jecht

I know that L81 was a 190hp brute made only for '81...

but why the big variation in performance times? I have seen 0-60 in 7.2 (1981 R/T comparo) but also figures at 9.2-9.5 and 17-second quarters @ 80-81. 124 mph top speed...That being said, only the Datsun 280ZX and Porsche 911 SC were quicker.

http://www.roadandtrack.com/tests/ca...rolet-corvette
7.7 for an '80 L82

http://www.roadandtrack.com/tests/ca...orvette_page_3
and yet on page 3, it shows the following figures...
Acceleration
Time to distance, sec:
0-100 ft 3.4
0-500 ft 9.2
0-1320 ft (1/4 mi) 17.0
Speed at end of 1/4 mi, mpr 82.0
Time to speed, sec:
0-30 mph 3.1
0-60 mph 9.2
0-100 mph 27.5
Speeds in Gears
4th gear (4400 rpm) 124
3rd (5200) 111
2nd (5200) 79
1st (5200) 52

Easy Mike

You'll have to ask Road & Track.

JLinCA

I would go with the 7 second figure. I have an 81, and while it is no C6 it is not that slow to take 9+ second to get to 60.

Maybe they used multiple cars for those figures? That 9.2 could have come from the 305 equipped car.

JLinCA

I read the article without even checking the title, they are testing an 80 Corvette, not an 81.

They must have used the L-82 engine for one time, and the 305 CA engine for the other.

While the L-81 had a little less power than the L-82 engine from 1980, the 81 Corvettes were much lighter.

AdamMeh

I had been told by a Vette restoration place that the 80's were the lightest of the late model C3 cars. Did they get lighter after '80?

Adam

JLinCA

The 81s and 82s were lighter than the 1980 Vette. They did a bunch of stuff like use thinner glass, and a big change was going to a fiberglass transverse spring to replace the heavy steel leaf spring.

jecht

thanks guys!
I can see the 305 Cali engine thrown in the mix, but to someone reading the mag and getting one set of figures in the road test and another set at the spec summary was a bit confusing.

9.2, 17.2@81, 124mph--about as fast as a 9th gen Corolla (2003-2008).



Even a Ford Windstar my mom had was slightly faster.

Dave McClellan said in Corvette From The Inside that those Vettes DID do 0-60 in 10 seconds--"about as equivalent to a modern-day Miata" (page 79) and he also said this about '81:

"This engine would prove to be our last low in performance (except for California) at 190 nhp, and also a crude beginning for the technology that would ultimately make it possible for us to recover all of our performance losses. With this engine, the 1981 car was the slowest Corvette in about two decades." (p. 79)

AdamMeh

I called up my buddy and asked him about this. There was a pause on the phone and then he told me "no... that's not what I said. The 80's were lighter then the mid and late 70's cars and the 81's and 82s were lighter yet". He mentioned the same things... thinner glass and the rear spring. I think there were also some changes in the front bumper bracing that helped a little?

I think I have a broken memory chip.

JLinCA

They also replaced the steel exhaust manifolds with lighter stainless steel ones. They also went to magnesium valves covers, though I don't know what they saved there haha.

The 75-79s were were the heaviest C3s, over 3500 lbs.

I bought my 81 because I love the styling, I wasn't concerned with the performance. I have my C6 for that

One good thing is the cars are very easy to upgrade.

jecht

I thought the '81 were only 100 lbs or so at most slower?

The performance from L48/L82 from '75 to '82 was actually similar 0-60 7.7 at the low end to maybe 6.8 at the high end with a good L82). The top speeds were 124-132, no more no less.

The '84 was actually slower to 60 than older L82s (7.1 vs. a good '76 at 6.8) but with much higher top speed (138 vs. 125). Usually, the 6.8 car would be at a disadvantage with top speed, while taller-geared cars would reach 132. The old style of the C3 hindered aerodynamic performance.

qwank

has anyone actually taken on of these cars to the track in stock form to see what they really do?

Street Rat

I would have been too embarrased.
That engine is a dog. I can't wait to build another engine for it!

Stu's81

+1

wajulia

My bone stock 81 best lap is 16.3. It took a few weeks of tinkering and tuning to get it there. Now it runs 16.3 every lap

wajulia

I just read the road and track article and it says that the emergency brake will hold the car at a 30 deg grade That makes all the claims in the article suspect

7t9l82

road and track and motor trend both back in the day ( even now) never knew how to drive a car for 0-60 or drag strip times. more accurate times came from ss&di or hi performance cars hot rod etc. at least there writers knew what a drag strip looked like.

Priya

In my 79 Corvette specifications manual it gives a base weight for an optionless car and then the lbs per option. I calculated total weight for my heavily optioned 79 and it came to a little over 3700 lb.

jb78L-82

Beginning in 1980 and through 1982 all the C3's used the thinner lighter fiberglass panels. In addition the rear subframe was aluminum on the 80-82's with the base corvettes only getting the fiberglass rear spring in 1981 and offered on all 82's, saving 40 pounds over the steel spring.

Weights: 1981-A base corvette with NO options. The weight would be higher for a fully loaded 1981

curb weight= 3,282 Pounds(This is the calculated weight of a vehicle with standard equipment only, as designed with the additional load of oils,lubes and fuel all filled to capacity.

1980 Corvette Weight:

The 1980 Chevrolet Corvette's 3,330-pound curb weight sits on a 98-inch wheelbase with a front track of 58.7 inches and a rear track of 59.5 inches.

There is almost no difference between an 80 and 81 corvette from a weight perspective, certainly not anything that would contribute to a performance advantage for the 1981.

Engine:

The 1980 L-82 has a significant performance advantage with 230 Net HP over the 1981's L-81 at a much milder 190 Net HP-40 HP is significant. The 1980 L-48 rated at 190 is exactly the same power as the 1981 L-81. The 305 V8 used in the 80's was ONLY for california cars, no other states.

Performance:

I have tried hard to find credible performance figures on a 1980 L-82-Difficult to find since only 5,000 L-82's were produced all with automatic trans. However, one can extrapolate performance pretty easily from the 1978/79 L-82's performance which are available. There is no difference between an L-82 from 78-80 except different mufflers and exhaust pipes on the 80 accounting for the difference HP ratings of 220/225/230.

An 80 corvette L-82 is about 3,330 pounds and 78/79's are about 3,450-3,500 Lbs.-I have never since a figure higher than that number. A fellow forum member recorded this actual weight on his 78 L-48-Slightly heavier than an L-82:

1978 L48 3520 LBS, Full Tank of gas 100% stock Most options. Includes Original Spare Tire.

78/79's without A/C and other options are significantly lighter than 3,500 Lbs. My 78 has no AC, fiberglass rear spring, lighter wheels, 4 Speed instead of an auto which are much heavier, lighter McJacks shorty headers, a lighter battery, no cat, air pump and accessories, no spare tire or carrier etc. 24 gallons of gas alone weighs 150 Lbs! The 78 referenced above would weigh 3,370 with fuel removed alone. Lot's of variables.

I have the Road and Track figures for the 78/79 L-82's which are below:

78 L-82 4 speed-0-60 6.5 seconds

79 L-82 automatic 0-60 6.6 seconds

An 80 L-82 assuming the same gearing as the 79 automatic which I am fairly certain it was but not sure should do about 6.4/6.5 seconds 0-60 with the slightly lighter weight than the 79.

Hope that helps!

Priya

I was wrong when I said over 3700 lb for my 79. I used the figure for with a full tank of gas which adds 129 lb, added 17 lb too much for the L82 engine, and hadn't subtracted 14 lb for close ratio 4 speed. Here is the factory weight for my heavily optioned 79 direct from the GM specifications manual:

Base weight for a 79 L48 Corvette with no options 3 gallons of gas 3374

Options add lbs as follows:

Power windows 4
Power door locks 6
glass roof panels 14
rear defogger 1
air conditioning with L82 engine 58
Gymkhana suspension 5
tilt steering 7
heavy duty battery 5
AM/FM radio with tape player 13
power antenna 4
operating convenience package 9
convenience package 7
L82 engine +7
Close ratio 4 speed manual -14
----
Total 3497


So jb78L-82 was right and I was wrong.

Sorry jb78L-82.

jb78L-82

Do what intend to do soon- take it to a weigh station and weigh it with minimal gas and no t tops the way it is setup today. No worries.