Theoretical question for Fran (and others)
- Thread starter John Ross
- Start date
I doubt it.
Those cars weighed under 2000 lbs IIRC, and had 1300 HP in qualifying trim. Even accounting for slightly better brakes and much better tires, it would be hard to overcome the weight difference.
I have no idea about the original suspension geometry on the 917s, but it wouldn't surprise me if the SLC was as good or better than the original car.
I suppose you could pull an Alex and try to put a 2000 HP LS engine in the car, but I'm not sure how much that would help.
But it's an interesting thought experiement.
Those cars weighed under 2000 lbs IIRC, and had 1300 HP in qualifying trim. Even accounting for slightly better brakes and much better tires, it would be hard to overcome the weight difference.
I have no idea about the original suspension geometry on the 917s, but it wouldn't surprise me if the SLC was as good or better than the original car.
I suppose you could pull an Alex and try to put a 2000 HP LS engine in the car, but I'm not sure how much that would help.
But it's an interesting thought experiement.
Ron Earp
Admin
How many of the tracks that the 917 ran on still exist, or still exist in precisely the same configuration they did in 1973? Tracks change over time even if the "layout didn't change". Repaves, curbing, corner modifications, bank changes, grades, etc. have surely changed over the years.
How close in lap times is close enough, bearing in mind that a repave can make two seconds worth of difference over 3.5 miles of track?
Do you plan to limit yourself to 1973 rubber? If not, what would a Porsche 917 do with modern rubber?
How close in lap times is close enough, bearing in mind that a repave can make two seconds worth of difference over 3.5 miles of track?
Do you plan to limit yourself to 1973 rubber? If not, what would a Porsche 917 do with modern rubber?
In my thought exercise, I'm trying to compare what is possible in 2012 with what actually happened in 1973. Could a street legal car on the best rubber do what a 917 (the worlds most powerful road racing sports car, I believe) did in 1973?
I realize tracks get repaved, etc. but I'm curious to know if 40 years worth of brake/tire/chassis development could make up for a 20% weight penalty.
And of course it would have to have a monster TT engine, but those are being done more and more by various builders.
Fun thoughts on a rainy day...
I realize tracks get repaved, etc. but I'm curious to know if 40 years worth of brake/tire/chassis development could make up for a 20% weight penalty.
And of course it would have to have a monster TT engine, but those are being done more and more by various builders.
Fun thoughts on a rainy day...
I am reading this differently John wrote could you construct a street legal SL-C.
I don't see why not, signal lights and a horn your street legal.
build everything out of carbon fiber, body seats etc... maybe even the chassis add a 3000 hp twin turbo Alum racing engine, F1 transaxle and tires. its all about money, If you have the cash you can do it. You may be broke after winning the $500,000,000.00 powerball but you'll have a Freakin fast car.
I don't see why not, signal lights and a horn your street legal.
build everything out of carbon fiber, body seats etc... maybe even the chassis add a 3000 hp twin turbo Alum racing engine, F1 transaxle and tires. its all about money, If you have the cash you can do it. You may be broke after winning the $500,000,000.00 powerball but you'll have a Freakin fast car.
Well, the green race car ran at Mid-Ohio and so did the 917-30KL. That might be a starting pint for the question. I don't think the track has changed a whole lot but I was a little young to be there myself back then.
I found a Mid-Ohio pole time for Mark of 1:20:335 at 107 mph, even if the track has changed slightly the mph should be of value (?)
What was the 01 car's fastest lap?
Of course we should all keep in mind today's green 01 is a ''back yard'' effort in comparison to the then Porsche factory steamroller. Like was said before if money was no object (like Porsche back then) then the SLC would be much faster.
I found a Mid-Ohio pole time for Mark of 1:20:335 at 107 mph, even if the track has changed slightly the mph should be of value (?)
What was the 01 car's fastest lap?
Of course we should all keep in mind today's green 01 is a ''back yard'' effort in comparison to the then Porsche factory steamroller. Like was said before if money was no object (like Porsche back then) then the SLC would be much faster.
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Seymour Snerd
Lifetime Supporter
With the same budget as Porsche had, adjusted for inflation, why not? Don't know how you would define "SLC" as describing the result. Maybe use the same tail lights?
But seriously, if you're flexible enough with what constitutes an "SLC" .... it is, after all, a kit and there's no requirement to us all the supplied parts.
Jim Craik
Lifetime Supporter
Do you suppose that modern ground effects and tires could make up most of the difference?
I remember, we raced our C Sedan Mini at the SCCA Runoffs, at Road Atlanta in 1972, some guy had rented a first generation 917 turbo to run in A Sports Racing, kind of like bringing an ICBM to a gun fight. It was very fast!
I remember, we raced our C Sedan Mini at the SCCA Runoffs, at Road Atlanta in 1972, some guy had rented a first generation 917 turbo to run in A Sports Racing, kind of like bringing an ICBM to a gun fight. It was very fast!
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The course has had substantial improvements and changes - read here:
Mid-Ohio Sports Car Course - Wikipedia, the free encyclopedia
IMHO, today's DOT approved race rubber is better than the slicks and semi-treads we had back in the 60's and 70's.. Radial carcases alone are worth a TON of time vs. bias ply of the day..
Also - not taking anything away from the drivers of the SL-C racecars, I am not so certain that I would place them in the same league as drivers like Brian Redman or Vic Elford (et al).. Drivers make all the difference in the world...
Mid-Ohio Sports Car Course - Wikipedia, the free encyclopedia
IMHO, today's DOT approved race rubber is better than the slicks and semi-treads we had back in the 60's and 70's.. Radial carcases alone are worth a TON of time vs. bias ply of the day..
Also - not taking anything away from the drivers of the SL-C racecars, I am not so certain that I would place them in the same league as drivers like Brian Redman or Vic Elford (et al).. Drivers make all the difference in the world...
Wow. Just wow.
So the SLC really isn't that much different.
I take back what I said earlier. With sufficient power, race brakes, shocks, the right driver, etc., I now think that the SLC could indeed come close to or beat that 1:20 at Mid O.
Further, I'd venture to say that the SLC could make or beat those times with less power than the 917.
I think that the 01 car (not exactly a street car, but very close to what a street car could be less the cage part) with closer to 900 HP, a sequential box and bigger front tires might just be able to match that time.
If true, it says volumes about the capability of the SLC as a race car. One that, BTW, can be fitted with AC and driven to the Dairy Queen.
The 917 is my favorite race car of all time. That said, time marches on, and I have no doubt that an SLC could be made to go faster. The 917 was basically a spindly, ill-handling car with only the simplest of aero technology. Even the brakes would be outperformed by any number of factory original street cars.
As for "unlimited dollars", remember Porsche was a very small company then, and their racing budget would not have been too impressive.
As for "unlimited dollars", remember Porsche was a very small company then, and their racing budget would not have been too impressive.
Thanks for all the replies, even the ones that got off-track, so to speak.
What I meant by my original question was NOT "could someone with an unlimited budget build a car that would beat a 1973 917/30, and then call that car an SLC", it was more along the lines of
Could you build an SLC (meaning 95+% of the non-driveline parts came from RCR) with enough motor, brakes, tires, and electronic controls to do the job?
In my thought exercise, I was mentally limiting the budget to perhaps $150K, excluding labor.
One unspoken part of my question was how the two cars' chassis technology and aero characteristics would compare (remember it's the 917/30 I'm discussing.)
Thanks again for playing!
JR
What I meant by my original question was NOT "could someone with an unlimited budget build a car that would beat a 1973 917/30, and then call that car an SLC", it was more along the lines of
Could you build an SLC (meaning 95+% of the non-driveline parts came from RCR) with enough motor, brakes, tires, and electronic controls to do the job?
In my thought exercise, I was mentally limiting the budget to perhaps $150K, excluding labor.
One unspoken part of my question was how the two cars' chassis technology and aero characteristics would compare (remember it's the 917/30 I'm discussing.)
Thanks again for playing!
JR
Ian Anderson
Lifetime Supporter
Time for Fran to get a SLC to Nurburgring and see what it does
Here is a list of times
SUPERCARS.NET - Comprehensive Specifications, Galleries & Forums since 1996
7:30 for 917 Spider
Ian
Here is a list of times
SUPERCARS.NET - Comprehensive Specifications, Galleries & Forums since 1996
7:30 for 917 Spider
Ian
pssst, that's a typo- that is Porsche's estimated time for a 918 spider, not a 917, click the link and read the asterix as well.
Really,
This could be done, and fairly cheaply.
1. Modern tires and suspension, WAY better...advantage SLC.
2. SLC aero vs 917, I don't know drag coefficients, frontal areas, etc, but the 917 used very simple aerodynamics, so overall....toss up.
3. I don't think you could get the weight down to what a 917 weighed, it was just a minimal number of aluminum tubes and a fiberglass shell, but you could get reasonably close. Besides, aerodynamic drag is going to be your biggest problem at speed. However, advantage 917.
4. On the other hand, weight will be an issue with acceleration/deceleration (both linear and angular). That said, a nice set of carbon-ceramic brakes and a set of modern slicks will give the advantage to the SLC in braking and turning (remember, the 917 was limited to brakes that could fit in 15 inch wheels, and are nowhere near a match for a modern set of binders).
5. As for acceleration...Three factors; power, weight, and the ability to put that power down. Dry sump an LS motor, pressurize it and add some nitro, and you are within spitting range of the 917/30. With the better tires and suspension, and I'd give the nod overall to a well-tricked out SLC. Frankly, with the power that these two cars would be putting down, you'd likely be traction limited in either until (and maybe even in) the top gears.
As with the 917/30, you'd really need someone with the appendages of KING KONG to get the most out of it (assuming no traction control, stability control or antilock braking).
It sure would be fun trying...anyone want to pony up the cash for a monster motor and a Ricardo trans axle?
This could be done, and fairly cheaply.
1. Modern tires and suspension, WAY better...advantage SLC.
2. SLC aero vs 917, I don't know drag coefficients, frontal areas, etc, but the 917 used very simple aerodynamics, so overall....toss up.
3. I don't think you could get the weight down to what a 917 weighed, it was just a minimal number of aluminum tubes and a fiberglass shell, but you could get reasonably close. Besides, aerodynamic drag is going to be your biggest problem at speed. However, advantage 917.
4. On the other hand, weight will be an issue with acceleration/deceleration (both linear and angular). That said, a nice set of carbon-ceramic brakes and a set of modern slicks will give the advantage to the SLC in braking and turning (remember, the 917 was limited to brakes that could fit in 15 inch wheels, and are nowhere near a match for a modern set of binders).
5. As for acceleration...Three factors; power, weight, and the ability to put that power down. Dry sump an LS motor, pressurize it and add some nitro, and you are within spitting range of the 917/30. With the better tires and suspension, and I'd give the nod overall to a well-tricked out SLC. Frankly, with the power that these two cars would be putting down, you'd likely be traction limited in either until (and maybe even in) the top gears.
As with the 917/30, you'd really need someone with the appendages of KING KONG to get the most out of it (assuming no traction control, stability control or antilock braking).
It sure would be fun trying...anyone want to pony up the cash for a monster motor and a Ricardo trans axle?
Howard Jones
Supporter
If I was doing this, I am by the way, well sort of, AND had the money I would simply have Fran build me a #O1 car with a ALMS P2 power train and wheel/tire, brakes. You would need no more than 700HP and maybe as little as 500 if given the right tires. Spend some more money on aero and we would be there.
It should be very clear that a modern DP car or a ALMS P2 car is already quite a bit quicker than our 917 standard. It's all in the tires and downforce. Both give us a unfair advantage over the 917 of 1973.
$150K, would be very tight on parts and no money for develoment, labor, and time/people costs. These things could run several 10s of thousands more, depending how much you can do yourself. I'm giving myself 85K and three years to get mine done to a lap time standard about 20 sec a lap faster than my GT40. All my labor is free, and I can't pay anybody else.
It would be pretty easy to build a RCR 917 with a Porsche 800hp flat six, run it on big fat modern tires, and stop it with modern brakes. That buget would be less than 150K if you do the work yourself.
It should be very clear that a modern DP car or a ALMS P2 car is already quite a bit quicker than our 917 standard. It's all in the tires and downforce. Both give us a unfair advantage over the 917 of 1973.
$150K, would be very tight on parts and no money for develoment, labor, and time/people costs. These things could run several 10s of thousands more, depending how much you can do yourself. I'm giving myself 85K and three years to get mine done to a lap time standard about 20 sec a lap faster than my GT40. All my labor is free, and I can't pay anybody else.
It would be pretty easy to build a RCR 917 with a Porsche 800hp flat six, run it on big fat modern tires, and stop it with modern brakes. That buget would be less than 150K if you do the work yourself.
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