Stock 1/4 Mile performance of ZL-1 or COPO

[J Rod]

Howdy,

I came to this fourm in search of a little help. There have been numerous threads posted recently regarding Supercar performance as of late on corvetteforum.com, z06vette.com, and suprafoum.com. The big argument has been over two things.

1 - With the change from Gross to Net HP ratings there are some who claim that a ZL-1 on made about 360RWHP and that any other numbers are grossly inflated.

2 - That no COPO Camaro or ZL-1 equipped vehicle in an "as delivered state" will run 10's in the 1/4 mile. Now let me qualify this by stating that everyone understands we are not talking about running on F70 polyglass tires. But lets say on a 9" slick. It is also my understanding that headers for these cars were delivered in the trunk, so I lets say with open headers and on slicks.

The only magazine article anyone could produce was on a car that had been balanced and blueprinted and was modified.

Since this seems to be the center of the supercar universe I figured if anyone had either done this in one of their cars, or had links to proof that we could put alot of the speculation to rest.

Thanks in advance for your responses...

[Stefano]

J Rod,
Is 11.04s close enough (eight inch slicks were used as well as open headers).

This was the 'Drag Times' Yenko article and thus used the lower performance L72,not ZL1.

[JoeC]

Dick Harrell tested a 1969 ZL1 Camaro with 4:10 gear and TH400 trans in Super Stock magazine May 1969. The car had open headers, rear spring clamps, and 6 1/2 inch slicks. The remainder of the car was stock. It ran a best of 11.64 @122.15. Harrell commented that the tires were completely inadequate.

[Chevy454]

Stefano:

I don't have our copy in front of me, so don't kill me if I'm worng, but I was thinking the Yenko L-72 ran an 11.94? Still, pretty quick for such few mods.

Harrell did test a "stock" ZL-1 somewhere...I will have to dig it up.

What a lot of people don't realize though, is that the slicks back then and the slicks today are light years apart. B-I-G difference.

[Charley Lillard]

My ZL1 was Tested when new and ran a 13.16 @110

[COPO PETE]

Sorry Charlie, but that reminds me of a VW commercial.....Drivers Wanted! http://www.yenko.net/ubb/smilies/images/icons/wink.gif Actually that is a prettty decent time!
Peter


[Edited by COPO PETE (05-10-2002 at 07:29 PM).]

[JoeC]

I agree with Rob it was 11.94 on the Yenko and it had a bad clutch when they tested it. If I remember correctly it was the gold Yenko Camaro with the wierd emblem on back.

When Charley's ZL1 was tested it had the wrong Holley on it. It came from the factory with a 780 vac sec but should have had an 850 DP. It may have knocked off a few tenths or at least picked up a few mph.

[Stefano]

OK guys when I am wrong I'll take it like a man, but I picked the info up from our own site <A HREF="http://www.yenko.net/oldads/yad11.jpg

" TARGET=_blank>http://www.yenko.net/oldads/yad11.jpg

</A> While slightly opimistic I agree, we all know that if it is in print on this site it must be accurate.

I did dig up a couple of magazine reprints/reruns of the same article and they do say 11.94 @ 114.5 mph.

The #3 ZL1 could have turned in better times but for the fact that, Clill was the test pilot. Look at the pictures, it's him 33 years ago http://www.yenko.net/ubb/smilies/images/icons/wink.gif

[COPO PETE]

I did'nt realize Charlies car ws tested with the 780! When we rented the track to test for the Pure Stock Drags, the best we could get out of the 780 was 12.80's. When the 850 was put on we finally got it down to 12.40's that day. Also picked up 3 mph! This is on F70-14 polyglas tires. Since then it's gone better yet. Keep in mind we did certify and went with the heads off so they could check and measure everything and look for porting!
Peter

[JoeC]

Pete the ZL1 run of 13.16 was on 15x7 tires. The 15x7 may give a better 60 ft. but the 14x7 will give numerically high gear ratio. Do you think that will have any effect on the ET?

[COPO PETE]

Joe,...Yes I do think the 14" would help it get a better et, and maybe a better 60 foot, depending on the traction. Also, I'm running a 4:56 behind the ZL-1. On both my iron motor cars, the 4:56 gave the cars 2 tenths over the 4:10 ratio. The ZL-1 like to be treated like a small block.7000 shifts at each gear change and it goes through the end at 7200.
Peter

[mhassett]

Hey Guys, I found a Car Review Magazine from 1986 that tested 3 ZL-1's
Dick Harrell tested 2--adding headers and slicks to an automatic he turned an 11:85 at 119.06 with a full exhaust system. Uncapping the headers dropped the figures to 11:64 at 122.15.
The other Zl-1 received the Super Stock Race Treatment (engine remaining untouched internally) and managed a 10:29 at 132.05.
The 3rd Zl-1 (My car) then owned by Mr. Rusty Symmes during Car Review's Magazine Supercar Showdown, June 20-21, 1986 at Bowling Green, Kentucky's Beech Bend International Raceway, he slapped on a pair of slicks and ran through the quarter in 12:76 at 107.65.
Before that pass many in the crowd looked upon Rusty Symmes car as just another camaro, after the run they became educated joining the enlightened few who know full well the signifance of the RPO code "ZL-1"
Mark

[JoeC]

The article in Car Review Magazine 1986 was a reprint of the Super Stock magazine May 1969 article that tested the two Dick Harrell ZL1s. The one that ran in the 10s was a AHRA Super Stocker with a fiberglass nose and many other modifications.

[J Rod]

Thanks for the replys thus far. I have not had time to go digging through my magazine collection and try to find any print articles which might back up the 10 second performance data.

I along with many others have been "discussing" this topic with many of the "import" crowd who simply do not understand what Big Block torque and HP is all about.

As I said, I came on here because there seems to be quite a few owners, and quite a few folks who would be quite knowledgeable about these particular cars.

So anyhow, if any of you have any articles or sources of a 10 second run on a ZL-1 or COPO car in "stock" form. I would appreciate it

[shor]

Classic Auto Restorer, August 92
1969 Corvette ZL1 1/4 mi 13.5 @108(stock)
same car 5.13 rear, slicks, open exhaust, 10.5 @ 131
Cars Magazine,Classic Auto Restore August 94 (I guess they liked to do zl1 features in August!)1969 Camaro ZL1 # 3 1/4 mi 13.16 @110 stock with Nc8

[GRB]

Anybody know how much those cars weighed??

[COPO PETE]

Cars weighed about 3300 LBS. Mine weighs about 3500 with me in it. ( Depends on fuel in tank!)
Petert