Especially since automobiles became more common and affordable in the 1920s and 30s, people have been looking for ways to make their cars stand out. One common way is lowering the ride height. In those early days, suspensions were basic, and speeds were relatively low, so the changes made didn’t have too much impact on the way the cars functioned. But modern automobiles are different, and “slamming” them can have profound effects on a vehicle’s handling. Here’s a look at the engineering behind how lowering a car can ruin its handling.
Welcome to another edition of Ask An Engineer. I received a letter from a reader recently where he asked me for help with a problem he was having with his 2017 Skoda Combi. He wanted to lower the car by about an inch for a better look, but he didn’t want to mess up the suspension by doing it.
He knew lowering the car would screw up the roll centers but he wanted to find out if there was a way to fix it. It got me thinking about what happens to the suspension when we lower a car and how that might impact the way the car handles.
Roll Centers
For those of you who haven’t watched my videos (shame on you!), the suspension roll center is an imaginary point around which the body rotates when it rolls side to side in a corner (you’ve probably all felt a car “roll” when you take a turn really fast. The car is not literally rolling over, but the body shifts/rotates in such a way that it seems like you might if you’d taken that turn fast enough).
Both the front and rear suspensions have their own roll centers, and if you draw a line between them you get the axis the body rolls around in a corner, similar to how a door rotates around its hinge axis when you open and close it. In the video above I explain a few methods for determining where the roll center of a suspension is, but for the purposes of this discussion, we’ll stick with the simpler, geometric method. It works reasonably well and illustrates the point. To demonstrate we’ll use a computer model of a generic MacPherson strut, since that is the type of front suspension our friends 2017 Skoda has. (And it’s extremely common).
In a MacPherson strut, you can find the roll center by drawing a line from the top of the strut, perpendicular to the axis of the strut.
Then draw a line along the lower arm (specifically where it mounts to the body) and extend it until it crosses the line from the strut.
The intersection point is called the instant center, and it represents the instant center of rotation of the wheel and tire as they move up and down when viewed from the front. Next, draw a line from this point to the center of the tire contact patch.
Where this line crosses the centerline of the car is the roll center height, which in the case of our model is 95 mm.
But what would happen if we lowered the car by 30 mm? How would the roll center change? We can see this by moving the wheels up 30 mm which is the same as moving the body down:
If we zoom in on the suspension we can see how moving the wheel up 30 mm, or moving the body down 30 mm reduces the height of the roll center:
In fact, moving the wheels up 30mm (again, the same thing as dropping the car 30mm) has resulted in a roll center height of 16 mm. A reduction of 79 mm.
This is fairly typical of MacPherson strut designs. The distance the roll center moves will be over twice the distance the ride height changes.
So What?
The next obvious question is “ok, so what”? Who cares if the roll center drops when we lower a car?
Remember that the front and rear roll centers define the axis that the body rolls around when cornering. But the distance between this axis and the center of gravity determines how much the body WANTS to roll. It’s called the roll moment, and it is the cornering force multiplied by the roll moment arm which is the vertical distance between the vehicle center of gravity and the roll axis (that’s an axis created by a line from the front to rear roll centers).
Make this distance bigger and you make the roll moment bigger. Make it smaller and the roll moment gets smaller.
At this point, it is important to note that there are actually two moments happening at the same time here, and it is very important to understand the difference. We’ve been talking about the roll moment which controls how much the body wants to roll in a corner. But there is a second moment which I will call the cornering moment, and it determines the weight transfer that happens in a corner. They are related to each other only in the fact that they both depend on the location of the center of gravity, but otherwise they are unrelated.
When a car enters a corner, the inside and outside tires develop a cornering force that pushes the car around the turn. This force is balanced by an inertial force acting at the car’s center of gravity. Since the tires and the center of gravity are at different heights, these forces create a moment that wants to roll the entire car over. The reason the car doesn’t flip over is that the moment is resisted by the inside and outside tires through the lateral distance between them, i.e. the track width:
The weight transfer is equal to the vehicle inertial force (which is the same as the cornering force), multiplied by the vertical distance between the center of gravity and the ground, divided by the track width. Notice that the weight transfer gets smaller if the height of the center of gravity gets smaller or if the track width gets bigger.
Notice also that neither the height of the center of gravity above ground nor the track width have anything to do with the roll moment. It is strictly a function of the cornering force and the roll moment arm. Therefore, widening the track width of a car will reduce the amount of weight transfer but will have no impact on the amount of roll the body sees unless the act of widening the track also somehow changes the roll center height. Similarly, lowering the center of gravity will reduce the weight transfer but will have no impact on the roll moment unless it also reduces the roll moment arm.
Let’s go back to our example suspension. By lowering the car 30 mm, we increased the distance between the center of gravity and the roll axis by 79 mm, but we also reduced the height of the center of gravity above the ground by 30 mm. It is tempting think that because the center of gravity is lower and the weight transfer has been reduced, there must be a corresponding reduction in roll, but you see from our example why that is not true. The roll moment has nothing to do with how high the center of gravity is above ground. It only cares about how high it is above the roll axis.
Here’s another way to think about it. Let’s suppose we have a suspension design that puts the roll center at the same height as the center of gravity. In other words, the length of the roll moment arm is zero:
Since the roll moment is dependent on the length of the roll moment arm, you would expect in this case that the roll moment would be zero and the car would not roll at all. And you would be correct. Remember that the roll centers define the axis the body rolls around in a corner. It would be similar to trying to close a door by pushing directly on the hinges. It wouldn’t work. You have to push on the door some distance away from the hinges to get it to close. If the distance is zero, the door won’t rotate. Same here.
However, the center of gravity is still above ground so there will still be weight transfer happening. So, how can we have weight transfer but no body roll. The answer is in the way the weight transfer force travels from the body down to the tires.
There are two paths that the weight transfer force can use to get from the body down to the ground. One is through the suspension links:
while the other is through the springs:
Part of the job of the roll center is to control how much of the weight transfer force goes through the suspension links vs how much goes through the springs. The portion of the weight transfer that passes through the springs will cause compression in the springs since it is just responding to the extra force. This is why we get body roll. In the case of the car with the roll center the same height as the center of gravity, the lack of body roll means there must be no spring compression. The force in the spring must be staying the same. This means all the weight transfer is passing through the suspension links while none of it is going through the spring.
If we look at the opposite extreme where the roll center is on the ground, we have a situation where the roll moment arm and the center of gravity height are equal:
In that case, all the weight transfer force will pass through the spring and none of it goes through the suspension links. Remember, weight transfer is a vertical force pushing down on the outside tire and pulling up on the inside tire. There are still horizontal cornering forces that the tires have to resist, and these will still pass through the links regardless of what happens with the weight transfer force.
Roll Axis Skew
So far, we’ve talked about the roll axis and the roll axis moment arm as if it were purely determined by the front roll center height. The fact is that the roll axis is defined as a line going from the front roll center to the rear roll center and the two may not be at the same height. In fact, in my experience, the rear roll center is almost always a bit higher than the front. What this does is put a bit of skew into the roll axis. Having a skewed roll axis in this way adds a bit of understeer to the car. Here’s how that works.
If the roll axis were perfectly horizontal, i.e. the front and rear roll centers are at the same height, the car would roll horizontally side to side:
If, on the other hand, the roll axis is skewed with the rear roll center being higher than the front, the body will roll in a way that puts more pressure on the outside front tire:
Putting more pressure on that outside front tire means it has to work harder so its slip angle will be greater, adding understeer to the car.
In the case of our example suspension, lowering the car resulted in a front roll center that is 79 mm lower than it was before. If the rear roll center didn’t change, then the lowering of the front roll center would increase the skew in our roll axis considerably, adding more understeer. The reality, however, is that the rear roll center will also drop but it will likely not drop as much as the front. MacPherson struts are notorious for having a lot of roll center movement for a given suspension movement. Multilink and double wishbone designs (commonly found int he rear) are much better in this regard. They will still show some roll center change, but it will be much less.
So dropping our car 30 mm front and rear will very likely increase the skew in the roll axis and add understeer to our car.
Possible Fixes?
So, what can we do about this? Can we lower a car and then fix the roll center problems we’ve created?
There are things we can do that will help but, in most cases, there is no real fix.
Several aftermarket companies have special ball joints available that will move the lower ball joints down. This puts the lower control arm closer to the position it was in before lowering and moves the roll center back up but there are limits to how far you can go with these parts. An example are these ball joints sold by Hardrace for the Mitsubishi Lancer Evo:
These parts have an extended housing that moves the lower ball joints down 15 mm. This would certainly be help but doesn’t compensate for a 30 mm vehicle drop.
In some cases, though, it may be possible to move the ball joint down the full 30 mm. It depends on how the knuckle is designed. Toyota uses a two-piece knuckle in some of its cars and in those cases, we can install a spacer between the OE ball joint and the knuckle and get the full 30 mm change:
We need to be very careful here though, because moving the lower ball joint down has the added impact of changing the relationship between the lower arm and the steering tie rod. We can see the effect of this in our example strut. Before lowering, the lower arm to tie rod relationship looked like this:
After we lowered the car 30 mm it looked like this:
Now, if we install one of these roll center correcting ball joints, the relationship will look like this:
This relationship controls the change in toe angle as the wheel moves up and down. It’s called “bump steer” and it is a critical part of the whole understeer/oversteer behavior of the car. In almost all cars, as the front wheel moves up, it will simultaneously steer slightly outward. This has the effect of causing the car to understeer a little as the body rolls in a corner. It effectively removes some of the steering angle you put in at the steering wheel, thereby causing the suspension to steer a little less than you asked for.
Unfortunately, the amount of bump steer a suspension has is extremely sensitive to the relationship between the lower arm and the tie rod. Even a 1 mm change will have a noticeable impact on the way the car behaves, so a 30 mm change is absolutely enormous. And depending on where the steering gear is located, the change will either greatly increase or greatly decrease the amount of bump steer. If the steering gear is mounted behind the front wheel centerline, as it is on most front wheel drive cars, the change will increase bump steer. In a car with the steering gear mounted ahead of the wheel, centerline, it will decrease the bump steer and may even put the car into and oversteer condition.
[Editor’ Note: I’m including this picture of a slammed Conestoga wagon because Huibert’s first drafts referenced pioneer days and Huibert asked for it but then it got edited out but I already threw this together, so I decided I may as well throw it in, because a slammed covered wagon is funny. – JT]
Those of you who own Toyotas that use a two-piece knuckle are in luck because as you can see from the photo above, the part that holds the lower ball joint also holds the outer tie rod end. This means that the 30 mm spacers move both joints together. This avoids the whole problem I just mentioned, so you Toyota owners just read about an interesting problem that’s entirely irrelevant to your situation. For the rest of us, we still have an issue because most knuckles are single piece. Moving the lower ball joint down does nothing to fix the position of the tie rod end.
The only way to resolve the bump steer problem in that case would be to move the outer tie rod end down along with the lower ball joint somehow but this is often very difficult to do and would most likely require a custom knuckle.
The Rear Problem
Another problem you run into when lowering a car is that while there are some things you can do to help the front roll center, it is way more difficult to fix the rear roll center. In the case of our friend’s Skoda Combi, tha car uses a trailing blade rear suspension design and there is no good way to move a ball joint or two to get the roll center back to where it was.
You would have to move the entire suspension up and that would be quite impossible without cutting up the rear underbody.
The Bottom Line
What we’re left with now is a situation where, by lowering our car, we’ve increased the roll moment arm, thereby increasing the amount of body roll. We’ve also increased the skew of the roll axis thereby increasing understeer.
But then we go and install roll center correcting ball joints or spacers which moved the front roll center back up, but since we can’t really fix the rear roll center, we’ve now reduced the roll axis skew, reducing understeer. But (unless you own one of those Toyotas) we’ve changed the relationship between the front lower control arm and the tie rod which could have the effect of either increasing or decreasing bump steer and with it understeer.
The end result is a giant mess where the balance between the springs, dampers, bump steer, roll axis, and all the things that go into making a car handle properly has been upset. And no one knows where this balance has ended up. The reality is that for most people, under normal driving conditions, it won’t matter. Unless you regularly probe the limits of your car’s handling performance, like on a racetrack, you will probably never know anything has changed. But if you ever find yourself in an emergency where you have to quickly maneuver out of a bad situation, the change in handling balance can rear its ugly head and the car may behave in very unpredictable ways.
Knowing all this now, should you lower your car? If you like the way it looks and don’t care about much else, go for it. But don’t do it expecting your car to handle better. It very likely will not and may actually handle worse as a result. I hope you never get into a situation where you have to find out.
Working in a motorcycle shop i regularly have to explain this concept to people. “my buddy put a 200/55-17 on his bike. i know it will fit and it looks so cool” Dude you have a 5″ rim…. ya Im not gonna put it on there. Worse still is the “darkside” guys who run car tires like complete morons. Talk about a deathtrap
The car tire group intrigue me.As far as i can tell it’s all about money saving?
It’s like the motorcycle equivalent of winning an argument with your wife but that causes a divorce
What I don’t get is having an expensive hobby and skimping on probably the most important part of it. Like getting a Gibson and playing it through a Temu amplifier, you didn’t save money on an amp, you wasted money on a Gibson.
Exactly. People do try to self/wife justify buying a Harley or other large motorcycles with the thought that its cheaper to run than a car and total cost really isnt cheaper. Ive told people you wanna save money riding? get a 300cc or smaller bike. you will probably get 75mpg, the bike is cheap and parts are usually cheap. They always scoff and make a comment about being learner/girl bikes. Idiots
And after calling the 300cc a girl bike, they take their 1300 out to Starbucks at 35mph in a Cactus Jack costume.
Yup entirely about the money. I like that analogy alot
This makes me laugh even more at all the ’80s dude-bros in their camaros and firebirds with the 2 inch dropped front 4 inch lifted rear rake rolling through town like they were hot shit. I would have been more understanding had there been a decent drag strip that they used regularly within 50 miles of me, but nope they just liked cruising to burger king with their mullets flowing in the breeze.
Two of the more catastrophic results of guys cruising the drag car look that I saw were a Duster(?) with a stupidly-tall shackle that bent sideways, and a GTO which broke a skinny front drag wheel turning left in the biggest intersection on our cruise strip—in front of a cop. As the GTO guy was nearing 30 out there cruising for HS girls and also had way more BS than motor, you could hear the laughter & cheers even over the AC/DC, Quiet Riot, and Lynyrd Skynyrd 🙂
Strangely, I now want a Conestoga wagon on airbags
Be sure it’s the EV model. Word is if you add more than one horse to pull it, it throws off the GPS and you could end up in a bad place. Plus it annoys the Native Americans. YMMV
VW MK4 owners are triggered!
What would happen with a car that has a McPherson in the front and Chapman strut rear suspension?
Those are fairly similar so I suppose lowering them by the same amount would roughly translate in the same way regarding roll centers, leading to a similar skew in the roll axis compared to stock. At least understeer issues would be somewhat reasonable.
Chapman strut is more similar to double wishbone, it just uses the U-joint as a control arm ball joint. Can’t think of many modern cars with Chapman strut, since you can’t make it work with CV joints and those are noticeably more efficient. Last I can think of would be an E-type. Does the Z4 have something similar?
I was thinking about my 280Z.
Interesting, I thought they had semi-trailing arms like the later 280’s. I’d love to see how they work, is the strut fixed directly to the upright or does it have some sort of pivot where they meet? If it’s fixed that would mean it works very much like a MacPherson, otherwise it’s more akin to a double wishbone. From the pictures I’ve found, it just looks like a normal MacPherson with 2 lower joints instead of a lower joint and a steering link, which makes me wonder why the forums keep referring to it as Chapman strut.
Look up the E-type’s rear suspension for a picture of a textbook Chapman strut setup, where the axle acts as an upper control arm and the strut is just mounted to the LCA with no participation on alignment, then compare with the rear suspension of a Boxster, which is a MacPherson and looks (functionally) just like the 280Z, just with a more complicated 3-part LCA (This allows it to reuse the front LCA with a different traction rod and adjustable toe arm, presumably saving money).
I don’t claim to know more than the actual Z owners and experts, but it sounds like they might be repeating period Nissan marketing pamphlets instead of looking at the system critically. This is only my best guess and a hypothesis at best.
All this to say, a 280Z might react better than most cars to lowering because it’s effectively MacPherson all around.
I called it “McPherson” at first but changed my tune after reading up on the car. I’m not much of a suspension expert so I assumed I was wrong.
The strut is solidly mounted to the upright, and the half shaft has a compliance along its axis so I doubt it acts like an upper control arm. It really does look like a front McPherson sans bearing.
I guess I’m gonna have to lower it for science then!
Guess you are, for science. Worst case scenario, get adjustable coilovers so you can raise it to stock while getting the handling benefits.
I have to correct myself: A Chapman strut acts like a McPherson with 2-3 lower links, and the drive axle acts like one of the lower links, it saves weight by having 1 less link. The E-type has something else, altogether, it has a stressed axle but isn’t Chapman Strut because it behaves like a double wishbone.
That said, the 240Z still seems to be a normal McPherson to me, as it features a triangulated LCA with an unstressed axle, and as far as I can tell, the stressed axle is the defining feature of Chapman Strut.
Ah, but with some cars it works out nicely. Like with the E34-era BMW 5-series, the rear trailing arm suspension toe + camber works out pretty nicely once it’s lowered a certain amount, like it handles well and doesn’t rip through tires at all. The front suspension has the control arms + tie rods go into a knuckle that bolts onto the bottom of the strut housing, so a 35mm spacer plate takes care of the bump steer quite well, without really messing up the steering linkage.
bottom line you would get next to zero benifit on the street probably a net negative because of scrapage. lowering your car would gain you 1 or two seconds on a race track best case scenario.
On track, most of your gain would be from the stiffer springs/shocks, not from the actual lowering. Even then, it’s more so about the front/rear balance, as sports suspension kits usually stiffen them differently to change the balance in a favorable way. Chances are, a non-lowering sport spring/shock set would usually offer the same or more gain than the same kit lowered. Sadly, most of these kits are only available lower than stock because there aren’t enough people who just want the handling to get sales volume, so they need the aesthetic appeal of lowering in order to recoup R&D.
TL;DR below:
“Any suspension, no matter how poorly designed, can be made to work reasonably well if you just stop it from moving.”
-Colin Chapman
I love that gif
What if we just changed the tire size, say going from 31’s to 22’s
“No change in handling there.
It’s fine.”
-Guy going 85 MPH in a slammed Altima riding on mostly donuts-
That affects your scrub radius unless you change your offset, it would mostly change steering effort and response, sometimes giving you more feedback and sometimes less. I’d make sure to measure your kingpin angle and scrub radius to help you with that decision, but it’s definitely easier to solve than suspension lowering, because your roll centers and CG go down together. Plus, decreasing your rolling radius usually involves changing wheels anyway, so a judicious choice with the correct offset could be all you need, no other parts necessary.
That’s pure autopian right there.
Thank you
Any time!
Joke’s on you, Huibert. I don’t own a Toyota so I didn’t read an entire section that doesn’t apply to me.
I don’t ever plan on lowering my car so I spent 20 minutes reading an entire article that doesn’t apply to me!
I hope you slept well
But I do drive a car, and I always thoroughly enjoy your technical deep dives.
But now you have me thinking. I drive a big ol’ van that stands 10 feet tall. Maybe I should slam it. I think the parking garages and drive-thrus would be well worth the handling trade-offs….
Gottem.
Seconding the comments about this being a great article while not always grasping it all. Yeah, I know suspension engineering isn’t simple at all but sometimes it’s simply astonishing how complex it can be so such deep dives with a combination of lay terminology and engineering terminology are greatly appreciated.
This might be pretty niche and of little relevance nowadays but I daresay a few of us (dozens, maybe) might find it of interest to read about what it entailed in the 1930s and 40s to modify cars, with their primitive suspension systems, to handle loads of moonshine (famously, heavy-duty springs were used to keep the cars level so as not to draw attention from the revenuers or “revenoors”) while not compromising (!!) handling even as the engines were tuned for power so the moonshiners could evade the law on mountain roads.
Reading about roll center, etc, made me think of a notable moonshine runner and early stock car racer, Lloyd Seay, who would occasionally and intentionally drive his race car (usually a ’39 Ford two-door) up on its running board, that is, on two wheels, in corners in a crowd-pleasing maneuver:
https://dawsonnews.cdn-anvilcms.net/media/images/2021/08/16/images/Lloyd-Seay-car.max-1504×846.jpg
Lloyd Seay once finished a race in fourth place despite rolling his car two separate times, such was his driving skill.
And he won one of the first, if not the first, national stock car racing championships in 1941 (a few years before NASCAR was established.) Unfortunately the next day, after winning, he was shot to death by one of his cousins in an argument over a load of sugar; he was just 21 years old. In his hometown of Dawsonville, GA, his family put up a remarkable gravestone for him with a bas-relief carving of his ’39 Ford with a photograph of Seay in the window:
https://www.findagrave.com/memorial/10961109/lloyd-seay/photo
The Atlanta Journal published an obituary which mentioned him as dividing his time between Atlanta snd Dawsonville (an oblique reference to his moonshine running.)
So it’d be interesting to see what it took to negotiate mountain roads at speed (often at night and sometimes without the headlights turned on) while carrying heavy loads of moonshine, especially given the state of nascent suspension engineering (both factory and aftermarket.) Though a lot of skill, on the part of drivers and mechanics, was involved, that’s for sure…
Thanks for those links
As I like to cosplay as a WRC driver on dirt & gravel roads in the Blue Ridge, I’ve wondered myself about what it was like running a load over some of those passes.
Remembering my grandfather’s Model As, as well as the tail-happy jacked-up Nova a friend had in the 80s, I suspect they tended to oversteer quite a bit when loaded.
I’d like to read this, too, though I suspect a lot of these factors wouldn’t have applied to rum runners. A lot of cars were live axle front and rear, so the more complicated dynamic geometric changes would be minimal, but I would guess that with the tires of the day, driving at speed would have been far more about managing tire slip angles front and rear (and courage!), especially on unpaved roads. Local knowledge was also likely a major factor for successful runners, but that’s getting off the topic.
I always wondered why those runners didn’t just make a giant fuel tank and run their cars on pure ethanol. AFAIK that was legal and the most efficient way to transport it. After all the Model T was originally designed to run on ethanol.
Then when you get where you’re going just drain the unused “fuel” to be diluted as drinkable vodka. You could even set up the tank with a small tank filled with gasoline or methanol to denature the booze if you’re pulled over (thus keeping it legal). Sure that batch would be ruined for drinking but its better as fuel than as evidence.
McClaren learned this lesson with the F1 racing versions. Only so low you can go with set mounting points.
“so I decided I may as well throw it in, because a slammed covered wagon is funny. – JT”
Yeah, can’t argue with that.
Would also be funny if the covered wagon you used as an example turned out to have been made by Studebaker which was in fact founded in 1852 manufacturing such wagons.
I think it would be wise to point out that it’s lowering too far that is bad.
in the subaru world whiteline makes a roll center adjuster kit that comes with the lower longer balljoints and longer balljoints for the other tirerod ends. Also, on a subaru it seems that lowering it fixes some of the body lean in turns.
While I agree that lowering helps on (most) Subarus, I feel like there is a definitive line when you lower where the benefits stop and negative issues crop up. I owned an Impreza 2.5RS that a previous owner had lowered 3″. Lowered at 1.5″ was about perfect, but at 3″ the handling wasn’t any better but the ride and scraping were abysmal. The camber also made the car chew through tires like mad, not to mention the initial turn-in was number than at 1.5″.
IMO anything past 2″ “that is stance bro”. Also correcting that camber at 3″ drop without the roll center adjuster you will hit the range of movement of the balljoitnts if you do anything about the camber. Was your car aligned after the drop? tire wear will be increased somewhat because of the camber, but the toe will chew up the damn tires a lot faster. I had 90’s Hondas lowered 3″ and with 2 degrees of camber it wasn’t too bad, as long as the alignment shop got the toe within spec. Also, a legacy with 2″ drop as long as the toe were within spec at 2″ drop was fine on tire wear.
I am lifted 1″ on a 17 wrx and swear i could scratch my sideview mirrors in turns :). Can’t wait for the good weather to hit so i can drop it 1.5″ below factory.
Yep, it had a fresh alignment and new tires when I bought it. I eventually got tired of scraping on every dip in the road and went up to a 1.5″ drop.
So, today we got a Bishop design and a Huibert nerd-fest. In the immortal words of Ice Cube,
I can’t believe, today was a good day, shit!
Now do one on how lifting your vehicle affects its performance.
Mainly lifting means you can drink twice as much shitty beer which makes you more attractive and intelligent. /s
So from what I’m understanding lowering a car will increase the roll moment arm. By increasing the roll moment arm more of the “weight transfer force” will be handled by the springs and less will be handled by the suspension links.
Isn’t getting stiffer springs a solution to reducing perceived body roll? Most lowering kits/coilovers will use stiffer strings. I understand stiffer springs won’t fix the roll axis skew understeer problem.
Yep, that’s why all coilover kits have stiffer springs, while they all lower the car – talking about performance-oriented ones, the “for looks” coilovers might actually have softer springs, with a lot more lowering.
I would send this article to stance nation people but they can’t read
Yay! Huibert is back! Excellent article. And the slammed Conestoga wagon is hilarious!
That reminded me of the time my then very young nephew was looking at a lowered tuner cartastrophy. I thought he might declare that he thought it was cool, but instead he asked if it was broken. I replied that it might be, since it didn’t look very well cared for and asked why he would think so. I assumed he might mention the peeling tint, cracked body add-ons or something. Instead he said it was lying on the ground so something must be wrong. I told him some people think that’s a cool thing to do.
He then asked, why would someone want a horse with very short legs? Now I know how that Conestoga gets its propulsion. I have to show him this.
I am not a mechanical engineer, but alls I knows is… my 350Z was significantly objectively faster at autocross and around a track after installing coilovers and some other suspension bits and having corner balancing and suspension tuning done at a proper race shop. This involved lowering the car. Not slammed/hella flush style, of course, but they lowered it at least an inch. They said it would’ve been ideal to lower the car more but couldn’t because I didn’t have one of the parts to do it properly at the time (camber or toe arms, I forget). Same tires, no power adders. Also upgraded from the stock open diff to a nice OS Giken LSD.
It’s all about moderation.
You said it all: tuning done at a proper race shop. You got proper, balanced coilovers and the appropriate supporting mods/adjustments, exactly as the article says one should. The point isn’t that lowering is bad, it’s that it’s not as simple as throwing in shorter springs.
Okay so the solution is to buy a car that doesn’t have a shitty strut suspension and have double wishbones all around.
/s
Can’t this be counteracted with stiffer rollbars to get lower center of gravity and lower roll angle? What about goofy stuff like the C4-C6 where the easiest method “lowering” the car is actually effectively moving the control arms “up” in relation to the spring and/or (for front of the C4) the entirety of the suspension upward?
Our intuition comes from high school physics class where we learned about the center of gravity of ideal blocks. Suspending one block from another block with complicated geometry, springs, and variable friction changes everything.
Great article!! This is what sets the Autopian above the others. Did I grasp it all, nope. However it was very educational.
I love these articles! Stuff I never would have looked into but find fascinating.
What didn’t you grasp?
Truly, I never understood (outside of a true racing context) why people want to lower cars.
As a Pennsylvania resident, and knowing friends in a development with enormous speed bumps that I’d already bumped my undercarriage on once, I got my 2012 Prius v lifted 1.5″ using the Prius Offroad spacer kit. I didn’t particularly notice handling changes, but it seems to have been a practical decision.
Because an enormous proportion of people, perhaps even most people, care more about the social image of their car than the function of their car.
Cuz it looks mad tight, brah! Those people don’t really drive, anyway, and they must exclusively date people with really low self-esteem or completely different, high-tolerance personalities as I don’t think anyone I’ve been with (even those with lower self esteem) would have tolerated being driven around in a car with a shitty ride that bounces all over to an extent that it is obvious to outside observers even on roads that seem pretty smooth in anything else all for handling that makes their car less capable in real world corners than a full sized pickup. Of course, I’m talking the extreme cheapskate lowering crowd that one commonly sees (without going so far as the hopeless stance crowd), not the few who know what more about they’re doing (you don’t see them bouncing around, anyway).
If it weren’t for the effective loss of torque at the wheels, I’d keep my winter setup of two-size -taller sidewalls on my GR86 year round for the extra ground clearance and longer 6th gear (obviously all the gears are effectively longer, but it’s 6th that annoys me—it’s significantly lower than 5th was on my ’90 Legacy with about 100 less hp and the same as 5th on my ’83 GL that had literally 1/3 the hp and 1/2 the torque). The stock ground clearance is actually pretty reasonable for a sports car, but the extra 7/8″ or so makes it pretty much worry free and the tires fill the wheel wells while giving it an almost safari stance. That said, that first drive with the lighter normal package is always nice.