| Author |
Message |
    
Patrick Lockyer.
Grand Master
Username: pat_lockyer
Post Number: 294
Registered: 9-2004
| | Posted on Friday, 04 February, 2005 - 23:52: |    |
Perfect cold weather and morning testing high speed runs,Crumbs that was a suprise first run up to 120mph and still climing how much can we get out of LPG.
A quick stop and some manual ajustments and still more.
so more of course to come.
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Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 552
Registered: 4-2003
| | Posted on Saturday, 05 February, 2005 - 00:33: | |
Interesting.
If you look back on a few 1970s long-term Silver Shadow tests on Europe's unrestricted highways, there were often complaints from the testers that these cars could easily overspeed. With their 3.08 final drive, the maximum engine speed of 4,500 RPM is achieved at 120 mph on full throttle and a little converter slip. If you back off on the gas a little, less converter slip means that 125mph is the highest safe speed for the motor. Maybe that is why there is no tachometer afterall. I know of some Shadows converted to the early Turbo 2.69:1 ratio for this reason. Speeds we can only dream of in Australia. |
Patrick Lockyer.
Grand Master
Username: pat_lockyer
Post Number: 295
Registered: 9-2004
| | Posted on Saturday, 05 February, 2005 - 05:59: | |
This is tops.
Water injection may improve but no more till i do the rear end mods.
Tyre pressures 40lbs vrs ,air con off.
air vents closed down
Stainless exhaust,less back pressure more noise though.
At this speed i have the dreaded wind noise.
Is it pressure inside or suction outside, high or low pressure?.
secondry door seals, maybe.
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Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 553
Registered: 4-2003
| | Posted on Saturday, 05 February, 2005 - 06:27: | |
This giant is sleeping here, but he does have secondary door seals on all four doors and no wind noise when trundling down the motorway at a very gentle 110 clicks on the legal limit.
Note the export gear selector end knob. The cruise control switches are visible, located on the left beneath the main dashboard segement. The year after this car, the B on the speedo sadly disappeared and was replaced by an R-R one. This car was delivered with R-R bages everywhere else: motor, Australian (ADR) compliance plate marked Silver Shadow and all, apart from the main winged badges.
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Robert Chapman
Grand Master
Username: shadow
Post Number: 166
Registered: 5-2003
| | Posted on Saturday, 05 February, 2005 - 19:21: | |
Gentlemen,
Something even more important from a Shadow, than top speed is pulling .9G from 100kph, now thats impressive.Vic-roads RWC requirement is .4G from 20 kph!
Patrick, will your 500bhp twin turbo engine be LPG fueled and what will be its safe engine speed? |
Patrick Lockyer.
Grand Master
Username: pat_lockyer
Post Number: 297
Registered: 9-2004
| | Posted on Saturday, 05 February, 2005 - 19:34: | |
Yes Robert we have 70 mph speed limit on motorways.
Any testing is off road,ie private track or ofcourse runways. |
John Dare
Grand Master
Username: jgdare
Post Number: 163
Registered: 12-2004
| | Posted on Sunday, 06 February, 2005 - 10:25: | |
I trust that these ambititous 125 mph early/mid 70s Shadows (LPG or Petrol) are fitted not only with appropriately speed rated tires, but more importantly, front spoilers (a la SS11 etc) so that these bespoke touring cars dont begin to believe that they are aeroplanes as they approach runway lift off speeds. Probably not much chance of that though, given the bluff frontal and overall "angular" shape of the dated Shadow/Spirit genre compared to say that of the Bentley Continental GT or even the preceding Seraph/Arnage series. I submit, that at the theoretical, indicated road speeds being optimistically advanced, these poor old groaning, straining and heavy cars behave more like old windjammers heading a fierce sou' wester, due to the face which their blunted "aerodynamics" present to the challenging and ultimately dominant wind; see "air resistance". In any event, at, or within the 4500 rpm "range", I would certainly install (as I indeed have) an oil pressure gauge in preference to an ammeter, and (for a Shadow) a rev. counter also, as per Corniche. Additional instruments, incl. a known accurate coolant temp. gauge (ALL checked for calibration of course!) might assist at the eng./road speeds being approached, as I suspect that whilst attempting to focus and activate a camera, one could, at their moment of historical conquest, become arithmetically confused by ratios, revs, tire size, convertor slip, incl. misc. frictional losses and other opposing factors. Such distractions could lead to disorientation, the results of which could well prove to be fatal, either upon a "test" track or (worse) via a public road. |
Patrick Lockyer.
Grand Master
Username: pat_lockyer
Post Number: 299
Registered: 9-2004
| | Posted on Sunday, 06 February, 2005 - 18:57: | |
JD. Not just the correct speed rated tyres are needed but the load index number must be correct for the car.
I would sure agree that an old dog of a car as you describe groaning and straining with the carbon and slugde floating around at speed within the engine sump would need all the instruments you could put on the car.
Even then i would not be happy to run a car as such.
As you may now be aware my car is grace and space with true pace.
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Robert Chapman
Grand Master
Username: shadow
Post Number: 167
Registered: 5-2003
| | Posted on Thursday, 10 February, 2005 - 19:55: | |
Hi Patrick,
Sorry but I dont understand you post of the 05/02 in answer to my question of the same date,which was will the 500bhp engine you are building be LPG fueled? |
Patrick Lockyer.
Grand Master
Username: pat_lockyer
Post Number: 308
Registered: 9-2004
| | Posted on Thursday, 10 February, 2005 - 20:30: | |
Robert, No not lpg. |
Robert Chapman
Grand Master
Username: shadow
Post Number: 168
Registered: 5-2003
| | Posted on Thursday, 10 February, 2005 - 21:14: | |
Patrick ,
You must have something up your sleave to get this much power,what will it run on?
I recon it must be nitrous oxide injected to get this much power. |
John Dare
Grand Master
Username: jgdare
Post Number: 176
Registered: 12-2004
| | Posted on Thursday, 10 February, 2005 - 21:48: | |
That might be right since nitrous oxide is more commonly known as "laughing" gas. A 500+hp R-R V8 would need PLENTY of that! |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 564
Registered: 4-2003
| | Posted on Thursday, 10 February, 2005 - 22:12: | |
To be fair, 74HP/Litre is not really a big ask for a special motor. Even an Opel can be ordered with a stock 2 Litre 150HP motor.
The 6230cc motors were designed, developed and tested in the 1950s at 600HP even without the late 1980s cross-bolted crankcase. As for driveability and reliability, who knows, but the late single turbo cars were delivered with 420HP, not far off the mark, and that with full warranty etc.
I assume some wild camshaft will be at the heart of it.
Robert, if you are interested, in another thread I could post the drawings and lift/duration specifications of my R-Type camshaft as modified, along with the necessary new valve spring data. As part of the package, it made quite a marked improvement to power and torque. Of course, starting off with around 33HP/Litre, there was plenty of room for an easy improvement there. And, yes, I still have the original camshaft and springs put away.
RT. |
John Dare
Grand Master
Username: jgdare
Post Number: 178
Registered: 12-2004
| | Posted on Thursday, 10 February, 2005 - 22:47: | |
Thank you RT. I take your point re bhp/litre available from modern engines such as the "Opel" etc. Most of us obtain our initial information from reference books and although I have read most of the "common" works, I have never read any reference suggesting that the original S2 "R-R" V8 of 1959/60, was designed, developed and tested during the 50s (in its BASIC configuration) to 600bhp. If you have any reference material to support this I would be GENUINELY interested in receiving details to file for future historical purposes. I am not suggesting that what you advance is UNTRUE, but rather remain sceptical of the claim, given that the original production S2 V8 suffered such a basic fault as inadequate camshaft lubrication. I would have thought that such a failing would have been addresed at some point between 1953 and 1959. |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 566
Registered: 4-2003
| | Posted on Thursday, 10 February, 2005 - 22:52: | |
JD: I'll find the article. It think it's on the RREC site. It covers development and testing, and also outlines which US companies assisted and how. It explodes a few myths about the design origins.
RT. |
Robert Chapman
Grand Master
Username: shadow
Post Number: 169
Registered: 5-2003
| | Posted on Friday, 11 February, 2005 - 22:01: | |
Richard T,
Thank you, yes I would be very interested in the camshaft figures.
I would like to feed them into my computer engine modelling program ,this will show where the torque and bhp gains are made.
(Did you happen to do any before and after dyno testing).
It will also print a comparative superimposed graph.
I have modified several engines using cam spec's and other mod's simulated on this program and to date it has been within 5% accurate when tested on the real dyno.
The first one was a carburettered Spirit when we had that half lead fuel(low octane) rubbish and was limited by compression and a brief not to drastically change the under bonnet apearence, but it still managed to give us comparable performance to an injected Spirit.
There were quite a few changes needed but the results were worth it.
This is why I am so interested in Pat's mod's, (come on Pat spill the beans). |
Richard Treacy
Grand Master
Username: richard_treacy
Post Number: 568
Registered: 4-2003
| | Posted on Friday, 11 February, 2005 - 23:07: | |
Robert,
I shall post theexact engine data under Mk VI & R-Type. I need to scan some of my sketches first
RT. |