Diff Final Drives
05-24-2013, 06:25 AM
#21
Registered User
Originally Posted by lovegroova' timestamp='1369399746' post='22564271
Here's an interesting thread from the Racing forum: https://www.s2ki.com/s2000/topic/101...t__p__22489718 which Floppy should definitely read.
[quote name='aozora' timestamp='1366622248' post='22489718']
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.c...h?v=tYTIu2VoZvY
4.44 gears with 1.5 Way ATS/Carbonetics LSD.
http://www.youtube.c...h?v=cnoWbZLxlXQ
[quote name='aozora' timestamp='1366622248' post='22489718']
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.c...h?v=tYTIu2VoZvY
4.44 gears with 1.5 Way ATS/Carbonetics LSD.
http://www.youtube.c...h?v=cnoWbZLxlXQ
[media]http://www.youtube.com/watch?v=NtdOU-yyZ_w[/media]
Now I'm FI I actually tempted to just stick a stock 4.1 diff back on, but it seems a waste to have such a high top speed that I'll never make use of.
[/quote]
Depends on how you look at it.
If you see 5 gears and overdrive, makes a lot of sense.
05-24-2013, 06:49 AM
#23
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Am doing the 4.77 build 
Am renewing all the bearings,seals and bolts. Honda bearings&cups £70 each x2 seals £15 each x3 reline diff oil honda gasket sealant and honda blue lock tight. Thats the extra expense that you need to budget for
https://www.s2ki.com/s2000/topic/102...#entry22564534
Am renewing all the bearings,seals and bolts. Honda bearings&cups £70 each x2 seals £15 each x3 reline diff oil honda gasket sealant and honda blue lock tight. Thats the extra expense that you need to budget for https://www.s2ki.com/s2000/topic/102...#entry22564534
05-24-2013, 07:08 AM
#24
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Here's an interesting thread from the Racing forum: https://www.s2ki.com/s2000/topic/101...t__p__22489718 which Floppy should definitely read.
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.
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.
- 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.
05-24-2013, 09:48 AM
#26
UK Moderator
I'm not sure what you are trying to argue?
All I've said from the start is that FD will help sometimes and hinder at others.
Then again quoting for an AP2 seems odd as that has different ratios.
All I've said from the start is that FD will help sometimes and hinder at others.
Then again quoting for an AP2 seems odd as that has different ratios.
05-24-2013, 10:10 AM
#27
Registered User
Thread Starter
Blimey I didn't expect to start such a heated discussion but all great! Thanks for the input everyone, I'll definitely take a read of those threads tonight, just got in from work so I shall throw another question in when I have more.
Ian that sounds like a great plan! I'm interested in the drivability of the car. Overtaking at 50-55 on an A road is a PITA as you either have too short a rev range left or you're not on cam!
I can definitely see the points made about track use as well though as I remember being in the car with Dixon at Silverstone and I think the only time he was in 5th was on the Hangar Straight IIRC with him commenting the gearing is too long.
Ian that sounds like a great plan! I'm interested in the drivability of the car. Overtaking at 50-55 on an A road is a PITA as you either have too short a rev range left or you're not on cam!
I can definitely see the points made about track use as well though as I remember being in the car with Dixon at Silverstone and I think the only time he was in 5th was on the Hangar Straight IIRC with him commenting the gearing is too long.
05-24-2013, 10:16 AM
#28
UK Moderator
Blimey I didn't expect to start such a heated discussion but all great! Thanks for the input everyone, I'll definitely take a read of those threads tonight, just got in from work so I shall throw another question in when I have more.
Ian that sounds like a great plan! I'm interested in the drivability of the car. Overtaking at 50-55 on an A road is a PITA as you either have too short a rev range left or you're not on cam!
I can definitely see the points made about track use as well though as I remember being in the car with Dixon at Silverstone and I think the only time he was in 5th was on the Hangar Straight IIRC with him commenting the gearing is too long.
Ian that sounds like a great plan! I'm interested in the drivability of the car. Overtaking at 50-55 on an A road is a PITA as you either have too short a rev range left or you're not on cam!
I can definitely see the points made about track use as well though as I remember being in the car with Dixon at Silverstone and I think the only time he was in 5th was on the Hangar Straight IIRC with him commenting the gearing is too long.
Which illustrates how tricky this all is.
05-29-2013, 12:25 PM
#29
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Just trying to add some positive stuff about changing gears .... too much negativity on the thread.
This was the discussion we had a *long* time back when a few of us decided to change the final drive.
4.57 gears - real life performance improvement?
If I were doing it again I would go for the 4.44 gear.
This was the discussion we had a *long* time back when a few of us decided to change the final drive.
4.57 gears - real life performance improvement?
If I were doing it again I would go for the 4.44 gear.
05-29-2013, 10:35 PM
#30
Member
Floppy, I think Dixon has a 4.4?
I have a 4.4 and where I do feel it benefits is off the start line. After that I'm not so sure, and a race track isn't a good comparison to the road anyway.
On the road I think I'd prefer the feel of 4.4
But from what you say you are after, I think the 25 plus bhp mid range you can gain from breathing mods would help.
I have a 4.4 and where I do feel it benefits is off the start line. After that I'm not so sure, and a race track isn't a good comparison to the road anyway.
On the road I think I'd prefer the feel of 4.4
But from what you say you are after, I think the 25 plus bhp mid range you can gain from breathing mods would help.