18 aug 2009 22:08
Diablo schreef:Leg eens uit?
18 aug 2009 22:09
axe schreef:Mij hebben ze gisteren verteld dat de constructie van een G50 volledig anders is dan een gewone (veel grotere klok enzo...)
En als ik het niet misverstaan heb... De overbrenging van de versnellingsbak naar de achteras ook een andere constructie... (Dit maakt dan ook het gewichtverschil)
correct me if i'm wrong
18 aug 2009 22:11
cabrio wim schreef:Diablo schreef:Leg eens uit?
Bedoeld waarschijnlijk haar 2 x beentjes.![]()
19 aug 2009 12:00
Where do you get the 30kg weight from? Most often folks quote the 1210kg vs 1250kg weight difference as the difference between 915 3.2s and G50 3.2s, but the standard spec of the car changed as well as the gearbox changing so the difference in gearbox weight is not 40kg.
In fact its 13kg according to the weighting scales like for like and nearly half that weight difference is in the clutch. Put like for like clutches on and there is very little difference in weight.
There is also a slight gearing difference that favours the 915 for track driving. Fact is that the G50 offers 240mm hydraulic clutch, modern synchros and an internally gated shift. It is a technically better gearbox, fullstop. Sure, people are still entitled to prefer the 915 because it has character, is fractionally lighter, has fractionally shorter gears and may be in better condition due to a recent rebuild, but that doesn't make it a better gearbox, just a subjectively preferred gearbox. The buy on condition advice still stands, though the newer gearboxs are generally in better condition absent rebuilds.
[quote name='Richard Bernau' ]
Came across this on Pelican looking into the respective weights - its from Pete Zimmerman. Funnily, I was quoted in this regard as well, but this is as definitive as I have seen and also goes on to mention gearing. I maintained 27lbs difference, Tyson says 25lbs and Pete Zimmerman says 27lb - call it 12-13kg :
Let's look at this a little closer. The weight of a filled 915 RoW version 915/67 with cooler is approximately 60 kg (132 lbs). The cooler weighs almost nothing (I can testify to this because I've cleaned a number of them), so let's call the USA 915/68 at 130 lbs. The weight of a filled RoW G 50 version 950/00 is 66 kg (146 lbs), which is virtually identical to the USA version 950/01. So we have a weight difference between the two transmissions of 16 pounds [8 kilos].
The 915 flywheel weighs 12 lbs, and so does the G 50 flywheel, so that's even.
The stock 915 clutch weighs 18 lbs, the G 50 clutch weighs 29 lbs. So, in total, the G 50 package is approximately 27 lbs heavier, which was offset (in 1986) by an increase in rear torsion bar size from 24.1mm to 25mm. Something else comes into play here that contributes to the 915 car "feeling quicker" to some drivers. Back in the day of Hemi-Cudas, 427 Vettes, etc., the ticket to really quick quarter mile times was having a "short", 4.11 rear end (final drive) ratio, or an even shorter 4.56 ratio. Of course, the big compromise with a short ratio was having to run at much higher revs at freeway speeds. Cars with a taller, aka longer, 3.00, or 3.30 rear end (ring & pinion ratio) just wouldn't come out of the hole as quick, and the race was usually over in 2nd gear. In 1974, 911s were fitted with a 7:31 ring & pinion, which is a final drive ratio of 4.43 (remember, the bigger the number the shorter the ratio). Later SCs and early Carreras w/915s had an 8:31 (3.88) final drive ratio, BUT, G 50s are fitted with a 9:31 (3.44) final drive ratio. Yes, the factory fitted all new, "shorter" ratios to 1st-5th to try and make up for it, but, while striving for better mileage and reliability, couldn't overcome that "longer" ring and pinion, which can make, combined with the extra pounds, a G 50 car feel more sluggish than a 915 car. A lightweight clutch will help the G 50 car, but on a road course there should be very little difference between the two because the rpm drop between second and third, between third and fourth, and between fourth and fifth, is very similar when comparing a 915 to a G 50. Yes, the 915, in some situations, will "feel" quicker, but can it generate quicker lap times on a road racing course? I doubt it.
As I have said before, if you put a spring centred clutch in a G50 you can get back to equivalent clutch weights. Add a LW flywheel and alley pressure plate and you may be equivalent all in or even a tad lighter than a std 915.
RB
20 aug 2009 11:38
20 aug 2009 20:28
20 aug 2009 22:20
Eric 3.2 schreef: maar je moet ouderwets 'roeren' bij het schakelen.
20 aug 2009 22:37
21 aug 2009 1:30
Eric 3.2 schreef:Ander groot voordeel van de 915 is de achterlichtbalk met de zwarte PORSCHE-letters (zònder rommelig 'loshangend' achtermistlicht!), hetgeen ik persoonlijk veel mooier (meer cult, jaren '80-look) vind dan de rode G50-balk (met ingebouwde achtermistlicht).
21 aug 2009 6:48
Eric 3.2 schreef:De jouwe is vast die ene regel die de uitzondering bevestigt haha.
21 aug 2009 7:53
21 aug 2009 19:20
23 aug 2009 10:36
cabrio wim schreef:Had vandaag nog iemand verwacht, maar waarschijnlijk was het druk op het naaktstrand.![]()
23 aug 2009 10:38
cabrio wim schreef:Had vandaag nog iemand verwacht, maar waarschijnlijk was het druk op het naaktstrand.![]()
23 aug 2009 10:43