Porsche 951

[Jon LawesParticipant @jonlawes51698]

StevieGTR,

There are more figures to consider here, such as gearing, co-efficient of drag, weight, and distance you had available. Air density would affect both aerodynamics and efficiency of intercooling and the temperature of the air charge. Wind direction, gradient, tyre pressures, ground clearance, underfloor aerodynamics, following another vehicle and making use of its slipstream. An autobahn is longer than Elvington. Your skyline had (assuming it was the GTR and not a GTS or similar) an additional gearbox, propshaft and drive shafts to spin, presumably fatter rubber, so lots of additional parasitic drag as you are obviously aware. You are obviously aware of these factors as you are a petrolhead from your previously owned cars.

There are certainly enough variables that I wouldn't be decrying the integrity of another forum member.

Edited By Jon Lawes on 13/05/2021 05:25:34

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

hi Steve

Pretty much so although the Cossie hasn't been on the dyno yet, the work has been done by a top outfit or so I'm told, I'm not into Ford's these days so a little out of touch.

As for my own car, very confident in the figures given, I used to be very much involved in the 944 Turbo UK league. Details can still be found on google, back then the car was the 5th most powerful in the league, this was at only 368bhp, the top car being over 400, figures that were proved numerous times on a number of rolling road sessions across the country. Such sessions were closely monitored for the accurate shoot-out setting to ensure we always had factual figures, it's very easy to trick rolling roads. This is going back nearly 15 years and the car has been developed a hell of a lot further since. The last round of upgrades cost over £12k in parts alone, machining is done by Serdi UK. Compared to the guys in the US, my car is only mildly tuned, there are plenty of YT vids with details..

174mph with 282bhp, easy…a few things to note, the 951 came in two guises, the 220bhp with Porsche stats giving it a top speed of 152 and the 250bhp with stats at 162. Now Porsche always gives lower figures than a car actually does, for example, all road tests of the day achieved higher performance figures in both acceleration and top speed, the 220 coming in at 159mph. Ok, so we need to note a few things about Porsche, from day one they did all they could to keep the 951 slower than the 911, at the time they said this was to make the car easier to drive, to do this the boost was allowed to leak long before the car actually hits max boost (which btw was 0.75 and 0.82 bar for the two variants) and the engine was never allowed to hit the redline in higher gears, this is a fact. Even after this attempt by Porsche they themselves admitted in the late '80s, early 90's that the 951 was the fastest car in the fleet, this included the 911 turbo. With A DPW fitted, this alone changes everything and allows a red line in all gears, even without extra power the car will be much faster.

end part 1

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

part 2

The 951 has very long legs, as stated before there are cars in the US with approx 500bhp that have recorded 200mph, as for that matter have cossie Saph's, IIRC at Brungtindon,, sorry can't recall the name of the runway. These things were published in one of the Ford mags a few years back.

Back to the 951, BTW there is a video on YT of a 280 PS 951 doing the ring in just over 8 secs..an impressive bit of driving and at 280, barely tuned. The 174 trip was in a column of cars, a number of which had Sat nav, these are where the speed was recorded, as I said my speedo being the early car maxed out at 170, later cars was 180. The speedo in these cars is out by 6mph from 40mph all the way to max, this has been checked a number of times but as I said, my speedo was bouncing off its pin at the time anyway so not what was used.

I year or so back I had a short run-in with an Audi RS, I never stay at high speed so just play for a few seconds, actually, the last such game was with a new GT3, I had observed him coming up fast in the outside lane, I didn't know it was a GT3 at the time, just that it was a new 911. I waited for his approach, I was doing 95 in fourth, the 951's sweet spot, as he got close I noted he booted it as the car squatted, probably trying to show how good his car was. I waited until he was just about to disappear from my door mirror and then increased power, this was for a few brief seconds only, He got as far as my front wing before my car hit boost and shot past him at over 140 mph at which point I had made my point and backed off. It was only when he passed that I noted the GT3, but then having watched 951's in standard form beat brand new GT3's on the race circuit for some years it didn't surprise me.. BTW, on checking my data log I only actually used 65% throttle, good job the poor GT3 owner wasn't aware of that little fact… I digress,, back to the RS, doing a similar thing to the GT3 but in this case, I missed a gear, not a big deal as I can easily catch but it's what the data log showed and later entered into gear calc that was interesting. I hit 92% throttle, I never rev the engine that high even if it has been designed to do so, max rpm was 7134, this equates to 196mph with the final drive and tyre sizes entered into gear calc, so yes I believe the chaps in the US who have recorded more than 200mph.

The other thing to bear in mind about these cars is they are just as planted on the road at max speed as they are while cruising, something a 911 owner noted while a passenger in my car at 130mph, he couldn't believe the speed due to how solid the car felt, something his own 993 C4 could never do. The aerodynamics of the 951 is leap years ahead of its time, for example, the rear diffuser was the first for any car and is patented for it, this is before such things appeared in F1. IIRC it produces 25kg at 50 mph, ok, not even close to something like the Ferrari F50 but I think you get my point?

There are very few cars on the road in any form that can compete with a well-sorted 951, its handling is supreme and recognised so by those who were involved with racing development in Porsche, giving the early car the highest praise, but then the 951 was a race car before it was a road ca and as I think I pointed out, is a registered Group B race car. It truly is a one of a kind type of car, a very special car and I know many Porsche enthusiasts who have sold their 951 in search of the iconic 911 only to regret it and either sell the 911 for another 951 or own both. When challenged to which is the best though, it's nearly always the 951.

Anyway, that's enough rambling from me, lets just say that I am very confident in the car's ability, it's just after 5:30 am here and I should be asleep..

Cheers

Pete

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Posted by Jon Lawes on 13/05/2021 05:25:02:

StevieGTR,

There are more figures to consider here, such as gearing, co-efficient of drag, weight, and distance you had available. Air density would affect both aerodynamics and efficiency of intercooling and the temperature of the air charge. Wind direction, gradient, tyre pressures, ground clearance, underfloor aerodynamics, following another vehicle and making use of its slipstream. An autobahn is longer than Elvington. Your skyline had (assuming it was the GTR and not a GTS or similar) an additional gearbox, propshaft and drive shafts to spin, presumably fatter rubber, so lots of additional parasitic drag as you are obviously aware. You are obviously aware of these factors as you are a petrolhead from your previously owned cars.

There are certainly enough variables that I wouldn't be decrying the integrity of another forum member.

Edited By Jon Lawes on 13/05/2021 05:25:34

Thanks, John, you just brought up a few points something which I had forgotten…there is no prop shaft on the 951, it has a torque tube which is a direct link between the engine in the front and gearbox (transaxle) in the rear, power loss through geartrain is mush less, yes it loses some through the drive shafts but not a lot. My car is much lower than standard, more than 30mm lower, the staggered tyre setup I have kept at original sizes, bigger tyres generally mean less performance, although they are now the highest speed rating available.

Cheers

Pete

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

hmm.. not sure what happened to the text size in my last reply, sorry about that, hope tis one is better?.. I also forgot underbody aero panels.. the 951 is covered in them which are not only designed to affect downforce but also to direct the lowest pressure of air through the intercooler, the air literally gets sucked in due to the front shape and the underbody panels around the engine.

Pete

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

I was sitting here thinking how can I show just how good a 951 really is as I know many don't believe it until they actually get behind the wheel. So here's the YT vid I mentioned of the 951 with just 280PS, well he says 270-280 , this is with road tyres and from a guy who learnt the circuit on a PlayStation?…..I have no idea of his driving experience, he's clearly switched on if a little mad… but then he's driving a car that can be trusted, you feel when it's near the limit and it's an easy car to correct when required, not something that most other cars can do in similar circumstances.

[Tim StevensParticipant @timstevens64731]

Readers might like to think about a rear-drive car with a torque tube but no prop shaft inside it, resulting in much less power loss. The age of miracles is not dead, indeed.

Regards, Tim

[SteviegtrParticipant @steviegtr]

Posted by Tim Stevens on 13/05/2021 15:45:47:

Readers might like to think about a rear-drive car with a torque tube but no prop shaft inside it, resulting in much less power loss. The age of miracles is not dead, indeed.

Regards, Tim

Tim there is a propshaft inside the torque tube. Connected at the engine end with the clutch. The rear being a transaxle layout. Still the friction, just a nice layout.

Steve.

[SamsarandaParticipant @samsaranda]

I am afraid that the “mystique “ of Porsche cars is lost on me, my son in law owned a 924 and one day I got a phone call from him, he had broken his arm which was in plaster, could I meet him and drive the Porsche home and keep it my garage. I was distinctly unimpressed with the drive home, I found the car very uncomfortable and the ride harsh, maybe I missed something or the car was a bad example, I grant it was at the bargain end of Porsches but it didn’t meet my expectations. If you really want to frighten yourselves then a number of circuits on a real racetrack in an Atom does it for me. Dave W

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Peter Seymour-Howell on 13/05/2021 06:13:03:

hmm.. not sure what happened to the text size in my last reply, sorry about that […]

.

It’s very mundane compared with the car stories, but here goes:

You were replying to Jon … But you did so within your quotation of his post, instead of below it.

The final part of Jon’s post was an Edit, which the forum puts in a smaller font

… and that formatting is carried over to what you are writing.

MichaelG.

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

hmm.. guys.. the shaft does not have the Uj's as found on a car with a prop shaft, hence it loses less power than a car with a prop shaft.. The shaft is also lighter and thus less rolling mass. NO play from the U/J's and lighter makes a big difference on power loss from the engine to gearbox and thus to wheels It's years since I've played around with prop shafts but IIRC they are pretty heavy and large in diameter, 2, perhaps 3 inches? The solid shaft on the transaxle cars is only 1" diameter, ok it sits in a pretty substantial tube but that is not part of the turning mass, a lot of power is lost through a U/J.

BTW this tube adds a lot of strength/rigidity to the chassis, for example, you could remove the body and the rest of the components would remain upright just as with cars with separate chassis and body., it's also a huge safety factor, again IIRC back in the 80's the EU NCAP tried to enforce stricter safety rules in how high a speed, occupants in a car must be able to survive in a head-on crash. Today tests are performed at a speed of 50kph, the 951 was designed for people to be able to survive a head-on crash above 60 mph, nearly twice the speed of tests performed today. IIRC, only two vehicles ever passed this test before it was dropped as too ridiculous a requirement to put on manufactures. Before this was dropped only two cars passed this stricter test, the 944/951 and I believe the Renault 5 turbo, coincidentally both Homologated as Group B race cars.. This particular feature of the car is fairly new to me so please forgive me if I have any of this incorrect, I don't have the notes in front of me.

I know people who have been involved in very high-speed head-on crashes in a 951 and walk away with little injury, try doing that in any other car from any other period. The secret of the design is the torque tube casing having substantial steel claws which in a crash, grip the chassis tunnel and thus helping to stop the cabin from being squashed in a head-on crash, simple but clearly effective.

Regards

Pete.

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Posted by Michael Gilligan on 13/05/2021 17:51:57:

Posted by Peter Seymour-Howell on 13/05/2021 06:13:03:

hmm.. not sure what happened to the text size in my last reply, sorry about that […]

.

It’s very mundane compared with the car stories, but here goes:

You were replying to Jon … But you did so within your quotation of his post, instead of below it.

The final part of Jon’s post was an Edit, which the forum puts in a smaller font

… and that formatting is carried over to what you are writing.

MichaelG.

Thanks for explaining that Michael..

regards

Pete,

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Posted by Samsaranda on 13/05/2021 17:38:02:

I am afraid that the “mystique “ of Porsche cars is lost on me, my son in law owned a 924 and one day I got a phone call from him, he had broken his arm which was in plaster, could I meet him and drive the Porsche home and keep it my garage. I was distinctly unimpressed with the drive home, I found the car very uncomfortable and the ride harsh, maybe I missed something or the car was a bad example, I grant it was at the bargain end of Porsches but it didn’t meet my expectations. If you really want to frighten yourselves then a number of circuits on a real racetrack in an Atom does it for me. Dave W

Sorry, I missed this one.. the 951 is leagues away from the humble 924, that's like comparing a racehorse to a mule, mind you, it does have a lower drag co-efficient at only 0.30…

Pete

[SamsarandaParticipant @samsaranda]

Was commenting on the Porsche as a marque and not being dazzled by its “mystique”, are 924s not from the same stable! Dave W

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Posted by Samsaranda on 13/05/2021 19:02:03:

Was commenting on the Porsche as a marque and not being dazzled by its “mystique”, are 924s not from the same stable! Dave W

Hi Dave

The 924 was originally a joint venture between VW and Porsche during the 70's. VW was forced to pull out, I think this was the time of the fuel crisis and they decided that launching a new sports car might not be a good idea. Porsche had put a lot of time and money into this design and thus not wanting to lose that investment launched the car under the Porsche badge. this is why the 924 was seen as the poor man's Porsche and not a true Porsche, although a lot of Porsche was in the design the engine wasn't Porsche and that's sacrilege to Porsche fans. It had an engine originally found in the Audi 100 cars and VW LT vans although it was redeveloped by Porsche techs to increase power a little. The 944 which shared the basic chassis is a different car altogether with a true Porsche engine that was years ahead of its time, it first saw action on the race track at Le Mans, it was a race car, a very successful race car that became a road car.

Pete

[Robert Atkinson 2Participant @robertatkinson2]

Nice car,

I had an early 932 (S1 924 Turbo) for many years. Great little car. A liittle old lady drove into the side of me on a roundabout and the insurance wrote it off . They refused to honour the agreed value (PCGB valuation). Obudsman won't deal with "valuation" disputes dispite this was insurance denying an agreed valuation. After a lot arguing and further damage while they had it in storage I gave up. At least someone bought it at the auction as it's still on road according to the DVLA.

Robert G8RPI.

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Posted by Robert Atkinson 2 on 13/05/2021 19:25:26:

Nice car,

I had an early 932 (S1 924 Turbo) for many years. Great little car. A liittle old lady drove into the side of me on a roundabout and the insurance wrote it off . They refused to honour the agreed value (PCGB valuation). Obudsman won't deal with "valuation" disputes dispite this was insurance denying an agreed valuation. After a lot arguing and further damage while they had it in storage I gave up. At least someone bought it at the auction as it's still on road according to the DVLA.

Robert G8RPI.

Sorry to hear this Robert, the 932 is a great car and has risen in value a lot recently. A bit concerned to hear your insurance company wouldn't honour the PCGB valuation, that should be sacrosanct? I'm with Lockton's under the PCGB scheme, they keep increasing the value and suggested it may need to increase again. On their advice it's set at market value, the reason being that the prices are increasing so fast that I could lose out if on an agreed value. I keep meaning to get a PCGB valuation just in case values stabilise and for any future dispute should an accident happen. These cars cost a small fortune to repair in body panels…

Pete

[SamsarandaParticipant @samsaranda]

Hi Pete

thanks for the clarification, explains why my impression of the Porsche marque was a bit jaded, 924 not a true blue Porsche! Dave W

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Posted by Samsaranda on 13/05/2021 21:01:00:

Hi Pete

thanks for the clarification, explains why my impression of the Porsche marque was a bit jaded, 924 not a true blue Porsche! Dave W

well I don't believe it isn't a true Porsche per se….without the 924 and then 944 series, Porsche wouldn't be here today, the purists seem to forget this fact…

[Robert Atkinson 2Participant @robertatkinson2]

Posted by Peter Seymour-Howell on 13/05/2021 19:35:08:

Posted by Robert Atkinson 2 on 13/05/2021 19:25:26:

SNIP

Sorry to hear this Robert, the 932 is a great car and has risen in value a lot recently. A bit concerned to hear your insurance company wouldn't honour the PCGB valuation, that should be sacrosanct? I'm with Lockton's under the PCGB scheme, they keep increasing the value and suggested it may need to increase again. On their advice it's set at market value, the reason being that the prices are increasing so fast that I could lose out if on an agreed value. I keep meaning to get a PCGB valuation just in case values stabilise and for any future dispute should an accident happen. These cars cost a small fortune to repair in body panels…

Pete

Hi Pete,

The issue was the insurance company was taken over by a bigger one a couple of years previously and the new company "don't do agreed value". This is despite them renewing the policy without issuing new T&Cs.
It was all a bit of a nightmare. I'm pretty certain it was part of a deliberate policy to get rid of the classic car business. I wasn't in a position at the time to buy the salvage and get the work done myself.

Robert G8RPI.

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Posted by Robert Atkinson 2 on 13/05/2021 21:49:35:

Posted by Peter Seymour-Howell on 13/05/2021 19:35:08:

Posted by Robert Atkinson 2 on 13/05/2021 19:25:26:

SNIP

Sorry to hear this Robert, the 932 is a great car and has risen in value a lot recently. A bit concerned to hear your insurance company wouldn't honour the PCGB valuation, that should be sacrosanct? I'm with Lockton's under the PCGB scheme, they keep increasing the value and suggested it may need to increase again. On their advice it's set at market value, the reason being that the prices are increasing so fast that I could lose out if on an agreed value. I keep meaning to get a PCGB valuation just in case values stabilise and for any future dispute should an accident happen. These cars cost a small fortune to repair in body panels…

Pete

Hi Pete,

The issue was the insurance company was taken over by a bigger one a couple of years previously and the new company "don't do agreed value". This is despite them renewing the policy without issuing new T&Cs.
It was all a bit of a nightmare. I'm pretty certain it was part of a deliberate policy to get rid of the classic car business. I wasn't in a position at the time to buy the salvage and get the work done myself.

Robert G8RPI.

ah ok, sorry to hear that, I would hope that Lockton's would honour all policies, after all, they are the official PCGB sponsor and specialise in Porsche, Ferrari and Aston cars. They have diversified over the last few years to other forms of insurance but it would be very bad business for them to not honour a club member car. They are also the cheapest that I have found, they cover mods too.

Hope you find another car in the future, they are worth the heartache…IMHO, of course.

Pete

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

I hope that I'm not boring you all with this video, I thought it might show better what I was saying about the 951. Car is pulling 0.95 Bar of boost so only very slightly modified, faster than the other video, and better controlled. In his comments, he has recorded sub 8 secs a number of times which I can believe as he's held up a number of times due to bikes getting in the way. I would never drive like this today, I doubt that I have the skill now, far too old but it does pose the question of how fast this guy could get around the ring with the 1.5BAR that my car has under the bonnet The good thing about this video is it shows speed and gravity forces, plus an overall of position on the circuit. ..

Hope it's of interest to some

[Peter Seymour-HowellParticipant @peterseymour-howell39349]

Today I took the old girl for her MOT, all good again for another 12 months, well 13 actually as I took her in early. The picture was taken at my son's place a short while before the test. emissions are still very, very low, the engine is clearly in top condition. C0= 0.32% and HC = 49ppm, those in the know will know that a pass for my model year is 4.5% and 1200ppm respectively. I must get out and drive her more though, only covering 2090 miles, mind you that's nearly double of last year so I'm going in the right direction. Next job….. fresh paint…

Pete

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