Fitted Thicker Tb's

[Rich_p 23]

Will be fitting some 25mm tb's to the back of the 309.

 

Does having thicker bars raise the ride height due to less sag?

 

If we set the bolt centres the same as before will it still be the same height it is now?

[welshpug 1,657]

Q1, yep

 

Q2, nope.

 

 

 

try 310mm to start with, I "think" this would give you somewhere near standard height, easy enough to just slide them in and lower the car down on tis wheels to check how it looks.

Edited May 17, 2009 by welshpug

[Rich_p 23]

Thanks for that.

 

I think it's at 300 at the moment on standard bars so rather low. I might keep the distance the same and see how it goes from there.

[Baz 421]

25's!! What front setup sre you running and what ARB to match then?

[Rich_p 23]

Will be getting a 28mm arb for the rear. I have tarmac billies to go on too.

 

I'm looking for some front tarmac billies or similar and will experiment with springs but go from 250 or 275 upwards I guess.

 

When money allows I'll try and get some more neggy camber all round.

[Baz 421]

With 25's and a 28 ARB that'll be pretty hairy on the road, and trouser-browning in the wet.

 

To match the rears you'd want around 350lb springs at least i'd say!

[Rich_p 23]

I got them for an ok price so can always sell them and change if it's too hardcore.

 

It's for track use so I'll just have to be carefull on the journeys there and back.

[Cameron 16]

That's going to be a pretty scary ride!

[James_R 3]

With the right damping the car will be fine on the road, just tread carefully in the wet, my old 306 had a 25/30 rear end and I commuted 140miles a day in it all weather no problems (bar speed humps)

 

You're probabaly not too far wrong with 275 on the nose with that rear set up.

[Baz 421]

No offence James but we all know you're a bit nuts anyway, () and the 306 was a heavier car from the off so not really directly comparible IMO.

 

I don't mean be scared of it or be put off, it's just a massive jump from std, and certainly going to be very smooth tarmac orientated only, airfields will be a bit rough!

[James_R 3]

I would say the 205 was fine on it's 285front 24/27 set up, and it was, I blame the diff and Parada's in the wet more than the sus, with PE2's it's was alomost "fun" in the wet

 

Agree it will be a touch stiff for belgium motorways (or old WW2 airfields)

[Tom Fenton 1,542]

This makes interesting reading, I've got 225lb springs on the front of my car, just about to fit a 309 rear beam, with 23mm torsion bars and a 24mm ARB. I'm hoping it is not going to be too harsh for the road but we will see.

[Anthony 1,003]

So long as you're using decent dampers I doubt you'll find it too harsh for the road Tom.

 

When I went from standard 20mm to 22mm torsion bars in my 309 beam I noticed very little different to ride quality and the car was fine to use in all weather and road surfaces still. Shortly before I took the car off the road, I swapped back to 20mm torsion bars again, and again, didn't notice any significant improvement in ride quality.

 

I've driven both James's 205 with 24mm TB's/275lb springs and his 306 with 25mm TB's (can't remember the spring rate) and found the ride quality on both was surprisingly good, mainly I suspect because of the dampers they were running - AST's on the 205, and top spec Gaz's on the 306. Both cars I've driven non-stop over to the 'Ring with James fast asleep in the passenger seat to give you an idea, and I'd go as far as to say that both were perfectly useable on the road - yes a bit of respect was needed in the wet, but no more so that an standard 205 on cheapo budget tires I'd say.

 

Going back to the OP, I'd say that with 25mm TB's you'll need something around 290mm distance between shock centers - the car will sit much higher for a given height than it will on the standard 20mm TB's, and 300mm will make the car sit higher than standard I would suspect.

[309PUG 2 1 Cars]

Hi,

I had a 309 with 25mm TB's and a 28mm ARB with 425lb front springs (was not used on roads just a dedicated track car) and I would say that is the minimum spring poundage up front, I found this very over steary !!

 

PS I can make you a 28mm ARB or any other size if you want one.

 

Chris

[Cameron 16]

Wow, 425lb minimum! Is that on slicks though?

[skeggyrik 3]

My experience in fitting 23mm bars is here:

 

http://forum.205gtidrivers.com/index.php?s...&hl=torsion

 

Includes spacings used and pictures of ride height.

 

These 23's I have are for sale if the 25's prove too much btw

[Rich_p 23]

I'm slightly concerned they might be a bit overkill now as I will use it on airfields.

 

I didn't want to turn them down though as 24/25 mm bars for the 309 don't come up to often second hand and I didn't want to buy new.

 

On the look out for a 2nd hand arb too.

[James_R 3]

The 306 was running 400lbs front springs, and built for road tyres, I'd have been looking in the 800lbs area for slicks.

 

But to follow what Chris as said, the above rates were for road tyres, on semi slicks I found the 205 too soft on the nose, which although gave a "sharp" feel to turn in wasn't all that good it was just the sensation of body roll rather than a nice flat lateral change in direction. I'm looking at startign with 300lbs and a 309 front ARB this time and have 350's if needed.

 

As Anthony said provided you have good damping you'll be ok, I would try it first with a std rear ARB if you're on a bumpy surface and see how you go.

[Cameron 16]

I'm fitting 350lb fronts to mine and 24mm bars so I'll let you know how it works out (although you'll probably be finished before me). The car should be pretty light though, what with all the carbon porn.

[309PUG 2 1 Cars]

Wow, 425lb minimum! Is that on slicks though?

 

 

Of course old boy !

[AdamP 0]

What dampers are you lot using to cope with these huge spring rates? Bilsteins?

[James_R 3]

they're only good if you keep to the spring rates they're designed for on the fronts from what I've seen.

 

My 205 Had AST's on and now Gaz "Golds" or whatever they are. The rears are Billi tarmac GRP N's the motorspo ones

 

The 306 ran modified Gaz golds. and rears which were far too soft, but they're designed for std bars, I would have had them revalved if I'd kept it. (reads the engine hadn't detonated)

 

Really need an adjustable dampers if you're switching rates around.

[Cameron 16]

Thought so!

Mine will be 350lb on semis, and even that's probably going to be a bit harsh on the roads!

[James_R 3]

If you get the damping right it's ok really, you won't really notice it till you start trying to dive down pot holes, and the dreaded speed bumps, I hit the first one in mine at 20mph and the back pretty much bucked off the ground, so it's an uber slow mince on them (the rubber strip badboys)

 

I'm warming up on 300's so we'll see, be interesting to see how they fare as they're very similar suspension wise right now

[Cameron 16]

You haven't seen the roads around me then..