Notices
718 GTS 4.0/GT4/GT4RS/Spyder/25th Anniversary Discussions about the 718 version of the GT4RS, GTS 4.0, GT4, Spyder and 25th Anniversary Boxster
Sponsored By:
Sponsored By: Cobb

GT4RS PDK Gear Ratios Published

Old 03-02-2022 | 12:38 PM
  #1  
TXshaggy's Avatar
TXshaggy
Thread Starter
RL Community Team
Rennlist Member
 
Joined: Nov 2018
Posts: 6,143
Likes: 3,972
From: Texas Hill Country
Default GT4RS PDK Gear Ratios Published

Some additional technical specifications have been posted over on the Porsche Newsroom.

Thought there'd be enough interest in posting a dedicated thread for discussion. Once it winds down I'll combine it into the main thread for archival purposes.

As published the GT4RS reaches max speed in 7th gear:

3.75 2.38 1.72 1.34 1.11 0.96 0.84
Reverse gear 3.42
Rear-axle gear ratio 4.17

Here is the GT4 PDK for comparison:

3.91 2.29 1.65 1.30 1.08 0.88 0.71
Reverse gear 3.55
Rear-axle gear ratio 3.62

Here is the GT4 Manual Gearset:

3.31 1.95 1.41 1.13 0.95 0.81
Reverse gear 3.0
Rear-axle gear ratio 3.89

Attached is the full tech spec bulletin

Looking forward to these ratios in my Spyder RS!
Attached Images
The following 7 users liked this post by TXshaggy:
2XIPA (03-02-2022), Adrift (03-02-2022), electron mike (03-02-2022), enduro (03-02-2022), GTFede78 (03-13-2023), Larry Cable (05-22-2022), marinb (05-13-2024) and 2 others liked this post. (Show less...)
Old 03-02-2022 | 12:49 PM
  #2  
2XIPA's Avatar
2XIPA
Burning Brakes
 
Joined: Oct 2012
Posts: 1,187
Likes: 318
From: Seattle
Default

It'll be interesting to see what the speed in gears will be on a comparative basis.
Old 03-02-2022 | 12:52 PM
  #3  
TXshaggy's Avatar
TXshaggy
Thread Starter
RL Community Team
Rennlist Member
 
Joined: Nov 2018
Posts: 6,143
Likes: 3,972
From: Texas Hill Country
Default

Originally Posted by 2XIPA
It'll be interesting to see what the speed in gears will be on a comparative basis.
If you know the wheel diameter there are calculators that are pretty close.
The following users liked this post:
Larry Cable (03-02-2022)
Old 03-02-2022 | 02:39 PM
  #4  
jmartpr's Avatar
jmartpr
Rennlist Member
 
Joined: Jul 2015
Posts: 4,759
Likes: 1,488
Default

So not only all 7 gears were revised but also the final gear ratio...
Old 03-02-2022 | 04:23 PM
  #5  
wizee's Avatar
wizee
Rennlist Member
 
Joined: Nov 2016
Posts: 1,534
Likes: 835
From: Waterloo, Ontario, Canada
Default

Really nice ratios, with closely spaced gears.
Old 03-02-2022 | 04:31 PM
  #6  
electron mike's Avatar
electron mike
Rennlist Member
 
Joined: Mar 2015
Posts: 1,468
Likes: 634
From: Austin, TX
Default

Looks like a snappy combination. The PDK GT3 has the same ratios except for the final drive is 3.97 compared to the GT4RS 4.17. The GT4RS should be quick!


Old 03-02-2022 | 05:56 PM
  #7  
usctrojanGT3's Avatar
usctrojanGT3
Rennlist Member
 
Joined: Feb 2013
Posts: 16,901
Likes: 4,192
Default

It's the same GT3 engine so not surprised that it has the same gear ratios. I'm hoping PDK Sport will have as violent shifts.
The following users liked this post:
mr965 (03-03-2022)
Old 03-02-2022 | 06:07 PM
  #8  
jmartpr's Avatar
jmartpr
Rennlist Member
 
Joined: Jul 2015
Posts: 4,759
Likes: 1,488
Default

Originally Posted by usctrojanGT3
It's the same GT3 engine so not surprised that it has the same gear ratios. I'm hoping PDK Sport will have as violent shifts.

Probably....plus you get a final drive a bit higher than the GT3 (faster acceleration)
Old 03-02-2022 | 07:10 PM
  #9  
lovetoturn's Avatar
lovetoturn
Three Wheelin'
 
Joined: Mar 2017
Posts: 1,425
Likes: 1,252
From: Dallas
Default

It has a higher final drive ratio ...... shorter 20 inch tires (27") on the rear instead of the GT3's 21s (28.5") ..... and is lighter than a GT3. Yes, it should be really quick.
Old 03-02-2022 | 07:15 PM
  #10  
wizee's Avatar
wizee
Rennlist Member
 
Joined: Nov 2016
Posts: 1,534
Likes: 835
From: Waterloo, Ontario, Canada
Default

Some calculations comparing the ratios. The peak acceleration numbers in each gear I calculated assume zero drivetrain loss and perfect grip, neither of which are true of course, but are useful for comparison at least.

The following 4 users liked this post by wizee:
2XIPA (03-03-2022), JamesBruen (03-03-2022), UncleDude (03-02-2022), very green R (07-27-2024)
Old 03-03-2022 | 12:07 AM
  #11  
JAhmed's Avatar
JAhmed
Drifting
 
Joined: Jan 2012
Posts: 2,811
Likes: 1,953
From: CHICAGOLAND!!!
Default

Damn, significant difference.

Yes, Spyder RS will do nicely with this
The following users liked this post:
Adrift (03-03-2022)
Old 03-03-2022 | 07:38 AM
  #12  
theEnd's Avatar
theEnd
Instructor
 
Joined: Jan 2020
Posts: 206
Likes: 174
From: New York City
Default

Originally Posted by JAhmed
Yes, Spyder RS will do nicely with this
It’s great that the GT3 has the same 1st-4th gear ratios regardless of manual or PDK.

Hopefully Porsche can adapt the GT3 manual gearbox for the Spyder RS. If it doesn’t fit, just leave out 5th and 6th. I don’t need them.
Old 03-03-2022 | 07:42 AM
  #13  
jmartpr's Avatar
jmartpr
Rennlist Member
 
Joined: Jul 2015
Posts: 4,759
Likes: 1,488
Default

Originally Posted by theEnd
It’s great that the GT3 has the same 1st-4th gear ratios regardless of manual or PDK.

Hopefully Porsche can adapt the GT3 manual gearbox for the Spyder RS. If it doesn’t fit, just leave out 5th and 6th. I don’t need them.

That wont happen...check the other thread were it's explained why any 911 gearbox wont work on the mid-engine platform.
Can they revised the gears of the current mid-engine platform transmission? Yes they can but then it brings the issue of that transmission capacity...in the manufacturers eye, not aftermarket.
Old 03-03-2022 | 09:27 AM
  #14  
Adrift's Avatar
Adrift
Rennlist Member
 
Joined: Nov 2008
Posts: 3,998
Likes: 2,765
From: North of Dallas
Default

Originally Posted by JAhmed
Damn, significant difference.

Yes, Spyder RS will do nicely with this
I knew you were a true believer in there, somewhere.
Old 03-03-2022 | 10:05 AM
  #15  
enduro's Avatar
enduro
Burning Brakes
 
Joined: Mar 2021
Posts: 1,065
Likes: 607
Default

Another way to look at it; my biggest complaint with the non RS gearing is the 1-2, tho the two fuel econ gears in the non RS car's PDK are also an annoying nod to fuel econ requirements.

The drop at an 8k RPM 1-2 shift for the 4RS is 364 less than for the 4 M6 and 392 RPM less than for the 4 PDK -> it'll drop you less out of the power when tooling around. I'll find a dyno plot to further make my point, but max power is pretty much at redline, and there's a torque bump at 5.5kRPM or so which makes things even more noticeable. I've found the 1-2 to be similar in some other cars I'm familiar with, and theirs didn't bother me, so this could be more that the engine is peaky than the 1-2 is extra long, but IMO it'd be nicer to have a 1-2 that's more tuned to the engine.

In a drag race, what matters is power * time and for the GT4 engine, the 4RS is PDK is going to do this better than the GT4 PDK, at least for the GT4 power curve. I'll run the numbers at some point, but I bet it's worth at least a time average of 20hp applied.

The RS ratio stack is more what I'd expect in a performance car, and would like to have seen it in the GT4.

Maybe there is a performance benefit to the extra long 1-2, like being able to stitch together corners without upsetting the car, but esp for the PDK with smooth and lightning fast shifts, it's not intuitive to me.


Last edited by enduro; 03-03-2022 at 10:21 AM.

Thread Tools
Search this Thread
Quick Reply: GT4RS PDK Gear Ratios Published



All times are GMT -3. The time now is 10:04 PM.