phazed Posted October 23, 2023 Report Share Posted October 23, 2023 Was just about to order some Black series ARB bushes from Powerflex. I noticed there are different thicknesses of ARB bushes available. I have a 24mm front and an 18mm rear. Powerflex list 19, 20 and 21mm ARB Black rear bushes and 24mm and 23.5mm ARB Black front bushes. Now I’m questioning my measuring at the front as my ARB has lost its powder coating and has a smattering of rust so it’s hard to measure. accurately. The rear, which I measured at 18 mm May will be a 19mm I guess with the powder coating. What are the standard ARB’s on a 2002 S? if I stay with these ARB’s, I can always use the 23.5 and squeeze the ARB in rather than the other way round. Are there stiffer upgraded ARB‘s available before I order bushes for my standard ARB’s? Carl will be used for Track Days only so stiffness is paramount. Quote Link to comment Share on other sites More sharing options...
MickH Posted October 23, 2023 Report Share Posted October 23, 2023 Pretty sure Eibach do an ARB. Quote Link to comment Share on other sites More sharing options...
½cwt Posted October 23, 2023 Report Share Posted October 23, 2023 D911 list an H&R kit with 26 & 22mm bars. 23.5 is standard front for M030 sports suspension on the 2.5/2.7 and is standard on the S. 19.2 is standard on the rear of the S, with 19.8 on the M030. Hope this helps. Quote Link to comment Share on other sites More sharing options...
edc Posted October 23, 2023 Report Share Posted October 23, 2023 The issue is just like springs and dampers you will struggle to find any actual data to qualify whether a spring is stiffer. And of course you need 2 sets of data to evaluate that. Quote Link to comment Share on other sites More sharing options...
phazed Posted October 23, 2023 Author Report Share Posted October 23, 2023 I haven’t driven the car so I’ve no idea what standard suspension is like. Is the S quite taught as standard? I will upgrade the suspension at some point when I become confident with the mechanics of the car. Quote Link to comment Share on other sites More sharing options...
edc Posted October 23, 2023 Report Share Posted October 23, 2023 Personally I would not change the arbs now unless knackered. If yours is going to be a full time track car then you'll probably want to uprate the springs and dampers anyway and certainly aspects of the braking. At that point you might look at the arbs for a bit of fine tuning. Quote Link to comment Share on other sites More sharing options...
phazed Posted October 23, 2023 Author Report Share Posted October 23, 2023 I will get the car up and running and tested out to see what the suspension is like I only have experience of my own RS60 with its standard and sports suspension setting, which I find very good. Looking forward to seeing what this is like. A good suggestion to wait and see. The car has new standard springs recently fitted but looks like it has the original dampers which I’m sure will be past it. I do like my cars on track to have some suspension feel, not looking for a “hard as nails“ride. Maybe a set of upgraded dampers with the standard springs and stiffer bushing on suspension will be sufficient. I want to run a track car that is safe and fun to drive, not the fastest thing out there, which it certainly won’t be on my budget! Quote Link to comment Share on other sites More sharing options...
½cwt Posted October 23, 2023 Report Share Posted October 23, 2023 6 minutes ago, phazed said: I will get the car up and running and tested out to see what the suspension is like I only have experience of my own RS60 with its standard and sports suspension setting, which I find very good. Looking forward to seeing what this is like. A good suggestion to wait and see. The car has new standard springs recently fitted but looks like it has the original dampers which I’m sure will be past it. I do like my cars on track to have some suspension feel, not looking for a “hard as nails“ride. Maybe a set of upgraded dampers with the standard springs and stiffer bushing on suspension will be sufficient. I want to run a track car that is safe and fun to drive, not the fastest thing out there, which it certainly won’t be on my budget! Remember the bushes are part of how the suspension works, particularly the coffin arms. Going too stiff on the rubber can overload the coffin arms and is known to have lead to failures. Competition coffin arms are £££. Quote Link to comment Share on other sites More sharing options...
phazed Posted October 23, 2023 Author Report Share Posted October 23, 2023 That is interesting.. are you saying that the existing coffin arms actually fail! ? wow! maybe when I get to that stage, I will just use the purple Polly bushes and not just the black. I will do some investigating. Of course, I haven’t tried the car yet. I do know that my RS60, completely standard and handles brilliantly on the track. I wouldn’t want it any stiffer then with the sports mode engaged.. I’m assuming that this car bar by reverse development won’t handle as well, we will see. Quote Link to comment Share on other sites More sharing options...
½cwt Posted October 24, 2023 Report Share Posted October 24, 2023 5 hours ago, phazed said: That is interesting.. are you saying that the existing coffin arms actually fail! ? wow! maybe when I get to that stage, I will just use the purple Polly bushes and not just the black. I will do some investigating. Of course, I haven’t tried the car yet. I do know that my RS60, completely standard and handles brilliantly on the track. I wouldn’t want it any stiffer then with the sports mode engaged.. I’m assuming that this car bar by reverse development won’t handle as well, we will see. If you put too much load into them by putting in very stiff polybushes, yes. The inboard ends and the tuning fork joints work by clamping the central bush (which is why you must always torque up the suspension bolt with suspension in the position as if the cars was on the ground, Z=0, not at full droop with it in the air) and the rubber around them flexes as the suspension moves. If you make that bush more solid the forces have to go somewhere.... Quote Link to comment Share on other sites More sharing options...
phazed Posted October 24, 2023 Author Report Share Posted October 24, 2023 Thanks for the tip. Most useful. Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted October 24, 2023 Report Share Posted October 24, 2023 Yes I think I remember a post about overly bushed arms and the unintended consequences - ie, don't do it again. Wait and see sounds good. The plus point is, once you've reassembled to see how it feels, disassembling is so much easier as everything should free up simply. Quote Link to comment Share on other sites More sharing options...
phazed Posted October 24, 2023 Author Report Share Posted October 24, 2023 Exactly. Just dropped the cats and the rear main silencer to my Welder/metalworker friend. He’s going to grit blast them and see if he can tidy them up to save me a few quid until other things are sorted. Quote Link to comment Share on other sites More sharing options...
Patt Posted October 25, 2023 Report Share Posted October 25, 2023 I put black series on my OEM ARB's. I had the smaller ARB on the rear, coupled with B4 shocks, New OEM coffins and OEM M030 springs. The chassis is stiff as standard - just stick the jack on the rear point and watch it lift the whole side up ! Quote Link to comment Share on other sites More sharing options...
½cwt Posted October 25, 2023 Report Share Posted October 25, 2023 2 hours ago, Patt said: I put black series on my OEM ARB's. I had the smaller ARB on the rear, coupled with B4 shocks, New OEM coffins and OEM M030 springs. The chassis is stiff as standard - just stick the jack on the rear point and watch it lift the whole side up ! But if you watch carefully the door gaps do move a small amount when you do it!!! Quote Link to comment Share on other sites More sharing options...
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