oldtimer
PCGB Member
I have been asked by a few people about how my 'new' 964 trackcar compares with my 'old' 964RS lightweight ( 'carpet') .
So here is an initial analysis based on a few weeks of ownership , but only about 100 road miles and about 100 track miles.
The weights are roughly comparable .
On the scales at Oulton Park 21-7-10, 964RS weighed 1265kg with 3/4 of a 90 litre tank , spare tyre , tools , helmet .
On same scales 17-2-12 , 964 weighed 1242kg with 1/3 of a 70 litre tank , spare tyre , tools , helmet .
As a check data point , the 964 corner weights totalled 1250kg when Unit11 set it up 1-3-12 after fitting a primary silencer.
Both cars have a full steel cage , lightweight carpet , the 964RS was made lighter at the factory with thinner glass and very little equipment added , the 964 was stripped out towards a target of under 1200kg empty fuel tank.
The 964 trackcar's engine is more powerful
Both the later 1992 RS engine and the early 1990 C2 engine had ECUs remapped by the same person (!) Wayne Schofield and measured on the same rolling road(!!) . The 964 has standard alloy induction system and standard airflow meter but rebuilt 2011 with Cup cams , RS flywheel , pistons lightened , bigger oil pump , cases gas flowed and live remapped by Wayne Schofield for 315 bhp / 295 ft-lb.
The 964RS on the same dyno in 2001 was measured at 290 bhp after Tech9 had fitted 993 hot-film airflow meter and a younger Wayne had remapped the ECU.
On the road the 964 feels fast and throttle response is immediate , however it does seem to be quite a bit thirstier !
Not enough seat time on the track to judge whether the extra power makes a difference for me , and until I get used to the difference in handling- and in brake performance - it probably wont !
The 964RS brakes are more powerful
I used aggressive pads on the RS , Pagid RS29s in recent years , and before that Pagid Blacks , Pagid Greys , and even some Japanese Carbonetix pads. In combination with the high pressure brake booster , all of these gave rapid bite and the car never felt underbraked. The downside was cracking of discs and also warping of discs.
The 964 has big 993 "˜two-piece' turbo discs and callipers front , 964RS discs and callipers rear , with 993 master cylinder , vacuum boost. Pads are Textar all round . The bite is not as immediate , probably because the pads are not as aggressive , deceleration does not feel as rapid , however the car does not feel underbraked . I will probably stick with the Textar pads to assess whether disc life is improved !
The suspension/ set up are different!
The 964 was built up for hillclimb and sprint . In particular the front ride height was higher than RS as a "˜bump steer' elimination measure. Center Gravity had done a custom set-up for the previous owner.
The 964 has 993GT2 struts , tie rods and hub carriers fitted , with 964RS ARB , and solid RS monoball top mounts drilled out to make adjustments to KW Clubsport coilover suspension legs.
Rear suspension uses KW Clubsport with KW monoball top mounts , and 964RS ARB.
All suspension bushings replaced with Powerflex bushes.
The 964RS had revalved 993 Cup front shockers and front polybushes , otherwise standard with standard settings.
On the road the 964 feels a bit skittish and more interested in following "˜tramlines' , however the "˜light feel' of the power-assisted steering is probably a significant part of that. Turn-in is pretty sharp , there is probably a bit less understeer , but not enough track time yet to confirm this "" based on using same actual set of 17 inch wheels + Toyo R888 tyres between both cars.
Conclusions to date
The biggest change for me is the effect of power assisted steering . After 10 years of wrestling with the LHD RS on sticky tyres , this pensioner was ready for some R&R ! The 964 is not an RS..but it's a pretty good example of what a 911 is all about, with less downside if you 'bin it' on circuit .....[
]
So here is an initial analysis based on a few weeks of ownership , but only about 100 road miles and about 100 track miles.
The weights are roughly comparable .
On the scales at Oulton Park 21-7-10, 964RS weighed 1265kg with 3/4 of a 90 litre tank , spare tyre , tools , helmet .
On same scales 17-2-12 , 964 weighed 1242kg with 1/3 of a 70 litre tank , spare tyre , tools , helmet .
As a check data point , the 964 corner weights totalled 1250kg when Unit11 set it up 1-3-12 after fitting a primary silencer.
Both cars have a full steel cage , lightweight carpet , the 964RS was made lighter at the factory with thinner glass and very little equipment added , the 964 was stripped out towards a target of under 1200kg empty fuel tank.
The 964 trackcar's engine is more powerful
Both the later 1992 RS engine and the early 1990 C2 engine had ECUs remapped by the same person (!) Wayne Schofield and measured on the same rolling road(!!) . The 964 has standard alloy induction system and standard airflow meter but rebuilt 2011 with Cup cams , RS flywheel , pistons lightened , bigger oil pump , cases gas flowed and live remapped by Wayne Schofield for 315 bhp / 295 ft-lb.
The 964RS on the same dyno in 2001 was measured at 290 bhp after Tech9 had fitted 993 hot-film airflow meter and a younger Wayne had remapped the ECU.
On the road the 964 feels fast and throttle response is immediate , however it does seem to be quite a bit thirstier !
Not enough seat time on the track to judge whether the extra power makes a difference for me , and until I get used to the difference in handling- and in brake performance - it probably wont !
The 964RS brakes are more powerful
I used aggressive pads on the RS , Pagid RS29s in recent years , and before that Pagid Blacks , Pagid Greys , and even some Japanese Carbonetix pads. In combination with the high pressure brake booster , all of these gave rapid bite and the car never felt underbraked. The downside was cracking of discs and also warping of discs.
The 964 has big 993 "˜two-piece' turbo discs and callipers front , 964RS discs and callipers rear , with 993 master cylinder , vacuum boost. Pads are Textar all round . The bite is not as immediate , probably because the pads are not as aggressive , deceleration does not feel as rapid , however the car does not feel underbraked . I will probably stick with the Textar pads to assess whether disc life is improved !
The suspension/ set up are different!
The 964 was built up for hillclimb and sprint . In particular the front ride height was higher than RS as a "˜bump steer' elimination measure. Center Gravity had done a custom set-up for the previous owner.
The 964 has 993GT2 struts , tie rods and hub carriers fitted , with 964RS ARB , and solid RS monoball top mounts drilled out to make adjustments to KW Clubsport coilover suspension legs.
Rear suspension uses KW Clubsport with KW monoball top mounts , and 964RS ARB.
All suspension bushings replaced with Powerflex bushes.
The 964RS had revalved 993 Cup front shockers and front polybushes , otherwise standard with standard settings.
On the road the 964 feels a bit skittish and more interested in following "˜tramlines' , however the "˜light feel' of the power-assisted steering is probably a significant part of that. Turn-in is pretty sharp , there is probably a bit less understeer , but not enough track time yet to confirm this "" based on using same actual set of 17 inch wheels + Toyo R888 tyres between both cars.
Conclusions to date
The biggest change for me is the effect of power assisted steering . After 10 years of wrestling with the LHD RS on sticky tyres , this pensioner was ready for some R&R ! The 964 is not an RS..but it's a pretty good example of what a 911 is all about, with less downside if you 'bin it' on circuit .....[
]
