Skylines Downunder NZ Car Club

Technical => Suspension, Steering, Braking, Wheels & Tyres => Topic started by: sonoramicommando on February 26, 2016, 11:10:28 PM

Title: low ratio rearend on street car
Post by: sonoramicommando on February 26, 2016, 11:10:28 PM
has anyone tried c23 rear diff 4.6 or 4.9 on a street car? i have a 4.3 and not sure if its best to stick with it or go lower with c23 one.


Sent from my iPhone using Tapatalk
Title: Re: low ratio rearend on street car
Post by: Phlex on February 27, 2016, 04:04:49 PM
4.3:1 is a perfect balance of torque and acceleration for street cars. Ive run 3.5:1 in a road car and that had awesome acceleration but absolutely no torque through corners etc.  Mate swears by a 4.6:1 serena diffs for drifting and it would have less wheel speed but a lot more torque available so perfect for keeping a skid going. 

I've tried a few ratios on the track as well and found 4.3:1 is adequate for acceleration and powering out of corners / barrel turns (grip racing / sprints)
Title: Re: low ratio rearend on street car
Post by: westybob on February 27, 2016, 04:52:17 PM
Depends how much power you got. I would think 4.3 is the lowest you want - 4.6 etc sounds far too busy.
My RB30 powered Stagea had a 4.1 diff but i looked for ages without success for a higher gearing - a 3.54 R34 GTR diff would have been ideal - just to make highway cruising more laid back.
Title: Re: low ratio rearend on street car
Post by: sonoramicommando on February 27, 2016, 10:13:13 PM
Depends how much power you got. I would think 4.3 is the lowest you want - 4.6 etc sounds far too busy.
My RB30 powered Stagea had a 4.1 diff but i looked for ages without success for a higher gearing - a 3.54 R34 GTR diff would have been ideal - just to make highway cruising more laid back.
i'd ve thought 3.5 are dime a dozen - they came with R32 GTS25 auto...
Title: Re: low ratio rearend on street car
Post by: sonoramicommando on February 27, 2016, 10:22:54 PM
4.3:1 is a perfect balance of torque and acceleration for street cars. Ive run 3.5:1 in a road car and that had awesome acceleration but absolutely no torque through corners etc.  Mate swears by a 4.6:1 serena diffs for drifting and it would have less wheel speed but a lot more torque available so perfect for keeping a skid going. 

I've tried a few ratios on the track as well and found 4.3:1 is adequate for acceleration and powering out of corners / barrel turns (grip racing / sprints)
I think 4.3 gets you 100kph at 3000rpm on 5th gear, so it's not too bad. That said, I'm tempted to go 4.6 - I wonder if Serenas come with LSD's? (I guess your mate either locked it or put some big bucks aftermarket centre...)
Cheers
Title: Re: low ratio rearend on street car
Post by: westybob on February 28, 2016, 06:23:06 AM
I think 3000 at 100K/h is too much and if you were to get a 4.6 and cruise at 110 that would be 3530 which would be pretty noisy and tiresome on a trip. Plus your top speed  at 7000 rev/min would be 200 - don't you have ambitions to hit 250 - 280 on the track?
Title: Re: low ratio rearend on street car
Post by: sonoramicommando on February 28, 2016, 09:11:12 AM
I think 3000 at 100K/h is too much and if you were to get a 4.6 and cruise at 110 that would be 3530 which would be pretty noisy and tiresome on a trip. Plus your top speed  at 7000 rev/min would be 200 - don't you have ambitions to hit 250 - 280 on the track?
I'm used to it, I had a few cars that sit at 3000 - 4.6 would bump up a couple of hundred rpms probably still bearable.
I don't think I would want to go that fast in my car, if it's capable... :o
By the way it occurred to me that R33 (and Stagea) has different diff mounting/housing than R32...
Title: Re: low ratio rearend on street car
Post by: sonoramicommando on March 09, 2016, 02:41:51 PM
does c23 diff straight swap on r32? i think r32 and r33 housings are a bit different and need some work to swap out.


Sent from my iPhone using Tapatalk