1982 Top Speed?

[Zektor]

Hi Guys,
I've heard in the past that the 1982 Corvette's top speed was 125mph. But the thing that confused me was that 125mph is attainable in 3rd gear, but in all the specs I've seen it shows as the top speed in 3rd and 4th (overdrive) as being 125mph. I thought this was weird... I thought that maybe the car did not have enough power to beat 125mph once it had shifted into 4th.

But, for Christmas my brother bought me Dave McLellan's book "Corvette from the Inside". In this book he says that the 700R4 for '82 was setup so that it would not shift from 3rd to 4th at WOT. They changed this for the 1984 Corvette. In the 1984 Corvette the tranny would shift into 4th at WOT and achieve a higher top speed, something just over 140mph.

Also, the top speed attainable in 3rd is not 125mph... according to Dave's book, it's rpm limited to 128mph.

My question is this, the 1982 had 200bhp and the 1984 had 205bhp. My modified 1982 has about 235 - 240bhp and therefore more power than the stock 1984. So surely, if I back off from full throttle just enough to allow the tranny to shift back into 4th it should still carry on up to just short of the cars top speed. Let's face it, you've still got your foot 95% of the way to full throttle, the car should definately go faster because the 205bhp 84 model can do just over 140mph.

I'm estimating that my 1982 with the extra power it develops and at a 95% of full throttle condition it should at least achieve 140mph too, even 145mph might be attainable.

What's everyone's thoughts on this?

Cheers
Dazza

 

[lytemup]

82 & 84 can't be directly compared for top speed with hp because their drag coefficients are different (82 is worse). i don't remember what they are, but a little makes a big difference at high speeds.

 

[Twin_Turbo]

anything above about 70% throttle is considered WOT for thr tranny.

Only the Corvette 700R4 would NOT downshift from 4th to 3rd on WOT, all other cars would do this. The book is probably correct but mine would do WOT in 4th no problem, I've driven speeds up to close to 140mph with it.

Marck

 

[Larry82]

My "limited" experience at high speeds is the tranny wants to come out of OD to 4th. But never 3rd. And, this is at speeds near 100 or more - who knows, with the lovely 85 mph speedo. I have nipped off the stop tab at 85 so the needle just keeps climbing. Guessing on the speed, though.

 

[Twin_Turbo]

Uhm, 4th gear is overdrive, you must mean the tCC. TCC is always disengaged at throttle positions above 30%.

Marck

 

[topless82vette]

hey marck

just curious, did the 90 vette 700r4 stay in overdrive at high speeds, if so I might just have to give mine a whirl and see what it can really do, I know at around 75mph its turning about 1700rpm, but with the high freeway gears that are in the car could it even accelerate good at highspeeds when in overdrive, my motor is totally stock so my guess is that the the 200horse motor cannot possibly pull overdrive at anything much over 130 anyways.

 

[Twin_Turbo]

If it's a true vette one w/ the correct governor it should.

 

[Zektor]

'82 700R4

Twinnie,
Ok, if the '82's tranny will shift into 4th at WOT... then why do GM state that the top speed is 125mph? ...the same as in 3rd?

If Dave McLellan is wrong then, then at what speed will the tranny shift into 4th at WOT... redline?

Cheers
Dazza

 

[Twin_Turbo]

I'm not saying Dave McLellan is wrong, he is right of course and so that must mean the 82 tranny does NOT support WOT in4th. Mine did and I did not modify it. It could ALSO be, and I think this is more likely, that w/ the highway gears the CFI does not have enough higher rpm power to make the revs for higher speeds in 4th. Mine was not stock (yuck.. stock !

Marck

 

[Larry82]

Twinnie - Right your are. Meant TCC.

 

[mmvette80]

When BTO did my 700R4 I had the option of 75% throttle or the wide open throttle option. I chose the 75% throttle, this way the car didnt jump in and out of OD a the slight touch of the gas. When running at top speed she jumps out of OD as soon as the hammer goes 75% to the floor. My top speed is limited to 3500rpms and 125 mph. If I put the shifter into 3rd I can go about 135mph. I also chose the 75% so Im not doing high speed runs every other day!