Hey guys,

I'm not sure if this has been asked before, I've searched and haven't found anything, but here it goes. It might be a dumb question though, any help can be appreciated.


I recently purchased a 2005 Mini Cooper S (R53) and for some reason my suspension doesn't feel as stiff as my girfriends Mini Cooper S, the only difference is that hers has 18" JCW rims and 205/45/18 Nitto NEo GEn tires and mine has some aftermarket 17" rims with 215/45/17 Khumo Ecsta tires. (Both cars are same years although mine has double her mileage).

I thought that every R53 came with sport suspension, is this true? Or can it be my tire setup? If not, can it be that my shocks have had all they can have?


Thanks!

 

Not a dumb question at all, as tires alone can make a significant difference in stiffness feel. I'm probably no more enlightened on this than you are, but here's my thinking anyway.

First, I couldn't find the Nitto tires you mentioned in size 205/45/18. If they're actually 205/40/18 instead, they have a very similar overall diameter to your 215/45/17s, but with a shorter sidewall (82 mm versus 97 mm). Other things equal, that alone might be enough to provide a stiffer feel.

Second, which Kumho Ecstas do you have? The Ecstas come in six different tire categories; from Extreme Performance Summer to Grand Touring A/S, with those toward the latter end providing somewhat softer feeling handling. The Nittos are Ultra High Performance A/S tires, so if your Ecstas are Extreme or Maximum Performance Summer tires, that probably wouldn't help explain the difference you feel.

I think the R53 sport suspension was an option, but most R53s probably weren't ordered with it.

From what little I know, spring rates affect stiffness, while shocks affect dampening (recovery from spring compression). Your springs are probably still okay, but if your car tends to bounce a bit in a corner instead of taking a firm set and keeping it, that could be an indication of worn shocks. MINI shocks don't seem to be of very high quality anyway, so Konis seem to be a popular switch.

I realize that my response raises more questions than it answers.

 

Yes, i totally meant 205/40/18's hehe i might have slipped my finger somewhere.

I was looking at my tires right now and they are Kuhmo Ecsta AST 88H XL.

There is probably nothing wrong with my car and the only difference is that her car has the sport suspension and mine doesn't... but I don;t know how to tell the difference. Her seems a lot more stiff, to the point that when you make a turn you can hear the car chassis creaking hehehe. Does the wheel size matter?

I've also noticed that when I go over a speed bump I can actually hear the shock absorber dampening (it absorbs the bump and the just a little bounce afterwards, it doesn't keeps bouncing), is this normal or should the car not even bounce after going over a bump?

 

I just went from a 2005 MCS with a sports suspension to a 2006 MCS with a sports suspension, and they feel totally different. Because my old one had 72k miles and my new one only has 42k miles . . and the suspension was obviously shot on the 2005!! So both you and your girlfriends cars may have an SS - it was an option which not a lot of cars seem to have, but if you do a VIN check you should be able to see whether or not your car has it.

 

The Kumho Ecsta AST tires are High Performance A/S, so they are probably toward the softer sidewall end of that Ecsta Extreme to Grand Touring A/S continuum I mentioned above.

The wheel size difference matters only because her tire size has a shorter sidewall while making the overall tire diameter very similar to your tire size. The shorter sidewall (her 82 mm versus your 97 mm) means less sidewall flex in corners. Thus, the ride in her car should feel firmer even just driving down the road. That sidewall difference alone could be enough to account for the difference in feel.

Of course, her car could still have the sport suspension, and your car could still have worn shocks. Shocks (dampeners) reduce the bounce-back from spring compression and release. You can do a very rough check of your (and her) shocks yourself. With the car on relatively level ground push all the weight you can muster down at one corner so that corner is compressed and release quickly. If the corner "bounces" more than 1.5 times, your shocks might be too worn. Do that for all four corners. Even with worn shocks these compressions and bounce-backs might be very shallow and slight, leading you to wonder if you have any suspension at all. If so, you might need a bigger guy to push down on the corners.

As Noonzio's post suggests, shocks do eventually wear out, and working them hard probably hastens their demise. They tend to wear out very gradually rather than all at once, so it's sometimes hard to tell when they're worn enough to need replacing.

You didn't say how many miles (and what kind of miles) are on your shocks, but your shocks may not be the prime suspect in the difference you're feeling anyway. I'm still thinking it's probably mainly the difference in sidewall width and flex between the 18's and 17's.

 

For the case of the Mini it's difficult to feel much from pushing down on the corners because it's almost at rest on the bumpstops.

In this case I'd lean towards the tire size difference being key here.

 

Check out this thread and you may be able to find out the packages on both cars!

 

I appreciate everybodies response! I'm glad to see people help around here..

Thanks!

 

The R53 series from 2002 through 2006 all came with Sport Suspension Plus. The factory shocks only last 25,000 - 30,000 miles before they give up. Install a good set of Koni shocks and enjoy the new ride.