated ones (*ducks), especially if you have an MI / GTI-6 up front.

 

Also don't lower it too much or you kill the camber that any camber mods such as 309 bones gives you.

I would also look into bump-steer kits, as any lowering is going to increase bumpsteer!

 

Brakes, if you can afford it, go lighter, i have 307hdi whoppers too, and would love a set of AP, avoid anything that isn't a road caliper with all the dust seals, or it will kill the piston seals quicker than you can inhale at the rebuild costs.. that and avoid willwood, they are not very durable, and have rubbish pads as standard.

 

307 Caliper 4kgs

HiSpec racing 4 pots 1.45kgs

 

Anything you can do to reduce unsprung mass is a win, will reduce axel tramp, increase the time the wheel is in contact going over bumps... hence the reason why i ended up with c5 alloys to offset the weight of the brakes!

Edited July 2, 2012 by kyepan

[Doof 11]

Any ideas where to get torsions bars / arbs?

 

Definitely going to get a bump steer kit from Bridgecraft.

[welshpug 1,655]

Anthony does torsion bars and ARB's, I would say stick a 205 beam on with the bars mentioned, stop that rubbing, also do fit the bump stops, you will wear through your fuel filler eventually.

 

 

is it a standard engine? I find standard 1.9 brakes enough, I also run the C5 wheels and Michelin tyres for much less rotating +unspring weight.

[Tom Fenton 1,540]

Chris Penrose (309PUG) also does uprated bars.

 

Getting the bumps stops sorted has to be top of the list. I would also have the beam to pieces for a clean, regrease and new seals at the very minimum.

 

With uprated bars you are struggling a bit for springs on fixed platform dampers unfortunately. There are the Peter Lloyd Rallying ones but you may find them a little high on ride height for a tarmac/track car.

[Doof 11]

Is the 309 beam not really worth keeping over the 205 beam then? I suppose the narrower track will get the wheels away from the arches which can only be good. I thought it was considered an upgrade.

 

Tom, You surely don't want the rear stiffer than the front. I can imagine it being very snappy like that. Would coilovers be the only option to compensate having stiffer torsion bars / ARBs at the back? Keeping the balance must be very important.

 

For reference the engine is an S16 lump so it's a bit heavier and should be running 220bhp ish.

[GeorgeXS 32]

Faulker springs can make you some custom springs to save you going to coilovers.

[Miles 331 1 Cars]

Bilstein directly now service them only down the road from you as well, If you need a contact name let me know.

I;d swap to GTi6 callipers, Pads are cheaper and disc's lighter (Cheaper again) and keeps a nice feel to the brakes, I know people say good 1.9 callipers are good but coming from anything modern to a 205 you find the brakes pretty poor

[Alan_M 66 1 Cars]

What to aim for to get it handling / braking superbly once again...

 

Front springs - I think they're probably ok. Some Eibachs might be nice.

Rear suspension - updated torsion bars, roll bars. I've absolutely no idea what thickness i should go for. Any thoughts?

Shocks - would it be wise to get them overhauled. Anyone know where it can be done and how much?

 

Brakes. Should I ditch the heavy 307 HDi calipers in favour of something lighter? Standard 205 calipers with good pads are ok on track days aren't they? (it's been ages since i did one but once i'm happy with the brakes I'd like to do another. I'm even wondering about hi spec 4 pots, though i'm not sure they're needed / any good...

 

For an occasional trackday & fastroad car, the shocks you have are fine. I run the Challenge shocks with Eibachs and is very nice indeed. But, you'll be limited to what you can match on the beam regarding bars.

 

If it was me (for an occasional trackday/fastroad)

• Keep the Sprintlines and pair them with Eibachs.
  
• Keep the beam torsion bars standard, but consider an uprated ARB? Fit a refurbed 205 beam. The rubbing on the arches from my 309 beam is getting on my tits.
  
• Fit new mounts and bushes everywhere.
  
• Fit 306 calipers/brakes (think you'll need the bigger MC though).
  

When I built my 205 all those years ago, I did the above except the 306 brakes, and the car handled very nicely. Was meant to have them but someone 'sold' me the wrong type and refused a full refund. Matt Cony had recently rolled his 205 and sold me his Wilwood 4 pots for a very good price (and have stood up to the job for the last 5 years).

[Doof 11]

Sounds like good advice to me but won't changing just the ARB upset the balance?

 

Any recommendations for where to get a refurbed 205 beam?

[Doof 11]

Took a look at the car tonight and something definitely isn't right with the rear beam. Can they be misaligned when installing? I didn't think it was possible but judging by the difference between the two sides and where the wheels seem to sit in the arches I'm thinking it is possible...

 

[welshpug 1,655]

could be a few things, mismatched beam front mounting brackets, worn bushes, bent components, worn bearings.

 

there isn't very much scope for misalignment when fitting to the body tbh.

[Anthony 1,002]

There is a small amount of slop in the beam mounting holes that will allow a small amount of movement/adjustment, but I'm not sure that it'll take that much difference out! Only thing I can think is that maybe it has a 1.9 beam mount on one side and a 309 one on the other, as they have differing offsets, or that something is distinctly bent...

[Alastairh 47]

Rear shocks do sound like they need checking out. Sound soft.

 

Al

[Alan_M 66 1 Cars]

Took a look at the car tonight and something definitely isn't right with the rear beam. Can they be misaligned when installing? I didn't think it was possible but judging by the difference between the two sides and where the wheels seem to sit in the arches I'm thinking it is possible...

 

 

Mine's like that too, and never worked out why!

 

Bodyshop confirmed shell is straight (I visited when the car was on the jig so checked myself). I'm now thinking of pulling the beam off (I'm swapping to a 205 beam anyway) and checking the mounts.

[Doof 11]

Dragging this thread back up as in ever really got to the bottom of the issues with the suspension. I took the beam off and put some bump stops on which has cured the rubbing. The beam is still clearly not straight though even though the mounts looked identical and nothing is obviously bent.

 

Any other thoughts on what this could be? I don't know where to go from here. Do I splash out on a new beam only to find out the shell is bent? Do I just ignore it and get the tracking done to match the crabbing car.

 

Talking of tracking, I've not had it done since putting the beam on and the wheel is quite far from centre. It was fine with the old beam on which makes me think its something to do with the beam not the shell.

 

Really not sure how to fix this damn issue.

[Alan_M 66 1 Cars]

As I'm facing a similar problem to you, I propose to start measuring my shell. There is a thread on here giving out previously unknown information regarding shell measurements.

 

http://forum.205gtidrivers.com/index.php?showtopic=144846

 

My rear passenger wheel is clearly toeing in loads compared to the drivers side. I'm hoping with simple measurements that it'll show a bent shell or the problems lies with the beam. Considering the old beam was bent after my smack with armco, and that the new beam didn't just 'slide' in (the threads on the stud rubbed against the hole, the previous beam didn't) kind of tells me the shell is slightly twisted/bent.

Edited October 28, 2012 by Alan_M

[welshpug 1,655]

I'd check that you havent got bent stub pins or trailing arms, or just non matching ones.