endurance record - Page 5 - ZR-1 Net Registry Forums

LancePearson · 05-30-2013

I'm a touch confused. I thought the gpm ratings of our water pumps were too much, hence the flow system and double thermostat. At speeds over 6,000 rpm it cavitates? These guys get pushed to 7000 rpms quite often. Then, what do the highly tuned 415's, 427 resleeved or turbo boosted LT5's do for water pumps and effective cooling?

Is there a solution which deals with it in modern times? These cars are all still running around if they haven't been wrapped around a tree seems to me.

Lance

vettebrett · 05-30-2013

Quote:

Originally Posted by Daniel_Mc

Yea about that...

You don't count D

ZRXMAX · 05-30-2013

Reading about the history of the 24 Hour Record Run is great ! Its full of great people with drive, talent, and determination accomplishing what many others failed to accomplish. In my not so humble opinion nothing could be more exciting that making another attempt on the record with our fabled ZR-1. Why, how, and with what resources? That would be left to those that want it badly enough to see it become reality. I would like to see the direction of the conversation turns towards how it could happen. We are like Baja 1000 racers watching "Dust to Glory" for the 23rd time. Its makes great entertainment but misses the energy of undertaking a project that turns the automotive world into a spectator. I am willing to donate something relative to my expendable resources. The question is would any private entity really want to spend the money to make it happen? Very doubtful... Most would agree that on the outside nobody wants to invest in a project no matter how much fun it is with no real financial reward.

Hib Halverson · 05-31-2013

I was there.

Jim Van Dorn was not. In fact, Jim did not get into the ZR1 hobby until year or so later.

The car was stock. In fact, it weighed significantly more than stock due to the cage, the fuel cell, telemetry, radios and the spare parts it carried.

The engine was as discussed earlier, a stock LT5, built by the LT5 Gang in Stillwater and held from shipping to BG because of a minor QC problem.

It was used in the Record Run car as-is with stock manifolds no cats and open exhaust. The calibration was changed to optimize engine performance in that configuration. The engine was throttle-stopped except for a few laps at the very end which Stu Hayner ran at WOT in fifth.

The car had a 3.07 axle, no rear stabilizer bar and no sideview mirrors.

The tires were special race tires Goodyear built for the Run.

It is unlikely another production car would ever set the 24. The cost would be astronomical. Finding a venue would be difficult. It would be unlikely a production car would be able to exceed the VW prototype's 24-hr. speed to set a record.

LancePearson · 05-31-2013

I can only imagine what that engine sounded like thundering down the straight at 190 mph or so. Open exhaust, no cats. What was that like to listen to, H.H.?

Lance

Hib Halverson · 05-31-2013

Quote:

Originally Posted by LancePearson

I'm a touch confused. I thought the gpm ratings of our water pumps were too much, hence the flow system and double thermostat. At speeds over 6,000 rpm it cavitates? These guys get pushed to 7000 rpms quite often. Then, what do the highly tuned 415's, 427 resleeved or turbo boosted LT5's do for water pumps and effective cooling?

Is there a solution which deals with it in modern times? These cars are all still running around if they haven't been wrapped around a tree seems to me.

Lance

These highly tuned 415s or 427s or turbo LT5s are not running WOT/high-rpm for sustained periods, thus they don't run into cooling problems.

While I've not tested LT5 coolant pumps, I do know that one of the final validation tests was WOT fifth gear for a tank of fuel. The cooling system must have worked well enough to pass that test.

I've not experience the "cavitation problem" but I've always thought a quality, all-alumium radiator, a 20 psi system and a blocked or restricted coolant bypass would improve high rpm cooling.

Additionally, I'm not sure I understand how the pump could cavatate when the system is bypassing coolant around the radiator, but again, there are probably those here better versed in hydrodynamic subjects than I.

Meanmyz · 05-31-2013

Hib, I remember first reading your article on this in the 1990 Road & Track "Specials" Corvette issue. Awesome stuff. As a matter of fact, just thinking about it brings back memories of "the electricity in the air" over the new ZR-1.

ZR-1 Franz · 06-01-2013

When I began to drive Corvettes, my first one was a '74 Coupe, many people here
could not understand. I often was asked, why I would not drive an European sports car.
I never wanted, even the Corvette's reputation wasn't good here. In German car
magazines the Corvette did not often get fair critics. Me for myself often told those
who criticized the Corvette, that the day would come when they all would shut their big mouths! And this day came and you could not read a lot about this record in European car magazines.
This is what the Europeans understand as "fair". I think
there was no European sports
car at this time which would have been able to get this record and the Europeans
had to take a purpose built race car, yes this VW is a race car, to beat the ZR-1.
May be they would never have it this way easy, if they had to drive it in Fort Stockton.
In Nardo you have side rails on the whole track, it is much better illuminated and so on.
All of these facts make me so proud to have a ZR-1 in my garage, especially here in
Europe!!!!

Meanmyz · 06-01-2013

Quote:

Originally Posted by ZR-1 Franz

When I began to drive Corvettes, my first one was a '74 Coupe, many people here
could not understand. I often was asked, why I would not drive an European sports car.
I never wanted, even the Corvette's reputation wasn't good here. In German car
magazines the Corvette did not often get fair critics. Me for myself often told those
who criticized the Corvette, that the day would come when they all would shut their big mouths! And this day came and you could not read a lot about this record in European car magazines.
This is what the Europeans understand as "fair". I think
there was no European sports
car at this time which would have been able to get this record and the Europeans
had to take a purpose built race car, yes this VW is a race car, to beat the ZR-1.
May be they would never have it this way easy, if they had to drive it in Fort Stockton.
In Nardo you have side rails on the whole track, it is much better illuminated and so on.
All of these facts make me so proud to have a ZR-1 in my garage, especially here in
Europe!!!!

I know how you feel Franz.

TCurtner · 06-04-2013

Quote:

Originally Posted by Paul Workman

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.

Would someone share what parts to use to correctly add the electric unit? Part numbers? Sources? Can the whole bypass circuit be BYPASSED? What radiator? I want to go VERY FAST for very long - and all between 5k and 7.1k rpms regularly :-)
Thanks in Advance

05-30-2013	#41
LancePearson Join Date: Dec 2012 Location: Chester, Virginia Posts: 457	Re: endurance record I'm a touch confused. I thought the gpm ratings of our water pumps were too much, hence the flow system and double thermostat. At speeds over 6,000 rpm it cavitates? These guys get pushed to 7000 rpms quite often. Then, what do the highly tuned 415's, 427 resleeved or turbo boosted LT5's do for water pumps and effective cooling? Is there a solution which deals with it in modern times? These cars are all still running around if they haven't been wrapped around a tree seems to me. Lance

05-30-2013	#43
ZRXMAX Join Date: Jan 2004 Location: Murrieta, CA Posts: 240	Re: endurance record Reading about the history of the 24 Hour Record Run is great ! Its full of great people with drive, talent, and determination accomplishing what many others failed to accomplish. In my not so humble opinion nothing could be more exciting that making another attempt on the record with our fabled ZR-1. Why, how, and with what resources? That would be left to those that want it badly enough to see it become reality. I would like to see the direction of the conversation turns towards how it could happen. We are like Baja 1000 racers watching "Dust to Glory" for the 23rd time. Its makes great entertainment but misses the energy of undertaking a project that turns the automotive world into a spectator. I am willing to donate something relative to my expendable resources. The question is would any private entity really want to spend the money to make it happen? Very doubtful... Most would agree that on the outside nobody wants to invest in a project no matter how much fun it is with no real financial reward. __________________ 91 ZR-1 #661 Watsons, 3" exhaust, Borlas... Hurst, 4.11s, Samco, RD radiator, gel coated motor... turquise / black

05-31-2013	#44
Hib Halverson Join Date: Jun 2005 Location: CenCoast California Posts: 898	Re: endurance record I was there. Jim Van Dorn was not. In fact, Jim did not get into the ZR1 hobby until year or so later. The car was stock. In fact, it weighed significantly more than stock due to the cage, the fuel cell, telemetry, radios and the spare parts it carried. The engine was as discussed earlier, a stock LT5, built by the LT5 Gang in Stillwater and held from shipping to BG because of a minor QC problem. It was used in the Record Run car as-is with stock manifolds no cats and open exhaust. The calibration was changed to optimize engine performance in that configuration. The engine was throttle-stopped except for a few laps at the very end which Stu Hayner ran at WOT in fifth. The car had a 3.07 axle, no rear stabilizer bar and no sideview mirrors. The tires were special race tires Goodyear built for the Run. It is unlikely another production car would ever set the 24. The cost would be astronomical. Finding a venue would be difficult. It would be unlikely a production car would be able to exceed the VW prototype's 24-hr. speed to set a record. __________________ Hib Halverson Technical Writer former owner 95 VIN 0140 current owner 19 VIN 1878

05-31-2013	#45
LancePearson Join Date: Dec 2012 Location: Chester, Virginia Posts: 457	Re: endurance record I can only imagine what that engine sounded like thundering down the straight at 190 mph or so. Open exhaust, no cats. What was that like to listen to, H.H.? Lance

05-31-2013	#47
Meanmyz Join Date: Feb 2006 Location: Springfield, Minnesota Posts: 444	Re: endurance record Hib, I remember first reading your article on this in the 1990 Road & Track "Specials" Corvette issue. Awesome stuff. As a matter of fact, just thinking about it brings back memories of "the electricity in the air" over the new ZR-1.

06-01-2013	#48
ZR-1 Franz Join Date: Aug 2005 Location: Solothurn, Switzerland Posts: 144	Re: endurance record When I began to drive Corvettes, my first one was a '74 Coupe, many people here could not understand. I often was asked, why I would not drive an European sports car. I never wanted, even the Corvette's reputation wasn't good here. In German car magazines the Corvette did not often get fair critics. Me for myself often told those who criticized the Corvette, that the day would come when they all would shut their big mouths! And this day came and you could not read a lot about this record in European car magazines. This is what the Europeans understand as "fair". I think there was no European sports car at this time which would have been able to get this record and the Europeans had to take a purpose built race car, yes this VW is a race car, to beat the ZR-1. May be they would never have it this way easy, if they had to drive it in Fort Stockton. In Nardo you have side rails on the whole track, it is much better illuminated and so on. All of these facts make me so proud to have a ZR-1 in my garage, especially here in Europe!!!! Last edited by ZR-1 Franz; 06-01-2013 at 07:54 AM.