ANY car with a light body and decent tires/brakes can handle?

as always I should preface that i don't know anything about anything.

when I posted before about a standard metric of what's good on a track some of the hive mind suggested that anything that was light would work. but other times i've read that certain cars aren't setup right for road racing/autoX, like when someone was asking about getting a classic muscle car that could be made to handle. then i see the full sized van thread which certainly didn't come out of the factory setup to turn, unless they did it by accident.

So which is it? Assuming the weight and power was magically the same would a dodge van compete with a Miata or a Z06? Or would it always be crippled by its basic setup

Different CG

Weight is only part of making a car handel. 

A light car with a terrible suspension (swing arms for example) will handle badly.

That said, all else being equal, lighter weight should translate to better handling. Now, for lower lap times, a heavier car with tires, brakes, power and such bigger roughly in proportion to weight will tend to be faster, as the power to drag ratio will likely be better, for better acceleration and top speed.

RX8driver said:

A light car with a terrible suspension (swing arms for example) will handle badly.

Corollary:  A suspension that is not allowed to move will do nothing wrong.

Given that a lot of "performance" setups make the suspension so stiff that it does nothing, geometry becomes moot.

This always gave me a laugh in my 20-something, SCC-reading days, when they would simultaneously laud the incredible suspension geometry of the EG Civic and then talk about the latest spring/shock package that made the car basically a zero-travel go-kart.

In reply to P3PPY :

You need to read Fred Puhn’s book, How to Make a car Handle.  It’s an oldie but goodie so it should be cheap on Amazon.  

The key word in your tittle is "Can" handle.

Given unlimited access to parts and  the task of getting two cars around a track using the same drivetrain, I would always opt for the lighter of the two as a starting point.

Race teams spend an inordinate amount of $$$ to get rid of weight, must be a reason.

Pete

In reply to P3PPY :

First how do you define handle?  

To racers it means  predictable  and fast. 

But a good race car will likely make a miserable  car on the street.  

That’s because race tracks differ.   Some with big smooth high banked large radius turns require one sort of suspension. Others  with tight radius  bumpy turn require another and then there can be tight radius smooth turns.  Banked, unbanked turns, transitional turns,  sweepers leading to straights,  etc etc etc. 

Look at cars like the Lotus Elan. ( OK Miata for those without the experience of the original. )  and the Morgan +4   Totally on the opposite end of the spectrum. Yet will turnout similar lap times if driven by similar drivers.  

One has a wooden chassis that is the definition of flexible with an antique tractor engine as power. The suspension is so stiff it would knock the fillings out of an old man.  

The other has a stiff chassis with sophisticated suspension and a state of the art engine.  

Yet both drivers will come out of their cars happy and excited, having diced the whole race with each other.  

Addendum 

Then you have the driver.. Some prefer a car to understeer, some to oversteer,  some a stiff car others a smooth car.  Some want to dominate  their car,  others prefer their car to communicate with them. 

The how to achieve that is a subject far too complex to cover here but it can be done and sometimes in remarkably simple ways. 

There's a saying that goes "any suspension will work if you don't let it".  What that means is you can take a suspension with E36 M3ty roll center, camber curve, etc and simply make it so stiff that it doesn't articulate much. Assuming the vehicle itself is light and the track is smooth, this will be reasonably fast. You're basically talking about a Kart, just scaled up. Now, you can't drive something like that on the street, because it will lose traction so often over bumpy surfaces that it will be unsafe. You couldn't even drive it on a bumpy track. 

But yeah, if you take any given thing, lose as much weight and bring what remains as low and close to the center as possible, give it a decent static alignment and make it stiff enough that it doesn't change too much, it will turn well on very smooth surfaces. 

This is not a recipe for building a good dual-purpose street/track car or even a good track car. It's just a way to make things that suck at turning do a specific set of tricks for a specific audience while otherwise 'ruining' the car. And i'm all for it. 

NOHOME said:

The key word in your tittle is "Can" handle.

 

Given unlimited access to parts and  the task of getting two cars around a track using the same drivetrain, I would always opt for the lighter of the two as a starting point.

 

Race teams spend an inordinate amount of $$$ to get rid of weight, must be a reason.

 

Pete

But where to lose weight?  The lower the center of gravity is the better. Ferrari took their beloved V12 and turned it into a boxer12  to lower the center of gravity.  Then they went back to a V12 when ground effects became critical. 

Sprung and Unsprung weight are different and have a different impact. 

Finally fore and aft weight centers plus left and right weight centers enter the discussion.  

In  the end it’s all about compromise.  Lighter is better until it isn’t.  

In reply to P3PPY :

Dodge van or Miata?  Handling and power to weight ratio are not the only thing. 

Aerodynamics play a significant part as well. Open your car window going  down the freeway and stick out your hand.  Hold it straight up and down like you’re telling someone to stop then turn it sideways like you’re telling them to sit down.  

The difference you feel is the effect of more and less frontal area.   Less is better.  A knife edge will be better than a blunt edge. And a knife trailing edge is better than a blunt edge as far as drag. 

There is much much more we can discuss such as how aerodynamics affects handling and ways to balance one goal against the other. 

Most of the stuff I was going to say about "any suspension can work if it's stiff enough as long as the road is smooth enough" has already been said.

But you also need to define what "good handling" is. To some people that means a car with lively, playful manners when cornering. Other people will define it as having the most roadholding grip possible, being "grounded to the ground".  The two states do not necessarily go hand in hand. I would say that the former is probably easier to attain. 

In reply to freetors :

That's so much of it right there. Everybody has what they like best. Idle Clatter has raced two very different cars with identical suspension setups and most of the guys prefer the one that is lighter but has a much worse weight distribution whereas I prefer the heavier more balanced car as it is less tail happy. Fast lap times in both cars are near identical. 

In reply to P3PPY :

I think you are confusing a couple concepts. 

When someone says they worked to make a classic muscle car handle, they mean “handle much better than most classic muscle cars”. 

When they say they made a full sized van handle, they mean “handle ridiculously well for a full sized van”. 

They are both E36 M3ty starting points. 

If you start with a car that is a reasonably good handling vehicle (like a Miata, or Z06), you will end with a better handling vehicle. 

Assuming equal time, money and effort, a full sized van is NEVER gonna out-handle an equally prepped Miata. 

But that doesn’t matter. I think there is a different question hiding under the surface of your question...

I think you’d rather have a classic muscle car, or a ridiculously silly handling van. I think perhaps Miatas are not your thing. And if I’m right, that’s fine. I think you should have one. 

Own what you want to own and enjoy. Make it the best you are able to with your available resources for the purpose you want it for. Then enjoy the heck out of it!!

There is something to be said for the amount of work involved. For example, you can often improve the handling of MacPherson strut cars by increasing static camber. 

Increasing the static camber on some cars is ridiculously easy (for example, on E36 BMWs you can add a washer to the lower front hub bolt and add a degree or so of negative camber), while on other cars it is so hard it requires swapping to different parts entirely or cutting and welding existing stuff.

The cars that are easy are almost always considered better handling cars (and this might be because the engineers left an easy way to improve handling on purpose, because they were already focused on good handling).

In reply to Robbie :

You can improve the CORNERING GRIP with more camber.  You may also negatively affect the handling.

Let's say you get that camber with offset strut ear bolts.  Now you have moved the contact patch outboard of the steering radius and you may experience more kickback on bumps, and torque steer in a front driver.  Ironically, it also affects the camber curve and roll center negatively - you gain less negative camber in bump,and it lowers the roll center.

Or let's just say that the increased grip means you are cornering harder, so you have more body roll.  It is entirely possible that the suspension geometry does unsavory things when loaded more heavily at the extremes of its travel.  Roll oversteer combined with insufficient damping and hitting the bump stops can make for a hair raising corkscrewing effect.  (Roll oversteer meaning the tires tend to steer you into the corner as the suspension compresses under cornering loads.  This is a positive feedback loop that feels "fun" and responsive, in mild cornering)

Even if you take suspension design out of the equation, CG heigh vs. track width is going to have a huge impact on which vehicle will end up on its roof first.

And if you have the track to account for the higher CG, you run into dimensional limitations.  If 2 vehicles can achieve the same cornering force, the smaller/narrower one is going to slalom a lot faster because it physically offsets less than the larger one.  Or to word it another way, for a full size van to out slalom a miata, it actually needs to corner harder than the miata does.

In reply to Knurled. :

A little bit of roll oversteer in the rear of a RWD vehicle can be useful.  It requires you to stay on top of it, however.  As in, reduce steering input a little when crossing the crown of the road on the street or when adding power.  But it does mean less slip angle on the rear tires (as they're steered slightly outwards), so it can let you put down a bit more power coming off the turn. 

weight distribution is just as important as being lightweight and having a low center of gravity. For example, I had a Triumph GT6, which is very lightweight but is extremely nose-heavy (to say nothing of a mediocre-at-best rear suspension). Even with substantial changes in suspension setup, the car still was not a particularly good (or predictable handler). Conversely, a stock Porsche 944, even with a lot of body lean, is very predictable with its nearly 50-50 weight balance. Tail-light also makes it harder to put down power, if you have significant power. Most of this stuff can be mitigated via suspension setup, of course. It's all about how much work and modifications you want to make. All other things being equal, a well BALANCED car will be quicker on the track than one that isn't well-balanced. duh. 

rslifkin said:

In reply to Knurled. :

A little bit of roll oversteer in the rear of a RWD vehicle can be useful.  It requires you to stay on top of it, however.  As in, reduce steering input a little when crossing the crown of the road on the street or when adding power.  But it does mean less slip angle on the rear tires (as they're steered slightly outwards), so it can let you put down a bit more power coming off the turn. 

A little bit, and only at low loadings.  At high loadings it is spooky as all hell.

All manufacturers trive for roll understeer, not roll oversteer.  Mazda played with roll oversteer (well, kinematic oversteer) in the FC RX-7 with their weird bushing arrangement in the rear suspension, but only under very light "whee!" side loads.  (DTSS?))  Under light side loads, the outside wheel would toe out, steering you into the corner more.  But under heavier loads, a different bushing would deflect and you'd get toe-IN.  So basically a passive way of doing what Mitsubishi and Nissan tried with their computer controlled high performance four wheel steering setups.  (And then after 80-100k or so the bushings are junk and the car just feels spooky until you replace the bushings ($$$) or use an eliminator kit, which turns it into a multilink Z31)

VW were the same way, all of their front drive beam-axle cars have ramped bushings so that under side loads, it steers the rear axle away from the corner.   Negative feedback loops are predictable.

If you want interesting, Evan took a video of his rear tire while autocrossing his Miata on sticky-ish street rubber.  The amount of toe-in in bump engineered into the rear suspension is mind-boggling!

Now, I have described a whole list of vehicles that are generally considered to have "GOOD" handling....

Miata has a the answer.  Though the S2000 and even the GM Kappa can be great or good contenders.

The 924S/944 are great handling platforms, despite their relatively common lineage.  Mostly due to a great amount of balance and lots of wheel travel with a decent amount of bumpsteer.  The 944 has been raced in Spec series and they often compete directly with the Spec Miata, so they are both great chassis.

The C4 corvette can be pretty decent, but the C5 is obviously better with the C6 better than that.  That said they are all great starting points for the heavier side of things.

BMW E36 is also well balanced and a great platform to work with.  Lots of improvements and knowledge available for them and the parts are usually less expensive than the 944.

To the OP, I think this is round two of asking for a simple answer to a complex question. Which is fine, mind you! But I think it's going to take a bunch of questions, none of which will have the simple answer suggested by "which is it?"

As the conversation is showing, there are many factors. And poorly defined terms. And semi-interchangeable terms with different connotations.

Reading up is good, because explanations of the underlying concepts and factors will help. Playing with different cars is good, because different cars will expose you to their different advantages, disadvantages, and elements of character that you like, don't like, or just enjoy for their differences. All this will give you a background that will help you reach your own understanding, after which all these myriad observations which are being given in response to your "simple" questions will make more sense.

In reply to Knurled. :

So you're saying it's better to have the rear axle steer inwards than outwards?  I've never found roll oversteer hard to manage, provided it's only a little bit.  If it's too much to manage, that means there's too much of it. 

In reply to rslifkin :

To a degree, yes it is.  It's much more predictable and confidence-inspiring.

Interestingly, some autocrossers finally figured out that they could put the bushings in their A2 Golfs backwards, so they get side load toe-out from from the bushing deflection as well as from the beam deflection (those beams squish around a LOT).  The word I heard is that it works, although you wouldn't really want to try it at speeds higher than autocross.

Swingarm suspensions like E30s and such typically had a lot of static toe-in to counteract the natural bushing-deflection side load oversteer. 

So I'll throw in some thoughts:

Part of why muscle cars handle so badly partially because they're flexi-fliers. This is naturally brought on by their being built to a price. Stiffening up the chassis goes a long way to make them handle........not just handle better.

There is nothing stopping someone making a van handle well, and not just handle well for a van.

Welding on some latice framework on to the ladder chassis along with would take car of the flexi flier issue. Think Maserati Birdcage. 

Most vans come with A-arm type suspension in the front which is as slam dunk to get the geometry right / redesign the suspension 

Because it's a van you could move the motor and trans several inches rearward. As for the rear suspension, that ladder frame would make it quite easy to weld in the crossmember from a good IRS A-arm suspension. 

Vans typically have a very wide track whic is good for handling but they are also saddle with a rather high CG. Options there would be cut the roof out and use the steel panel as a mold for attaching a carbon or aluminum roof (many van derivitives have the steel roves removed and a composite cap installed such as camper vans) As we've already stiffened up the chassis this will have no effect on rigidity. If it's a panel van you could use the same treatment for the sides. If the van has side windows replace the glass with Lexan would work as well. A really crazy person could further lower the frame on the chassis. He in my fantasy van build I've already cut the floor to install a proper tube frame.

So yes you could make a van that would handle quite well (and not just for a van) but it would be pretty useless as a van and while the parts would be cheap you'd have 2000hrs in the thing.

Conversly you could turn a Miata into a van; one that handles great but only had a 300lb payload. 

Among my top items for handling is wide track; my Datsun now has a 3 inch wider track width. It's made a huge difference. The geometry is next on the list but changing out the strut front suspension and beam rear axle for pieces with better geometry is a huge undertaking, whereas installing a wider rear axle and longer control arms was relatively easy.  Same goes for lowering the car.

In reply to Tom1200 :

I would respectfully submit that if that much effort was put into a Miata it would out handle the modded van by a long shot. 

The wheelbase alone would make it more maneuverable.

Yes, you can make a van handle.  But you can’t make a silk purse out of a sow’s ear.