Nismo front and back LSD

[Sleepergm]

Hi all,

 

was wondering anyone upgrade these and what are their opinions? Worth the time to install for daily driver or just helpful for track cars. Or should just got with a full r34 transmission 6 speed swap. Are the lsd really neccessary with horse power over 600hp? Thanks 

[Dose Pipe Sutututu]

What's your intended usage for the car?

GT-Rs already have a mechanical LSD at the back, provided the clutch packs are still in good condition, it should delivery 50/50 torque split between LHS & RHS rear wheels. 

Wouldn't hurt to put in a helical front diff, however would avoid a clutch pack front if you want to keep it streetable.

[joshuaho96]

1 hour ago, Sleepergm said:

Hi all,

 

was wondering anyone upgrade these and what are their opinions? Worth the time to install for daily driver or just helpful for track cars. Or should just got with a full r34 transmission 6 speed swap. Are the lsd really neccessary with horse power over 600hp? Thanks 

For street use I wouldn't bother with a clutch type LSD on the front especially on a mostly RWD car like the R32 GTR. It will affect steering feel and you're really not going to get much benefit out of it. If you insist on putting in a front LSD I would go with a Quaife or similar Torsen/helical LSD as that will have less impact on steering feel.

R34 6 speed swap is not really worth it IMO. If you don't swap the final drive on the front and rear differential the car will rev much higher on the highway. For 120 kph it will sit at 3700 RPM, perceptually higher because the factory tachometer reads a little high. Stock transmission it's closer to 3050 RPM for 120 kph. If you change the final drive ratios you will have to either change the gear on the vehicle speed sensor or use some kind of converter because the gauge cluster is taking RPM of the transmission output shaft, not the differential output shafts. Add in the cost and the fact that it's not actually that much stronger than an FS5R30A especially in hard use due to the specification of ATF and I've given up on the idea of using a Getrag 233 in these cars. It's just not worth it considering the huge cost.

If you want a stronger transmission build the FS5R30A. PAR Engineering supposedly will do whatever gear ratios you want. You can move things around so 1st and 2nd are not so clearly optimized for 0-100 kph acceleration. The gap between 2nd and 3rd is gigantic for autocross. OS Giken and a few other shops do this, take your pick.

[niZmO_Man]

From being around here a decade or so, generally: Quaife in the front, rebuild standard mechanical rear (since they're like 1-way or whatever from factory).

[Butters]

8 hours ago, joshuaho96 said:

R34 6 speed swap is not really worth it IMO. If you don't swap the final drive on the front and rear differential the car will rev much higher on the highway. For 120 kph it will sit at 3700 RPM, perceptually higher because the factory tachometer reads a little high. Stock transmission it's closer to 3050 RPM for 120 kph. If you change the final drive ratios you will have to either change the gear on the vehicle speed sensor or use some kind of converter because the gauge cluster is taking RPM of the transmission output shaft, not the differential output shafts. Add in the cost and the fact that it's not actually that much stronger than an FS5R30A especially in hard use due to the specification of ATF and I've given up on the idea of using a Getrag 233 in these cars. It's just not worth it considering the huge cost.

If you want a stronger transmission build the FS5R30A. PAR Engineering supposedly will do whatever gear ratios you want. You can move things around so 1st and 2nd are not so clearly optimized for 0-100 kph acceleration. The gap between 2nd and 3rd is gigantic for autocross. OS Giken and a few other shops do this, take your pick.

 

Counter opinon. Having both an OS gearset car and the getrag 6 speed, will take the 6 speed for the street all day long thanks. First gear on most gear sets are ASS, the bloody gear you spend heaps of time in on the street too.   I run the 4.11 and it is fine at 110, (not sure who gets to do 120) 

I do find the gears a little short and doing a 3.89 setup. 

 

Anyway back to your question, running stock LSD rear, love it. Tried an S15 helical rear, it was aweful. In the process of doing a quaife front on advice as part of the 3.89. Seems like a good option. Let you know  

 

Car is 800awhp and mostly street. 

 

 

 

[joshuaho96]

5 hours ago, Butters said:

 

Counter opinon. Having both an OS gearset car and the getrag 6 speed, will take the 6 speed for the street all day long thanks. First gear on most gear sets are ASS, the bloody gear you spend heaps of time in on the street too.   I run the 4.11 and it is fine at 110, (not sure who gets to do 120) 

I do find the gears a little short and doing a 3.89 setup. 

 

Anyway back to your question, running stock LSD rear, love it. Tried an S15 helical rear, it was aweful. In the process of doing a quaife front on advice as part of the 3.89. Seems like a good option. Let you know  

 

Car is 800awhp and mostly street. 

 

 

 

What’s wrong with 2.6 first gear? I’ve done lots of 2nd gear starts from almost a dead stop and it just requires more clutch slip. A 2.6 first gear would be easier than that. I feel like the stock first gear is only good for severe traffic congestion where you need to be able to do 5 kph idling in first gear. Out in the US 120 kph is a very normal speed to be doing on the highways. If anything it’s slow, I regularly get passed by CA highway patrol doing that kind of speed. Out in the desert and plains even 18 wheelers are doing 130-140 kph.

I would be less down on the Getrag if not for the fact that they cost north of 10k USD used and you’ll spend probably another 5k on a rebuild at least. I got my FS5R30A from Nissan for 1.5k USD. The cost of building one is maybe an extra 3-4k if you keep it reasonable. The final drive change to account for the 0.793 6th gear is also a pain to deal with. 

[Sleepergm]

Great info guys thanks alot …

[Sleepergm]

7 hours ago, Butters said:

 

Counter opinon. Having both an OS gearset car and the getrag 6 speed, will take the 6 speed for the street all day long thanks. First gear on most gear sets are ASS, the bloody gear you spend heaps of time in on the street too.   I run the 4.11 and it is fine at 110, (not sure who gets to do 120) 

I do find the gears a little short and doing a 3.89 setup. 

 

Anyway back to your question, running stock LSD rear, love it. Tried an S15 helical rear, it was aweful. In the process of doing a quaife front on advice as part of the 3.89. Seems like a good option. Let you know  

 

Car is 800awhp and mostly street. 

 

 

 

Please let me know how the quaife on the front goes… thanks 

[Sleepergm]

18 hours ago, Dose Pipe Sutututu said:

What's your intended usage for the car?

GT-Rs already have a mechanical LSD at the back, provided the clutch packs are still in good condition, it should delivery 50/50 torque split between LHS & RHS rear wheels. 

Wouldn't hurt to put in a helical front diff, however would avoid a clutch pack front if you want to keep it streetable.

Will mainly be steering the car as tracking it in China would reduce its value a lot and mines a near mint condition v spec 2. Just weighing out the options for the next improvement. Thanks 

[Butters]

2 hours ago, joshuaho96 said:

What’s wrong with 2.6 first gear? I’ve done lots of 2nd gear starts from almost a dead stop and it just requires more clutch slip. A 2.6 first gear would be easier than that. I feel like the stock first gear is only good for severe traffic congestion where you need to be able to do 5 kph idling in first gear. Out in the US 120 kph is a very normal speed to be doing on the highways. If anything it’s slow, I regularly get passed by CA highway patrol doing that kind of speed. Out in the desert and plains even 18 wheelers are doing 130-140 kph.

Fair play on the 120k, sorry just live in nanny Aus.  High rpm on cruise would kill me too. 

 

On the gears, its not just first, so beside the fact I really enjoy that nice punch you get when you accel in first. 2nd is all messed up in the gearsets too. Most people I know with gearsets(even sequentials) have to drop into 1st for tarmac rally slower corners as second gear is too low in rpm, its painful. Translate to the street, I am using a 2.3 gear out of a low speed turn, gearset you got a 1.7 second. I can tell you now between my two cars which one is a LOT more fun.   

On a track its a different story, once the car is moving the gearset ratios are supreme, 1st gets you going on a big rpm launch, then 2nd is no issue for the corner speed on most tracks. 

 

Yer the price sucks  , old enough to remember these selling for $1500usd here in Aus. 

[Dose Pipe Sutututu]

3 hours ago, Sleepergm said:

Will mainly be steering the car as tracking it in China would reduce its value a lot and mines a near mint condition v spec 2. Just weighing out the options for the next improvement. Thanks 

Helical front diff, refresh the rear mechanical if needed and enjoy life.

 

Save that money for a twin scroll, single turbo setup and modernisation of the car such as DBW, cruise control via DBW, canbus keypad etc.

[Sleepergm]

43 minutes ago, Dose Pipe Sutututu said:

Helical front diff, refresh the rear mechanical if needed and enjoy life.

 

Save that money for a twin scroll, single turbo setup and modernisation of the car such as DBW, cruise control via DBW, canbus keypad etc.

Will look into the helical front diff thanks.  Sounds like everyone just says keep the rear as is. 👍🏻

[joshuaho96]

5 hours ago, Butters said:

Fair play on the 120k, sorry just live in nanny Aus.  High rpm on cruise would kill me too. 

 

On the gears, its not just first, so beside the fact I really enjoy that nice punch you get when you accel in first. 2nd is all messed up in the gearsets too. Most people I know with gearsets(even sequentials) have to drop into 1st for tarmac rally slower corners as second gear is too low in rpm, its painful. Translate to the street, I am using a 2.3 gear out of a low speed turn, gearset you got a 1.7 second. I can tell you now between my two cars which one is a LOT more fun.   

On a track its a different story, once the car is moving the gearset ratios are supreme, 1st gets you going on a big rpm launch, then 2nd is no issue for the corner speed on most tracks. 

 

Yer the price sucks  , old enough to remember these selling for $1500usd here in Aus. 

PAR specifically offers stock ratios in their gearset and you could do whatever ratios are physically possible supposedly for no extra cost. I agree 6 ratios is better than 5, the factory 2nd gear is equivalent to the Getrag 2nd gear if you account for the differing final drive ratio though. The Getrag 3rd gear with a 3.916 final drive is equivalent to a 1.6 2nd gear in the FS5R30A.

I'm about to swap the transmission out on my car, I'm tempted to send the one I have now out for rebuild with the standard "cross ratio" gearsets out there to see if it really makes such a big difference the next time I pull the transmission.

[Duncan]

Yeah PAR is all custom cut to order, so you can move the ratios around for what you need