90 ZR-1......the quickest??

[JT ZR-Won]

Hey everyone, I read somewhere that the '90 ZR-1 (stock) might be the fastest ZR-1 made. If this is true, is it because of the weight to horsepower ratio? Is it that much lighter than the other years?

Jay

 

[Rob]

It is true that the '90 was the quickest because of the lower weight. Even though the second generation LT5 engine was putting out 405 vs. the first generation's 375hp, the weight gradually increased over the years as well.

Actually, the '89 test mules were actually the quickest because they were even lighter than the '90 production models. I can't remember what it's called, but there is a special beam or shaft that was added under the car on the '90 model year that was not present on the test mules. I can't remember the purpose of it, but this is what added more weight to the production model over the test mules.

-Rob Loszewski, Site Administrator
Corvette Action Center

 

[JT ZR-Won]

How much lighter were the 90's??

 

[Steel Half-Shafts]

Jay,
The Curb Weight of the 1990 ZR-1's is listed at 3,465 lbs in my Specification Book.
I'm not sure what the other ZR-1 model years were

Maybe someone else will know!

Also, I'm waiting for the NCM to make the LT5 Dyno sheets they got from Mercury Marine available so we all can see if the 1990's really are faster. Rumor has it that the early LT5's delivered more HP than advertised

Right Rob!!!! :s

 

[Rob]

Mmmmmmmm, that's news to me. From what I've seen, horsepower output of the LT5 engine is all over the place. You can get lucky and get a real strong one, and you can also luck out and get a slightly weak one.

I have the test numbers that Corvette Powertrain Engineer, Jim Ingle obtained on all the model years. I have to dig them out. I'll be making them available soon over the CAC.

 

[JT ZR-Won]

That's interesting.....thanks for the info 3400lbs. seems like it would be a tank, but running high 12's....I guess not!

 

[Steel Half-Shafts]

Sounds Good Rob.

I'll be interested to see the Test Numbers from Jim Ingle.

I had heard that the first 600 or so 1990 LT5's were meticulously hand-balanced and assembled due to the then New ZR-1's "front stage" position!

We'll See!!!!
-Gordy

 

[ZRWON]

Have you heard anymore about when the NCM will have the LT-5 test sheets available for specific ZR-1s. Last I heard, it was a shortage of manpower to get the test sheets catalogued and available for coping. Would really like to see mine. It sure feels stronger than my first '91 ZR-1???

 

[Steel Half-Shafts]

ZRWON,
Last I heard the NCM was still working on the LT5 test sheets.
Guess it's a lot of work to catalogue them, but I'm sure they will be available shortly. They will add some more needed income!

I just ordered a copy of my Build Sheet and Window Sticker from the NCM.

-Gordy

 

[Steel Half-Shafts]

ZRWON,

Just saw this on the ZR1Net!

-Gordy

------------Original Message----------------
In a message dated 2/2/01 8:55:19 AM Central Standard Time,
BobbieJo@corvettemuseum.com writes:

RE: LT5 Dyno sheet availability
MerCruiser has advised us that the remainder of the LT5 information will not be released to the National Corvette Museum until after 11/2001.
It will be some time after that before the information will be made available for the enthusiast. Even though we have approximately 50% of the files, we will not be releasing any information until we have all the files from MerCruiser.
We will notify the enthusiast through press releases and announcements in the America's Sports Car.
---------------End of Message---------------