endurance record

[Hog]

Originally Posted by WVZR-1

Heat and stress would have killed the ZF!

Heat and stress at 3/4 throttle? Obviously the appropriate gearing would have to swapped in, eg. 4.56's for 184mph. Just like they actually did for the record run to run in 5th gear.

peace
Hog

[Paul Workman]

Couple of things...

The water pump breaks into cavitation somewhere about or above 6000 rpm, and they needed to keep the rpm down below that for the run, obviously. And, 5th gear at about 5500 rpm is nearly at the torque peak for a stock LT5; both were valid considerations.

As for the ZF 6th gear issue, I have first hand experience with that, so I know what you're talking about. However, I haven't run across any reading that acknowledges that as being an issue with new ZFs. I wonder if it is an issue that appears after some miles are put on the car. In my case it happened at about 45,000, and the ZR-1 mileage was essentially new at the time of the record run.

FWIW,
P.

[Fully Vetted]

Originally Posted by Hog

Since teh 175 includes some periods of time at 0mph and at speeds other than 180mph, 175mpgh IS the cars actual average speed over the 24hour period.

To get the figure you seek, the stopwatchs would have to have been stopped everytime the driver deceled for a pit stop, the restarted when after the stop after peak speed had been re-attained. I doubt this was calculated.

peace
Hog

If I remember correctly in the seminar they said their cruise speed was closer to 183-185mph to make up for stopping for driver change and fuel. Keep in mind this is a time vs. distance experiment. The 2 big records here were 24 hours and 5000 miles. At the end of 24 hrs you divide the miles driven by 24 hours and you come up with the average speed. At the end of 5000 miles you do the same thing still coming up with the average speed.

In the seminar they explained that after they had broken the 24 hr record they called Dave McLellan and told him the news. After congratulating them he asked, "Do you still have fuel?" "Yes, we do," they reported. "Do you still have tires?" Again, they reported, "Yes, we do." He responded with, "Let's go after the 5000 mile record, too, then!" They had travelled a little over 4221 miles. Another 800 miles wasn't that far of a stretch. The rest is history...

Originally Posted by Paul Workman

The water pump breaks into cavitation somewhere about or above 6000 rpm, and they needed to keep the rpm down below that for the run, obviously. And, 5th gear at about 5500 rpm is nearly at the torque peak for a stock LT5; both were valid considerations.

Doesn't an electric water pump solve that issue?

[FU]

Ask JVD , he was on the crew for the record run.

[LancePearson]

Originally Posted by XfireZ51

What was their actual average speed given that 175 includes stops and accel/ decel times?

The information I had was that the 5500 rpm with the 3:08 rear end run in fifth gear ran the car hour after hour at 190 mph on the straights and drifted down to 177 or less in the curves with the centrifugal force then crew changes, fuel, etc. The car also was required to carry 48 gallons of fuel. There are rules that a car must meet to qualify for the record. Remember, they beat a fifty year old record run by "the Mormon Meteor" at 161 mph and that was hardly a production car. Several others tried to do what our cars did and failed. I don't know if modern production cars could do it but something like a ZO6 prepped well ought to be able to I would think as could something like a Lambo, probably some of the BMW's. For that matter, I'd like to see what a 415 lt5 could do at it on the same track. The track is over 7 miles long and lightly banked but if you ran 220 mph and less in the corners I'd wonder if it would even be safe to try it. It's Bridgestone's tire test track now I believe.

What would be a serious hoot is to take 25 of our Z's as presently configured and run ten or twenty laps on that track one day. That would be a hell of a hoot.

[Hog]

[QUOTE=Fully Vetted;174469]If I remember correctly in the seminar they said their cruise speed was closer to 183-185mph to make up for stopping for driver change and fuel. Keep in mind this is a time vs. distance experiment. The 2 big records here were 24 hours and 5000 miles. At the end of 24 hrs you divide the miles driven by 24 hours and you come up with the average speed. At the end of 5000 miles you do the same thing still coming up with the average speed.

QUOTE]
My 180 mph cruise was hypoothetical as I didnt know the actual cruise figure. Thanks for the info.

XFire asked what their actual average speed was. I was giving him an answer to his question, which is based on data that wasnt gathered.

Here is an article with good data. I wonder what the ole' L98 would have done?
http://www.corvetteactioncenter.com/...r1/record.html

peace
Hog

[Hog]

Originally Posted by LancePearson

The information I had was that the 5500 rpm with the 3:08 rear end run in fifth gear ran the car hour after hour at 190 mph on the straights and drifted down to 177 or less in the curves with the centrifugal force then crew changes, fuel, etc. The car also was required to carry 48 gallons of fuel. There are rules that a car must meet to qualify for the record. Remember, they beat a fifty year old record run by "the Mormon Meteor" at 161 mph and that was hardly a production car. Several others tried to do what our cars did and failed. I don't know if modern production cars could do it but something like a ZO6 prepped well ought to be able to I would think as could something like a Lambo, probably some of the BMW's. For that matter, I'd like to see what a 415 lt5 could do at it on the same track. The track is over 7 miles long and lightly banked but if you ran 220 mph and less in the corners I'd wonder if it would even be safe to try it. It's Bridgestone's tire test track now I believe.

What would be a serious hoot is to take 25 of our Z's as presently configured and run ten or twenty laps on that track one day. That would be a hell of a hoot.

A 415 LT5 wouldnt do much better with its throttle castrated to 70%. Power wasnt the limiting factor for the record run.

peace
Hog

[rkreigh]

the Nardo has upped the bar to 200+ average which would require a few things

1. the attempt to be run at Nardo, the only track this would be realistic to try.
2. lots of sustainable HP, going a average of 200+ is a whole different ball game than going 175
3. a really big check!!

I talked to Graham at length about what it would take from an engineering standpoint to retake the record for a ZR-1 and he stated quite simply

a check with many zeros after the 1

with no real incentive other than bragging rights it is a daunting and difficult task to muster the cash

a 415 with a big tank, roll bar, proper gearing, and aero mods would likely be challenged.

but I'd sure like to see a vette (new or old ZR-1, C7, C6R) or what ever it takes to set the bar up to 205 or so.

it's another thing on my "bucket list" - retake FIA record

now if we can just talk to Mr. Leno, and Mr. Lingenfelter about sponsoring the effort, I'm all in.

Graham, how about it?? my bet is that you could build the car given the check with the right number on it.

it would be a great honor to be a part of this effort, and we need to get this one BACK!!!

yes, the LT5 is still the only "production line" engine even with the minor tuning and mods to own this record.

I believe that a modern "run what ya brung" effort and something like the yellow bird 415 capable of lapping at 218 might even have a shot.

gonna take the right team to do it, and Nardo is the place.

[Paul Workman]

Originally Posted by Fully Vetted

Doesn't an electric water pump solve that issue?

Yes. And, Pete feels it may be worth about 8-10 hp too. However, if ever the damn thing stops working, you run the risk of cooking the gaskets (at the very least) on your LT5. (Pete can talk from experience on that issue as well!)

p.

[LancePearson]

I'm not sure what the merits of setting a record above 200 mph for 24 hours would be. For me the 175+ is pretty rare air over that length of time. Anything more gets to be a demonstration of spending without much merit in the car you are going to buy in the real world. Where can you even run them 175 now? Not in Virginia I can tell you.

Back in 1990 it was done for marketing with a specific real purpose: to overcome two decades of waning power and slowing speed by government fiat in the USA for a flagship race car product for a car company. It worked, established that Vette was fast and durable to counter two decades of decline.

Today, isn't it a given that all the upper end Vettes are fast? I'd guess Porsche, BMW, Ferrari, et al, already accept that and having watched some modern ZR-1's run at VIR I'd say they are very fast. So, why fuss with an endurance record when the speed of the marque is so well established now?

I think it's not worth re doing but would think a few laps on the same test track would be a heck of an anniversary event if it could be arranged for the owners of the cars.

Today, just about every engine in race cars can be made to generate more than one horsepower for every cubic inch of displacement or more so power is relatively cheap. Proving endurance isn't necessarily in GM or Porsche who owns the Nardo track now's best interest. It's okay to have it but with race cars what's the warranty?

I have been fascinated with the record and the doing of it but I think it was a one time thing and have often wondered why VW later tried it with their car. Outside of a very small fraternity, no one really knows about that record. Just my two cents but I don't see the merits of mounting any effort. The question seems to me to be: why? What's the purpose of doing it now? The cars already go faster than small aircraft fly.

I'd rather see them support DP and Gt racing and things like that, frankly.

Just my opinion and everyone has one.