C7 Corvette Mid-Engined?

[Matra et Alpine]

Originally Posted by culver

50-50 is ideal assuming you have identical tires at all four corners and you are intent on maximizing lateral grip while neither accelerating or braking.

WHere are you getting your information ?
With anti-dive suspension set up then the dynamics are totally different
Wiht active steering geometry, again it altars the mix.
So when you talked about assumptsion you missed 80% of them
If you want to turn corners AND accelerate then you want larger width rears and near 50:50 weight.
WHy ? Because on breaking the weight transfer will let the fronts do most of the retardation. Then on exit the extra rubber makes up for the less than ideal weight balance at that point ( about 60:40 )

AWD cars certainly can have uneven sized tires front and rear however, unless you want to play some tricks with the gearing you want equal diameter front and rear (I assume that is what you meant). Equal width isn't a requirement at all.

Now realised that when you meant different SIZE wheels you were only consindering width As is clear my first reply covered width and diamter.
It's not ideal to have different width on AWD cars either as under braking you get different retardation at front and rear and the transmission has to cope with the torque backlash - this not only risks damage in the drivetrain but it can lead to unexpected handling pitches during braking and acceleration.

Here is a post I wrote on this topic:

Interesting. But seems to isolate the weight and not fully consider the dynamics of the car movement. In particular polar MOMENT is what makes rear/mid engine config "better". How you get 50:50 is critical - weight away fomr the centre is bad As said in my first reply, weight transfer is important in drivng a car fast on varying conditions and cornering. With a near perfect balance the driver has more scope for more adjustment using the brake and throttle. ( Hence why in early 911 if it started to break away at the rear you BETTER keep the throttle down or you just exited backwards - VERY LITTLE driver-options )

[culver]

Originally Posted by Matra et Alpine

WHere are you getting your information ?

A race car designer and my own looking at the problem. I admit the generalizations are very large but the point still stands (and you seemed to agree), a 50-50 weight distribution is not "ideal" and the devil is in the details.

With anti-dive suspension set up then the dynamics are totally different
Wiht active steering geometry, again it altars the mix.
So when you talked about assumptsion you missed 80% of them

In my neutral case I don’t think it does but I will let you convince me otherwise . I do stand by my claim that maximum cornering grip will occur when all four tires reach the limits of their traction all at the same time. If any one tire looses grip before the others you have left available grip on the table. Now as this is based on discussions with the designer I know the information is based on formula car suspension, not road car suspensions. Also, the cars like the Formula Ford use basically no anti-dive or anti-squat geometries.

If you want to turn corners AND accelerate then you want larger width rears and near 50:50 weight.
WHy ? Because on breaking the weight transfer will let the fronts do most of the retardation. Then on exit the extra rubber makes up for the less than ideal weight balance at that point ( about 60:40 )

I don’t believe that is true. Why would virtually every formula car choose something over 55% on the rear axle? Perhaps you are correct in that 50:50 would be preferred if you didn’t also have to decelerate. I think we both can agree that moving weight aft helps the deceleration end of things by making sure the rear wheels get to help slow the car. I think it is more accurate to say in each case we want to look at the relative weight transfer between the front and rear axle. We then want to balance that with the relative size of the tires as well as playing with our theoretically infinitely adjustable center of gravity.

Now realised that when you meant different SIZE wheels you were only consindering width As is clear my first reply covered width and diamter.
It's not ideal to have different width on AWD cars either as under braking you get different retardation at front and rear and the transmission has to cope with the torque backlash - this not only risks damage in the drivetrain but it can lead to unexpected handling pitches during braking and acceleration.

I’m not convinced of this but I certainly can’t think of any examples (aside from radio controlled cars) that are raced yet use different front and rear tire sizes. I have not through out your claims so I can’t decide one way or the other.

Interesting. But seems to isolate the weight and not fully consider the dynamics of the car movement. In particular polar MOMENT is what makes rear/mid engine config "better". How you get 50:50 is critical - weight away fomr the centre is bad As said in my first reply, weight transfer is important in drivng a car fast on varying conditions and cornering. With a near perfect balance the driver has more scope for more adjustment using the brake and throttle. ( Hence why in early 911 if it started to break away at the rear you BETTER keep the throttle down or you just exited backwards - VERY LITTLE driver-options )

I certainly agree about the polar moment of inertia! I recall at least one netizen claiming that a rear mount motor would be good for handling. Clearly the polar moment of inertia wasn’t fully considered before making that statement
Anyway, most of what I’m looking is based around race car design. In general, and especially with the SCCA F1000 class of race cars it’s actually a struggle to get as much weight to the rear of the car as the designers want. The race cars are different than road cars in many ways including the very low CG relative to their footprints. The wheel base of a Formula Ford is about the same as a BMW 530 (114in). That certainly makes for a different suspension design and the like as compared to say my Miata with its 89in wheelbase. Basically the race cars are not moving around nearly as much as a road car would so looking at weight and weight transfer is very important.

[-What-]

Great execution silences the complainers. A good bargain priced mid-engined Corvette is the best thing that could have happened to the Corvette...and all the sissy "traditionalists" will fall in line if Chevy bangs out a winner.

If it's branded a Corvette, it is a Corvette...I don't care what YOU say.

America is the sh*t.

[h22a]

Originally Posted by -What-

Great execution silences the complainers. A good bargain priced mid-engined Corvette is the best thing that could have happened to the Corvette...and all the sissy "traditionalists" will fall in line if Chevy bangs out a winner.

If it's branded a Corvette, it is a Corvette...I don't care what YOU say.

America is the sh*t.

Would be horn to see a mid engined vette. further improving the package.

america eats shit -what-

[Lets Gekiga In]

Originally Posted by h22a

america eats shit -what-

Why say things like that?

Unless you're being sarcastic...

[adrenaline]

Originally Posted by h22a

america eats shit -what-

I lol'd.

[Vindesh17]

I was under the impression Lutz already said its not happening for the C7. That would render this thread usless.


/thread

[KFA-R]

Originally Posted by Ferrer

If they do it won't be a Corvette then.

It'd be like having a front engined 911.

this is true!!!! the vette is somthing that should be left as is... same with a front engined NSX (or whatever they will call it)

no thanks

[LandQuail]

Originally Posted by Ferrer

If they do it won't be a Corvette then.

It'd be like having a front engined 911.

Brilliant point.

[Matra et Alpine]

Originally Posted by LandQuail

Brilliant point.

Pictures = louder than words

[Ferrer]