AutoZeitung 991 GT3 vs Turbo S test
#17
Read that article too, a few observations:
- interestingly, during their test cycle the Turbo S was not more fuel efficient than the GT3, that included of course driving under full load, they state that both vehicles consumed almost the same amount by 0.1 liter/km (discussed in the 'engine/gearbox' section) and that the Turbo S missed the manufacturer claimed figure. GT3: 14.0 liter/100kms Turbo S: 14.1 liter/100 kms.
- the GT3 was markedly faster in corners than the Turbo S that caught the GT3 on the straights.
- in the conclusion section ("Fazit"), they explain that the Turbo S won for being a better 'all rounder' but they also state that verbatim (in German, of course) "every meter in the GT3 was a revelation. No other 911 was ever faster around the track and at the same time safer at the limit than the GT3. It is the current benchmark for the entire sportscar elite".
- interestingly, during their test cycle the Turbo S was not more fuel efficient than the GT3, that included of course driving under full load, they state that both vehicles consumed almost the same amount by 0.1 liter/km (discussed in the 'engine/gearbox' section) and that the Turbo S missed the manufacturer claimed figure. GT3: 14.0 liter/100kms Turbo S: 14.1 liter/100 kms.
- the GT3 was markedly faster in corners than the Turbo S that caught the GT3 on the straights.
- in the conclusion section ("Fazit"), they explain that the Turbo S won for being a better 'all rounder' but they also state that verbatim (in German, of course) "every meter in the GT3 was a revelation. No other 911 was ever faster around the track and at the same time safer at the limit than the GT3. It is the current benchmark for the entire sportscar elite".
peter
#18
Rennlist Member
Join Date: Feb 2006
Location: Wishing I Was At The Track
Posts: 13,663
Received 1,889 Likes
on
973 Posts
Wider rear body for Turbo allowed increase from 1.5 in GT3 to 2.8 in Turbo. Porsche seems to think more is better with RWS, at least up to 2.8. Given RS is expected to use wider Turbo S bodywork we're likely to see 2.8 there as well assuming they keep RWS.
#20
Rennlist Member
Join Date: Feb 2006
Location: Wishing I Was At The Track
Posts: 13,663
Received 1,889 Likes
on
973 Posts
They didn't increase the RWS to compensate for the wider body, if that's what you're asking. The wider body allowed engineers to increase RWS - they want more RWS, again at least up to 2.8 seen on Turbo, regardless of body width. The wider body on the Turbo allowed them to do that, hence my comment that there's a good chance we'll see the same if the RS has both the wider body and RWS as speculated. Still unclear whether 2.8 applies to both low and high speed application.
Last edited by Nizer; 11-11-2013 at 11:08 AM.
#21
Race Director
The Porsche web site says up to 3 degrees for the Turbo.....
#22
A few different theories why this could be the case, speculation on my part:
1. The PZero street tires probably need a slightly larger slip angle than the GT3s semi-slicks to build up the same cornering side-loads. This would be due to the Turbo S's heavier weight, more tread block squirm on the street tires, and the Turbo S's slightly narrower rim. It would make sense that the Turbo's RWS would need more angle to tune for that.
2. The GT3's rear wing might produce more downforce, planting the rear end and thus requiring less additional stabilization from the RWS at speed.
3. The GT3 might be tuned to have a more neutral high speed balance suitable for a track car, while the Turbo might be tuned for slightly more high speed understeer more suitable for a road car.
It will be interesting to see what comes on the RS. If #1 and #2 above are correct, and if the RS gets even wider rubber (and hence less slip angle), then the RS might get less RWS than the GT3, not more. We'll see...
1. The PZero street tires probably need a slightly larger slip angle than the GT3s semi-slicks to build up the same cornering side-loads. This would be due to the Turbo S's heavier weight, more tread block squirm on the street tires, and the Turbo S's slightly narrower rim. It would make sense that the Turbo's RWS would need more angle to tune for that.
2. The GT3's rear wing might produce more downforce, planting the rear end and thus requiring less additional stabilization from the RWS at speed.
3. The GT3 might be tuned to have a more neutral high speed balance suitable for a track car, while the Turbo might be tuned for slightly more high speed understeer more suitable for a road car.
It will be interesting to see what comes on the RS. If #1 and #2 above are correct, and if the RS gets even wider rubber (and hence less slip angle), then the RS might get less RWS than the GT3, not more. We'll see...
#23
Race Car
Join Date: Apr 2005
Location: With A Manual Transmission
Posts: 4,728
Likes: 0
Received 2 Likes
on
2 Posts
The GT3 is faster in the corners because it has stickier tires. This looks like ~2 second gap on equal tires.
The AWD on the Turbo requires more effort to mitigate understeer. It's likely the GT3 simply required less effort while the safety factor of AWD also allows for more rotational input from the rear wheels since the fronts are driven too and can be used to essentially pull the car through the turn. AWD grants a much bigger safety net.
They tuned it just enough to make it slower than the GT3 all things considered (tires mostly). If Porsche wanted to, they could easily have made this car a low 7:1x at the ring. But it doesn't fit their business model.
The AWD on the Turbo requires more effort to mitigate understeer. It's likely the GT3 simply required less effort while the safety factor of AWD also allows for more rotational input from the rear wheels since the fronts are driven too and can be used to essentially pull the car through the turn. AWD grants a much bigger safety net.
They tuned it just enough to make it slower than the GT3 all things considered (tires mostly). If Porsche wanted to, they could easily have made this car a low 7:1x at the ring. But it doesn't fit their business model.
#24
Race Director
exactly. the upcoming gt3rs and gt2 must all fall inline to fit the Biz model
#25
The way I understand it is that the Turbo RWS in the same direction (above 50 mph) is 1.5 degrees like the GT3's. When RWS operates in the opposite direction (below 30mph), it allows 3 degrees. So on track, they are the same.
#26
What's crazy is that they are so effective at doing that while still making the most compelling sports cars out there.
#27
Burning Brakes
Hard to call any tire that sets a new track record a "Crap Tire"
Been driving them on the track for many years. Not as good as R compound
and perhaps some of the newest street tires, but very predictable and hardly "Crap" IMHO.
Been driving them on the track for many years. Not as good as R compound
and perhaps some of the newest street tires, but very predictable and hardly "Crap" IMHO.
#28
Burning Brakes
Perhaps, but the new compounds are worlds beyond the decade old tech of the Pirelli. Why pay same money for worse tire. That's my point.
#29
Race Director
Thanks to the new rear-axle steering which is fitted as standard, everyday practicability and performance have both been equally increased. The system consists of two electromechanical actuators fitted on the rear axle instead of the conventional tie rod. It therefore steers the rear wheels of the new 911 Turbo models from +3 to –1.5 degrees in the same or opposite direction as the steering angle on the front axle, depending on speed.
#30
Maybe I'm confused by the way it's worded, but I read the Porsche description as just the opposite: up to 3 degrees above 50mph and 1.5 degrees below 30. Am I wrong?
Thanks to the new rear-axle steering which is fitted as standard, everyday practicability and performance have both been equally increased. The system consists of two electromechanical actuators fitted on the rear axle instead of the conventional tie rod. It therefore steers the rear wheels of the new 911 Turbo models from +3 to –1.5 degrees in the same or opposite direction as the steering angle on the front axle, depending on speed.
Thanks to the new rear-axle steering which is fitted as standard, everyday practicability and performance have both been equally increased. The system consists of two electromechanical actuators fitted on the rear axle instead of the conventional tie rod. It therefore steers the rear wheels of the new 911 Turbo models from +3 to –1.5 degrees in the same or opposite direction as the steering angle on the front axle, depending on speed.