Question for you guru's.

I'm setting my S up for Autoxing and have chosen to run this coming season in STX. My tire & wheel choices are set (15x7 Kosei K1s with 225/50/15 BFG Gforce TA-KDs), and I have just this AM picked up the car with the new quaife installed (I'll post my impressions in a day or two). I'll have the new Madness rear sway on within a week.

I had planned on H&R Springs and Koni Sports all around. I'm a bit concerned on the clearance issues with the wheel/tire combo. but I'm also now considering coilovers instead. Other than costing more what specifically are the advantages & disadvantages of a Springs/shock setup versus a coilover choice.

I'm concerned that I could make the MCS suspension worse not better. Also, I read about adjustable control arms and camber plates and wonder do I even need more suspension mods.

David

 

There are a couple of advatages to the coil-over setup.

Because the strut was designed to work with the springs, you get the full travel of the shock.

You can corner balance the car.

You can decide what the ride height you want is, usually within a range of about an inch and a half.

With a few coil over systems, the struts will aloow you to adjust compression and rebound (currently the Koni struts allow compression adjustment, and the Spax allow two way adjustablity; the H&R has no adjustment).

I am planning on doing an evaluation of the Spax system shortly, as well as the Eibach system when it becomes available mid-year. The Eibach system sounds like it will be the front runner so far - compression and rebound adjustment, ride height adjustment, and aluminum bodied struts .

Let me know if you have any other questions.

Randy
randy@mini-motorsport.com

 

Thanks for your response Randy.

Some followup questions.

1. With coilovers can I change the ride height at will - or does that require alignments after every change? Where I'm going with this is to have a setup for Autox and one for street.

2. How hard is it to adjust ride height w/coilovers?

3. How hard is it to find the correct (Or preferred) adjustment for my car for autox?
Both compression and height.

4. Which coilover set do you like for the S and why?

Thanks in advance

 

with most strut suspensions, the camber changes through the range of travel. If you lower the car, you will most likely introduce more negative camber at ride height than you want for the road and long term tire wear. The only way to reduce the extra negative camber is to move the top of the strut. This can happen at the rear as well, but here you can alter the control arm lengths. Both of these adjustments require non-stock doo-dads such as camber plates and adjustable controls arms. here is a sample link: these aren't out yet, and expect to pay about 500$ for the camber plates and about 120 for each control arm (you need 4 max: http://www.hotchkistuning.com/ )
with those items and after a testing session in the alignment device, you could possibly have a road setting and an autox setting, involving say 30 minutes to change over using ordinary wrenches that could be done anywhere.

As far as toe-in, hard to say. if your toe-in changes through the range of travel, you have "bump steer" not desireable and not fixable with an alignment.

You have to really look at the suspension in detail, measuring on your car to figure this out.

 

You can adjust the ride height at will with the coil overs, but as jlm stated, it alters the camber - the more you lower, the more negative (not bad - positve and negative is how you measure camber) camber you get. The MINI could stand some negative camber, so for the track, it really isn't too bad. I would like to be able to reduce the rear negative camber slightly, and add more negative camber in the front.

The ride height adjustment itself is very straightforward. Usually the kit comes with its own spanner wrench and you just turn the perch down or up. You still have to jack it up and pull the wheels, but other than that, not much is involved.

The set-up will take some testing, and depends on your particular driving style. You can also weigh each corner and set the suspension up accordingly. Go to a well known race shop. Just call up the local SCCA chapter guys and ask who to take it to.

As far as the systems out there, I am still in the evaluation stage, so I can't give you truly objective opinions yet. In the running are the Eibach double adjustables and the Spax system. I'll post more as it comes available.

The H-Sport product line hasn't been launched yet, and I'm working right now with Mark Hotchkis to do some testing and product analysis. These products should be available the second week of February, and again, more to come as the evaluation process is completed.

Let me know if I can help with any other questions.

jlm offerd some very good advice, also.

Randy

 

jlm and Randy:

Thanks for the great responses - I think I'm going to take a wait and see approach on the Suspension mods for now. I have much to learn in this area of tuning.

David

 

Is there any way to improve the Sport+ Suspention on the S WITHOUT lowering the car? DOn't get me wrong, I'd LOVE to lower the car, but I have to use it as a daily driver in the Poconos, and I have to be quite careful as it is, I'd be scraping all the time if I dorp the car. Any suggestions short of pneumatics (Wouldn't you love to see a MINI hop? )

 

Randy,
I would think the H&R system would be a very good unit. They are highly respected, and while the dampers are not adjustable, I would think the factory set up would be very good, and give excellent value for the money. KW seems to be very active in the mini coil over market also. Any reason you are not pursuing these units?