Turbo ARB's

[zcacogp]

Chaps,

A quickie.

My S2 has the smallest size of ARB on it (I seem to recall that there are three front sizes and two rear sizes.) I have been offered some "944 turbo" ARB's - both of them, secondhand.

So, a couple of questions.

1. Did all turbo's have the same size of ARB? If so, what was it?
2. What is a reasonable price to pay for boh front and rear ARBs?
3. Is it worth swapping for larger ones? (I am guessing so.)
4 Do ARB's "Go Off" or "Wear Out" with time? I know that springs slightly lose their springiness, do ARB's suffer the same to any noticable degree?

Having fitted new bushes to mine about 18 months ago I am pretty au fait with the process of swapping them, and assume that all I will need to fit larger ARB's is the correct size bushes - they will fit into the existing holders OK. Can anyone confirm (or deny) this?


Oli.

 

[James_G]

Oli

I have the larger ARB on the rear (18mm vs 16 mm IIRC) and I struggled to fit some new bushings so popped in to the OPC to compare the two sizes. They were identical but the inner diameter was less for the 16mm one so for the rears at least, same holder I would say.

But....remember my tale of woe of shearing off a bolt in the captive nut on the torque tube? Rear ARB bushing holder............[]

Good luck

 

[Fen]

I think it's a bit hit or miss which ARBs a Turbo would have had. Your suggestion that there were 2 rear and 3 front sizes across the range rings a bell, and I think 26mm, 28mm and 29mm might even be the front sizes though as that's from memory I could be very wrong (Thom is goos on this stuff I think).

I believe that '89 had the thick ones and that early cars had smaller ones and they got thicker until '89 then got thinner again for '90. There may also have been jiggery pokery in terms of the combination front vs. rear.

In terms of fitting them at the back I have no recollection right now of how they mount (an age-related problem I assume), but on the front the ends should fit into the bushes you currently have as they all taper to the same size but the middle ones bracketed to the car will have to be the correct size. The brackets themselves are the same though, it's only the thickness of rubber that changes.

 

[Diver944]

Oli I'm just out the door so no time to check myself but look at PET on the Porsche website. It lists all the ARB sizes in the suspension section

 

[appletonn]

So Oli, have you now seen the light and decided to convert your car to a Turbo piece by piece...?![]

[][]

 

[TTM]

"944 turbo ARB" is like "M030", it does not mean much if the year and model are not listed along.
Also the PET is a not the best help on the matter of which ARB goes on what model. I have seen discrepancies between some turbo 220 and the official litterature.

Physically ARBs are exposed to torsional stress. When checking a used one put it on a perfectly flat surface and see what happens.

First make sure what sizes are on your car.
What suspension set up do you have for now?
I have found the original 26.8 mm front ARB of my S2 good enough for any set up softer than M030 and for general road use. If you run nothing more "serious" than M030 you may actually only want to modify under/oversteer by fiddling with the size of the rear ARB.
I upgraded the original 16 mm rear ARB of my S2 with an 18 mm and I don't see myself going any further for road use.

 

[zcacogp]

Chaps,

Thanks for the replies.

PET - why have I never come across that before! What a fantastic document. Now downloaded, and carefully studied - thanks Paul!

It lists the fronts as being 21.5, 25.5 or 26.8mm and the rears as 14, 18 or 20mm. I think I have the smallest of each on my S2, although it sounds like I need to check both that which I currently have as well as that which is being sold. Thanks for the advice.

Fen - you've confirmed what I had dim memories of in the back of my mind. When I changed the ARB bushes on my S2 about 18 months ago, they sent me the wrong size of end bush for the fronts, and hence they didn't fit the bar but they did fit the housing. Sadly, I have just checked and discovered that I binned the incorrect bushes they send me initially - crying shame, as I will now have to go and buy some more (if I change the ARB's!) It really grates to have to buy things that I have thrown away!


Oli.

 

[zcacogp]

James - thanks ... I had the ARB's off mine a while back, and think they should shift without too much grief.

Nick - I won't dignify that comment with a response. []
Oh bu99er, I just did. []


Oli.

 

[Big Dave]

Oli.
The best upgrade is to fit a set of 968 M030 arb,s . They are 30mm fronts + 19mm rear..
They are ... £273.40 incl bushes from Exeter OPC.... Ive just priced them up last week .. For somebody else....
Yes they will fit to a S2 as i did it to my old one....

 

[appletonn]

ORIGINAL: Big Dave UK

Oli.
The best upgrade is to fit a set of 968 M030 arb,s . They are 30mm fronts + 19mm rear..
They are ... £273.40 incl bushes from Exeter OPC.... Ive just priced them up last week .. For somebody else....
Yes they will fit to a S2 as i did it to my old one....

Hi Dave - just thinking about booking for Oulton this Saturday with MSV, still a few places left and it might even be dry....![]

 

[Big Dave]

Go for it Nick.
I wont be there , as my car is having some "surgery" soon...
Nothing bad, just few more "tweeks"....[][][]
First outing is the Rs day..

 

[Peter Empson]

ORIGINAL: Big Dave UK

Go for it Nick.
I wont be there , as my car is having some "surgery" soon...
Nothing bad, just few more "tweeks"....[][][]
First outing is the Rs day..

You can't leave it there Dave... I'm far too impatient to wait till Oulton to find out what you're having done. Any hints? []

 

[Fen]

Actually I'd disagree the "best" upgrade is 968 ARBs. Yes they are better than any of the 944 ones, but they are still not great.

The best (IMO) is Weltmeister as they are proper adjustable and come with proper solid mounts for the front so they don't wobble about. Downsides are the weight and the US origin (purely from a shipping & currency exchage perspective).

 

[TTM]

Not sure what's on Oli's car for shocks/springs but if it's the original tired ones then 968 M030 ARBs won't provide the expected improvement and handling might be even worse than before.

 

[Fen]

Oli's suspenders are quite fresh.

 

[sawood12]

Fen's right - you're not going to notice much of a difference between the different OEM sizes of ARB. It certainly won't be night and day. I'd say the first thing to do is to ensure your current ARB's are working properly.

I think as a first step and not a particularly pricy one is to make sure your current ARB's are working fine (Weltmiester ARB's are very pricy!!) That means replacing all of the bushes for brand new standard ones or poly ones (if you can stand the squeaking) as I can guarantee that your current ones if old will not be working great. Also I feel the front drop links are not a great design. They are just flat plates which can bend and buckle as the ARB location point is loaded in compression thereby not working the ARB as hard as it could be. For about £20 you can buy the KLA Industries ARB drop link brackets which triangulates the drop down links and prevents them from buckling. If you are still unsatisfied with your ARB's after this then it is time to look to upgrade.

 

[zcacogp]

ORIGINAL: Fen
Oli's suspenders are quite fresh.

Ooo-er Mr Coull! And to think - you accused me of flirting with other members on here just the other day!

He's right tho'. Shocks were done about 20k* miles ago, with Koni adjustables. Poly bushes from Powerflex were fitted at the same time. I have yet to do the camber mounts, but they will follow soon (hopefully.)

Triangulation plates are a good idea. Although I suspect I'll make some rather than buying them.

Scott, Thom, thanks for the input. I'd have expected a fair difference from the larger ARB's, but have just found out that the second hand ones I had my eye on are the same size as the ones on the car, so won't be buying them! If even the bigger turbo ones are not going to make that much difference then maybe I should start thinking about other options.


Oli.

* - 20K miles. Flip me, time flies eh! I clearly remember struggling to do that job in the heat of the summer around 18 months ago.

 

[Big Dave]

ORIGINAL: Fen

Actually I'd disagree the "best" upgrade is 968 ARBs. Yes they are better than any of the 944 ones, but they are still not great.

The best (IMO) is Weltmeister as they are proper adjustable and come with proper solid mounts for the front so they don't wobble about. Downsides are the weight and the US origin (purely from a shipping & currency exchage perspective).

Fen.
Ok "best" poss wasnt to most apropriate word....
It all depends on how much "messing about" Oli is wanting to do.
Personally i think the Welts are a step to far, especially for a road / occasional track car...In fact im not even contemplating fitting a set + ide say my car is more track than road now... Just too many variables / adjustments + too much messing around to try + "dial" in the correct / comfy settings...Not to add the extra weight.. + "we" dont want more weight... [][8|][][8|]

PS.
Pete, im not having it done,, more doing it myself....Nothing too radical....[][]

 

[pauly]

ORIGINAL: Big Dave UK

Oli.
The best upgrade is to fit a set of 968 M030 arb,s . They are 30mm fronts + 19mm rear..
They are ... £273.40 incl bushes from Exeter OPC.... Ive just priced them up last week .. For somebody else....
Yes they will fit to a S2 as i did it to my old one....

Dave,
Do you have the part numbers handy, or a link to them, I was going to poly bush my ar bars but it doesn't seem much more to upgrade them.

Paul.

 

[zcacogp]

Paul,

Bushes from Powerflex are about 12 quid a pair. And I think it takes three pairs to do the whole car.

It's MUCH cheaper than new ARB's!


Oli.