# gearing down a R34 with 33 or gts-4 diffs questions.



## mattysupra (Oct 31, 2008)

o.k, following on from this thread - http://www.gtr.co.uk/forum/116388-gts-4-diffs-r32-gtr-top-speed-8000rpm.html

I have started a new thread as this thread is about 32 gtr's and i would like to know about 34 gtr's!


So to save you all reading the other thread (the lazy people LOL) im at this point-

I want to gear down the 34 GTR. I think this is what MINES did to there 34 gtr?

So i was looking into fitting Gts-4 diffs. But as the gearing is different on the 34 due to different gearbox, well will i be gearing it down to much? 

I belive that 33 gtr diffs are a lower ratio to the 34 gtr? would these be a better option? 

As my car is a V-spec with a electronic diff???? would i be causing problems doing this?


Do i just swap the crown wheel and pinion? or the whole diff? 


would i reduce my quarter time? or increase it due to another gear change? 


Also could someone work out what what sort of top end i would be looking at with both gts-4 diffs and R33 GTR diffs please? 


Sorry for all the questions! :thumbsup:


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## GTaaaaaarrrrrr! (May 4, 2006)

Hi Matty, this is exactly what I did with my 34 :thumbsup: From memory, Tweenie changed the crown wheel and pinions to that of an R32 (4.11). This lost me around 15mph off my top speed (185mph theoretical maximum) but sharpened up the cars pick up. It probably slowed it down over the 1/4 mile because I ran out of revs in fourth gear (circa 120mph) so I needed four gear changes :lamer:





mattysupra said:


> o.k, following on from this thread - http://www.gtr.co.uk/forum/116388-gts-4-diffs-r32-gtr-top-speed-8000rpm.html
> 
> I have started a new thread as this thread is about 32 gtr's and i would like to know about 34 gtr's!
> 
> ...


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## mattysupra (Oct 31, 2008)

i was hoping you would reply as i know you did this with tweenie! 



What quarter did you run tho? 

Also you had some engine work etc done at the same didn't you? so am i right saying that you never ran the car with the same BHP with both diff set ups?

what power you running also?


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## R.I.P.S NZ (May 7, 2004)

theoreticly your acceleration will be quicker as long as you have the grip but the extra gear change "may" counteract the gians you get.

I had 4.4s in a GTS4 about 7 years ago, with around 550-600whp we ran 10.2 with a stock box and 4 full off throttle gear changes.......here's the vid:

YouTube - RIPS RB30 GTS4 10.2 @ 134mph www.ripsltd.com

Rob


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## mattysupra (Oct 31, 2008)

cheers robby, did you get my pm by the way about the diffs? 


Well i think i would like to gear the car down but i would like to hope for around the same sort of quarter time. I guess the problem depends on how quick you are and if you need 4th gear in the first place? 

I cant see the point in having a car geared to do 180+ mph when you will never hit these speeds. 

I want my car to run a 10! (i dont care if its 10.999!) But i will only have around 600 bhp (flywheel). Also i hope to do this with full trim. is this possible? would the diffs help me as i should not need the extra gear change?


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## R.I.P.S NZ (May 7, 2004)

yeah I have the PM,....... for what you want, I'd go with 4.1s, get some good tyres, old stock suspension and get as much weight out of it as you can, then with a good drive, a 60ft in the 1.4s or low 1.5s you should be able to get a 10 with 600hp.

Rob


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## GTaaaaaarrrrrr! (May 4, 2006)

Best 1/4 I ran was 11.2 with about 640hp and full weight mate (with the 4.11 diff set up). You are correct that I never ran the same power with the different gearing set ups. I reckon you have got your work cut out to run a 10 second quarter with full weight and 600hp even if you run on drag tyres :bawling:



mattysupra said:


> i was hoping you would reply as i know you did this with tweenie!
> 
> 
> 
> ...


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## mattysupra (Oct 31, 2008)

GTaaaaaarrrrrr! said:


> Best 1/4 I ran was 11.2 with about 640hp and full weight mate (with the 4.11 diff set up). You are correct that I never ran the same power with the different gearing set ups. I reckon you have got your work cut out to run a 10 second quarter with full weight and 600hp even if you run on drag tyres :bawling:


Ye i figured that lol, i was aiming for a 11 but after what "cliff" has managed on stock tubs etc i decided i/you also should be able to see a 10 ! 

Your power is flywheel? 

are you running the 2530 turbos tweenie had lying around ?


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## mattysupra (Oct 31, 2008)

R.I.P.S NZ said:


> yeah I have the PM,....... for what you want, I'd go with 4.1s, get some good tyres, old stock suspension and get as much weight out of it as you can, then with a good drive, a 60ft in the 1.4s or low 1.5s you should be able to get a 10 with 600hp.
> 
> Rob


just so im clear, the 4.1's are 32/33 gtr diffs that i only need to change the crown and pinnion to my 34 diffs so worries with the electronic lsd etc?


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## GTaaaaaarrrrrr! (May 4, 2006)

mattysupra said:


> Ye i figured that lol, i was aiming for a 11 but after what "cliff" has managed on stock tubs etc i decided i/you also should be able to see a 10 !
> 
> Your power is flywheel?
> 
> are you running the 2530 turbos tweenie had lying around ?


Flywheel power mate, yes. The turbos were new 2530's and the car is now sold. With NOS installed and running on race gas it ran a comfortable 10.7 at Santa Pod :thumbsup:


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## mattysupra (Oct 31, 2008)

GTaaaaaarrrrrr! said:


> Flywheel power mate, yes. The turbos were new 2530's and the car is now sold. With NOS installed and running on race gas it ran a comfortable 10.7 at Santa Pod :thumbsup:


It was you that stole them 2530's from under my nose then lol! 

They was going to be fitted to my car but you got there quicker :thumbsup:

you have 32 now then? how come you got rid of the 34?


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## mattysupra (Oct 31, 2008)

did you run direct port or single fobber nos? 

how much?


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## GT-R Glenn (Nov 9, 2002)

Matty 
http://www.gtr.co.uk/forum/104443-your-top-speed-5.html

Find the Gearcalc app ....
Work it out for yourself...its easy 
Punch in the gearbox ratios, tire size MAX RPM / it will work it all out for you,


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## Sub Boy (Jan 28, 2008)

I think the big thing to find out Matty (As I'm not sure on this also) is can you put Crown and Pinions from a NON V-Spec diff onto a car that HAS a V-Spec diff centre(A-LSD)???


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## GTaaaaaarrrrrr! (May 4, 2006)

mattysupra said:


> It was you that stole them 2530's from under my nose then lol!
> 
> They was going to be fitted to my car but you got there quicker :thumbsup:
> 
> you have 32 now then? how come you got rid of the 34?


32 owner now :thumbsup: Just had too much money tied up with the 34 mate 

I was a single fogger shot, 75hp and cost about a grand fitted from memory. It made quite a bit of difference on the strip mate :smokin:


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## mattysupra (Oct 31, 2008)

GT-R Glenn said:


> Matty
> http://www.gtr.co.uk/forum/104443-your-top-speed-5.html
> 
> Find the Gearcalc app ....
> ...


thanks, where can i find the gear box ratio? i will try a search


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## mattysupra (Oct 31, 2008)

Sub Boy said:


> I think the big thing to find out Matty (As I'm not sure on this also) is can you put Crown and Pinions from a NON V-Spec diff (A-LSD) onto a car that HAS a V-Spec diff centre???


can anyone else answer this for me?


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## GT-R Glenn (Nov 9, 2002)

Ok from memory
3.83
2.36
1.6
1.3
1
.79

GTS4's would IMO be too short with that gearbox....
If you search here for guys that have fitted the 6 speed into the 32 or 33..ask them how useable 1st gear is ....
So altho its definatly doable you might end up effectively with a 5 speed as 1st will be useless...
My os 5 speed has similar ratios but my 1st is like your second etc:...
So im saying the 4 ratio into a 3 or 2 is good, into a 4 might render the 6 speed , a 5 speed, which isnt necessary a bad thing either ....


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## tyndago (Oct 24, 2002)

Some trans gear ratios and info - tyndago - GT-R Transmissions

Stock R34 is 3.545
Stock R32-R33 is 4.111

I ran an R32 with a Getrag and 4.111, and it wasn't too short. 

Mr Tamura says 3.7 is best. However that ratio, getting my hands on one is a little harder than it is for him to get his hands on it. 

You have at least 8,000 rpms, and if you rev it higher, you get more mph's...


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## Sub Boy (Jan 28, 2008)

Sub Boy said:


> I think the big thing to find out Matty (As I'm not sure on this also) is can you put Crown and Pinions from a NON V-Spec diff onto a car that HAS a V-Spec diff centre(A-LSD)???


Sorry Matty, I [email protected] that up and have now changed it.

So....Can someone answer the above question for Matty?:sadwavey:


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## blue34 (Jul 28, 2005)

ill post proper rreply tomorrow as on phone have fitted 33 4.1 diffs to my 34 vspec. Front is cwp swap rrear cwp must be from a vspec but easieer to just fit a 33 vspec diff. I also have a 6 speed sequential so have a taller first gear. Equalled my best time of 11.07 second run end of last season but not been out since. All i would say is get used to steering with one hand as gear changes are needed very close together with lower diffs. My 6th is very slightly taller giving in theory 203mph 8500revs i also have a jun 2.7 bottom end.


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## mattysupra (Oct 31, 2008)

blue34 said:


> ill post proper rreply tomorrow as on phone have fitted 33 4.1 diffs to my 34 vspec. Front is cwp swap rrear cwp must be from a vspec but easieer to just fit a 33 vspec diff. I also have a 6 speed sequential so have a taller first gear. Equalled my best time of 11.07 second run end of last season but not been out since. All i would say is get used to steering with one hand as gear changes are needed very close together with lower diffs. My 6th is very slightly taller giving in theory 203mph 8500revs i also have a jun 2.7 bottom end.


thanks for thr reply, what power are you pushing? and is your time on stock tyres?

You say you have a taller 1st gear? Would you be better lauching the car in second gear to save one gear change or do you still need first gear?


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## GTaaaaaarrrrrr! (May 4, 2006)

mattysupra said:


> thanks for thr reply, what power are you pushing? and is your time on stock tyres?
> 
> You say you have a taller 1st gear? Would you be better lauching the car in second gear to save one gear change or do you still need first gear?


Don't be a wuss, use first gear  Seriously, I think first gear is fine but when you are launching at 7k RPM then second does come mighty quick so you have to be ready, hence the one hand on the wheel comment :thumbsup:


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## xxfr (Apr 28, 2009)

Mattysupra, any updates on this. 

I am paying a keen interest. 

Will be good to get some hard facts. 

Mattysupra is your 34 a V-Spec or above? What internals and turbos are you currently running?


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## moleman (Jun 3, 2002)

There aren't enough threads on this. 

Tamura-San told me that 3.7 diffs are best. Good spread of gears for road/track and almost on the dot 200mph at 8krpm. Nismo 3.7's ain't cheap though.

4.111s with stock 34 tyre size gives a top end of 187mph at 8krpm.

4.375 is 176

Stock is 217.


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## GT4 Addicted (Feb 16, 2005)

i'm thinking about doing this 4.11 conversion too... really interesting thread.


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## mattysupra (Oct 31, 2008)

xxfr said:


> Mattysupra, any updates on this.
> 
> I am paying a keen interest.
> 
> ...



Mine is a v-spec. Howevermy car has a broken piston at the moment so i have not moved any closer to changing the diffs.


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## gibson (Feb 21, 2005)

good thread.. So the r33 v-spec rear diff complete and a r33 front CWP will do the job...

better response 

lower top end speed


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## mattysupra (Oct 31, 2008)

gibson said:


> good thread.. So the r33 v-spec rear diff complete and a r33 front CWP will do the job...
> 
> better response
> 
> lower top end speed


As i understand thats correct.


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## blue34 (Jul 28, 2005)

welllll not neccesarily I haven't yet been able to rev mine out to 8500 with the 4.1 diffs with a theoretical 203mph - so actually it's probably no slower top end with the 4.1 diffs than it was before.

It is more responsive but you do need more gear changes, however that's not a problem with the sequential. I have reduced my best 1/4 only very slightly slightly though to 11.003 with an additional gear change (should have left my socks off for 10 lol!). But I can crack off very low 11s now pretty consistently when I need to. 

I've just changed the whole fuel system so with a little mapping I hope I'll be getting very high, 10s by the next HKS round ie 4 thousands of a second quicker!. 

With a weight of 1752 kilos including my lardy arsss I'm quite happy with the small incremental improvements. Coupled with some practice off the lights and a slightly slower HKS Series field this year I'm doing OK..

I'll have my first go on track this weekend with a 15min session at Castle Coombe - sequential will be hard work to get right on track


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## DrGtr (Jul 18, 2009)

Where can you buy them? blue34 how much did you pay for them? is it really worthed? 
do you thing on a 2.8 with 2860-5 will be an overkill ? did you noticed a lot of difference it pulls much faster? I am curious to see what will be the result on my set up.


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## nismo.gt500 (Apr 19, 2007)

I have just changed my gearbox to a 34 getrag, from a uprated 33 whit os gearkit..
And i must say, its much better than i expected, its just so much more fun to drive on the track, and street. the gears are just gone in a splitsecond. :chuckle:
The car drives 65kmh. in 1 gear and 120 in 2. and it is reving to 9400rpm.
The car have done a 11,23 on 19 inch falken 452 and in fully street trim whit the old box.
I will find out how much slower it goes whit the new box on the 6th of june.


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## GT-R Glenn (Nov 9, 2002)

Theres very little difference between the two gearboxes as far as ratio's go, after you forget 1st gear in the 6 speed.

This is the os type a vs the 6 speed getrag / on 255/40/17's with a 4.11 final ratio
All things equal.


OS BOX


Gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 10.43 94 94
2 16.51 149 149
3 22.81  205 205
4 28.06 253 253
5 34.22 308 308

Km/h RPM (in Gears)
-------------------------------------------------
1 2 3 4 5 
-------------------------------------------------
10 959 606 438 356 292
20 1917 1212 877 713 584
30 2876 1818 1315 1069 877
40 3835 2423 1753 1426 1169
50 4794 3029 2192 1782 1461
60 5752 3635 2630 2138 1753
70 6711 4241 3069 2495 2046
80 7670 4847 3507 2851 2338
90 8628 5453 3945 3208 2630
100 6059 4384 3564 2922
110 6665 4822 3920 3215
120 7270 5260 4277 3507
130 7876 5699 4633 3799
140 8482 6137 4990 4091
150 6575 5346 4384
160 7014 5702 4676
170 7452 6059 4968
180 7891 6415 5260
190 8329 6771 5553
200 8767 7128 5845
210 7484 6137
220 7841 6429
230 8197 6722
240 8553 7014
250 8910 7306
260 7598
270 7891
280 8183
290 8475
300 8767

Gear Change RPM drop (change @9000) RPM drop (change @9000)
-------------------------------------------------------------
1 -> 2 -3312 (to 5688) -3312 (to 5688)
2 -> 3 -2488 (to 6512) -2488 (to 6512)
3 -> 4 -1683 (to 7317) -1683 (to 7317)
4 -> 5 -1620 (to 7380) -1620 (to 7380)


6 Speed Getrag

Gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 7.35 66 66
2 11.89 107 107
3 16.70 150 150
4 21.58 194 194
5 28.06 253 253
6 35.38 318 318

Km/h RPM (in Gears)
----------------------------------------------------------
1 2 3 4 5 6 
----------------------------------------------------------
10 1361 841 599 463 356 283
20 2723 1682 1197 927 713 565
30 4084 2523 1796 1390 1069 848
40 5446 3364 2395 1853 1426 1130
50 6807 4205 2994 2317 1782 1413
60 8169 5047 3592 2780 2138 1696
70 5888 4191 3243 2495 1978
80 6729 4790 3707 2851 2261
90 7570 5389 4170 3208 2544
100 8411 5987 4633 3564 2826
110 6586 5096 3920 3109
120 7185 5560 4277 3391
130 7784 6023 4633 3674
140 8382  6486 4990 3957
150 8981 6950 5346 4239
160 7413 5702 4522
170 7876 6059 4805
180 8340 6415 5087
190 8803 6771 5370
200 7128 5652
210 7484 5935
220 7841 6218
230 8197 6500
240 8553 6783
250 8910 7066
260 7348
270 7631
280 7913
290 8196
300 8479
310 8761

Gear Change RPM drop (change @9000) RPM drop (change @9000)
-------------------------------------------------------------
1 -> 2 -3440 (to 5560) -3440 (to 5560)
2 -> 3 -2593 (to 6407) -2593 (to 6407)
3 -> 4 -2036 (to 6964) -2036 (to 6964)
4 -> 5 -2077 (to 6923) -2077 (to 6923)
5 -> 6 -1863 (to 7137) -1863 (to 7137)



//////////////////////////////////////////////////////////////////


And here side by side ....

OS

Gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 10.43 94 94
2 16.51 149 149
3 22.81 205 205
4 28.06 253 253
5 34.22 308 308

Getrag
Gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 7.35 66 66
2 11.89 107 107
3 16.70 150 150
4 21.58 194 194
5 28.06 253 253
6 35.38 318 318



*The exact same thing with a 4.375 Ratio*
Getrag + 4.375 ratio



Gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 6.90 62 62
2 11.17 101 101
3 15.69 141 141
4 20.28 182 182
5 26.36 237 237
6 33.24 299 299

Km/h RPM (in Gears)
----------------------------------------------------------
1 2 3 4 5 6 
----------------------------------------------------------
10 1449 895 637 493 379 301
20 2898 1791 1275 986 759 602
30 4348 2686 1912 1480 1138 903
40 5797 3581 2549 1973 1517 1203
50 7246 4477 3187 2466 1897 1504
60 8695 5372 3824 2959 2276 1805
70 6267 4461 3452 2656 2106
80 7163 5099 3945 3035 2407
90 8058 5736 4439 3414 2708
100 8953 6373 4932 3794 3008
110 7011 5425 4173 3309
120 7648 5918 4552 3610
130 8286 6411 4932 3911
140 8923 6905 5311 4212
150 7398 5691 4513
160 7891 6070 4813
170 8384 6449 5114
180 8877 6829 5415
190 7208 5716
200 7587 6017
210 7967 6318
220 8346 6619
230 8726 6919
240 7220
250 7521
260 7822
270 8123
280 8424
290 8724

Gear Change RPM drop (change @9000) RPM drop (change @9000)
-------------------------------------------------------------
1 -> 2 -3440 (to 5560) -3440 (to 5560)
2 -> 3 -2593 (to 6407) -2593 (to 6407)
3 -> 4 -2036 (to 6964) -2036 (to 6964)
4 -> 5 -2077 (to 6923) -2077 (to 6923)
5 -> 6 -1863 (to 7137) -1863 (to 7137)


OS + 4.375 Ratio

gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 9.80 88 88
2 15.51 140 140
3 21.43 193 193
4 26.36 237 237
5 32.15 289 289

Km/h RPM (in Gears)
-------------------------------------------------
1 2 3 4 5 
-------------------------------------------------
10 1021 645 467 379 311
20 2041 1290 933 759 622
30 3062 1935 1400 1138 933
40 4082 2580 1867 1517 1244
50 5103 3225 2333 1897 1555
60 6123 3870 2800 2276 1867
70 7144 4515 3266 2656 2178
80 8164 5159 3733 3035 2489
90 5804 4200 3414 2800
100 6449 4666 3794 3111
110 7094 5133 4173 3422
120 7739 5600 4552 3733
130 8384 6066 4932 4044
140 6533 5311 4355
150 6999 5691 4666
160 7466 6070 4977
170 7933 6449 5288
180 8399 6829 5600
190 8866 7208 5911
200 7587 6222
210 7967 6533
220 8346 6844
230 8726 7155
240 7466
250 7777
260 8088
270 8399
280 8710

Gear Change RPM drop (change @9000) RPM drop (change @9000)
-------------------------------------------------------------
1 -> 2 -3312 (to 5688) -3312 (to 5688)
2 -> 3 -2488 (to 6512) -2488 (to 6512)
3 -> 4 -1683 (to 7317) -1683 (to 7317)
4 -> 5 -1620 (to 7380) -1620 (to 7380)




6 Speed
Gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 6.90 62 62
2 11.17 101 101
3 15.69 141 141
4 20.28 182 182
5 26.36 237 237
6 33.24 299 299

OS
gear Km/h per 1000 RPM Km/h @9000 RPM Km/h @9000 RPM
--------------------------------------------------------
1 9.80 88 88
2 15.51 140 140
3 21.43 193 193
4 26.36 237 237
5 32.15 289 289


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## RSVFOUR (May 1, 2006)

could we have a bit more detail please


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## DrGtr (Jul 18, 2009)

Thanks GT-R Glenn 

But this is just to compare the 2 gearboxes over an r32 or r33 in this occasion i agree there similar but much better for time attack and drag is the os g, and for drift the getrag but what about comparing the standard getrag 3.545 with 4.111 with same gearbox?? 
Ok this is what i found:
All the below are in MPH.
Normal gtr 34 3,545 diffs
245/40/18



Rpm Gear ratio 
1st	2nd	3rd	4th	5th	6th
3,827	2,36	1,685	1,312	1	0,793

1000	5,8	9,4	13,1	16,9	22,1	27,9
2000	11,6	18,7	26,2	33,7	44,2	55,8
3000	17,3	28,1	39,4	50,6	66,3	83,6
4000	23,1	37,5	52,5	67,4	88,4	111,5
5000	28,9	46,8	65,6	84,3	110,6	139,4
6000	34,7	56,2	78,7	101,1	132,7	167,3
7000	40,4	65,6	91,9	118,0	154,8	195,2
8000	46,2	74,9	105,0	134,8	176,9	223,1
9000	52,0	84,3	118,1	151,7	199,0	250,9


Normal gtr 34 and this is with the 4.111 difs
245/40/18
Rpm Gear ratio 
1st	2nd	3rd	4th	5th	6th
3,827	2,36	1,685	1,312	1	0,793

1000	5,0	8,1	11,3	14,5	19,1	24,0
2000	10,0	16,2	22,6	29,1	38,1	48,1
3000	14,9	24,2	33,9	43,6	57,2	72,1
4000	19,9	32,3	45,3	58,1	76,3	96,2
5000	24,9	40,4	56,6	72,7	95,3	120,2
6000	29,9	48,5	67,9	87,2	114,4	144,3
7000	34,9	56,6	79,2	101,7	133,5	168,3
8000	39,9	64,6	90,5	116,3	152,5	192,3
9000	44,8	72,7	101,8	130,8	171,6	216,4


Maybe its not 100% accurate due to the formula i used but you can see the big difference of speed due to change of the diffs. so for the r34 does make a big difference. I would say that the 3.7 diffs would be the best combination but i have not found any info for the anywhere.
But i still don't know where you can buy them and for how much does anyone knows


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## Madden (Nov 14, 2004)

I think you should do it mate.

Its only 1st that is short so have a go at launching in 2nd :chuckle: ( which is close to what the ratio for the os giken 1st gear)

I change into 5th well before the line but it hasn't slowed me a bit mate. On the stock box i was doing 11.1's at 133 mph and with the getrag i was doing 11.1 @129 mph. hahaha

Just done a 10.7 with 550 hubs and that was a bad run. Going back for a 10.4 

Also my top speed at marham was 187.3 mph at 8500 rpm on 6th on the limiter  Worn tires though. 

Real good for my big single turbo as it keeps it on boost


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## DrGtr (Jul 18, 2009)

I will have to give a call to Japan i guess to find out , i am curious for those 3.7 . Maybe above 650 hp crank will not be a good idea for the 4.111 though who knows.


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## blue34 (Jul 28, 2005)

4.11 diffs work well in 34s - and they are readily available out of any 33gtr... who needs the 3.57 theoretical 250mph top end... unless you are tuning for the salt flats..


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## DrGtr (Jul 18, 2009)

Its not for the 250 miles its about drivability and performance wise, i thing for the time being on a 2.8 litre i would try first as it is and if it doesnt pull like a train i will prob try it


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## greyBnr32 (Aug 29, 2006)

very good info, off to the phone for prices on parts...lol


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## rb30r34 (Jun 30, 2008)

DrGtr said:


> I will have to give a call to Japan i guess to find out , i am curious for those 3.7 . Maybe above 650 hp crank will not be a good idea for the 4.111 though who knows.


Why would that diff ratio not be good at that power level? I'm putting 4.3's into my r32 which is effectively the same as putting 4.11 into an r34 and ill be way over 650 crank hp.


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## DrGtr (Jul 18, 2009)

rb30r34 said:


> Why would that diff ratio not be good at that power level? I'm putting 4.3's into my r32 which is effectively the same as putting 4.11 into an r34 and ill be way over 650 crank hp.


So you are the one who can finaly let as know how it is your expiriance first with that setup keep us posted, when are you going to fit them? If you have a chance make some time testing 0-100km, before and after and if you can at a track count the time of some laps before and after. For drag we already know for time attack we dont.


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## xxfr (Apr 28, 2009)

So we have to do both the front and the rear diffs to 4.11 for this to work on a 34? Just the rear will not work?

Also any ideas on what which cars diffs would be ideal for a r34 gtr non-vspec model? The r33 vspec ones are good for the v-specs and above but what would be ideal for a non-vspec.


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## Sub Boy (Jan 28, 2008)

xxfr said:


> So we have to do both the front and the rear diffs to 4.11 for this to work on a 34? Just the rear will not work?
> 
> Also any ideas on what which cars diffs would be ideal for a r34 gtr non-vspec model? The r33 vspec ones are good for the v-specs and above but what would be ideal for a non-vspec.


Yes both front and rear are required, or the transfer box will melt it's self!

You can run the R32 and R33 Non Vspec diffs front and rear in your non Vspec R34.


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## xxfr (Apr 28, 2009)

Sub Boy said:


> Yes both front and rear are required, or the transfer box will melt it's self!
> 
> You can run the R32 and R33 Non Vspec diffs front and rear in your non Vspec R34.


Thanks mate. Its for a friend's car and we are doing all the research before getting the necessary parts.

Would we be able to do a straight up diff swap front and rear or will it be CWP for both? 

Cheers.


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## mattysupra (Oct 31, 2008)

xxfr said:


> Thanks mate. Its for a friend's car and we are doing all the research before getting the necessary parts.
> 
> Would we be able to do a straight up diff swap front and rear or will it be CWP for both?
> 
> Cheers.



from waht i have worked out, you can do a straight swap. The pinion etc only needs changing if swapping the insides of diff only. 

Get that confirmed tho!


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## xxfr (Apr 28, 2009)

mattysupra said:


> from waht i have worked out, you can do a straight swap. The pinion etc only needs changing if swapping the insides of diff only.
> 
> Get that confirmed tho!


Thanks.

Any ideas if the v-spec diffs can be installed in a non-vspec car to gain the LSD?


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## Sub Boy (Jan 28, 2008)

xxfr said:


> Thanks.
> 
> Any ideas if the v-spec diffs can be installed in a non-vspec car to gain the LSD?


Both are LSD on the back, but the Vspec has the Active diff(The front diff is the same on both Vspec and Non)

By just putting the Vspec diff in will not get you the Active system, And no you should only be replacing Non with Non.


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## tyndago (Oct 24, 2002)

Sub Boy said:


> Yes both front and rear are required, or the transfer box will melt it's self!
> 
> You can run the R32 and R33 Non Vspec diffs front and rear in your non Vspec R34.


Actually what will happen is the car reacts violently. On an engine swap one day, way back when, someone mixed an R32/R33 diff with an R34 diff. As soon as you started to get some power to the front wheels, the car started to go into violent bucking. 

Took us a little while to figure out exactly what it was. It almost felt like a hard fuel cut.

Live and learn. 

Vspec diffs have an extra hydraulic feed line to the diff and from the ATTESA pump. The pump controls the lockup of the diff. So you need the diff, the pump, the ATTESA ECU, and some wiring to make it work. Its not impossible, as we did put a Vspec diff on an R32 GT-R, but its impractical for most people.


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## rb30r34 (Jun 30, 2008)

DrGtr said:


> So you are the one who can finaly let as know how it is your expiriance first with that setup keep us posted, when are you going to fit them? If you have a chance make some time testing 0-100km, before and after and if you can at a track count the time of some laps before and after. For drag we already know for time attack we dont.


Cant do any before the change testing sorry, when the car was pulled apart it was a standard rb26 etc. The diffs are been changed at the same time as the engine upgrade, going to a full noise rb30.

In theory it should be awesome on the track, expecially on really twisty stuff. Top speed wont be an issue for me either as the straights on our racetracks are not long enough to hit 9k ish rpm in 5th gear.

Ill keep you posted.


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## DrGtr (Jul 18, 2009)

Never mind if i decide to change the diffs i will do this kind of test, just let us know your results and opinion about the ratios even with the rb30, how many horses are you planing will appreciate it.


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## rb30r34 (Jun 30, 2008)

DrGtr said:


> Never mind if i decide to change the diffs i will do this kind of test, just let us know your results and opinion about the ratios even with the rb30, how many horses are you planing will appreciate it.


Around the same as the high octane r34. Its got hks GTRS's on a very good head with all the fruit so around 800.


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## DrGtr (Jul 18, 2009)

I thought that they were running 2860-5 on that rb30 someone mentioned it i thing on a video


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## Sub Boy (Jan 28, 2008)

DrGtr said:


> I thought that they were running 2860-5 on that rb30 someone mentioned it i thing on a video


On their early runs they were, Now it has GT-RS turbos.


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## rb30r34 (Jun 30, 2008)

^^^ What he said, my setup is the same as theirs, both dry sump and everything.

They have lowered their diff ratio too.


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## Dave C (Mar 19, 2010)

Is £1000 about the right price for an R33 front and rear diff.

Seems a shame to pay so much and then end up throwing most of the diff away as i would only be salvaging the crown wheel and pinion from the front and rear diff for a 4.1 conversion on an R34 (vspec)

Do they sell the crown and pinion wheel separately?

Any breakers fancy selling me just the bits i need?


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## BenTaylor200 (Dec 5, 2001)

You should be able to find a set for closer to £600


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## Dave C (Mar 19, 2010)

BenTaylor200 said:


> You should be able to find a set for closer to £600


Thanks for that :thumbsup: £600 sounds much better. I'll see what Nissan say first for just the parts then head to eBay and keep an eye on the breaking section too


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## nismo.gt500 (Apr 19, 2007)

Dave C said:


> Thanks for that :thumbsup: £600 sounds much better. I'll see what Nissan say first for just the parts then head to eBay and keep an eye on the breaking section too


I might have a set off what you need from the time i had a 33 gtr 
I went the other way with a 34 drivetrain in the 33
I can look today and Ifi have you can have for 250£


Send me a mail [email protected]


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## Dave C (Mar 19, 2010)

Sounds ideal, will email you later

Thanks


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