[samj2k]

Has anyone ran KW HAS and swapped to BMW M Performance HAS? I've had the KW fitted with a full geo and corner balancing. The ride height is perfect, and on a smooth road the handling is completely transformed, but they are very harsh, it feels like I'm in Sport+ all the time, on our UK roads, it's not ideal. Does anyone know if the MP HAS Kit is any softer or would it just be the same? Don't want to pay for fitting and more suspension just to find out it's exactly the same.

[samj2k]

So I tried to find out spring rates for both the BMW HAS kit and the KW HAS kit and received the following:

"The springs used on the KW HAS kit are progressive just like the design of the original springs from BMW so the kit should not be really harsh! These types of springs have lots of different spring rates through them so we have no record of the rates. The springs have to work with the BMW damper so again the rates cannot change greatly from standard.

We have zero information on the BMW HAS kit springs as this is private to BMW and not released, but I would expect them to be the same as the KW kit or very close due to the working with the BMW damper.

2 reasons for a less comfortable ride are tyre size and ride height. The lower the ride height the firmer the ride so you could try raising the car maybe 5mm and this can make a big difference."

I have actually raised the rear about 10mm as it was sitting too low and seems to be a little softer, but still definitely no where near OEM level of comfort. Really can't tell much different between comfort and sport now. I may try the BMW kit later in the year. My suspension shop has a spring tester coming so I'm going to buy the BMW HAS and test the spring rates, if they are softer, I will go down that route.

[samj2k]

They've got back to me again, still no spring rates, but they confirmed the following:

KW do make the BMW HAS kit but the agreement between BMW and KW Germany is private so no information about the BMW kit is made public.

[Simon H]

Try and have a drive in an M5 CS, imho the suspension is outstanding, it is so compliant, and the initial 1" of travel is far more forgiving and comfortable, than the Competition, and stays so flat when cornering. You could then maybe find out just what spring rates the CS is running, and we know it has the M8 dampers, just like the LCI Competition, allegedly.

[samj2k]

Originally Posted by Simon H

Try and have a drive in an M5 CS, imho the suspension is outstanding, it is so compliant, and the initial 1" of travel is far more forgiving and comfortable, than the Competition, and stays so flat when cornering. You could then maybe find out just what spring rates the CS is running, and we know it has the M8 dampers, just like the LCI Competition, allegedly.

I'm a little scared to try the CS at the moment, I'll probably end up buying one and my FA keeps telling me I'm spending too much money on cars. Think I'm going to give the MP HAS a go. Also thinking that as it's a BMW part, when I come to sell the car it might help, probably not, but trying to justify going through 3 sets of lowering springs in the space of two months. I want height adjustable so my suspension guy can do corner weighting. Also trying to get any spring rates from BMW is proving difficult.

[Simon H]

Originally Posted by samj2k

I'm a little scared to try the CS at the moment, I'll probably end up buying one and my FA keeps telling me I'm spending too much money on cars. Think I'm going to give the MP HAS a go. Also thinking that as it's a BMW part, when I come to sell the car it might help, probably not, but trying to justify going through 3 sets of lowering springs in the space of two months. I want height adjustable so my suspension guy can do corner weighting. Also trying to get any spring rates from BMW is proving difficult.

I still think you should drive one, because i think the ride you are looking for is in the CS. I resisted buying one, even after being accepted by BMW, because, to me, its just not worth the extra money over my LCI Comp with CCBs.

[RS61]

I've got my Comp set up with the pagid endurance brake pads (from BMW directly), uprated brake fluid, and pilot sport cup 2s. The only thing I'd love to sort out now is the suspension
Does anyone know how I can replicate the CS suspension on an LCI Comp? Based on the comment above they both use the same M8 dampers, so it must be just a spring setup. Anyone taken a CS apart yet to work out what exactly is happening with the suspension?

[samj2k]

Originally Posted by RS61

I've got my Comp set up with the pagid endurance brake pads (from BMW directly), uprated brake fluid, and pilot sport cup 2s. The only thing I'd love to sort out now is the suspension
Does anyone know how I can replicate the CS suspension on an LCI Comp? Based on the comment above they both use the same M8 dampers, so it must be just a spring setup. Anyone taken a CS apart yet to work out what exactly is happening with the suspension?

Which pads did you go for? The BMW Sport pad? I'm considering them or Endless pads. Are the BMW Sport pad the same as the Pagid RS29?

[RS61]

Yeah the M Performance pads which are the same ones the ring taxi uses and are made by pagid. Not sure if they're the same as rs29s as I first tried to buy those direct from pagid but they weren't in their catalogue. Wouldn't be surprised if they were the same though and there was just an arrangement that they could only be bought as m performance branded pads.

[samj2k]

Ended up trying the M Performance Suspension, ride quality is identical to the KW, I actually prefer the KW as it seems to corner flatter than the MP HAS kit and seems to have less bounce, with the same ride quality, booked in to get it swapped back. I've now tried Eibach, MP HAS, KW HAS, and out of all of them Eibach was the closest to OEM in comfort, but can't corner balance, it also rode a little high on the front, KW gave the perfect drop, but quite stiff, very flat through the corners though, and the BMW HAS kit doesn't go as low as the KW, rides the same comfort wise, and isn't as flat through the corners. If I was going to do it again, I'd go for the KW from the start and just put up with the diminished ride quality, or a set of coilovers.

[Simon H]

Originally Posted by RS61

I've got my Comp set up with the pagid endurance brake pads (from BMW directly), uprated brake fluid, and pilot sport cup 2s. The only thing I'd love to sort out now is the suspension
Does anyone know how I can replicate the CS suspension on an LCI Comp? Based on the comment above they both use the same M8 dampers, so it must be just a spring setup. Anyone taken a CS apart yet to work out what exactly is happening with the suspension?

When i have time, i will ask my friendly parts manager, to check the part numbers for dampers and springs on both the M5 Competition, and the M5 CS, and just see what becomes of that. If the dampers are the same part numbers, and the springs are different, then it may be prudent to try and get hold of CS springs, fit them, and run the same geo as the CS on the Comp ?, if BMW will do all that ?. The CS suspension, is right on the nail, they have done a great job with it.

[samj2k]

Originally Posted by Simon H

When i have time, i will ask my friendly parts manager, to check the part numbers for dampers and springs on both the M5 Competition, and the M5 CS, and just see what becomes of that. If the dampers are the same part numbers, and the springs are different, then it may be prudent to try and get hold of CS springs, fit them, and run the same geo as the CS on the Comp ?, if BMW will do all that ?. The CS suspension, is right on the nail, they have done a great job with it.

I have my setup done by a company called Suspension Secrets, they are the best in the business when it comes to corner weighting and geometry. They literally changed the car with they're custom fast road geo. They do a lot of GT3's, Pistas, BTCC cars etc… It just felt better on the KW's. Was quite stiff, but actually felt like it softened up after around 500 miles, or I'd gotten used to it, but the MP HAS are no different comfort wise, he said spring rates are virtually identical, just no helper on the MP, but even he said he'd go for the KW's after testing both. The MP actually feels bouncier for some reason.