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2 things I noticed

3K views 27 replies 10 participants last post by  padgett 
#1 ·
First of all. Have any of you guys noticed where they rear view mirror is for this car...take a look and u might find it interesting. and the nother things is, i dont know how the miata is gonna be able to beat this thing cause has better power/weight ration that the miata. if anyone knows the power/weight ratio for the miata let me know cause as fas as i can tell....the miata will not even touch this thing.:cool :cheers
 
#7 · (Edited)
I'd never seen that picture of the concept before. I like that idea of where the mirror is at. Hadn't noticed that before.
As for the Mazdaspeed Miata weight/hp ratio... let me see what I can dig up.

*EDIT*

From what I found the Mazdaspeed Miata will weigh around 2400lbs with 178hp/166lb-ft torque. The base Miata is sitting at 142/125. With the Solstice at 170/170 and 2800lbs. The base Miata doesn't really stand a chance but the Mazdaspeed... 400 pounds less and 8hp more :skep We will see.
 
#8 ·
Otravez said:
[From what I found the Mazdaspeed Miata will weigh around 2400lbs with 178hp/166lb-ft torque. The base Miata is sitting at 142/125. With the Solstice at 170/170 and 2800lbs. The base Miata doesn't really stand a chance but the Mazdaspeed... 400 pounds less and 8hp more :skep We will see. [/B]
What's a Mazda Speed? Is that a version of Miata?
 
#13 ·
Darkhamr said:
Well looking at another article from C&D, they mention the prototype Solstice to have been rumored at 2860lbs and the production version coming in at 350lbs more! If that's the case (3200lbs) I may reconsider a Solstice purchase.

http://www.caranddriver.com/article.asp?section_id=29&article_id=7724
Ok... That is more than a 350z weighs. That number cannot be correct. Once you break the 3000 lbs barrier, is it still even considered a roadster? :rolleyes

Seeing as how the Z is still selling more than any other sports car - the solistice had better toss out some better numbers than that to tap into the Z's market - and even the miata's possibly. Even with its extremely low price. I would shoot for about 2700 lbs or less. Why could it not be done?

Maybe that electric hard top is throwing on the extra meat :D

-Whit
 
#14 ·
Darkhamr said:
Well looking at another article from C&D, they mention the prototype Solstice to have been rumored at 2860lbs and the production version coming in at 350lbs more! If that's the case (3200lbs) I may reconsider a Solstice purchase.

http://www.caranddriver.com/article.asp?section_id=29&article_id=7724
The C&D figure is generally believed to be wrong (pure speculation on C&D's part or deliberate mis-information by Pontiac).
 
#16 ·
zcar222 said:
Ok... That is more than a 350z weighs. That number cannot be correct. Once you break the 3000 lbs barrier, is it still even considered a roadster? :rolleyes

Seeing as how the Z is still selling more than any other sports car - the solistice had better toss out some better numbers than that to tap into the Z's market - and even the miata's possibly. Even with its extremely low price. I would shoot for about 2700 lbs or less. Why could it not be done?

Maybe that electric hard top is throwing on the extra meat :D

-Whit
Might want to look over the thread entitled "Weight on Autoline Detroit"

http://www.solsticeforum.com/forum/showthread.php?s=&threadid=78&perpage=15&pagenumber=2

BTW the 350Z comes in around or over 3400lbs. And in summary, it looks like the 2860lbs curb is correct and appropriate.

The C&D is largely incorrect, GM's official info seems to be 2860 curb and "around" 50% distribution.
 
#17 ·
See yeah I could see that 350Z coming at that weight but it puts out a lot of hP to boot, we all have to think power to weight. Hp is only as good as how fat the thing is its moving. lets say we got 240hp with 225 ft/lbs right, and the car wieghs lets just say 2800 lbs. youve got a ratio or 11.somethin to 1 so for every HP you got you have 11 pounds. think of go-karts the normally have 5HP lets just say on average plus the driver and kart its self and they move half decent....all I'm sayin is just think of power to weight thats all that matters really.:cheers
no matter what this car will be super fun to drive around just cause of how small it is plus rear wheel drive...man this car is going to rock.
 
#18 ·
The mazda is about 17.2 lb/hp. The solstice is 16.8 at "advertised" specs.

And the 350Z works out to be 11.9.

Now the MazdaSpeed Miata, as measured by C&D weighs in at a hefty 2540lbs - and about 14 1/2 lb/hp.

If the Solstice *Charged (insert your favorite bent here, be it turbo- or super-) weighs in at an additional 40lbs (for argument's sake), at 2900lbs, then:

It only needs about 205 hp to get to the same lb/hp of the miata, and 245 hp to get to the same lb/hp of the 350Z. At the fantasy level of 300 hp, it approaches 9.6, which is tantalizingly close to the Corvette Convertible (9.1) but still not beating it.

Just had this info around since I was gathering it for my other weight chart.
 
#19 ·
solsticeman said:
The mazda is about 17.2 lb/hp. The solstice is 16.8 at "advertised" specs.

And the 350Z works out to be 11.9.

Now the MazdaSpeed Miata, as measured by C&D weighs in at a hefty 2540lbs - and about 14 1/2 lb/hp.

If the Solstice *Charged (insert your favorite bent here, be it turbo- or super-) weighs in at an additional 40lbs (for argument's sake), at 2900lbs, then:

It only needs about 205 hp to get to the same lb/hp of the miata, and 245 hp to get to the same lb/hp of the 350Z. At the fantasy level of 300 hp, it approaches 9.6, which is tantalizingly close to the Corvette Convertible (9.1) but still not beating it.

Just had this info around since I was gathering it for my other weight chart.
so, what will it be with ~600hp? :D :wink
 
#20 ·
Never have understood why people get so wound up about horsepower, really it just tells you what the top speed is liable to be, not how long it will take to get there.

Accelleration is a function of torque, gearing, and weight and then not what the peak torque is but what the curve looks like.

A car with a sudden torque peak at a high rpm will have impressive hp but without a CVT or driving an electric motor, will not be very useful.

A diesel-electric locomotive or a generating station is designed to run at peak efficiency at one specific rpm and everything is optomised for that. Passenger cars need to operate over a wide range of engine speeds and with the emphasis today on economy, the typical cruise rpm is at or below 2000 rpm to minimise pumping losses.

Now advances in computer controls and Variable Valve Timing (VVT - note this is not *duration* whiich is what you really need but *timing* - saw the first VVT design for a small block chevvy quite a long time ago - was a timing chain with a bar between the crank and cam gears having two small gears, one at each end. By sliding the bar to one side or the other, the cam timing could be advanced or retarded. Of course the controls and sensors required to be useful were not available then.

Just as a hysterical note, the concept of variable valve timing is truely ancient going back to at least the 1700s and the first steam engines. During the heyday of steam locomotives, the engineer used the "johnson bar" more than the throttle.

My point being that hp may help to sell cars (why untill about 1971, American engines were rates by gross rather than net hp and gasoline octane was quoted by the research method - the numbers were bigger) but it is the area under the torque curve that determines how fast it will accellerate.

Side note: in Europe things were different: manufacturers played games to keep the hp as low as possible since in many places in the early days taxes were based on hp. Later it became more common to tax on displacement since you could not play as many games with the cylinder size as ratings. That and high taxes on gasoline are why you find so many high powered/small displacement engines coming from overseas. The rules are different.
 
#21 ·
So is the amount of torque per vehicle weight useful?

If so, is the unit expressed as a linear distance (feet, as in ft-lb per lb) or as the inverse (inverse feet? ft^-1? ).

I've been in vehicles with a peaky hp curve and no low end torque (Quad-4, Honda S2000), and I've been in cars with engines that have higher torque at the expense of hp (2.4 l version of the Q-4 comes to mind, called the twin-cam?, in the Sunfire - gained something like 20 ft lb torque but lost 25 hp).

I prefer the cars with more hp, once I learn where the working range is. I'd love to get into the new Honda S2000, they got a bit more power but a decent amount of extra torque.

On a track, hp is extremely important, on an autoX course probably Tq is more important. I think that the range of RPM from pk torque to pk hp is probably most important, (larger is better), IMHO.
 
#22 ·
How about this, you guys let me drive all the cars in question, and I'll tell which one sucks me in my seat best while putting the biggest grin on my face. That what sells a car for me! I will give your such technical specs like, well the Z seemed more balzy to me and the Corvette got the most girls in the car in da hood. lol :D
 
#24 ·
The important thing as I mentioned is the *area* under the torque curve and I have never seen an expression for it. Probably to most, the shape of the curve is most important because that is what makes the car "feel" fast.

Many associate the felling of a steadily increasing torque curve (and associated high HP value) with high performance, a really flat curve may actually be faster (the 3800 is a good example) on the time slips but seems slower.

To make a peaky engine work properly, you need have lots of gears and shift a lot to keep it "up on the cam". On the race track, the car that wins generally has a broader curve than the one that sets the fastest lap, partially because it is much less tiring for the driver and is usually better mannered in traffic.

Mountain motors like those used in the old Can-Am series often had intake stacks of different lengths to broaden the torque curve by having different cylinders peak at different revs.

Now making a street engine live at least for the duration of the warrenty and meet CAFE rules means you want to have the efficiency at 2,000 rpm (average cruise on Amerrican highways is going to be in the 1600-2400 rpm range) and that means you want the torque near the peak there since IHP (Internal Horse Power or pumping losses) is minimised.

Back in the bad old daze of 400 cubic inch engines turning 3000 rpm at 60 mph a good part of the 13-15 mpg was that as much gas was expended turning the engine as moving the car.

One of my experiments at GMI involved a 67 Camaro ragtop, 275 hp 327 & wide ratio (3.11:1 first) 4-spd fitted with a Rochester FI and geared for 70 mph at 2000 rpm. Would give in the mid-20s mpg on the Interstate, very close to the "official" club 2nd Gen Firebird with 250 cid 6 and a turbo. The difference was the amount of tire smoke (and it had posi) available in lower gears (with much shorter tires was also a successful autocross car).

So one way to get acceptable MPG with an engine that has excess power is to turn it slowly when possible.

Add in "drivability" and with a five speed you have three "performance" gears (first is for starting up hills and top is for MPG) and the torque curve had best match them. (With an automatic you have a torque converter to spread the gears a bit but not with a manual trans. OTOH a manual is smaller/lighter/less expensive to manufacture but tends to have a higher incidence of warrenty work.

With a six speed you can have four usable gears but what I see out of Detroit is that both fifth and sixth are usually overdrive ratios. Personally I would just as soon have only three shift gates to worry about and preferably with a lockout or ramp on first and reverse.

A good rule of thumb for classing an engine is to look at the stroke: close to or under 3" and you have an engine that can wind to the moon but is likely to be peaky. Over about 3.25" stroke and you will have more torque than revs and the rest of the drivetrain should be designed accordingly. The 2.4 EcoTec apparently has about a 3.7" stroke (2.2 is a 94.6 mm stroke and I doubt that the 2.4 will be less)

Nothing really magical about the above, just a matter of what you can do with a spark ignition engine running on pump gas.
 
#25 ·
I don't mean to sound stupid but those posts of yours padgett... I read them three times and I still have no idea what you are talking about!!! I mean, I read it and I understand the words but when it comes to putting it together for the 'big picture'... I'm more lost than a virgin boy on prom night :confused

Keep it up though, I'm sure it's helpful and enlightening for someone here. :cheers
 
#26 ·
I see where he is going with all that, basically hes saying that tourqe is important more than exretmely high HP, really with lots of HP comes lots of tourqe too. lots of american V8's have more touqe than HP thats whats hes saying. little 4 cylinders have to hit high RPM's to get max HP but that dosent change the fact that there 4 cylinders. so there gonna put out little tourqe. thats basically whats hes saying.

and I love the virgin boy on prom night analogy.:cool :cheers
 
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