5 speed mileage gains.
02-06-2011, 05:39 PM
#17
One of the best things about a Porsche is the fuel mileage you get out of a performance car. Dr. Porsche always stressed the importance of fuel economy as part of the whole package, did'nt he?
02-06-2011, 05:51 PM
#18
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
The Porsche Owners manual 1980 version lists minimum upshifts as ... 1-2nd 15 mph, 2-3rd 25 MPH, 3-4th 40 mph, 4-5th 48 MPH and that is with the 2.75 
Being in 5 th at 25 MPH with a 2:20 ?? might save gas but .......
Being in 5 th at 25 MPH with a 2:20 ?? might save gas but .......
02-06-2011, 06:22 PM
#21
Archive Gatekeeper
Rennlist Member
Rennlist Member
A well-controlled before/after dyno comparison on an auto-manual conversion would be really interesting, from a driveline loss perspective.
02-06-2011, 06:29 PM
#22
Rennlist Member
02-06-2011, 06:33 PM
#23
Rest in Peace
Rennlist Member
Rennlist Member
Thread Starter
Join Date: May 2006
Location: Bird lover in Sharpsburg
Posts: 9,903
Likes: 0
Received 2 Likes
on
2 Posts
The new C6's get around 35 from what I have been told.
That is not bad out of a car that will run damn near 200 mph and a 1/4 around 12 seconds.
02-06-2011, 06:39 PM
#25
Pro
It would have been better if 5th gear (or 4th in an auto) was an overdrive instead of 1:1. High 20s maybe even 30 would be possible on the highway. The V8's torque could pull you along quite nicely at low RPM.
02-06-2011, 07:13 PM
#26
Nordschleife Master
To the comment about porsches fueling system being set on economy.
Not the case in the S4.
It runs at 14.7:1 at most times due to the adaption system.
I enquired about having it disable off idle. Meaning it would only be active with the idle switch. And I was told that it couldn't be done with the sharktuner.
So now I will be disabling the O2 adaption and custom tuning the idle.
I did find that tuning for economy in the cruise area dropped some power, and that the maf was much less responsive to these changes than a MAP system.
One of the reasons the newer vettes can achieve 35+ and still pass emissions is due to 5th and 6th being overdrives.....
Not the case in the S4.
It runs at 14.7:1 at most times due to the adaption system.
I enquired about having it disable off idle. Meaning it would only be active with the idle switch. And I was told that it couldn't be done with the sharktuner.
So now I will be disabling the O2 adaption and custom tuning the idle.
I did find that tuning for economy in the cruise area dropped some power, and that the maf was much less responsive to these changes than a MAP system.
One of the reasons the newer vettes can achieve 35+ and still pass emissions is due to 5th and 6th being overdrives.....
02-06-2011, 07:28 PM
#27
Rest in Peace
Rennlist Member
Rennlist Member
Thread Starter
Join Date: May 2006
Location: Bird lover in Sharpsburg
Posts: 9,903
Likes: 0
Received 2 Likes
on
2 Posts
I would have thought that the MAF would have been better as you are actually measuring the amount of air going into the engine.
I know that with some factory hop kits, like the older Ford GT-40 kits for the Mustangs we used to do changed from the stock MAP systems to MAF units.
I know that with some factory hop kits, like the older Ford GT-40 kits for the Mustangs we used to do changed from the stock MAP systems to MAF units.
To the comment about porsches fueling system being set on economy.
Not the case in the S4.
It runs at 14.7:1 at most times due to the adaption system.
I enquired about having it disable off idle. Meaning it would only be active with the idle switch. And I was told that it couldn't be done with the sharktuner.
So now I will be disabling the O2 adaption and custom tuning the idle.
I did find that tuning for economy in the cruise area dropped some power, and that the maf was much less responsive to these changes than a MAP system.
One of the reasons the newer vettes can achieve 35+ and still pass emissions is due to 5th and 6th being overdrives.....
Not the case in the S4.
It runs at 14.7:1 at most times due to the adaption system.
I enquired about having it disable off idle. Meaning it would only be active with the idle switch. And I was told that it couldn't be done with the sharktuner.
So now I will be disabling the O2 adaption and custom tuning the idle.
I did find that tuning for economy in the cruise area dropped some power, and that the maf was much less responsive to these changes than a MAP system.
One of the reasons the newer vettes can achieve 35+ and still pass emissions is due to 5th and 6th being overdrives.....
02-06-2011, 07:41 PM
#29
Rennlist Member
There was no 300hp Vette in the 80's, not stock anyway. The 928 was pretty much the king of the hill back then. It wasn't until the ZR-1 came along in 1990 with a 375hp LT-5 that the Vette edged ahead in the HP dept.