Bingo! Not only do coilovers allow corner balancing, they REQUIRE it. If you get coilovers and don't have them corner balanced, your handling could be WORSE than stock.

 

Why?

I would think that if you set each shock up the same way as per recommended instructions from Bilstien, then you statement should not be true. How can throwing on a set of springs to stock shocks be a better set-up then the PSS9s installed correctly?

Corner balancing is a plus, but I don't see it a necessity to get much improved handling over stock setup.

 

I didn't know just how bad my shocks had gotten until I installed front camber plates. These set me the jarring "BANG" that let me know something was very wrong with my front struts. I'd bottomed out before, but this was getting real bad.

Upon the removal I now saw that my shocks were wet noodles. I realize now that I had been sent some signals way prior that this set-up of H-sports and stock shocks was not lasting. As I said before, under 10K and all was a loss.



If you have the time I would recommend that anyone with the H-sport ( or any lowering spring) and stock shock setup, should really look at their setup and see if all is really alright. I tracked my care twice with these blown shocks and I never really felt the car handle poorly, until the last few runs.

I'm tracking my PSS9s for the first time later this week and I'm very much looking forward to seeing an improved car.

 

Picture installing a refrigerator in a house, and never checking to make sure that you adjust the feet. The fridge will tip. In a car, all four wheels will touch the ground but each will be pushing on the ground with a different level of force. If you just install a set of springs, there is a fixed stop that determines the height of the spring. With coilovers, that stop is adjustable, and if not done in conjunction with scales, WILL result in wildly different pre-loads on each corner.

A good thing to check would be people who have had corner balancing done after installing their coilovers, how much off were they before balancing? Check the instructions for installing the Bilsteins. I'd be astonished if they didn't list corner balancing as a step in the process.

 

MISFITOY- ok.


onasled- I guess with progressive rate springs, there is so much distortion on the rates where it varies that it's harder to tell if the dampers went bad at first... (?) I use aftermarket dampers on my other car that runs
lowering springs and when i installed the dampers, it was a huge
improvement. I'd like to expect the same from Koni's or watever I
choose to install down the road on the MCS, but the current setup
isn't all that bad. And i only drive street and about 7k miles tops
each year.


>If you just install a set of springs, there is a fixed stop that determines the height of the spring. With coilovers, that stop is adjustable, and if not done in conjunction with scales, WILL result in wildly different pre-loads on each corner.

But most coilover kits use linear rate, aren't they? It shouldn't vary that
much.

 

.... just to note, I have scales, though I need to mingle with the pros to learn the tricks of tuning. Any tips would be appreciated no matter how basic.

Weighed the car just after I installed the PSS9s and it was quite close.

 

A couple of things here;

Lets assume first a set of adjustable coilovers with the same srping and damping rates as a stock Mini; If one were to get the hieght of adjustable coilovers EXACTLY the same as the stock set up on all four corners, the car would not handle worse than stock - it wouldn't handle better either, which IS the purpose behind adjustable coilovers. Personally, I would not invest the time or money in a set of adjustable coilovers unles I was willing to corner weight the car - the results may not feel dramatic on the street, but are quite noticable on a track with lots of left and right hand turns; the car will react with the same amount of balance going right and left.

Ground Control make some very nice adjustable perches. These mate up to many types of springs - Eibach comes to mind as does Koni. This particular combination does not offer the sophistication of a unit designed together - a given spring with a given damper. The advantage here is that Eibach and Koni will make custom equipment that will get the job done, but these components are not necessarily designed to work with one another.

Stock dampers will often fail when asked to work with heavier shorter springs...I'm tempted to write always fail...they will always wear prematurely; Koni's single adjustable yellows are at their absolute limit with a 400lb/in spring. They might be effective for 20,000 miles with a 400lb/in spring. If you want more spring, then ask Koni to custom valve your Koni dampers to SST specs - good for 600lb/in springs.

I think it is fair to compare any combination so long as price is noted too.

Outta time, gotta run! Sorry for the rushed response...


Michael

 

Wow, this thread has blossomed to cover a nice wide spectrum of information! So much so, I'll ask my question here, as opposed to starting a new thread .

It's my understanding that a coilover system is valved in conjunction with specific spring rates in mind. Is that correct? Because if so, and one decides later to change spring rates, would a revalve (different valve) then be necessary? I'm guessing the answer might depend on how much of a spring delta is being contemplated...

I currently have 250 F, and 325 R, and I'm looking to ratchet this up 75 lbs ea, or 325 and 400. These are Ledas, with the springs being Leda (front barrels), and Hypercoil rears...

I have a call in with Karl Poeltl at Racer's Edge as well, and I'll share what I find-out... Thanks!

Also, with respect to corner-balancing, I find it seemingly necessary for those of us with coilovers, especially where we've altered the MINI's weight (distribution) significantly, like me

 

Just curious if you know what the wheel-rate of the Mini is, or how it compares to most honda/acuras. 400 is the number 'oft thrown around the honda boards. I've been meaning to find out if the effective rate of a 400lb spring is higher or lower on a Mini than I'm used to. I have the feeling it's pretty close to the same.

The "ideal" settings for a particular spring can vary by condition, and opinion of the operator. The range you have to work with depends a lot on what type of adjustments you have on your damper. For instance, if you had double-adjustable dampers, with a fairly broad adjustment range, then 75lbs should be well within adjustment range. Now that I think about it, 75lbs should be within range of just about anything.

My personal feeling is that as spring rates increase, compression damping should be reduced to prevent a needlessly harsh ride. Rebound damping should be increased to control movement. I almost always found myself adjusting in these directions when making spring rate increases. This is why I personally try to stay away from shocks that adjust both compression and rebound in a single adjustment. Anyway, just my 2 cents.

Given the cost of a revalve, I would definitely try the new springs before spending the extra money - unless, of course, it's about time for a service anyway.


TonyB - if you're reading this... do you feel the Ledas are suitable for the street? I'm ASSuming that's been your primary purpose given the relatively low rates. Just wondering if they're on the harsh/jarring side.

 

On corner balancing see
https://www.northamericanmotoring.co...d.php?p=537334
See the grassroots article link

When upgraded coilovers are installed you get to set the ride height for each corner. Even if you do measure each height perfectly to get it to be the same the weight on each wheel may or may not be where you want it. There is no way to tell how close to being balanced you are except by scales and weighing the car.

Since the MINI is front wheel drive you will have about 60-61% of the total weight over the front wheels and the remainder over the rear wheels. Another goal is to get about 50% of the weight over the left front and rear wheels.

When adjusting each corner height you are trying to balance the weight of the left front and right rears to be as close to 50% as possible with YOU in the car as it is set up for track or autocross with a full tank of gas and fluids. Wearing a helmet and with the full setup for how you'd be driving.

You can make very very small adjustments to the height of one corner that will send more weight to another corner. The total weight over the front wheel will not change while the total weight over the left two wheels will not change. You are shifting the distribution of weights when you adjust ride height.

As for re-valving, check with your coilover manufacturer but it is not uncommon to change springs and go with something stiffer. For the PSS9 which has progressively rated springs for front and rear, it's been suggested to me to change the front spring to one that is linear and up it to 350 or 375 pounds. Some comment that the PSS9 front spring can be too soft- depends on how you drive and have set up the rest of your suspension. I would say you don't have to re-valve with that amount of change.

In my case after installing the PSS9s (but before cross balancing) my cross weight was about 53% so roughly 3% too much on one diagnonal. It's certainly possible to get that number very very close to 50%. I had 61% on the front and 51% on the left.

If you install upgraded coilovers for street use and don't cross balance then you'd never know what your weights are and for most street driving it won't make much difference. On the track it makes a big difference in how the car handles on right vs left turns at speed.

If cross balancing is your goal you'll likely need adjustable endlinks for your front and rear swaybars so that you adjust them to unload your swaybars effect while balancing.
Front and rear swaybars are disconnected while adjusting ride heights then reconnected in a neutral load setting after everything is balanced.

 

Good info , but unfortunatly that link is dead ..

 

That link was working a few weeks ago

Try this cached version
http://64.233.187.104/search?q=cache...+balance&hl=en

and from a search
http://www.google.com/search?hl=en&l...ce&btnG=Search
including
http://www.nsxprime.com/FAQ/Performa...nerbalance.htm

 

Awesome info, minhune!

 

Jeff, I'm certainly reading... For me, yes, the Ledas are fine for the "street." I feel very fortunate to live in a canyon where 4 miles of ideal roads greet me at my driveway (just one of the reasons I made the purchase, of the house, and MINI ). Then there is another 8 or so rural miles with no traffic lights/signs. Then civilization, and the right foot eases upward...

The ride is rough, but to be honest with ya, in the Summer I often take my dune buggy into work, and that's even more brutal. It's all relative I suppose...

Maybe I will track my car someday, I don't know. I tend to over-build everything I make, just in case. I just know that if I leave work at certain times on certain days, I tend to meet-up with a host of fun cars at just the right spot on the way home .

Jeff, I appreciate your thoughts on the spring rates and valving. The only reason I'm considering the change in spring rates is that I'm bump stopping in the front now, and that should remedy it. My MCS does not appear low, but with my tire of choice, 16's 205/45, a 23.3" diameter, I guess it is contributing to this issue. I otherwise might not be contemplating stiffer rates...

I have some shorter Ledas (.75" shorter) sitting in my living room awaiting some testing, hopefully next week, along with Webb's ver 2 camber plates (4mm shorter). If bump stopping still occurs (putty test), the stiffer springs might go on...

When I hear back from Karl, I'll share his thoughts...

 

Just curious if you know what the wheel-rate of the Mini is, or how it compares to most honda/acuras. 400 is the number 'oft thrown around the honda boards. I've been meaning to find out if the effective rate of a 400lb spring is higher or lower on a Mini than I'm used to. I have the feeling it's pretty close to the same.

I don't know how similar they are; the suspension systems are quite different - MacPhearson strut vs double wish bone. I would expect the motion ratio to be different - this is the distance from the pick-up point on the lower control arm and the center of the tire's contact patch...if I remember. I bring this up because it defines the level of mechanical leverage inherent with each design; if you try to lift 500lbs with a lever arm 5 feet long with a given effort, a lever arm twice as long will require half the effort. Same with a lower control arm; if it is leveraged really well, you can use a lower spring and damping rate to achieve the same amount of control as a less leveraged set-up with heavier rates, make sense?. Motion ratio is part of wheel rate, as is suspension friction, the weight of unsprung components and the weight the wheel and tire etc (wheel/tire/brake weight may not be much of a factor with a road car, but are however critical with light weight purpose built race cars - they are sitting way out at the end of the control or lever arms). Also, the Honda/Acura products are designed with unequal length control arms. This geometry allows these cars to keep and even gain a little negative camber as they lean. So, to a point, and relative to where they are being driven and set up for, they do not require aggressive static camber settings or heavy spring and damping rates to achieve the same cornering grip as a MacPhearson Strut - all else equal.

I've only begun to inspect the Mini so I have no comparison...yet.

My personal feeling is that as spring rates increase, compression damping should be reduced to prevent a needlessly harsh ride. Rebound damping should be increased to control movement. I almost always found myself adjusting in these directions when making spring rate increases. This is why I personally try to stay away from shocks that adjust both compression and rebound in a single adjustment. Anyway, just my 2 cents.

Agreed! And, I personally believe that compression damping should be about half to one third rebound. Otherwise, the car never settles down.

We have to consider what we are driving and more and more spring and damping will not cure - as I've written - the nose heavy, front wheel drive nature of the mini. Comfort on the road, and, race track believe it or not, is also a key to a great handling car. Stiffer ain't always better...well almost never...

EDIT, PS...whatever - motion ratio is as defined above, but is further characterized by the geometry of the entire suspension; relative location of all pick-up points for control arms and spring/dampers, length of lever arms, height etc. Packaging defines many of these relationships for road cars. Racing cars, especially F1 cars get around typical road car packaging with with elaborate cam actuated, inboard systems. Forgive me, I'm old and can't remember squat these days.

...okay, some more for clarification as I'm usually writing from work and really should be working...so I'm usually writing faster than I can think.

Regarding motion ratio - long arm control arms offer better camber control when compared with short arm control arms. However, a longer arm, as implied above requires heavier spring and damping rates to control road inputs for the same reason that it is easier to move a 500lb block with a lever arm twice as long as pointed out above. The reverse is true for a short control arm suspension. There is always a sweet spot for a given set parameters.

 

i beat the hell out myself running the Ledas in the fine streets of NY without bump stops, finally added the stockers by coring out the id a bit to clear the shaft.

Tony- I opened a shop in Oakland, run by one of my sons (a 4wd Bronco nut and ducati nut), for our west coast architectural work and am angling to get my own butt out there where the riding is good.

productanddesign.com

 

jlm,


Ever consider making a set of light weight lower front control arms for our Mini??? Any market? I don't really know what you manufacture but some of your proponents have said you've forgetten more than most people will ever know...bet you could make some really nice stuff...

Michael

 

jlm, I initially didn't have bump stops, and the noise was incredible, and quite scary. I was able to bottom-out hitting mild bumps in my driveway, so the impacts at higher speeds were quite impressive. This was with Webb's ver 1 plates also...

Randy had Leda make me units .75" shorter, and with 4mm off of his ver 2 plates, I'll keep my fingers crossed. Having 23.3" tires doesn't help because visually one then wants to lower things even more to eliminate wheel well gap, thus further reducing travel...

What are your F/R spring rates, and have you checked to see if you are bump stopping? It's not always so easy to discern, at least when there are bump stops in place .

How cool is that!? You and Luke joining forces . The website is very clean and informative. I love the from 'anvil to CNC' line. Oh, and the staircases are awesome! I'll be adding on, and up to my home in the coming years, and I've been visualizing a spiral staircase, but one with a firefighther like pole down the center, as a fun option . I will certainly keep you guys in mind! Also, do you guys work with titanium any? I'm still contemplating improved rear bracing for the MINI, in Pilo's area, but with a couple of triangles involved. I see titanium on eBay, but not many seem to work with the stuff...

Sorry for the OT!

Back to coilovers...

 

Great info from all!!!

I'm planning to run an auto-x set up and take the effort to corner weight the car. I will also lower the car for competition.

Question: Can I mark the positions and raise the car and get it back to spec easily for competition? I don't clear much of the occaisonal road-kill as it is with a stock ride height. I would have a problem running competition trim all the time.

 

In my case I didn't want to make any changes from street to track or autocross driving so I had to set a compromise height that would work for everything. This was lower than for street use but not that low about 1/4 to 1/3" clearance from the tires. Once you corner balance you have set the heights and can then align. If you mark the settings on each spring/perch then you can change the height but you will be also changing alignment.

How much change I don't know, depends on your set up and degree of change. Also if the markings rub off or wear off you will not know where to adjust to. There is no way you can do it by eye- you'll need the scales to corner weigh again. All four settings on ride height are critical for corner balancing.

For track use I'd like the height to be a bit lower still. For street use and with passengers in the car the back end does rub a little under load and on rough roads but mostly with stiff shock settings- better with softer settings.

 

I agree with minihune; all four points are critical. I would advise picking a set-up - height - that works for the bulk of your driving.