Just pondering light-weight cars in general. Is there a point where a car doesn't weigh enough to stick to the road? Or start having other handling/braking issues?

Hows about aqua-planing? Sure, a wider tire on a dry road should give you more traction, but wouldn't you be better off with a narrower tire to avoid this? Can you corner better on a wet road with a narrower tire than you could with a wider one?

How's about lift at higher speeds? I suppose you'd have to minimize the air flowing under the car to prevent it.

Whatever...I need some coffee to wake me up. Gimme your thoughts.

I know that the Geo Tracker is almost dangerous on the interstate with wind from semi's and crosswinds. I was told that is because of how light they are.

Brad

Never light enough.

quote Originally posted by RWDPLZ: Never light enough.

I agree.
Lotus Exige 2,015 lb
Ariel Atom 1,350 lb
Caterham CSR 1,268 lb

quote Originally posted by RWDPLZ: Never light enough.

Ditto. Look at the Caterham Super 7 and Ariel Atom. If that isn't enough, many sportbikes weigh in at under 400lbs (181kg) and they do just fine with only two very small contact patches.

If the car is built correctly to compensate. You cant take a light weight car with a high center of gravity and expect it to perform.
But you lower it and chop the top and it will perform better.

quote Originally posted by RWDPLZ: Never light enough.

BWAHAHA...LOL...LMAO

They are TOO light....try driving a 76 Elite in high winds....That thing will go over 2 lanes just because somebody breathed on it....Its like flying a Fleet Cunnuck...the winds ARE gonna ruin yer plans.....

quote Originally posted by twofatguys: I know that the Geo Tracker is almost dangerous on the interstate with wind from semi's and crosswinds. I was told that is because of how light they are. Brad

Just looked it up, ~2200lbs. Wouldn't be a problem if it was 4" off the ground. A longer wheel-base might help a bit too.

Hmm...short wheel-base = better handling or just easier to knock around? I have 2 different 2 seater cars and they both require a lot more steering adjustments to keep them inside the lane than any longer vehicles I drive...

quote Originally posted by RWDPLZ: Never light enough.

A Super-7 replica vs a good size puddle on the road, I'm betting on the puddle winning.

But yeah, I think the lighter the better, I'm just trying to figure out if there's a point where you should start changing your running gear to match the weight of the vehicle. Don't need huge brakes to stop a 1,200lb car, even if it's going fast...don't need massive tires to keep it on the road when cornering, either.

quote Originally posted by MidEngineManiac: BWAHAHA...LOL...LMAO They are TOO light....try driving a 76 Elite in high winds....That thing will go over 2 lanes just because somebody breathed on it....Its like flying a Fleet Cunnuck...the winds ARE gonna ruin yer plans.....

Try a motorcycle that is >600lbs with rider in 50+ mph gusts (80+kmh). If I can do it on the bike then replace the drive of the 76 Elite.

quote Originally posted by Xyster: Try a motorcycle that is >600lbs with rider in 50+ mph gusts (80+kmh). If I can do it on the bike then replace the drive of the 76 Elite.

Didnt say I couldnt do it...just said its not as advertised ...and yeh, I have taken a GS650 over skyway bridges in 80KPH winds....and have landed planes withouth breaking them in roughly the same conditions....

No need to replace the driver, just accept the machine for what it is and live with it....

quote Originally posted by MidEngineManiac: No need to replace the driver, just accept the machine for what it is and live with it....

Fair enough.

Someone needs to tell me why the new Camaro weighs in at 3800lbs...that's just...rediculous. Too many modern conveniences, or did they jsut want to make sure it didn't perform anywhere near a Corvette?

quote Originally posted by MidEngineManiac: No need to replace the driver, just accept the machine for what it is and live with it....

Good point.You may be crazy but you do have respect for your machines.

That's important.

.......................

Center of gravity is a big issue with light vehicles. The lower, the better.

Is it my imagnation, or do FWD vehicles corner better on wet roads than a RWD? Is this from the peculiarities of a MacPherson strut suspension vs a double-wishbone, the fact that the drive wheels are pulling instead of pushing, or simply the front-heavy weight distribution?

quote Originally posted by Stubby79: Someone needs to tell me why the new Camaro weighs in at 3800lbs...that's just...rediculous. Too many modern conveniences, or did they jsut want to make sure it didn't perform anywhere near a Corvette?

Hello, lot of reasons for the extra weight, some to comply with ever increasing safety requirements. Side impact door beams with front and side air bags higher door sill heights that you cant rest your arm out the window anymore. Front and rear crumple zones and of course power windows, air conditioning, OnStar, fancy sound systems and sound deadening all add that extra weight that we want for convience in a steel body to keep costs down. Thats why you see an ever increasing use of aluminium on the Camaro such as hood, front and rear bumper reinforcement bars. Not only the Camaro, but the Challanger and Mustang all have the same issues too.

quote Originally posted by Stubby79: Just pondering light-weight cars in general. Is there a point where a car doesn't weigh enough to stick to the road? Or start having other handling/braking issues?

Not really.

Most any vehicle, small lightweight or even a motor cycle as mentioned, will still readily stick to the road no matter what. The reason is due to mechanical grip, which is a term not often explored much when talking about vehicles and is typically just called "traction". The simple act of tires spinning against the surface of the road creates the necessary grip levels needed to 'stick' the vehicle to the ground. It is at the point mechanical grip is exceeded, such as on a slippery surface or when then is too much force applied (i.e., a burnout) that this traction is lost. It is also why even with crap or worn tires you will still see traction, but have a narrower window of when mechanical grip will be exceeded.

Light cars with short wheel bases and relatively high centers of gravity, like the aforementioned Geo Metro and such, do seem to have problems though. Remember that in places like Japan these type cars are very common, but their speeds hardly ever eclipse 100 KPH (about 62 MPH) through normal driving. Over here when you're driving nearly 65-70 MPH (the Geo Metro I had BARELY got up to that speed...) and you're next to a semi, you're going to get blown around quite a bit.

quote Originally posted by Fiero84Freak: Light cars with short wheel bases and relatively high centers of gravity, like the aforementioned Geo Metro and such, do seem to have problems though. Remember that in places like Japan these type cars are very common, but their speeds hardly ever eclipse 100 KPH (about 62 MPH) through normal driving. Over here when you're driving nearly 65-70 MPH (the Geo Metro I had BARELY got up to that speed...) and you're next to a semi, you're going to get blown around quite a bit.

That does seem a bit odd to me, since my uncle drove one for years after his divorce and he used to cruise at 85, where it topped out. 3cyl/5speed hatch. We called it the blueberry It did get blown around a lot.

I'd imagine other cars in that size segment would have similar issues with that. My boss drives a '11 Nissan Versa, and complains about that, too. Biggest issue is that it doesn't have enough power to get a good passing speed rolling around a semi. Too heavy for the power it has because of safety requirements, I suppose.

[This message has been edited by skuzzbomer (edited 01-22-2012).]

Talking about Geo Metros...
Anyone driven one of the 4-cylinder Suzuki Swift GTi's? The ~100hp DOHC 1.3l ones. I'm curious how entertaining they are to drive.

quote Originally posted by Stubby79: Talking about Geo Metros... Anyone driven one of the 4-cylinder Suzuki Swift GTi's? The ~100hp DOHC 1.3l ones. I'm curious how entertaining they are to drive.

I owned a '92 Swift GT and it was a ball to drive. It handled very well....you could toss it around corners without worrying about losing control and that little 1.3L loves to rev. I beat on mine and it still gave me 35MPG.....drive it nicer and 40+ isn't unheard of. They are getting hard to find now.....especially ones that haven't been "improved" by the previous owners. Find a bone stock one with low miles and you'll be happy. The one big issue with these cars is the keyway on the crank. The crank is soft and the key will wallow out the crank slot. That is what ultimately killed my GT.....the timing kept getting worse and worse, so I kept adjusting the distributor to keep it running, but eventually the key failed completely and it died on the way to work one morning.

BTW.....the '92-'94's are the better ones, IMHO. I think the interiors are better and there were a few minor exterior improvements too, but I wouldn't throw out an '89-'91 if someone gave it to me.

quote Originally posted by Stubby79: 1300lbs seems to be roughly the limit for a windhshieldless street car like the Super Seven or the Atom. About 1500 for something enclosed, and that being an old CRX or a Geo Metro...not exactly sporty. Any production sports cars ever made in that weight range?

The original Lotus Elise (1996) weighed in at 1,598 lbs before it got all bloated.

Look at how much performance you get out of motorcycles and how light they are with tiny tire contact patches.
It's all about being properly designed. Aerodynamics are the important factor for keeping it on the road at high speed.

quote Originally posted by Silentassassin185: The original Lotus Elise (1996) weighed in at 1,598 lbs before it got all bloated.

"Bloated" being a relative term here. Gaining 400lbs in a generation kind of sucks, though.

quote Originally posted by Silentassassin185: I agree. Lotus Exige 2,015 lb Ariel Atom 1,350 lb Caterham CSR 1,268 lb

Go-carts 150-300 lbs?

I think it's all about the center of gravity.

quote Originally posted by Silentassassin185: The original Lotus Elise (1996) weighed in at 1,598 lbs before it got all bloated.

Orlly? Didn't know that...wonder what they added to jump up so much...400lbs is more than the damned chassis weighs on those things.

quote Originally posted by skuzzbomer: That does seem a bit odd to me, since my uncle drove one for years after his divorce and he used to cruise at 85, where it topped out. 3cyl/5speed hatch. We called it the blueberry It did get blown around a lot.

This was a really worn on Metro with very high mileage, leaking tons of oil and lots of blow-by. Amazing it still held together for some time. It finally knocked a rod after it got oil starved.

The crazy thing was it was STILL getting above 40 MPG - even with the above problems. The little three cylinder engine held together pretty well.

I drove a gfs Tracker ONCE. I was on the freeway and got scared to death...it was all over the place. My GT40 kit weighed about 1800 pnds. It drove ok because it was so low and wide with a low CG. I wouldnt want to drive anything that light routinely or everyday.

quote Originally posted by Stubby79: Is it my imagnation, or do FWD vehicles corner better on wet roads than a RWD? Is this from the peculiarities of a MacPherson strut suspension vs a double-wishbone, the fact that the drive wheels are pulling instead of pushing, or simply the front-heavy weight distribution?

I think it might be more of an opinion/personnal preference. I have never found a FWD that doesn't underster in the slick stuff.
IMO oversteer trumps understeer. Why? Because you can still steer.

quote Originally posted by Silentassassin185: The original Lotus Elise (1996) weighed in at 1,598 lbs before it got all bloated.

quote Originally posted by skuzzbomer: "Bloated" being a relative term here. Gaining 400lbs in a generation kind of sucks, though.

25% in one year? Holy politician promises Batman.

[This message has been edited by Xyster (edited 01-23-2012).]

quote Originally posted by Stubby79: Someone needs to tell me why the new Camaro weighs in at 3800lbs...that's just...rediculous. Too many modern conveniences, or did they jsut want to make sure it didn't perform anywhere near a Corvette?

I'll take a crack...

First..its just a big car. Too big? That's for the buyers to decide.

Then we add side impact, front impact and a couple abs bags all over it and that adds weight.

Then we add convenience: AC is heavy, the interior looks to be made for comfort, not sports car performance. That thing have power seats and all that jazz?

It just wasn't designed to be light. It's way too big and they compensate for everything with a big heavy engine putting out a bunch of torque and call it a day.

Guess thats the difference between muscle car and sports car these days.

Can ya tell I'm not a camaro fan?

quote Originally posted by Gridlock: I'll take a crack... First..its just a big car. Too big? That's for the buyers to decide. Then we add side impact, front impact and a couple abs bags all over it and that adds weight. Then we add convenience: AC is heavy, the interior looks to be made for comfort, not sports car performance. That thing have power seats and all that jazz? It just wasn't designed to be light. It's way too big and they compensate for everything with a big heavy engine putting out a bunch of torque and call it a day. Guess thats the difference between muscle car and sports car these days. Can ya tell I'm not a camaro fan?

It is bloated.... it isn't all the safety items, it isn't the power options... it the fact that GM couldn't build it cheap enough and maintain a lighter weight. There are other vehicles which are lighter, more powerful and have all the luxury appointments, but again, they are not GM vehicles. GM is the "generic" car builder... it is heavy and they try to compensate with adding more HP. Right or wrong, that is how they work it. Too bad.

quote Originally posted by jaskispyder: It is bloated.... it isn't all the safety items, it isn't the power options... it the fact that GM couldn't build it cheap enough and maintain a lighter weight. There are other vehicles which are lighter, more powerful and have all the luxury appointments, but again, they are not GM vehicles. GM is the "generic" car builder... it is heavy and they try to compensate with adding more HP. Right or wrong, that is how they work it. Too bad.

Even a new Accord weighs 3400. Keep in mind that this is with half the drive train weight.

quote Originally posted by rogergarrison: I drove a gfs Tracker ONCE. I was on the freeway and got scared to death...it was all over the place.

I've never driven a Tracker but did spent several days with a Samurai in California (believe it or not it was a rental). It was fun to drive but at 80 MPH on the highway with strong crosswinds, it was terrifying everytime I'd go under a bridge or something. It felt like it would either flip or do a 180.

I'd buy one though. Its sort of like a Fiero. Different and fun.

Found something that fits:


1250lbs, 100hp. Sounds like an entertaining drive to me!

Edit:

Ha! Look at the chassis on the thing: Flex much, ya think?

It has a polyethelene body on top of that. You'd think it'd be even lighter, considering.
Reminds me of a manx, with it's all-fiberglass body. And the shape, too. (which weigh in at ~1500lbs)

[This message has been edited by Stubby79 (edited 01-23-2012).]

And, on a happy note...


The Campagna T-Rex is street-legal and considered an automobile(rather than a motorcycle) here in B.C...and the dang thing doesn't even have a windshield! I'd have thought that would be a requirement, at least. Then I thought a helmet would be a requirement...nope!

[This message has been edited by Stubby79 (edited 01-25-2012).]

quote Originally posted by Stubby79: And, on a happy note... The Campagna T-Rex is street-legal and considered an automobile(rather than a motorcycle) here in B.C...and the dang thing doesn't even have a windshield! I'd have thought that would be a requirement, at least. Then I thought a helmet would be a requirement...nope!

It's an option to get the windshield...

quote Originally posted by Falcon Fiero: It's an option to get the windshield...

An option? then you don't legally need it. The pics of the ones I found for sale here in BC didn't have a windshield.

Id say its more design that weight.. my Fiero and my solstice arent to far off form each other in weight... My Fiero would hold the road perfect in snow and rain Driving conservativly and carefully.. My solstice with the same driving habbis sucks in the snow and rain..

I used to own a 96 firefly hatchback 4cly, 3 speed auto. car is slow. i maxed out the speed where the speed limit is 110kms. i think i was able to get it up to 165kms before it couldnt go any faster. engine was screaming tho.
as far as handling goes. it was alittle floaty at high speeds. it was stable enough that i was comfortable. i was running 195s winter tires in the summer. i sure did beat on that little guy.

quote Originally posted by Stubby79: Just pondering light-weight cars in general. Is there a point where a car doesn't weigh enough to stick to the road? Or start having other handling/braking issues?

Much of the issue with light weight isn't with sticking to the road, handling, and braking, as engineers are good at designing for that.


But with your 1500 lb vehicle getting hit by a 5,000 lb SUV, you likely aren't going to do as well as if hit in a 3800 lb Camaro or a 3,400 lb Honda Accord.


I HATE that crash protection is a part of the consideration, but with the number of HIGH WEIGHT vehicles on the road, and the attentiveness of drivers decreasing, it probably merits some consideration as well.