KW HAS for M4

[Padfan9]

I intended to leave my M4 suspension alone since it handles so great already, plus I have the adaptive M suspension (a must have) so I didn't want to mess with it.

I was told the KW HAS springs were best if I want to lower the car. I am keeping my 19" black wheels, but I don't like the fender gap. I was thinking to lower it around .6 and get the suspension. My car is in the shop for a month anyways, so they will put them on for free while they are fixing a few other things.

What do you guys think? Will it be much harsher then stock? How will the car handle around corners vs stock? Any thoughts?

[Padfan9]

Originally Posted by Padfan9

I intended to leave my M4 suspension alone since it handles so great already, plus I have the adaptive M suspension (a must have) so I didn't want to mess with it.

I was told the KW HAS springs were best if I want to lower the car. I am keeping my 19" black wheels, but I don't like the fender gap. I was thinking to lower it around .6 and get the suspension. My car is in the shop for a month anyways, so they will put them on for free while they are fixing a few other things.

What do you guys think? Will it be much harsher then stock? How will the car handle around corners vs stock? Any thoughts?

See below

[tom @ eas]

Originally Posted by Padfan9

I intended to leave my M4 suspension alone since it handles so great already, plus I have the adaptive M suspension (a must have) so I didn't want to mess with it.

I was told the KW HAS springs were best if I want to lower the car. I am keeping my 19" black wheels, but I don't like the fender gap. I was thinking to lower it around .6 and get the suspension. My car is in the shop for a month anyways, so they will put them on for free while they are fixing a few other things.

What do you guys think? Will it be much harsher then stock? How will the car handle around corners vs stock? Any thoughts?

You would be fine with springs alone. However, the HAS will allow you to dial in the exact drop you want.

[Padfan9]

Originally Posted by tom @ eas

You would be fine with springs alone. However, the HAS will allow you to dial in the exact drop you want.

The springs seem cheap and I have heard its a harsh ride.

[tom @ eas]

Originally Posted by Padfan9

The springs seem cheap and I have heard its a harsh ride.

Not true at all. HAS consists of a replacement spring on an adjustable perch. In the end, springs will give a fixed drop vs adjustable height with KW's HAS.

Here's a comparison of OEM, H&R 435 Sports and H&R M3/M4 springs:

Stock


435 H&R Sport Springs


M3/M4 H&R Sport Springs

OEM Spring measurement


435 H&R Sport measurement


M3/M4 H&R Sport Spring Measurement


Front drop is identical. Approximately 1/4" different in rear height between 435 vs M3/M4. HAS will allow similar results, with the added adjustibility as an option.

[Padfan9]

Originally Posted by tom @ eas

Not true at all. HAS consists of a replacement spring on an adjustable perch. In the end, springs will give a fixed drop vs adjustable height with KW's HAS.

Here's a comparison of OEM, H&R 435 Sports and H&R M3/M4 springs:

Stock


435 H&R Sport Springs


M3/M4 H&R Sport Springs

OEM Spring measurement


435 H&R Sport measurement


M3/M4 H&R Sport Spring Measurement


Front drop is identical. Approximately 1/4" different in rear height between 435 vs M3/M4. HAS will allow similar results, with the added adjustibility as an option.

So the H&R Springs do the exact same thing as the KW HAS except the KW is adjustable? Do the H&R Springs take every car down the same exact height?

I was just worried about the ride...I have heard from people with H&R that you sacrifice some handling with them vs HAS being better.

[tom @ eas]

Originally Posted by Padfan9

So the H&R Springs do the exact same thing as the KW HAS except the KW is adjustable? Do the H&R Springs take every car down the same exact height?

I was just worried about the ride...I have heard from people with H&R that you sacrifice some handling with them vs HAS being better.

Both serve different purposes:

- Springs drop to a predetermined height
- Sleeve Kit/HAS allows you to adjust the drop you want with the included adjustment collars

There is a very slight change in handling. Most are happy with the drop springs offer.

[CanAutM3]

Originally Posted by tom @ eas

Not true at all. HAS consists of a replacement spring on an adjustable perch. In the end, springs will give a fixed drop vs adjustable height with KW's HAS.

Here's a comparison of OEM, H&R 435 Sports and H&R M3/M4 springs:

Stock


435 H&R Sport Springs


M3/M4 H&R Sport Springs

OEM Spring measurement


435 H&R Sport measurement


M3/M4 H&R Sport Spring Measurement


Front drop is identical. Approximately 1/4" different in rear height between 435 vs M3/M4. HAS will allow similar results, with the added adjustibility as an option.

Thank you for that post. Super great real world info!!!

Wouldn't another benefit of the HAS be the ability to do corner balancing?

Further, how easy is it to change the ride height on the fly with the K&W HAS? The reason for my asking is that my car is a four season DD and I am a bit hesitant going with lowered springs for the reduced ground clearance in the winter. But if it is relatively easy to change ride height with the HAS, that could be an interresting option for me.

[tom @ eas]

Originally Posted by CanAutM3

Thank you for that post. Super great real world info!!!

Wouldn't another benefit of the HAS be the ability to do corner balancing?

Further, how easy is it to change the ride height on the fly with the K&W HAS? The reason for my asking is that my car is a four season DD and I am a bit hesitant going with lowered springs for the reduced ground clearance in the winter. But if it is relatively easy to change ride height with the HAS, that could be an interresting option for me.

Good point.

Changing ride height is not too hard of a task if you are the DIY type. Most shops can do this in under an hour.

[kokopuffs405]

Originally Posted by tom @ eas

You would be fine with springs alone. However, the HAS will allow you to dial in the exact drop you want.

Do you lose adaptive suspensive ability with springs?

[CanAutM3]

Originally Posted by kokopuffs405

Do you lose adaptive suspensive ability with springs?

With springs only, the active suspension remains as it is only effective on the shocks.

However, the EDC was calibrated with the stock springs, so it might not be as optimal with aftermarket springs.

[Padfan9]

Originally Posted by CanAutM3

With springs only, the active suspension remains as it is only effective on the shocks.

However, the EDC was calibrated with the stock springs, so it might not be as optimal with aftermarket springs.

Are you saying the KW HAS will not keep the adaptive M suspension in tact or the H&R springs?

[Padfan9]

Originally Posted by tom @ eas

Not true at all. HAS consists of a replacement spring on an adjustable perch. In the end, springs will give a fixed drop vs adjustable height with KW's HAS.

Here's a comparison of OEM, H&R 435 Sports and H&R M3/M4 springs:

Stock


435 H&R Sport Springs


M3/M4 H&R Sport Springs

OEM Spring measurement


435 H&R Sport measurement


M3/M4 H&R Sport Spring Measurement


Front drop is identical. Approximately 1/4" different in rear height between 435 vs M3/M4. HAS will allow similar results, with the added adjustibility as an option.

Sorry Tom, I forgot to thank you for all of this information, it was extremely helpful!

[CanAutM3]

Originally Posted by Padfan9

Are you saying the KW HAS will not keep the adaptive M suspension in tact or the H&R springs?

If you change only the springs, as is the case with the K&W HAS and K&W, EDC remains active.

[Padfan9]

Originally Posted by CanAutM3

If you change only the springs, as is the case with the K&W HAS and K&W, EDC remains active.

Perfect, thank you!

Do you think I should go with the H&R spacers or the Macht Schnell? I heard the Macht Schnell have not been tested as extensively so H&R is a safer bet.

[CanAutM3]

Originally Posted by Padfan9

Perfect, thank you!

Do you think I should go with the H&R spacers or the Macht Schnell? I heard the Macht Schnell have not been tested as extensively so H&R is a safer bet.

Spacer are pretty simple parts, not much risk there. I would say you are safe with either one. You will need longer bolts with spacers, the quality of those is much more critical.

[tom @ eas]

Originally Posted by Padfan9

Perfect, thank you!

Do you think I should go with the H&R spacers or the Macht Schnell? I heard the Macht Schnell have not been tested as extensively so H&R is a safer bet.

The Macht Schnell spacers have been on the market for a number of years and come with everything needed for installation, most E9X M3s are running them since release. There's a dedicated thread here with plenty of examples of setups to base your decision upon:

F8X M3/M4 Macht Schnell wheel spacer reference thread
http://f80.bimmerpost.com/forums/sho....php?t=1000804

Do note that H&R does not come with extended lugs, you're on your own to source them.

[Padfan9]

Originally Posted by CanAutM3

Spacer are pretty simple parts, not much risk there. I would say you are safe with either one. You will need longer bolts with spacers, the quality of those is much more critical.

I think they would be from Supreme Power? Black ones. I am not sure if they are brand or not.

[Padfan9]

Originally Posted by tom @ eas

The Macht Schnell spacers have been on the market for a number of years and come with everything needed for installation, most E9X M3s are running them since release. There's a dedicated thread here with plenty of examples of setups to base your decision upon:

F8X M3/M4 Macht Schnell wheel spacer reference thread
http://f80.bimmerpost.com/forums/sho....php?t=1000804

Do note that H&R does not come with extended lugs, you're on your own to source them.

Ahh! That does help!

The options I have seen are :

Go with Macht Schnell and their own extended lugs or H&R (save a little) but pay an extra $80 for extended lugs.

I just can't seem to find the spacers on their website for the F8x

[supremepower]

Originally Posted by Padfan9

Ahh! That does help!

The options I have seen are :

Go with Macht Schnell and their own extended lugs or H&R (save a little) but pay an extra $80 for extended lugs.

I just can't seem to find the spacers on their website for the F8x

The H&R spacers are generic. There is no set individually made for the F8x. It's just in the BMW bolt pattern of 5/120 the bolts are not included with H&R though, as said in previous posts

[Buddy Revell]

Will my Macht Snell spacers and lugs that I used on my E92 work on my F82?

[supremepower]

Originally Posted by Buddy Revell

Will my Macht Snell spacers and lugs that I used on my E92 work on my F82?

Yes, they have the same bolt pattern of 5/120