Suspension bush options for e87 130i?

[Herbmiester 923]

I bought Koni SA's for my E92 after listening to some good debate here a few years back. I have also run Konis and Bilsteins on my various E36's over the years. My observations are as follows. The Koni SA when set up correctly on my E92 combined with M3 control arms and Tein springs has certainly made the car handle noticeably better than  stock and even with the transition from 17" to 18 inch  kept ride comfort acceptable on the rough roads where I live. On the highway the suspension works very well and I definitely have a more control in faster corners. Dialing the rear end in is a complete pain in butt as you have to remove the shock to  change the setting. The front is fine as you can adjust through the strut tower. Overall I am happy but the car needs an LSD but this will no doubt mean I need to change my roll bars to help dial out under-steer which is reasonably well controlled at present. although an LSD may allow me to rotate the car with the throttle something the E90 M3 owners I have talked to say works well. 

On my E36's I could not feel a noticeable difference between a B8 equipped 325i and Koni SA equipped car. Both I felt handled well but the Koni car had Re003's and the Bilstein car had Pirellis which I did not think were as good. I have a good test drive course, Whitemans Valley, and when things are not right it becomes pretty obvious. The best car through the valley was my E46 330ci with Ohlins Road and Track suspension, with Superpro bushings and revised roll bars, great ability to deal with the bumpy surface while still giving great feel and confidence in the corners. 

Edited June 29, 2020 by Herbmiester

[Herbmiester 923]

P Zero Rossos, dry grip was fine but average in the wet and they just felt a big vague.

[Herbmiester 923]

My Ohlins setup was quite stiff and I had 003 245's all round on the 330ci and that was a very neutral car with pretty high levels of grip. By the time I get 3 minutes into the valley I have turned 25 to 30 corners so I suspect getting heat in them is no problem. 

[PRC 7]

Visited my suspension and brakes specialist today for a detailed assessment. The dampers, bump stops and radius arm bushes are worn, and everything else is in good condition. So, fewer new parts required than first thought:

• Koni sports adjustable dampers
• BMW Performance bump stops
• Superpro radius arm/bushes
• Michelin Pilot Sport 4 tyres

Any recommendations on best source for Koni dampers? A NZ supplier preferred, but will order from reputable off-shore supplier if no local recommendations. Thanks.

Edited July 1, 2020 by PRC

[Herbmiester 923]

Price from NZ, Stocks and perhaps Adens tyres and then look at Demon Tweeks. DT were substantially cheaper even after freight and GST. That said I would prefer to shop local and would pay a small price premium over imported. 

Are the radius arm bushes replaceable of do your replace the whole arm?

Edited July 1, 2020 by Herbmiester

[PRC 7]

2 hours ago, Herbmiester said:

Price from NZ, Stocks and perhaps Adens tyres and then look at Demon Tweeks. DT were substantially cheaper even after freight and GST. That said I would prefer to shop local and would pay a small price premium over imported. 

Are the radius arm bushes replaceable of do your replace the whole arm?

Thank you. My suspension guy is checking with Stocks and I'll check Demon Tweeks for a private import comparison. Like you, my preference is to shop local (less hassle!). Also, we are checking option of radius arms complete v. replacement bushes (both are available from Superpro, apparently).

[PRC 7]

Order for Koni sport adjustable shocks placed (via Demon Tweeks).

BMW performance bump stops, and Superpro radius arms complete with bushes etc. will be ordered tomorrow.

Now we wait.

[PRC 7]

2 minutes ago, 3pedals said:

what did you pay for the front Konis? 

about £143 each.

[M3AN 4016]

It doesn't take much to make these cars ride a lot better and since the rear is terrible compared to the front (stock) then you should be in for a pleasant surprise.

[M3AN 4016]

You may be interested in this snippet from Koni themselves...

https://www.babybmw.net/viewtopic.php?f=11&t=129535

[Herbmiester 923]

I am a bit frustrated with my rear Konis. Such a pain to adjust that I am not sure I will bother. I did hours of reading to work out the best setting (I am using Tein springs with M3 spring rates) but I think I need a wee bit less rebound damping. I had this discussion with a friend in Sydney and he has a 330i sedan and chose a matched setup from Bilstein. He is of the belief after doing all the same reading I did that he has got it right. The suspension specialist he went to re-valves shocks and sets up race cars and was of the opinion that the Bilstein is a superior design and as long as the spring is matched will perform better. I would say technically he is correct re design. 

[Herbmiester 923]

4 minutes ago, 3pedals said:

Which specific vehicle are you talking about,  

what is the actual spring rate, what is the roll bar size, what have you set the rebound control to?  what is the ride height 

 repeat for the other end of the car 

 

All factored in. Not looking for advice just stating what a PIA adjusting rear Konis is. Will certainly give greater consideration towards Bilstein next time.  

[Herbmiester 923]

I am at one turn from memory, written on the shocks so will check at some stage, its Ok just not optimal. My take is that  the Koni is a twin tube design  and the Bilstein's are Mono so would say technically Bilstein is a better design. 

[Herbmiester 923]

30 minutes ago, 3pedals said:

Pretty sure the Koni is a mono tube and  twin tube are not inferior  to monos, just different. The advantage of a twin tube is the outer tube acts as an oil reservoir  so if you are looking for a long stroke shock in a short overall length twin tube  is often the way to go. The shocks for E87 /90 are a long body shock with a medium stroke so no need for TT 

The disadvantage of TT is they can over heat 

At one turn is suggests there are other issues, my pick is spring rate and possibly roll bar. 

 

They are twin tube and in day to day driving they are probably no better or worse but for performance applications a Mono is better. Spring rate is as E92 M3 and bar is 13mm so a bit smaller than M3. Control arms are M3 and were torqued at ride height so no issues. Only issue is I dialed in a bit too much rebound damping and its ok, but dialing in a little less would be optimal. As I wasn't using matched springs from Koni getting the damping right was always going to be an experiment. Got close second time round, may do it again when I put the car on the hoist to decide whether or not to remove the cats. 

[Herbmiester 923]

The Teins are actually pretty linear, yes a Little bit softer in initial rate but that extra little bit of compliance certainly helps on brittle surfaces. Most of the guys I talked to about them pair them with KW or Bilstein's I was told by one chap that he didn't like the Koni/Tein setup as much but I cant find the email detailing his reasons. I guess I was spoiled with the Ohlins setup on my E46, I felt that even though I had slightly higher springs rates than I have in my E90 it was a bit more compliant. Looking at the valve stack on a Koni I think its not particularly sophisticated.  

[Herbmiester 923]

The H&R's dont have the spring rate I am looking for which is why I dismissed them in the first place. I have the right springs just need shocks that will suit. All that said I am very close to my goals and with the rear being much better located due to the M3 rear arms I am only looking at minimal gains. I have driven an H&R sprung E90 on stock control arms and I feel my current setup is a little bit better especially over rougher surfaces. Through Whiteman's valley and over the Rimutaka's I had less rear end roll so just about there.

As to the stroke there is enough length for a monotube to work in this application so no need to stay with twin tube. 

 

Edited July 26, 2020 by Herbmiester

[Herbmiester 923]

5 hours ago, 3pedals said:

Too many anomalies, contradictions, inconsistencies  and some  flaws coming into your  narrative as you evolve it - good luck with that 

Not really as usual it just doesn't agree with your narrative so therefore you dismiss it. Same old Ron. 

[PRC 7]

Koni dampers arrived yesterday (8 days from UK, thanks Demon Tweeks and Parcel Force), so everything Is now on hand for fitment next week. ?

[PRC 7]

Thinking ahead to fitting the new Koni Sport dampers, radius arms and tyres....

Keen to hear any guidance about fitting the rear dampers, including what interior panels need to be removed?

Thank you in advance.

[Jacko 2156]

2 hours ago, PRC said:

Thinking ahead to fitting the new Koni Sport dampers, radius arms and tyres....

Keen to hear any guidance about fitting the rear dampers, including what interior panels need to be removed?

Thank you in advance.

The ones left and right of the boot, its about 5 min to get access. The rear end is easy.

 

[Herbmiester 923]

If you are looking to do radius arm its worthwhile considering the M3 setup. A lot of people just do the front as this gives you some more camber and stiffer bushes. The rear is often touuted as having less noticeable improvement but for me it was noticeble as the rear had a more stable feel on change of direction, it just felt more precise. When you look at the rear arms they are just folded steel, which at 75k had some very sloppy bushes.

[PRC 7]

On 8/1/2020 at 10:56 PM, Herbmiester said:

If you are looking to do radius arm its worthwhile considering the M3 setup. A lot of people just do the front as this gives you some more camber and stiffer bushes. The rear is often touuted as having less noticeable improvement but for me it was noticeble as the rear had a more stable feel on change of direction, it just felt more precise. When you look at the rear arms they are just folded steel, which at 75k had some very sloppy bushes.

Thanks John. My suspension specialist thought the bushes in the rear all ok (an in situ check). But he will check them again when the dampers and radius arms are fitted.

Edited August 6, 2020 by PRC

[PRC 7]

New dampers (Koni Sport, adjusted half-turn front and full-soft rear), radius arms (Superpro), bump stops (BMW performance) and rear shock mounts (OEM) now fitted, along with a fresh set of Pilot Sport 4 tyres (36 psi). The car is now settled when driven, and it is quieter and more comfortable than before too. Thank you for all the advice, which has been most helpful.

[Herbmiester 923]

5 hours ago, 3pedals said:

Congratulations - you  managed to navigate the treacle laden  minefield of suspension advice and get a good outcome - enjoy. 

AKA you did what I recommended. LOL.

[PRC 7]

4 hours ago, Herbmiester said:

AKA you did what I recommended. LOL.

??