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jmp
07-05-02, 01:53 PM
I read somewhere (Motor Trend, 1972 article found on www.corvettearchive.com (http://www.corvettearchive.com) ) that the top speed of the 72 LT-1 was 152 mph... Maybe I need a driving lesson, but exactly how do you get to that speed!? At 5500 rpm, in 4th, I was going about 115mph -- I don't think I can get to 152 by the time I reach the redline!

How fast have you gotten your LT-1?

0018
07-05-02, 06:12 PM
[QUOTE]Originally posted by jmp
I read somewhere (Motor Trend, 1972 article found on www.corvettearchive.com (http://www.corvettearchive.com) ) that the top speed of the 72 LT-1 was 152 mph... Maybe I need a driving lesson, but exactly how do you get to that speed!? At 5500 rpm, in 4th, I was going about 115mph -- I don't think I can get to 152 by the time I reach the redline!

How fast have you gotten your LT-1? [/QUOTE

Imp, If your after topend, try the 2.73:1 Axle. The 3.08 will give you about 140 mph at 5,000 rpm. LT-1s were geared for acceleration, not top end. I had my '70 with a 3.70 ratio at 135 mph and I figured I was still alive to tell about it, so I took my foot off the gas. There was more left.

jmp
07-10-02, 03:23 PM
Well, I'm not really after anything -- the car is stock and going to stay that way. I was more curious than anything, 'cause the LT-1 in the article was the same as mine (3.70 gears, btw) but it seemed to have a much higher top speed.

But I really do think I need a driving lesson (I guess driving Hondas isn't the best thing for prepping for a 'vette! :s ), b/c I also have a hard time launching the thing! More practice, I guess. ;) :D

0018
07-10-02, 05:04 PM
JMP,
I dont know how they got a 3.70 ratio '72 LT-1 up to 150 mph. Your readings are more in line with reality, and what my '72 with 3.70s does. I know theyll do 150+ with the right highway gears. With a 75mph limit, the 3.70 is just fine. I drive a Honda too, and it takes some getting used to switching back and forth. Stu

jmp
07-11-02, 05:41 PM
I forgot to ask this newbie question:

What do the different ratios mean, in real-world terms? I can see how the smaller the ratio, the higher the top-end speed, but what do the higher ratios get ya'?

Robert N
07-11-02, 05:47 PM
If I have this right:

smaller ratios (taller gears) are better top end speed and gas mileage

higher ratios (shorter gears) are better torque and off the line acceleration.

F4Gary
07-16-02, 11:54 PM
I've had mine up to 115 at Texas Motor Speedway and I was turning less than 4500 with a 3:08. I replaced the '66 4:11 rear end that was in my car when I bought it with the 3:08 for cruising purposes. The club I'm in here does alot of weekend cruises and with the 4:11 it was way too noisy.

tomtom72
05-15-04, 08:38 AM
HI jmp, I had read a test report from Car and Driver,1972, that tested a '72 LT-1 w/AC and they said that they "observed a top speed of 152 mph". I think with a 3.55:1 rear and using a 6500 rpm red line on one of those speed calculator formulas you get 152 mph, but I don't remember if the formula takes into account CoF, or body drag. I know the CoF on a '72 vette is .33, same as a '72 911S.

tonyk72
05-17-04, 09:55 AM
If somebody wants to do the math, my LT-1 turns approx. 3k RPMS at 80 MPH in 4th...thats with the 3.55's & Muncie M20...

F4Gary
05-17-04, 01:00 PM
Then at 6500 rpm you would be doing 173.333 mph!

JJS
05-17-04, 02:31 PM
The 3K RPM's at 80 in 4th are exactly what I see in my '71 LT1.
It feels like there's at least as much (if not more) left in my car.

Last year I had mine around 100, but I was white knuckled to the steering wheel as the car was "loose" as hell. I had some alignment work done, as well as some power steering adjustments, but I haven't had it up to those speeds yet this year. I also have new wheels, and more of a stock tire (I had wides all the way around last year) so I'm looking forward to running it wide open some Saturday or Sunday morning.

JJS
05-17-04, 02:43 PM
Oh yeah, I have 3.55's (4.11 original...I have these gears) with an M21.

lt1srule
05-17-04, 03:13 PM
Hi, new to the group... just found it surfin the net today. I bought one of the first LT-1s in 1970. I ordered it in Dec 1969 and it was delivered to Lou Bachrodt Chevrolet in Rockford IL the first week of Feb 1970 and of course I couldn't have it till Feb 28 (the official day of release and prices). It was a low option Marlboro Maroon Convertible, saddle leather, and AMFM. Pretty sure it had the M-21 transmission. When it was ordered, we didn't know if the LT-1 option was going to be available (it was only rumored), so I ordered a 3:55 rear end thinking I'd end up with a 350-300. The 3:55 was the performance ratio for 300HP, but economy ratio for 370HP. I was 25 in 1970 and wasn't afraid to test the limits... LOL. I seem to remember redline in first was 65 MPH... second was 90... and third was 115. I remember racing a Roadrunner one day and getting up to 135 (and he was ahead of me)... and it was just about as fast as that LT-1 was gonna go. I couldn't catch him. Worst problem with that 70 was I had to run Sunoco 260 to keep it from pinging, and it needed new plugs once a week, if u wanted to get to redline. I've owned 9 Corvettes (61-73), sold Chevrolets from 71-74, and was the President of Northern Illinois Corvette Club in 1973. The last Corvette I owned was a 72 LT-1 coupe w/air, back in the early 90s. So fire away, I remember way too much :-)