hatterasman

Just picked up a 2008 E61 with 66K miles. Body roll is excessive and I'm trying to decide on which suspension to go with. I don't really need the SLS so that isn't influencing my decision...other than wondering if air bags "wear" and affect handling and wondering about the life of the compressor.

I want to go with the best option for retaining as much ride comfort as possible while have the car handle flat.

Thoughts?

pocholin

How much money do you want to spend? If money is not an issue, perhaps K3s are the best choice and you'll have bragging rights ;-) Otherwise, ISC are your choice, just make sure you state to them that you want the comfort coilovers, they have longer shafts thus smoother handling. My 2 cents. Good luck.

hatterasman

I see you list the ISC's in your sig. Did you go with the SLS delete?

Why do you recommend the KW's over the ISC's?

I'm willing to go with the KW's if the handling is better, I'm trying to find comparison info to help make the decision.

I've read that the KW's can be rebuilt for a reasonable cost. Do you know if this is possible with the ISC's?

I'm curious if the ISC's with the SLS delete handles better than the KW's with the SLS in place.

ucsbwsr

Most KW owners don't buy for bragging rights, I bought for ride quality at lower than stock levels.
I would HIGHLY advise not deleting the rear bags on the wagon. People have done it for "absolute performance" but I have not seen any quantifiable data proving that the bags can not offer adequate performance, personally for my driven-hard-daily setup it is fantastic for performance and ride quality. Furthermore I think with the size and weight of the E61, especially when loaded up with people and/or cargo the bags are much better suited to handle the broad spectrum of loads and forces compared to a conventional fixed rate spring.

The first ISC release had less than ideal feedback and customers complained, from what I gather they made some adjustments to the setup with revalving the struts to better suit the system and performance is much improved.

Handling performance can be very subjective for the driver + car + intended use so "better handling" might be different for you relative to another so it is hard to give a blanket answer. If money is not an issue personally I would recommend the KWs, I had V1s on my old M5 and V3s now, I love the performance but I have had reliability issues with both sets, mainly due to me running the coilovers so low and driving so hard. Which brings me to my next point: KWs have a lifetime warranty to the original owner, it is non-transferable. IIRC you pay a deductible and/or cover shipping to their facility in Fresno, CA. Once they confirm the issue wasn't from improper installation, setup, or use; they will repair the strut for free.

I bought my V3s second hand with low miles and saved >50% off the new price but had to fork out the extra money for the rebuild. E61 V3s are a rare sight on the used market but the lack of warranty is something to consider before jumping on them.

Conversely, ISCs are so cheap you might as well buy a set, run them, adjust them, and if you can't get them dialed in for your application, sell them and you will likely only be out a couple hundred dollars, then you can buy the V3s knowing they are the best option.

Evan

RCB

I have had many experiances with KW V1 to V3 and ISC. The ISC experience ended with them being removed from an E61 and replaced with KWv3 after a few weeks.
I wouldn't touch the ISC suspension for a multitude of reasons, especially for an E61.
My strong suggestion is KWv3 and don't look back.

The build and ride quality for the KWs is a perfect pairing for the E61. Stainless steel construction is well worth it and there is more then enough adjustment to get these big heavy cars to handle well.
I have them in my E61 and my wife was a little bummed that I was going to compromise the ride quality for a low stance and better handling until she drove the car. The ride is great with my 20" wheels and would be even better with less rim and more tire. I also strongly agree with Evan on retaining the air ride.

pocholin

I did not remove my air bags, I kept them because I do put some load from time to time.

I haven't run the KWs in my car, so I cannot comment on their handling abilities, but I've read they are the best in the market.

pocholin

Evan,

Now that ISC has fine tuned the E61 coilovers, I don't see a reason to pay 3+ times for KWs other than better quality...but is it 3 times the better quality? I don't know. I've had my ISCs for 1 year and I am pretty satisfied with their quality and ride. That's why I said, if money is not an option for him to go with KWs, which also give him bragging rights (not because the only reason was bragging rights).

hatterasman

Thanks for the excellent info. I added a JB4 and last week found a local gas station with E85. 4 gallons of E85 and map 5 is an amazing change to this car...just a little scary, snapping a lane change in a hard 4th gear pull on the interstate. Everyone's input is very much appreciated...just what I was looking for to pull the trigger on the V3's.

Looks like Tire Rack saves a hundred bucks over KW's online store. Any better discount to be had?

I ordered a D+KAN cable and have downloaded INPA. From what I've read that setup will allow me to adjust rear height to match the front.

Do I need anything else?

5erTouring

I have used both and KW V3 are worth the price. The V3s were on my car for 3 years and had front struts rebuilt due to a leak. As I was the original purchaser, the rebuilt was free of charge and I only paid for shipping. During the repair period (about a week or so), I purchased a set of ISC (softest springs available at the time and set at the softest setting) to keep me on the road. It was way too harsh compare to the V3s. The construction and overall quality of KW far exceeds the ISC but is it worth 3 times the prices. I can't speak for all but I did not regard the purchase.

RCB

That is all you need to adjust ride height.
I love being able to load the car up for a road trip and bump the weighted rear end back up from the comfort of my drivers seat. I wouldn't give up the air springs for coils by any means. Especially a poorly designed ISC coil conversion that will eventually chew out the sheet metal trunk floor and has a horrible lower perch with an incorrect control arm interface angle.
Also if you want to increase the rear spring rate and maintain air springs you always have the option of a larger rear sway bar to increase the rate.