I came across an interesting discourse on the subject of handling, and thought I might throw it out here for discussion. For those interested, the forum is http://www.socaleuro.com/forum/showthread.php?t=17370 , and I have quoted it below. It points out the importance of deciding just exactly what goal you are seeking when modding suspensions, there is no one single definition of "handling". He defines 5 different kinds of drivers, and each would tune differently. I would like to think of myself as a GT, although I do some autocross and track days. Anyway, food for thought, as you ponder such questions as "should I do a 19 or 25 mm rear swaybar?" The correct answer, as usual, is "it depends". Balance, my friends, balance.



3. CATEGORIES OF DRIVERS

If you look closely at the posts to the suspension forum, you'll see that suspension enthusiasts tend to fall into several more-or-less clearly defined groups. We'll ignore those who want lowering for looks, as well as the people who simultaneously want pinpoint handling precision, a luxury ride, fantastic grip, and failsafe emergency behaviour (advice to these souls: save up for a nicer car). The remainder fall roughly into 5 categories (I'm grossly oversimplifying here!): there are track enthusiasts, divided between autocross and road-course aficionados, and then there are the roadies, whose 3 categories I'll explain in a moment. (As discussed in the earlier installment (#2), the track setups are considerably closer to "neutral" than are the road suspensions, and only the very skilled or commendably cautious should be running serious track/autocross cars on public roads.) We'll go through these categories one by one:

1) Track-Based Suspensions: Autocross

Autocrossers live in a flat, low-speed world with endless sharp corners. These characteristics -- the relative smoothness of the autocross tracks (e.g., parking lots with cones), the need for lightning-fast corner entry and left-right transitions between corners, and the low speeds necessitated by the constant tight turning -- define the autocross suspension. As we'll see in a later installment, there's probably more room for variety in a Golf/Jetta autocross suspension than anywhere else, and it's here that one might get away with the ultra stiff springs, big antiroll bars, and meaty wide tires that are the staple of common speed shops. That's not to say that the aforementioned parts are the fastest or best way to go, but at least in autocross they have a chance.

2) Track-Based: Road Course

Compared to an autocross course, a true road-racing track allows for much higher speeds and a much more flowing mode of travel. Agility in transitions starts to matter less than stability under trail-braking and an ability to put down power on corner exit. Although the surface of a good track is about as smooth as anything a car will drive on, the speeds are high enough to begin putting a premium on absorbing bumps while maintaining traction. The requirements of a good road-racing suspension start to converge on those of a good street suspension, and a dialed-back road-race setup (i.e., a road-race setup that's been given better ride comfort and more stabilizing understeer) can form the basis of a fast road car.

3) Street-Based: The Darter

"Darter" is not an official term, but it is descriptive. A darter is a person who wants his car to have the instantaneous, solid, no-roll response of a go-kart. "Handling" here equates to an ability to zig-zag through turns so suddenly that passengers lunge frantically for the grab handles and loose french fries go flying through the cabin, or to change lanes in a quick left-right snick-snick that supposedly looks cool but in fact is only dangerous -- it's sort of the Super Mario/ Nintendo view of the automotive world. I was a darter once, and a lot of sub-24 male car enthusiasts seem to start off in this category. Unfortunately, darters are rarely happy people (not least because, if darting is the goal, the Golf/Jetta IV is the wrong car). For the VW-loving darter, the car always rolls too much, the steering is always too slow, there's always too much understeer, and friends' Hondas and Integras are always better. Darters play an important role in the VW tuning ecosystem by single-handedly keeping the smaller tuning shops alive: it is the darters each year who go through enormous quantities of springs, shocks, bars, coilovers, urethane bushings, camber plates, rims, tires, spacers, spindles, strut tower braces, steering racks, spherical bearings, and general miscellaneous stuff, all guaranteed by the vendors to "tighten the handling while eliminating understeer!". There's nothing wrong with being a darter (as I said, I used to be one myself), but it's a frustrating existence if your car is a Golf/Jetta IV, and ultimately darters either gravitate towards autocross setups that don't work for the real world ("Selling complete suspension!! Wife having baby -- must sell!!"), or else they give up by selling their VW, or by becoming a Grand Tourer.... In any event, there is no suspension setup that is the ultimate Golf/Jetta IV street Darter -- if darting is the goal, you will need a different car.

4) Street-Based: The GT's

The acronym "GT" originally referred to Gran Turismo (Grand Touring) cars that were fast, comfortable, and effortless at rapidly covering ground on difficult, twisting roads (supposedly they developed when Europe still didn't have much in the way of superhighways).. And the GT version of the Golf/Jetta is what most non-darter street enthusiasts are looking for. If you fall in this group, you're looking for something that has a lot of grip, is reasonably comfortable, possesses good stability, and is relatively forgiving (so that you can converse with your significant other while zipping through the countryside). The setup for a good GT is essentially a dialed-back version of a good road-race car (with increased understeer and more comfort); the Shine SRSS is probably the exemplar here (although it apparently works well on the track as well), along with its softened permutations, and the GT enthusiast can essentially decide where on the ride vs. handling continuum he wants to be. We'll spend a good amount of time talking about the GT setup, when we eventually get to the appropriate installment.

5) Street-Based: Driving a Slow Car Fast

Finally, here is the smallest, least popular group, which I list primarily because I (Ceilidh) currently live here. A sad thing about aging is that some of us become steadily more boring and wimpy as the years go by, and eventually we resign ourselves to driving interminably behind the Volvo 240 with Delaware plates instead of searching for a way to pass it. When that happens, a "good" suspension becomes one that provides maximum feel, that responds somewhat to classical driving techniques even when driven at 3/10 to 5/10, and that possesses low enough limits (or more accurately, "perceived" limits) so that we get the occasional sensation we're actually driving. For people in this small category, a near stock setup with better damping (but skinny tires) is actually kind of nice.
So those are the categories. Each category has a different ultimate suspension solution (except for the Darters, who are doomed to disappointment), and a person wanting to modify his suspension had best figure out which category (or between which categories) is the one that really applies.

 

Hah, well the MINI is built for being a "darter" I guess, and a Cooper with skinny tires qualify for #4 and #5 at the same time.

 

Sounds like all mumbo jumbo.

The only thing you need to worry about is whether you hit the wall with the front of the car or the tail.

 

Actually, if you read the whole discourse, he has some very good points. Too big a rear sway bar will make things worse, unless you're autocrossing and are trying to get it to rotate. Lowering your car may in fact produce less overall grip. Just some interesting reading from another source. I think MINI's are interesting in that they can be built to be any of the various flavours, not every car can say that. Versatility. A very adaptable platform. We know they can autocross, we know they are darters. I think they can be capable GT's, long legged runners. And a Cooper with Conti's is, indeed, a slow car that you can toss around gleefully.

Chows, let's think about that CS. Definitely a GT, can be a good track machine, but not really designed for autocrossing. Whaddya think? Gibberish?

My whole point is that you really have to sit down and think about what you want to build before you start throwing parts at it.

 

MCS out of the factory a darter, eh?

 

I was teasing on the mumbo jumbo

Ahh, you had to bring up the croc. Several auto mags I can point you to now proclaim it the best handling car made ... period (UK mags).

Its not a GT at all. Many ppl say the 997 has "become" a GT. After reading many posts on why ppl buy the CS vice 997 its all about the handling. CS is a true sports car. 997 has become a bloated GT (with lots of power if you get up into the GT2, GT3, TT area). Our original plan was to save some more and get a 997 in the Winter. Decided it just wasn't worth the extra money because its too much a GT vice viscereal sports car now. Many have made that same decision.

Best car at AutoX. Agreed, probably not. Twisties? Absolutely .... sports car territory. You simply can't beat a mid-engined car for handling. Someone else asked me about cornering and they only way I could describe it is in a fast corner in the JCW, there was lots of drama (albeit on rails).... In the CS your just around the corner ... no drama, and the wife is fiddling with the radio. Some auto journalists call it "no soul" because its too efficient.

Track? Well its faster by 4 secs around the Ring than the 997 (not the S ... much more HP). That embarrasses them so they have to dial down the power. They can't have it stomping on their premier car at the track.

So yeah, I can agree ... but see https://www.northamericanmotoring.co...ad.php?t=80382

If your talking slalom, MINI is way down the list and the only car quicker than the 987S on the Slalom?... yup its bigger brother.

They are two different cars intended for two different reasons. I have repeatedly said the JCW was a ball to drive and it is WELL regarded in the community. I think AutoX is its stong suit.

But no way is the CS a GT.

My whole point is that you really have to sit down and think about what you want to build before you start throwing parts at it

Agreed 100%. Many ppl start talking about coilovers and changing tires, etc and tweaking the suspension but they tend to forget you can do the exact same thing in any car. But, I think you are correct

 

And also think of what the ultimate capabilities of the car are in the first place. Some cars are just not, no matter how many parts you throw at them, the right platform for a certain category. No matter what you do to a Viper or Corvette, they won't be auto-x cars. Period. Some cars like the MINI can fit well into multiple categories with the right modifications but still might not be "optimum" for them.

 

Several excellent points - always a little hard to push human beings into general categories, but I've believed for a long time that "good handling" or "improved handling" are phrases that mean many different things to different people. Personally, I think those of us who don't track our cars get way too caught up in absolute lateral g numbers - we're not going as close to the edge as we think we are 90% of the time. I like a car that doesn't understeer so much that it "pushes" I like to "feel" what the tires are doing, and I don't want them to squeal or break loose under "spirited" driving conditions like Hwy 18 to Lake Arrowhead. On the other hand, I want a reasonably compliant ride and I don't want to find the *** end of my car coming around if I (or my significant other) happen to misjudge and brake mid-curve. For me, my 15" holies with 195/60/15 rubber and a 19mm Hsport rear sway bar, feels really nice. Shortly, I'll add JCW springs and the Koni FSDs, and I hope I feel a meaningful improvement in response w/o screwing up the ride. My car won't be set up like I would if I were tracking it, but I think it'll feel good to me and qualify as "good handling" in my book.

 

I would also add that tires make a huge difference (and I'm not talking about RF vice non-RF) but rather in size.

For MINIs, I've read 15 and 16" best of autox, 17" for track, 18" for bling. Yet, you see only JCW wheels in 18". Never understood why or where this was coming from. I'm not discussing unsprung weight issues, just the tire patch.

Now I do know that the patch area remains identical because of the weight of the car but the width of the tire matters ... wider tires, I think, dissipate the heat better than thinner tires. I've read that on tirerack or somewhere about high speed, Z rated tires.

I would think the best investment and easiest to make is in the best tires you can buy.

However, in the CS, they are stock 18" and extra $$ for 19". Factory race driver says you want 19" for track, 18" for street. But why? The answer I kept hearing was turn-in (even heard it from the saleman). I ended up with 19" (which look a bit weird seeing this rubber band for a tire) and now truly understand "turn-in". The 19" DOES turn in quicker and therefore quicker around corners.

However, I dont understand why this doesnt apply to 18" MINI wheels ... should give better turn-in? The only thing I can think of is with the MINI everyone is hung up on unsprung weight (basically due to the low HP numbers).

Anyone know?

 

I did not mean in any way to disparage the croc by calling it a GT, everything I've ever read would agree that it is at the very top of the handling realm, but that would be handling in the sense of being able to handle any road, anywhere, with serious track capabilities. The Xcross guys might define handling differently, but that's fine. I love Xcross, but handling to me means going more than 60.

My guess on the 18 inchers and turn-in is that the difference is in a) the weight, and b) the steering geometry. What does the croc weigh? More, I'd think, than the JCW. The croc was designed for 18's and 19's, I doubt the JCW actually was. As the croc rolls into a corner, the camber probably doesn't go off-camber as much as the JCW will, and can actually maintain the contact patch that the 19 offers. The MINI has already rolled on the edges, and because of the geometry it might actually feel better with 16's or 17's. I can't figure out why they put them on there, either.

Ain't idle speculation wonderful? I actually have no idea what I'm talking about.

 

That makes sense.

I just could never understand why all JCW wheels were 18" including the GPs yet most ppl do not like 18"

 

I have a set just like that, and put them on whenever I'm going on a trip. I'll be curious to hear how the JCW springs work, I think you're on the right track. snid sure likes 'em.

 

I'd also like to know. Less sidewall should improve turn-in response but auto-x'ers tend to go with 15" wheels on the MINI. Is it just for weight savings? Aren't there any light 17" wheels out there?

 

Turn-in response is a big deal in autoXing and a wheel that is lighter over-all, especially at the circumference, will turn-in faster. The lack of profile is a trade-off. Just take a really heavy bicycle wheel and a super light racing bicycle wheel, spin both and try to turn each. The lighter wheel is easier to turn.

Wheel offset will also affect turn-in and ackerman angle. A higher numeric offset - 50mm - will turn-in way faster than say a 25mm offset. The compromise here is motion ratio and the center of gravity; a 50mm offset leverage a given spring and damper more effectively and position the center of gravity higher than a 25mm offset. A 25mm offset will increse track and therefore lower the center of gravity without touching anything else but will reduce the effectivness of the given damping system - due to a loss od effective motion ratio.

Larger wheels can house larger brakes, a big deal on some tracks, but another compromise.

Anything can be made to handle well, some with lots of effort and some with seamless effort. On a track, a car that extracts little in terms of sweat from the driver has the potential advantage. On the other hand, a car that is difficult to drive fast, but can still manage to be quick where it counts can also be an advantage.

The sum of the parts do not always make up the whole...and in some cases - the Mini - the whole is better than the sum of the parts. This car just works very well. In reality, a camber kit, the correct front to rear offset and good brakes and you've got a car that can move along very well on a track given its pedestrian roots.

In any event, it all begins with a proper Mass Centroid Axis.

 

The distance between the front axle centerline and the contact patch is smaller on the 15s, which alters the effective gearing.

I am doing 65+ in 2nd at the rev limiter on my JCS with 15" Kosei S1 and Falken Azeni 205/50, which is fast enough for the NER courses, so I can afford lower gearing to gain some acceleration.

It gets be to a game of tenths eventually, and small changes matter.

(Dammit Eddie Savage was right!)

 

I'm not sure which category I fall under. I autocross when I can and want good response. Yet I will only modify the suspension if I feel it will benefit me daily or on roads like the dragon.

Speaking of large wheels. I have a JCW which I immediately removed the s-lites for some 17"s I had. They weigh in a 16lbs each. Unfortunately I followed recommendations and put 215/45/17's on the rims. To me, even though they are the same tires as my previous, the 215/45/17's are less responsive in turns than my previous 205/50/16's. Even during autocross even though the stock v-spokes ran 2lbs per wheel heavier.

Less responsive in a way that it feels there is too much drag on the front tires when turning and it doesn't feel like being tossed in and out of curves. If that makes sense. I'm on the search for some 16's, possibly 15's, to replace the 17's but if I don't find anything by the time the tires wear. I'll be dropping back down to 205/45/17's to see if that helps.

It may just be me but in everyday use I feel 215's or larger are too much for the MINI. It looses its tossability. If that is a word.

I don't know much about autocrossing or tweaking suspensions. I just go on what my arms and butt tells me.

 

You also have to look at the relationship between the sidewall and wheel width. Often, the widest tire that can fit on a given rim width will not perform well because the sidewall is not stretched, but pinched. This causes the tire sidewall to roll over during cornering. rolling over generates lots of heat and scrubs off speed - with a potential increase in slip angle too.

A gearing advantage can be had with 17" rims as well; 205/40/17s posses a really nice gear advantage.