1.9 Rear Beam - Thicker Torsion Bars/arb/neg Camber/grpn Dampers

[Dino 3]

I am buying a rear beam which has the following spec:

 

Recently rebuilt rear beam

Bilstein GrpN dampers

24mm anti roll bar

23mm torsion bars (possibly 21mm - with any luck)

1deg negative camber

1deg toe in

 

My current suspension set up is as follows:

Std rebuilt & lowered rear beam

AVO adjustable sports dampers

 

Front suspension/drivetrain:

 

Quaiffe ATB LSD

AVO adjustable sports dampers

Eibach lowering springs

GrpN top mounts

poly wishbone bushes

 

My thoughts behind getting a higher spec beam are to match the rear suspension with the front however my car already has very good handling and is very neutral in the way it handles. When a car such as a 205 has stiffer springs and mounts upfront wouldnt it be wise to stiffen up the rear accordingly?

 

I'm just worried that I am going to ruin the balance of the car and have an oversteering and very bumpy/harsh riding car.

 

The new beam is currently on a race car and I am waiting to hear if it has 23mm tbs or 21mm items. I am hoping it has 21mm tbs as I think 23mm is far too stiff for what I need.

 

I have had a chat with Miles about this issue and had some very helpful advice and comments but was just wondering what any of you seasoned Gurus thought?

 

Oh and incidently here is an email a mate of mine sent me regarding this matter (he is a qualified racing driver and owns many 205s of varying specs including track cars and race cars)

 

Hi Dino

 

Cor --- what a bargain on that beam, would probably cost in excess £1000 to build from new parts? The car will oversteer *big time* now with all those thick bars at the arse end (for sure not assisted by the non adjustable Billies) and screw up any neutral balance you may have already dialed in. From memory - although I didn't push it due to only 3 wheel nuts, your car handled nice + neutral at Donington when I drove it.

 

You will need a massive increase on the front spring rate to get back the neutral balance due to the huge stiffness added to the rear (when I uprated the beam on the white car in Dec 05 to the same spec we had to up the front spring rates from 225 to 400 to stop the arse out antics) and then you end up with front dampers that don't have the correct rebound characteristics to manage the big springs. To make it all work to max benefit you really need some racey front coil overs although custom made std diameter front springs and possibly re-valve the front dampers would be a heath robinson fix.

 

Ultimately you will have a much better handling and quicker track car but it may well affect the ride qual and your desire to use the car on the road. So given all that I think the best thing to do is sell the beam to me before you totally screw up you georgeous car hiving spent a shedloada money in doing all the jobs to make the suspension work in it's new format.

Edited May 10, 2006 by Dino

[mfield 20]

could always try it with a 309 gti front arb with 300lb springs and if you hate it sell the beam on for a profit. Bit of a hassle but there will be no what if's then

[SimonJ 2]

I also have the 24arb 23tb setup. Even for a hillclimb car (we use closed public roads over here so not as smooth as GB hills) with hindsight I would go for 21mm tbs as a good compromise for variable weather conditions. It's like on rails in the dry but needs treated with caution in the wet. Then I have only 225lb fronts; maybe it would be better with 275lb, which a lot of people seem to have.

[Dino 3]

I have found out that the torsion bars are definitely 23mm items. Anyone with 21mm torsion bars want to swap for 23mm ones?

 

I'm gonna give it a go with the 23s and see what it's like first.

 

Does anyone have any idea what rate my Eibach springs are?

[tom_m 0]

do you wanna ride in mine dino (see sig for suspension details)? you're not that far from me now.

 

If you're happy with your car as it is and don't want a harsher ride i would say don't upgrade, or if you insist on upgrading go for 21mm bars. 23mm will be over kill unless you're dedcating yours to the track

[Butler 0]

Upgrade. Worst case is you have to ebay the bars and by 21mm ones new. Assuming you don't destroy your car in testing. lol.

 

Richyboy can test drive the car for you if your like. lol

[Dino 3]

Yeah I'm definitely upgrading there is no doubt about that! X Sport have put the word out that 23mm are up for swaps with 21mm if anyone wants to

 

Tom that sounds like a plan mate - whereabouts in Herts are you?

[veloce200 3]

Yeah I'm definitely upgrading there is no doubt about that! X Sport have put the word out that 23mm are up for swaps with 21mm if anyone wants to

 

Tom that sounds like a plan mate - whereabouts in Herts are you?

 

just change your driving style and don't ever go out in the wet again. You'll be able to drift it in the dry !

[tom_m 0]

Tom that sounds like a plan mate - whereabouts in Herts are you?

 

its basically harlow, so dead easy to get down to your neck of the woods

[Wurzel 16]

With good tyres it's not too bad in the wet either as I found out last Sunday. First time I really pushed it on the 'quick drive' and it gripped suprisingly well. I've always been very cautious in the wet before and accepted that I have a 'dry weather' set up.

 

It is a lot firmer (as you'd expect) over standard, depends on how you percieve comfortable though. The back end seems planted but able to drift it out when pushing hard on roundabouts, very controllable. Despite everyone guessing the rear end will be very twitchy, I don't find it to be so. With the thicker arb, you will deffo notice the sharper turn in. It can catch you out at first, but like anything else, you quickly get used to it.

 

I went back to standard bars (309 GTi) whilst waiting for the 23mm TB's and 25mm arb. The front went back to standard as well. I didn't like it one bit and didn't drive it until I'd fitted the new bars again.

 

I think the only thing you can do is try it out yourself

[205turbo 32 2 Cars]

here is my beam it should be all built up and ready to be fitted to my TT by the weekend its going to be a decicated track car its going to be 25mm torsion and 25mm arb, but might change these to 23mm / 25mm if is to twitchy for me.

 

 

[Alastairh 47]

Thats what you want Dino, very bling.

[Dino 3]

Thats what you want Dino, very bling.

 

Thats not bling!

 

THIS is bling:

 

http://smg.photobucket.com/albums/v324/din...nt=DSC01498.jpg

http://smg.photobucket.com/albums/v324/din...nt=DSC01496.jpg

http://smg.photobucket.com/albums/v324/din...nt=DSC01463.jpg

http://img.photobucket.com/albums/v324/din...am/DSC01461.jpg

 

Das' beam

[Alastairh 47]

Point taken.

 

Man that man has soo much patience.

[Wurzel 16]

I could nit pick but I can't be arsed

 

Nice looking beam

[B1ack_Mi16 67]

Mine, with 266x20mm vented discs

 

http://cortex.fa-s.ntnu.no/~kristian/205gt...06/CIMG1009.jpg

[pdd144c 0]

Just get it on there u big girl

[Dino 3]

Well the beam is on the car now

 

I went down to X Sport Racing today and had it fitted and many thanks to Greg and Miles for fitting it for me today of all days when they shouldnt really have been working!

 

There are a few teething issues with the beam that need to be addressed - namely the fact that both rear tyres are scrubbing the inside of the inner arches! Miles recommends some 3mm spacers so I will be ordering a pair of those pronto!

 

I didnt really have a chance to test the handling out on the way home as it was raining and I was wary of it.

 

I went out for a little spin after I'd got home and the roads had dried out and all I can say is WOW

 

The car corners like its on RAILS!!!! Its amazing! Turn in is sharper and the car feels much flatter on cornering. Oh the grip!!! I cant wait for the next track day now lol

 

It seems pretty smooth and compliant on most surfaces except the worst can really unsettle it and it does crash of the really uneven surfaces which is a little unsettling. I also had some GrpN rear beam mounts - could that be why its so noisy over bad bumps? Perhaps they need to bed in?

 

Overall one very happy Dino!

 

Oh and incidently a BoxsterS in front of me tonight decided he was in a hurry so I chased him briefly through some twisties! Lets say that he was humbled somewhat by my 13 year old French tinpot!!

 

Oh and here are some pics of the rear end

 

http://smg.photobucket.com/albums/v324/dino355/205/Beam/

 

Check out that neg camber and toe in

[Wurzel 16]

Told you

 

So what gives the camber and toe in adjustments then? SCB stuff or alternatives?

[Dino 3]

Told you

 

So what gives the camber and toe in adjustments then? SCB stuff or alternatives?

 

nothing like the SBC one which has some kind of spacer plate added to the trailing arm. Mine has a mod to the stub axle pin apparently (Im not good with the techie stuff )

[Alastairh 47]

Looks good.

[pdd144c 0]

Tidy!

[smckeown 1]

how many degress of neg. camber is that ? looks a lot for a road car

[tom_m 0]

bloody hell thats a lot of toe! looking good dino! sod 3mm get some 15mm hub centric and benefit from extra width too!

[Dino 3]

how many degress of neg. camber is that ? looks a lot for a road car

 

It's supposed to be 1deg but it looks like a lot more!!

 

It's not all great though - the car THUMPS over bad surfaces like you wouldnt believe - it feels like steel banging on steel - surely thats not right!?