997 2005-2012 911 C2, C2S, C4, C4S, GTS, Targa and Cabriolet Model Discussion.
Sponsored by:
Sponsored by: CARiD

Rate of acceleration 2nd vs 3rd gear

Thread Tools
 
Rate Thread
 
Old Oct 8, 2009 | 01:12 PM
  #1  
'08C4S's Avatar
Thread Starter
|
Registered User
Joined: Mar 2008
Posts: 121
From: PA
Rep Power: 25
'08C4S has a spectacular aura about'08C4S has a spectacular aura about'08C4S has a spectacular aura about
Rate of acceleration 2nd vs 3rd gear

So my '08 C4S 6 speed manual is relatively fresh in terms of miles but beyond the break in period. I've noticed a rather noticeable difference between 2nd and 3rd gear rate of acceleration. Both 2nd and 3rd, starting at approximately 3.5k rpms (and respective mph for each gear) and flooring it until it peaks at about 6.5k, the 3rd gear seems to have a greater "rate of acceleration" as compared to 2nd. While 2nd gear being a lower gear that "should have" greater rate of acceleration, by the "seat of the pants feel", the 3rd gear seems to pull the car harder and faster. I am pinned into the seat in 3rd as the car rockets forward, 2nd seems to be just OK.... It's counter-intuitive for sure.... Is it my imagination or is there an explanation for this?
 

Last edited by '08C4S; Oct 8, 2009 at 01:20 PM.
Old Oct 8, 2009 | 01:28 PM
  #2  
utkinpol's Avatar
Registered User
Joined: Jul 2007
Posts: 3,122
From: Natick, MA
Rep Power: 163
utkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond repute
Originally Posted by '08C4S
So my '08 C4S 6 speed manual is relatively fresh in terms of miles but beyond the break in period. I've noticed a rather noticeable difference between 2nd and 3rd gear rate of acceleration. Both 2nd and 3rd, starting at approximately 3.5k rpms (and respective mph for each gear) and flooring it until it peaks at about 6.5k, the 3rd gear seems to have a greater "rate of acceleration" as compared to 2nd. While 2nd gear being a lower gear that "should have" greater rate of acceleration, by the "seat of the pants feel", the 3rd gear seems to pull the car harder and faster. I am pinned into the seat in 3rd as the car rockets forward, 2nd seems to be just OK.... It's counter-intuitive for sure.... Is it my imagination or is there an explanation for this?
nope, you are right. I remember it quite well too, as I had same exact feeling with my car. 3rd gear gas kick was pressing my back into seat harder than same kick on 2nd gear, that was the feeling. Softronic fixed that, subsequent exhaust mods improved torque even more.

as a first remedy you can try to reset your ECU to see if it will make any noticeable difference or not, may be car is just out of tune completely.
 
Old Oct 8, 2009 | 01:36 PM
  #3  
'08C4S's Avatar
Thread Starter
|
Registered User
Joined: Mar 2008
Posts: 121
From: PA
Rep Power: 25
'08C4S has a spectacular aura about'08C4S has a spectacular aura about'08C4S has a spectacular aura about
Originally Posted by utkinpol
nope, you are right. I remember it quite well too, as I had same exact feeling with my car. 3rd gear gas kick was pressing my back into seat harder than same kick on 2nd gear, that was the feeling. Softronic fixed that, subsequent exhaust mods improved torque even more.

as a first remedy you can try to reset your ECU to see if it will make any noticeable difference or not, may be car is just out of tune completely.
I don't see how the engine would know if it is 2nd or 3rd gear and be out of tune on one but not the other. All the engine sees is a load. I have a feeling it has something to do with the gear ratio's. Is the 6 speed a close ratio gearbox on the 997? Come to think of it, the 2nd gear is pretty tall and will take the car to beyond 60 mph so maybe it's just the actual gear ratio at play.

I remember my friend's NSX had a really tall 2nd gear and he used to hit almost 80 mph in 2nd. Some guys switched to the european close ratio trannies with the NSX.
 
Old Oct 8, 2009 | 01:42 PM
  #4  
utkinpol's Avatar
Registered User
Joined: Jul 2007
Posts: 3,122
From: Natick, MA
Rep Power: 163
utkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond repute
Originally Posted by '08C4S
I don't see how the engine would know if it is 2nd or 3rd gear and be out of tune on one but not the other. All the engine sees is a
not enough torque I guess so you feel less on 2nd than on 3rd.
 
Old Oct 8, 2009 | 01:50 PM
  #5  
yrralis1's Avatar
Registered User
15 Year Member
Joined: Jan 2008
Posts: 9,108
From: South Florida
Rep Power: 529
yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !
Originally Posted by '08C4S
So my '08 C4S 6 speed manual is relatively fresh in terms of miles but beyond the break in period. I've noticed a rather noticeable difference between 2nd and 3rd gear rate of acceleration. Both 2nd and 3rd, starting at approximately 3.5k rpms (and respective mph for each gear) and flooring it until it peaks at about 6.5k, the 3rd gear seems to have a greater "rate of acceleration" as compared to 2nd. While 2nd gear being a lower gear that "should have" greater rate of acceleration, by the "seat of the pants feel", the 3rd gear seems to pull the car harder and faster. I am pinned into the seat in 3rd as the car rockets forward, 2nd seems to be just OK.... It's counter-intuitive for sure.... Is it my imagination or is there an explanation for this?

The effect is even more pronounced in the Turbo . Third gear is the one where it separates itself from all the other cars and with modified turbos and sofware it refuses to let off in every gear . Even at the high RPM it's asking for more time and just grabs into the next gear.

i find the stock 997.1S kinda weak in every gear in contrast but its more seamless and quite fun to drive .Software , intake and exhausr help enough to add a nice flavor to the car but not so huge that one might expect a drastic change.

The new Dfi car has this immediate response though even when its stock but when I replaced the cats , headers, and mufflers with the FVD system it just opened up a lot of low end punch .

Some had posted that when they opted for the Tubi which is not a complete system that they noticed more high end power but the low end was lacking .I have not driven the 997.2 Tubi so I woild not know but this lack of low end is NOT the case when the complete system is changed .

FVD has the real deal .Impressive system.
 

Last edited by yrralis1; Oct 8, 2009 at 01:53 PM.
Old Oct 8, 2009 | 02:07 PM
  #6  
utkinpol's Avatar
Registered User
Joined: Jul 2007
Posts: 3,122
From: Natick, MA
Rep Power: 163
utkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond repute
Originally Posted by yrralis1
The new Dfi car has this immediate response though even when its stock but when I replaced the cats , headers, and mufflers with the FVD system it just opened up a lot of low end punch .
...
FVD has the real deal .Impressive system.

did you do any pre- and post- dyno runs by any chance? Just would be curious to see how it looks like on a graph.
 
Old Oct 8, 2009 | 02:17 PM
  #7  
yrralis1's Avatar
Registered User
15 Year Member
Joined: Jan 2008
Posts: 9,108
From: South Florida
Rep Power: 529
yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !yrralis1 Is a GOD !
Originally Posted by utkinpol
did you do any pre- and post- dyno runs by any chance? Just would be curious to see how it looks like on a graph.
Nope I haven't . It's a separae topic but I somewhat have mixed feelings with dyno charts . I feel that when Porsche tests theur cars and releases Hp rating (even on the X50 and ppwer upgrades) they test the car in all climates and conditions . The dyno is more of a laboratory setting and even dynos themselves vary .
 
Old Oct 8, 2009 | 02:24 PM
  #8  
utkinpol's Avatar
Registered User
Joined: Jul 2007
Posts: 3,122
From: Natick, MA
Rep Power: 163
utkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond reputeutkinpol has a reputation beyond repute
Originally Posted by yrralis1
Nope I haven't . It's a separae topic but I somewhat have mixed feelings with dyno charts . I feel that when Porsche tests theur cars and releases Hp rating (even on the X50 and ppwer upgrades) they test the car in all climates and conditions . The dyno is more of a laboratory setting and even dynos themselves vary .
that`s understandable, I was more interested in particular pre- and post- difference of a curve shape on a graph than about any numbers on a side, really.

but I like your approach, it reminds me a notation of rolls-royce engine power -'sufficient'.
 
Old Oct 8, 2009 | 06:13 PM
  #9  
AlexM's Avatar
Registered User
Joined: May 2009
Posts: 385
From: A Lake in Minneapolis
Rep Power: 52
AlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant futureAlexM has a brilliant future
These cars are geared for competitions.
I would think a typical driver should be able to run them in 3rd and 4th on pretty much all major tracks.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ModBargains
Mercedes/AMG Vendor Classifieds
1
Oct 13, 2015 03:45 PM
ModBargains
Aston Martin Vendor Classifieds
1
Oct 13, 2015 03:43 PM
ModBargains
Bentley Vendor Classifieds
1
Oct 13, 2015 03:42 PM
ModBargains
Lotus Vendor Classifieds
1
Oct 13, 2015 03:42 PM
proTUNING Freaks
997 Turbo / GT2
17
Sep 15, 2015 07:28 AM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -6. The time now is 12:27 AM.