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Some of the Specs are Still Fuzzy

9K views 66 replies 20 participants last post by  dobrenyr 
#1 ·
We've had a lot of discussion over the past couple years about some of target specs we thought the C7 would attain.

Weight was one of the most important. Some thought that 3000 lbs was attainable. Given that GM had told us in the past that the Al HF frame rails were 130-150 lbs lighter (different people there at different times) plus the expected use of more Carbon fiber, my last guess was 3050 to 3075 lbs.

Yesterday I heard two numbers once citing a 99Lb weight reduction the other a 99Lb weight reduction. The Chevy website says the base C6 weight is 3208 which means the C7 weight should be 3109-3110. Not as good as we hoped, but certainly a positive improvement.

We were also wrong about GM aquiring an 8 spd Auto from Asan. Look for a new GM designed 8 spd Auto within the next two years.

AutoWeek published this (Clearly weight is too high - probably price is too low):
2014 Corvette
Overall length........177 inches
Wheelbase............106.7 inches
Width...................73.9 inches
Height..................48.6 inches
Engine..................6.2-liter V8
Horsepower...........450@5,900 rpm (est.)
Torque.................450@4,400 rpm(est.)
Curb weight..........3,200 (est.)
Base price............$52,000 (est.)

Motor Trend has published this online (Price probably too high, weight definately too high)
Base price.......................$59,000 (est)
Vehicle layout..................Front-engine, RWD, 2-pass, 2-door hatchback
Engine............................6.2L/450-hp (est)/450-lb-ft (est) OHV 16-valve V-8
Transmissions...................7-speed manual; 6-speed automatic
Curb weight.....................3300 lb (MT est)
Wheelbase.......................106.7 in
Length x width x height......177.0 x 73.9 x 48.6 in
0-60 mph .........................3.9 sec (MT est)
EPA city/hwy fuel econ.......18/29 mpg (MT est)
Energy cons, city/hwy........187/116 kw-hrs/100 mi (est)
CO2 emissions...................0.89 lb/mi (est)
On sale in U.S...................Fall 2013
 
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#26 ·
Thankfully C7 was NOT blessed with AWD and the attendant weight penalty (often 200 lbs., or more) associated with these systems. AWD = understeer too. I still can't recall a comparison test in the popular auto magazines where an AWD platform (produced by any manufacturer) out hustled ZO6 or ZR1 around VIR, Laguna Seca, etc.
 
#3 ·
I can't watch the vid from work, but last night I'm sure they cited a weight reduction of 98 99 lbs. Can anyone watch the debut vid and confirm.


True, the improved interior with A/C seats et al put some weight back on, but remember they took off around 130 using the Al rails and took another 20 or so off that we know of using CF on the hood, top and other places they haven't told us about.

A rather interesting reveal. Who was it that said, "Leave 'em wanting more" ? Not many hard stats were provided.

There will, no doubt, be another "stat unveiling" later that will garner more publicity. Maybe a smart way to do it, but a tad frustrating.
 
#5 ·
Guess I missed the 35 Lb comment. Are you saying that GM said its 134 Lb lighter? ...or did they only cite savings, and avoid net weight comments?

If it net, nets to 3208 minus 99 minus 35, that would be 3074. 1 Lb off my guess.
 
#6 ·
They only sited savings. They admit that the engine package weights slightly more (due to the additional components) but no numbers, and obviously no official curb weight yet.
 
#7 ·
That makes sense to me. There could still be some small production line changes that could have an impact of a pound or two and they know we are nuts about numbers.

Still, regardless of what the car rags are saying, I now think there will be a net reduction in weight a bit less than 100 Lbs. More stuff was added to the base, ...er... the Stingray than expected.
 
#8 ·
Seats are much more high tech and with the mag frames could actually be the same or lighter.

One place your going to see weight savings is the narrower tires (wheels too?).

I think this car will put out road course numbers closer to the earlier z's though.
 
#9 ·
I've heard there is no change to wheel or tire size.

The longer wheelbase (weight distribution) will help road course numbers.

I noticed they emphasized the CF Hood and CF top "...to take weight off the front and the top to lower center of gravity."
FWIW
 
#11 ·
Tires are the same diameter but they are not as wide. No official numbers but I have seen this quote several times.

narrower 18-inch front/19-inch rear wheels (19 and 20 inches, respectively, and forged on Z51 cars) that improve the turning radius without sacrificing grip. In one of many crossovers from racing development, the same Michelin engineer who designs tires for the Corvette Racing Team now also designs the standard Pilot Super Sport Run-Flats that are unique to the C7.
for what it's worth MT is quoting the car is about the weight of a c6Z. That would surprise me a bit, though I suspect a C7 Z51 would be a good road course match for a C6 Z06. I would think GM targeted it that way.
 
#22 ·
I can't wait to hear an accounting for the weight changes. Seems to me that a heavier C7 would be a huge FAIL.

C6 starts at 3208
C7 Al frame ~-130
CF panels ~ -33?
LT1 "a little heavier" per Tadge

0 - 60 in less than 4 sec with 14 more HP than LS3

Also, I could have sworn that Tadge said on video at one of the meets (carlisle?) that the C7 would be "significantly lighter." We bantered for a week here about what this quote meant. Something simply does not add up.
 
#25 ·
I think if there was a weight reduction something would have been said in the reveal or press releases. Something tells me the C7 will be heavier not lighter than the C6. Maybe the performance is better with a updated traction control system and the addition of 7 sp manual or updated 6 speed auto.
 
#29 ·
I understand your logic, but again, the Al HF rails are at least 130 lbs lighter - possibly as much as 150 lbs lighter. They said the CF body panels dropped 35 Lbs. So there is a minimum of 165 Lbs off of a 3208 LB C6. If it's heavier. Where were the adds that exceed the 165 lbs??
 
#31 ·
It was only a few weeks ago that I was getting flamed for suggesting that it would be difficult to get the C7 below 3100 lbs. Several here insisted that I was being unreasonable and that the C7 could come in at 3000 lbs.

I am not shocked at all that 3k was not attained, but what the hell happened??

OO, OO, I just figured it out. The problem with 0-60 is traction right!!? The entire rear fascia is cement! The weight went up but it's all behind the rear wheels! ... And all those folds and bends and extra lines are to keep it from cracking!!



:D
 
#32 ·
I think GMs inability to manage weight in vehicles has finally trickle down to the Corvette. The Camaro, CTS, SRX to name a few all weigh more than their competitors. I think Corvette had to us the CF and Aluminum just to keep it close to 3300 lbs. Gizmos and bling cost money and weight. The price will be up along with the curb weight. Hope I am wrong on both accounts but I doubt it.
 
#34 ·
estimated weight

Saving weight:
1.aluminium space frame: -99lbs
2.hollow control arms: -9lbs
3.carbon fiber hood: -10lbs
4.carbon fiber roof: -5lbs est.
5.electric steering: -8lbs est.
6.hollow front cradle: -5lbs est. ??
7.magnesium seat frame: -8lbs est. ??

est. weight saving +-144lbs

Adding weight:
1. wider and 2inch increase in lenght: +15lbs ??
2. 7-gearbox: +7lbs ??
3. stiffer door construction: +7lbs??
4.torque tube in steel instead of aluminium because of 4-cylinder mode: +25lbs ??
5.LT1-engine: +25lbs
6.BOSE audio on base C7 with 9speakers: +3lbs ?
7.computers, wiring, tunnel insulation,...: +20lbs ?

est. weight adding +-102 lbs

Base C6 coupe 3208lbs -42lbs = 3166lbs ?? a guess
 
#36 ·
Saving weight:
1.aluminium space frame: -99lbs
2.hollow control arms: -9lbs
3.carbon fiber hood: -10lbs
4.carbon fiber roof: -5lbs est.
5.electric steering: -8lbs est.
6.hollow front cradle: -5lbs est. ??
7.magnesium seat frame: -8lbs est. ??

est. weight saving +-144lbs

Adding weight:
1. wider and 2inch increase in lenght: +15lbs ??
2. 7-gearbox: +7lbs ??
3. stiffer door construction: +7lbs??
4.torque tube in steel instead of aluminium because of 4-cylinder mode: +25lbs ??
5.LT1-engine: +25lbs
6.BOSE audio on base C7 with 9speakers: +3lbs ?
7.computers, wiring, tunnel insulation,...: +20lbs ?

est. weight adding +-102 lbs

Base C6 coupe 3208lbs -42lbs = 3166lbs ?? a guess
The list of weight reduction is actually much bigger then that, the head lights are lighter. The suspension cradle was stated to be significantly lighter then the one on the C6. Pretty much every single part on the C7 is lighter then the ones on the C6.

Something seriously isn't adding up, considering that they stated that the C7 would be significantly lighter then the C6.

Also as far as GM keeping weight under control, the Cadillac ATS 2.5 is the lightest car in its class at 3,315 pounds and the 2.0T manual has a base weight of 3,373 pounds.

This is going to be interesting how things will all turn out, also which video did they state that the C7 was going to be heavier then the C6? I have seen a few videos and never heard that comment.
 
#37 ·
The LS3 was qouted as being about 450 pounds by GM, LT1 engine was stated as being 15 pounds heavier then the LS3.

Reason for weight gain, VVT, direct injection (beefy pump and injectors, and AFM.
 
#38 ·
Auto Bild (German car magazin)

I have bought "Auto Bild" today.
There are photos and specs of the new C7.
They say that the weight is under 3100 lbs. :partyon:
I hope that is true.

I think this vette has a lot of chance in Europe.
I love this car (you have to see it often) then you like all.
I will buy the C7 convertible next year. Can´t wait for the big vette! :D

Greetings from Austria
Horst
 
#39 ·
I have bought "Auto Bild" today.
There are photos and specs of the new C7.
They say that the weight is under 3100 lbs. :partyon:
Thanks Horst.

This weight makes a hell of a lot more sense.

The wheel base has been extended an inch and weight removed from the front. These changes should shift the weight distribution rearward and help improve the physics of the traction. At 3100lbs, add some better programming for a Launch control plus the LT1 [14 HP (450-436) + new Tq curve], the claimed 0-60 time is believable.

At 3200-3300 lbs, the under 4 second claim is very unlikely with the LT1 as it has been presented to us.
 
#42 ·
GM does not have a good track record when it comes to keeping vehicle weight down. The exception has been corvette where the weight has remained pretty consistent, ie the C6 is roughly the same weight as my C4. I hope I am wrong but I truly think that if the weight was reduced Tadge and his dream team of designers would be harping on that. JMHO
 
#43 ·
GM had a huge issue with weight, however this has been changing with the big change for the Cadillac ATS. Its development weight at one point got up to 3,800 pounds before they forced the engineers to put it on a diet. The result, the ATS 2.5 with 202BHP has a base weight of 3,315 pounds. For comparison the Lexus IS250 with 3,435 pounds, this was the first time in a long time where the GM vehicle was the feather weight.

Also every car mag says that the ATS is the best driving sports sedan on the market (beating out the BMW 3 series and Mercedes C class though has yet to be compared with the Audi A4).

I am not closing my mind to 3,300 pounds, sure its possible it is just that we were told this car was going to be lighter and all that they have talked about was weight loss. Less then 3,100 pounds makes sense to me considering this, if not where did the weight come from?. If its a safety thing then most of that weight would be in the chassis but we know for a fact that the chassis is 99 pounds lighter then the out going model.

The only part on the C7 that we know for a fact that is heavier then the C6 is the engine (465 LT1 vs 450 LS3).

It is just that at this moment at least until we get more info 3,300 pounds simply does not make sense.
 
#45 ·
If these numbers are accurate, the footprint didn't ready get any smaller:

C6
Wheelbase ...........105.7 inches
Overall length .......174.6 inches
Overall width ..........72.6 inches
Overall height .........49.1 inches

C7
Wheelbase............106.7 inches
Overall length..........177 inches
Overall width..........73.9 inches
Overall height.........48.6 inches
 
#48 ·
I am just going by what has been reported by the car rags referencing weight. Car & Driver video with Csaba Csere has a guestimate of 3350, but their print version of preview of the C7 says the GM weight goal was 3000lbs. I don't know what to think other than maybe I should quit drinking the car rag kool-aid and wait for the final numbers.
 
#49 ·
Exactly. If the car rag editors / reporters knew as much about corvettes as we do, they would have asked better questions about the weight and we wouldn't be trying to fix their mistakes.

JMHO
 
#51 ·
There are a number of inaccuracies with the reporting so far on the C7 Corvette. Not to say that this is or is not one such example of inaccurate reporting (though I sure hope it is). 3,000 pounds seems correct for all of the press of weight that GM has put out for weight savings (at least for the car in base trim).
 
#54 ·
Once more, GM stated that the LT1 is 15 pounds heavier then the LS3.

Also the seats are lighter then the C6 seats and last I checked aluminum and carbon fiber are not heavy materials. None of the gadgets in the C7 weigh much (I know some people think that a touch screen radio is 200 pounds). The interior is probably from the same weight as the C6 to slightly lighter (seeing that car seats weigh a lot more then stereos. The C6 driver seat with base is 56 pounds, and an after market double din touch screen car stereo is 7 pounds... you do the math on that one.
 
#59 ·
If it is lighter, I'm surprised GM wouldn't have tossed out some preliminary numbers or simply stated "Yes, it will be lighter." To me, not deal breaker either way. I don't track the car, but of course I'd take lighter. I wouldn't think all the new electronics gizmos would amount to much.

Anyone remember when we found out the C6 numbers?
 
#60 ·
At this point other than the braking improvement and frame weight, GM has given ZERO actual numbers related to performance. I'm wondering when the "numbers party" will be. They haven't released any numbers for the new trucks either, and those are a huge deal for GM's bottom line.
 
#67 ·
What about the Cd, drag coefficient have they mentioned that ?? I believe the C6 base coupe was .286 which made it the slipperiest corvette. I would really like to see what they did with that and the resulting top speed... something makes me think that it's not gonna be much faster with only 14 more hp. I think it might actually be slower, but i know that they'll say it will be more stable due to downforce objectives...
 
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