The new P4

I have ALOT more experience with PS's, I could never get the hang of racing on the 'puter. I cannot remember his name but he is a forum member and I believe runs Norwood Performance but I sent him a pm a few years back about checking out the shop. He asked that I call him first but said I'm more than welcome to stop by for a tour anytime, I gotta put that on my 'to do list' for 2012.

 

Beautiful car and great job.

But

The dyno chart seems very optimistic at 671 HP and 570 lb/ft out of a NA 5.7 Ferrari V12.

but later claiming 512 HP (a much more realistic number similar to the stock engine rating)

please don't say these are 1960 era engine gross power numbers which nobody uses today.

Ferrari 575M Maranello rated power: 515 PS (379 kW; 508 hp) at 7,250 rpm torque: 588.6 N·m (434.1 lb·ft) at 5,250 rpm

Even an Enzo 6.0 L engine only makes 660 PS (485 kW; 651 hp) at 7800 rpm and 657 N·m (485 lb·ft) at 5500 rpm.

The graph seems like it is just multiplied by 1.5 just for the hell of it. or should I say WOW factor.

 

Back in the Day it was a lot easier to hang in the Pits and meet people.

Years later I ran into him again at Goodwood when I brought my MK-IV and after that once again when I brought P 4/5. We talked about my Lola T-70 and how he'd done aero development on it for Pensky/Donohue and fitted it with a splitter. It was pissing rain the first year we were at Goodwood and he asked me to stay way behind the "vaccume" Chaparall as it threw up a lot of stones and in the rain he was going to go slower that I would.

 

Great story Jim and Jim Hall has always been a hero of mine aswell.

 

Thank you for your complement on our P4. If you were to dyno a 575 Maranello you would see numbers in the 379 kW; 508 hp range but this is not the case here.

This P4 was dynoed on a Dynojet 2 wheel drive unit with the latest software. Dynojet tested and checked the hardware and software (stack) on this unit one week before we ran the P4 on the dyno. We thought the numbers were high as well and asked Dynojet verify the accuracy of the pull we made, the tech at Dynojet said we should have been within 10 HP. Bob has dynoed tons of cars on this type of Dyno, one of the things we noticed is that the car spun up the drum very fast this is an indication of power similar to high power turbo cars.

This P4 has large throttle bodys and open headers (no cats and mufflers) it has a very light flywheel and clutch assembly, 15 lbs total. This P4 has titanium haft shafts, magnesium wheels, light weight tires and does not have power being being robbed from the motor by the power steering & water pump or emission system. Dynojet will no longer let you manipulate the settings of BARO or Altitude so what you get is what it is. The Drum wight is 3200LB and the dyno just calculates how fast you can spin the mass.

 

I must have been thinking of you Tim ^^^^?

 

I'm sure you have a very fine and powerful engine, Jim.

However, respectfully, dynamometers are tuning tools and are not reliable measurement tools for accurately determining a vehicle's "true" power output. This is especially so for naturally aspirated engines as they are greatly affected by the atmospheric conditions in which they happen to be operating.

Dynojet-brand dynamometers are, in particular, notorious for giving falsely high readings that cannot be duplicated with other brand dynamometers or in "real world" conditions. In the drag racing and tuner worlds, Dynojet power figures are so notorious that they are often separately referred to as "DJHP/DJTQ". Mustang-brand dynamometers, in contrast, are on the other side of the spectrum and are known to give some of the lowest readings.

Much has been written about the shortcomings of using drive-on dynamometers for attempting to establish "true" HP/TQ figures and I won't even bother going into all of the physics as it is far more complicated than attempting to figure out how much power is being lost through the drive train.

I will, however, refer readers to a link to Kart Racer magazine that discusses how dynamometers work:

http://www.land-and-sea.com/dyno-dynamometer-article.htm

And here is another link to a grid that discusses the various types (not brands) of dynamometers and the advantages and shortcomings of each:

http://www.land-and-sea.com/dynamometer/dynamometer-comparison.htm

 

thank you Infidel

my concern was the torque number (HP is a derived number based on torque and RPM and the chart does not give RPM just MPH)

a highly tuned non street legal Ferrari 6 liter 599 XX (will put out 720 bhp / 537 KW @ 9000 rpm and only 686 Nm / 506 ft lbs torque) a far cry from the claimed 5.7 liter motor giving 570 LB/FT and I stand by my claim. (~102 MPH on the chart is probably is 5250 RPM)

I don't want to start some flame war but the dyno chart is not accurate Tim.

It is just a tuned 575 engine redone on a poorly calibrated Dyno. I would love to see 2 cars run on THAT dyno to prove my point.

and your claim of "515 HP runs 125 MPH in the 1/4 mile" probably less than 11 seconds in a 1895 lbs car.

Again Beautiful car, great job, just no Shananagans please.

 

Phil,

I am certain that there was no intentional inflation of the power figures on Jim's part. He simply reported the Dynojet readings as they were provided to him.

Unfortunately, it seems Jim is (was) not aware of how unreliable are the power figures provided by drive-on dynamometers in general, and the Dynojet-brand in particular, and he understandably took the reading at face value. Most of us would.

Frankly, the company that performed the tests should have been more forthcoming to Jim about the fact that drive-on dynamometers are intended to be used as tuning tools rather than tools to establish concrete power figures and, consequently, the HP/TQ figures are not to be relied upon.

If one genuinely wants to know how much power is produced by a given engine, you pull the engine and run a series of bench tests with the engine attached at the crank shaft directly to an engine dynamometer, typically an eddy current-type dynamometer. Superflow-brand is the "gold standard" among professional engine builders and developers.

The maximum horsepower and RPM an engine dynamometer can measure is just shy of 3,000 and 15,000 respectively. However, some engines are so powerful (top fuel and funny car drag racing engines, for example, that produce est. @7,000-8,000 HP) that no engine dynamometer exists that is capable of harnessing and measuring the power produced by them. In those cases, the best that can be done is to estimate the level of power through math and physics.

###

 

Thanks for sharing that - I didn't mean to come across pushy with my request, just figured (correctly) that you'd have an interesting story.
So cool that he's still enjoying his creations so many decades after building them... hopefully you'll be doing the same with the P4/5c in 2040+

 

Some previously unseen shots I recently unearthed (taken by a close friends father) at the BOAC 500 on July 30th 1967.

These are:

Chaparal 2F driven by Surtees,
0854 driven by David Piper/Richard Attwood,

and the works P4's:
0856 driven by Ludovico Scarfiotti/Peter Sutcliffe
0858 driven by Jonathan Williams/ Paul Hawkins
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Great Shots!

 

Ferrari is the best car,It has a very nice looking style,and all image is very nice which is shared on this forum.

 

+1

I cannot remember what SN# you have Jim so is yours in those pics??

 

The 412P Coupe in the second photo is one of mine 0854.
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^^^^ Nice!!!

Thanks Jim.

 

fatarnie; fantastic photos. Please consider posting these in the "more old photos" thread in the vintage forum of this site.

thanks!

 

Thinking about this car is keeping me up at night! I had a chat with Tim and think this is just what I am after as originality is not the most important thing to me - just the fun and beauty of the car and I think this has both. 515 hp in a lightweight car will certainly focus the mind - he reckoned it was somewhere between 458/599 fast but much more engaging and visceral.

What do you all think of the longer car? Can you notice it/do you care? It is def longer than the original if you look side by side.

I think would look amazing in black with gold wheels. Unfortunately could only find this model - thoughts?
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Hello & Congratulations on a beautiful accomplishment. Can you please tell me the weight distribution of the car?....& also the weights of each corner of the car...Thanks!...Mark

 

Awesome looking car!!