IMO the excessive lowering is a bigger problem with the lowering springs on FSDs. JCW springs should do a lot better.

- andy

 

Anyone know the spring rates, JCW vs sport?

 

I wish I knew the actual Spring Rates for the various MINI springs. Our Cooper " sits almost 1" lower than our "S" with "Sport Suspension" and I suspect that is due to increased/stiffer spring rate. Where the "JCW" springs are in relationship to an "S" w/"Sport Suspension" is certainly a mystery to me.

Anyone know????

 

There are four different JCW spring rates depending on if you have a sunroof and/or auto trans. I am pretty sure all MINI rates are progressive. So, it is really hard to nail down a rate.

Bob

 

Sounds like MINI is being very specific with it's Suspension Tuning. It is a pity that ride comfort was not a consideration along with good handling.

So my automatic "S" with "Sport Suspension", no sunroof, could be different than anything but the same config. Interesting!

I like the way the FSD's handle for the driving I do, just not thrilled with the clunk. So, after much hassle I have one more thing to try before I rip them out and send them to KONI-USA with a terse note...

 

Realistically, how much difference can the spring rates be? I guess if anyone figures it out would it be best to get the stiffest of the 4 part numbers? Do they all have the same ride height?

 

My '09 Cooper Automatic W/sunroof is 1" lower than my '11 "S" Automatic without sunroof and w/Sport Suspension.

 

Just to clarify - the ride height is not affected by spring rate.....you could lower your current springs by 1" (cutting them) and it would only affect the height - the rate would still be the same (unless they are progressive springs).

Not sure if i'm reading some responses right, but it seemed some people are implying that ride height and rate are related (unless you are cutting progressive springs).

 

I think the ride height is being mentioned because FSD shocks aren't supposed to be used with lowering springs so if a particular spring rides lower than stock then it might cause problems.

 

Ride height is affected by spring rate. Let's say that you have springs that are 100 pounds per inch (spring rate). Let's say that your car weighs 2000 pounds and is evenly distributed between all four corners so that 500 pounds is compressing your spring. The spring will compress 5 inches - that is to say, the spring will be 5 inches shorter than if your car was sitting on it. Now swap that spring with another spring that has the same uncompressed length but with a spring rate of 250 pounds per inch. This time, the weight of the car (500 pounds on this corner) will only compress the spring by 2 inches. This higher spring rate spring would raise the ride height of the car by 3 inches.

Bob

 

Very true - maybe my post was a little badly worded/misleading. Thanks for the clarification to my clarification.

 

IOW, for a linear spring, cutting x% off its length invcrefases it's stiffness by x%...

 

When cutting springs, you need to be conscious of preload on the springs. When I put my TSW's on, the car looked like it was too high in the front. This is partly an illusion, because the wheel arches are not identical on the MINI, so the wheel gap was larger in the front, even though the rocker panels were about level with the ground.

I cut 1/4 coil off of the front springs, and there is very little preload (like 20 lbs) on the springs. My only point is that if I wanted the car lower, I would have problems keeping the springs in the seats. The TSW's are not progressive, so it may be a different case with progressive springs. FWIW.

Mike

 

Bobesser, any updates with this setup? How has D Stock been with them? I am considering this same setup in the near future. Thanks in advance.

 

No issues. Way smoother ride than the stock suspension. Handles much better than stock. I think I probably should have gone with a smaller rear sway bar than the H-Sport Comp. I keep it in the softest setting all the time.

Bob

 

Thanks for the update! Hopefully I will be able to test for my self here soon.

 

Very good read! Glad I found this thread.
I was planning on FSD's and Eibach Pro-Kit springs for my 07 MCS. With the proper bump stop height, I bet I could get away with it no problem. BUT with Koni themselves putting it in writing, I doubt I'll go for it. Such a shame as these are struts I really really like the look of in performance and streetability.

 

Injected,
I'm really happy with my Koni Yellows on my DD. I would not hesitate recommending the Sports, but I don't have a comparison with the FSD's.

Mike

 

I'm a big fan of the yellow's on most cars that I've been in or owned(Other than E30 BMW's. SOOOOO many better shocks out there for those it seems). I just really like what I'm reading about ride comfort from the FSD's. I imagine with TSW springs an cut bump stops, the FSD's should work fine.... but then again, it's a gamble on $800 I don't want to take lol.

 

I have never had yellows, so I can't comment. Given the warning from Koni, I am not sure if I would go with TSW springs. 45mm is a lot more lowering than 10mm.

I was amazed/surprised by the ride quality. I thought I had make a huge step in the wrong direction regarding performance when I first installed them - the ride was so soft compared to stock, how could it possibly handle well?

 

Well the link previously posted sounded like it was specifying first gens.
Then there have been some mixed OPINIONS. So I just called Koni tech support and asked.

The rep basically came to this conclusion:
It's not so much a whether you can or cannot use FSD's when lowered. It's that the more suspension travel, the better the FSD's perform. Lowering the car can adversely affect their ride quality, but as long as the bump stops are trimed accordingly so there isn't a frequent bottoming out issue, they're not going to prematurely fail.

In the end, he said to ensure the best ride quality and performance with lower than stock springs, Yellows are the safest bet. It's what they were designed for.

 

The explanation from the tech makes sense. Now you just need to determine how much lowering you want. If the decisions were only easy......

Have fun,
Mike

 

Yeah. Well I'm not "lowering" my car for the sake of making it look lower. And I'm certainly not buying into the stupid slammed/stretched tire/poking out the fender trend that's going on. I am looking at most likely the Eibach Pro-Kit springs for 1.2-1.5" drop providing better handling and a lower center of gravity. I feel that's a solid drop for a daily driver that might see a solo event from time to time.

From what the tech told me, it really does sound like Yellow's are going to perform AND ride better than FSD's for me as the FSD's are, honestly, designed to function the best at stock ride height.

 

After having Koni replace the first set of FSD's under warranty because of some pretty nasty internal clunking noises the second set is starting to do it.

It seems to take about 2,000 miles for the clunk to start in the right front and then by 3,000 miles the left front is making noises. The rears are always solid.

With everyone happy with their FSD's I cannot help but think the "Sport Suspension" springs are what is causing this. The car rides higher than our other MINI by almost an inch and the other MINI does NOT have the "Sport Suspension".

Bilstiens HD's w/Swift springs is going to be the next try. I do not track the car and I certainly do not need to lower it. I drive on dirt roads on occasion and over a lot of speed bumps, not to mention the radical driveway aprons , and I like the clearance. Leaving money on the pavement is not a goal...

I loved the way the FSD's handles but apparently they are not designed for those springs that came optional when I ordered my MINI. Pity...

 

good choice - i genuinely think this is the best non-coilover suspension choice for the MINI (and better than many cheaper coilover options)