S2000 Racing and Competition The S2000 on the track and Solo circuit. Some of the fastest S2000 drivers in the world call this forum home.

Final drive - Going backwards?

Thread Tools
 
Old Apr 22, 2013 | 01:17 AM
  #1  
aozora's Avatar
Thread Starter
Registered User
 
Joined: Apr 2006
Posts: 524
Likes: 0
From: Melbourne
Default Final drive - Going backwards?

Long story short - ever since changing to 4.44 final drive, I'm struggling to reach my previous best and after a lot of analysis (specifically around top speeds before braking, gears used etc), I can't help but come to the conclusion that the 4.44s are actually robbing me of time (7/10ths of a second) with an extra 3 gear changes? Is there really that much time lost in gear changes to negate any acceleration benefits of the closer gearing?

Just some videos for comparison...

Stock 4.1 gears with OEM LSD.
http://www.youtube.com/watch?v=tYTIu2VoZvY

4.44 gears with 1.5 Way ATS/Carbonetics LSD.
http://www.youtube.com/watch?v=cnoWbZLxlXQ
Reply
Old Apr 22, 2013 | 02:51 AM
  #2  
ZDan's Avatar
 
Joined: Feb 2007
Posts: 6,863
Likes: 125
From: Pawtucket, RI
Default

Gearing doesn't magic you any better power/weight or better overall acceleration, all it does is change your shift points. Optimal gearing is going to be different for every track. If going to 4.44's requires you to upshift more and/or to be in the next taller transmission gear at critical corner exits, it could easily be costing you that much time.

Never consider a gearing change without studying the ramifications at tracks you go to!
Gears are not an OVERALL performance mod. They may help in acceleration numbers from a dead stop, but from a roll, overall it's a wash, and if you pick the wrong ratio, you end up shifting more and out of the powerband where it matters.
Reply
Old Apr 22, 2013 | 03:07 AM
  #3  
robrob's Avatar
Former Moderator
Former Moderator
20 Year Member
Liked
Community Favorite
 
Joined: Jul 2005
Posts: 4,634
Likes: 28
From: West Virginia
Default

I agree with ZDan. Lower gearing can help or hurt depending upon the individual track you're going to run. I'm also convinced that my 4.44 gearing is hurting my lap times at Summit Main. I was hoping the 4.44 gearing would allow me to run 3rd gear instead of 2nd in Turns 1, 5 and 6 but instead it just put me into no-man's-land where 2nd is now too low and 3rd is too high for those corners. I also have to add an up and downshift between Turns 1 and 3 and down the front straight. So far I'm over a second a lap slower after the gearing change & addition of a clutch LSD. I'm eyeing a sweet set of 3.80 gears so I can go even faster than stock gearing! [edit: Just want to make sure everyone knows that last sentence is a joke]

The 4.44 gearing seems to be neutral to helpful on the tighter and more technical Shenandoah Circuit.

If I need to open my diff for anything I'll probably go back to the stock gearing since I run Summit Main more than any other track.
Reply
Old Apr 22, 2013 | 06:58 AM
  #4  
dan_uk's Avatar
15 Year Member
Photogenic
Photoriffic
 
Joined: Dec 2007
Posts: 4,525
Likes: 1
From: Savannah, GA, USA
Default

It depends on track at my local track I think the 4.44 hurts my times vs the 4.10 but at all other tracks here its better.
If you get into 6th gear that can realy rob you of time.
Reply
Old Apr 22, 2013 | 05:57 PM
  #5  
aozora's Avatar
Thread Starter
Registered User
 
Joined: Apr 2006
Posts: 524
Likes: 0
From: Melbourne
Default

Group buy on the 3.8 gears?

Foolishly I read too many of the "acceleration gains to beat your mate in his stock s2k drag" threads without thinking about the effects of speed/gear on track. Having had them at least now, it makes it bleedingly obvious why it's so important. The track in the video is probably the most technical local track around, with everything else having more sweeping corners. Even at one of the local hill climbs - 2nd gear was too short and 3rd too low in some corners which seems to be the general issue.
I have a few more rounds at tracks I haven't tried in the S2000 so I'll make a choice after figuring out if it adds any benefit overall. Thanks for the input all.
Reply
Old Apr 22, 2013 | 10:43 PM
  #6  
TWF's Avatar
TWF
 
Joined: Apr 2012
Posts: 907
Likes: 0
From: Reno, NV
Default

Originally Posted by dan_uk
If you get into 6th gear that can realy rob you of time.
6th? I have yet to get in 5th, never mind 6th
Reply
Old Apr 23, 2013 | 03:52 AM
  #7  
robrob's Avatar
Former Moderator
Former Moderator
20 Year Member
Liked
Community Favorite
 
Joined: Jul 2005
Posts: 4,634
Likes: 28
From: West Virginia
Default

I hit 130+ mph (data acquisition, not indicated) down Summit Point's front straight and have to hit 6th for the last 1/4--that's with 4.44 gearing.
Reply
Old Apr 23, 2013 | 04:44 AM
  #8  
SC_Highlander's Avatar
Member (Premium)
20 Year Member
Photogenic
Photoriffic
 
Joined: Sep 2002
Posts: 4,784
Likes: 2
From: Greer, SC
Default

Originally Posted by robrob
I'm eyeing a sweet set of 3.80 gears so I can go even faster than stock gearing! [edit: Just want to make sure everyone knows that last sentence is a joke]
You laugh, but I'm currently debating between 3.9 or 3.63's. My 23.5in tall slicks are only good for about 62mph in 2nd with the 4.1 final drive. I've got an entirely different use case, for sure, though.
Reply
Old Apr 23, 2013 | 05:01 AM
  #9  
dan_uk's Avatar
15 Year Member
Photogenic
Photoriffic
 
Joined: Dec 2007
Posts: 4,525
Likes: 1
From: Savannah, GA, USA
Default

Originally Posted by robrob
I hit 130+ mph (data acquisition, not indicated) down Summit Point's front straight and have to hit 6th for the last 1/4--that's with 4.44 gearing.
yea mines good for abouty 128mph with the 9500 rev limit. At rd Atlanta last dec I ran a 225/40/17 tires and on the data I lost something like 0.4 shifting to 6th at the end of the straight but with a 225/45/17 I could redline 5th - over the rest of the lap I was slower on the 225/45/17 though it was kinda frustrating
Reply
Old Apr 23, 2013 | 06:16 AM
  #10  
cracknut's Avatar
15 Year Member
Photogenic
Photoriffic
 
Joined: Oct 2008
Posts: 885
Likes: 13
From: Bay Area, CA
Default

Yes, it all depends on local tracks and tires. On 245/40-17 with an AP2 motor and AP2 transmission my analysis as follows:
- Laguna: 4.44 is best (can take T11 in 3rd meaning 1 less shift up the hill, can take T5 in 4th if no traffic)
- Thunderhill (4.44 works well everywhere except that 5th is too short on the straight)
- Sears (4.44 is too short up into T6 and the car is between 4th and 5th through the esses)

To give me a few more mph on the straight at Thill and into T6 at Sears, I'll be switching to 4.3 since my diff is being rebuilt. This will also give me the option to run 235/40-17 NT01s without being far to short.
Reply



All times are GMT -8. The time now is 06:24 PM.