Replacement Box For Gtr With Engine Mod

[Dohmar]

Heyas

I currently have 220kw on a stock gtr box which has a nasty synchro problem, (crunches 2nd, 3rd and 4th, very hard to shift into 1st at low motion). It had the shockproof oil in it when bought, whether that was the cause of the sync issue or an attempt to dampen the effect, I don't know. I only run mineral oil/semi synthetics in my boxes personally, not a fan of smurf blood.

I mainly street the car. I occasionally launch it and I do a little bit of drag racing too, but not much. Most of the time I'm just doing the usual driving, but I do like to have the gearbox change gears as quickly as possible (bear in mind that I have to be really gentle nowdays so I dont grind so much..).

Thing is, I'm gonna get new turbos and some other minor mods to try n get the engine to give me 300kw. Now, with that sort of power would the stock gearbox gears/synchros handle that enough? Depending on the answer to that, do I get a 2nd hand box, or just get my existing box's synchros/gears changed? I'm not aiming for anything super hardcore, but I don't want to spend any unnecessary cash...

Any suggestions would be greatly appreciated!

-D

Edited May 27, 2008 by Dohmar

[Snowman]

I'm running around with a 2nd hand R32 GTR gearbox in my car that has over 370rwkws and has run and won Dutton rallies which have over 70 lauches along with circuit work and 800m drags over 3 days and its never missed a beat.

Having said that when I 1st got my car I broke 2 gearboxes in the 1st 6 months I had it before I learned to drive.

[Angus Smart]

Getrag from a r34 GTR ftw!!

close ratio, nice and strong, synchro and 6 speed!!!

i think with whatever diff ratio i have it works out quiet nice, for street driving, track days and for the launch!

tho 60' times suffer a little but i'm not into drag racing at all.

[Dohmar]

I'm running around with a 2nd hand R32 GTR gearbox in my car that has over 370rwkws and has run and won Dutton rallies which have over 70 lauches along with circuit work and 800m drags over 3 days and its never missed a beat.

Having said that when I 1st got my car I broke 2 gearboxes in the 1st 6 months I had it before I learned to drive.

Thats pretty reassuring.... I think I'll stick with the 32 box, the 6 speed would be nice but I'm trying to keep it as inexpensive as possible.

So I'll probably get my current box reconditioned with new synchros, might cost me more than a straight 2nd hand box but at least I'll know its good for a while... that is unless someone out there is selling a 5 speed which they know is in good nick

thanks for your help guys... appreciate it!

-D

[Beer Baron]

Getrag from a r34 GTR ftw!!

close ratio, nice and strong, synchro and 6 speed!!!

i think with whatever diff ratio i have it works out quiet nice, for street driving, track days and for the launch!

tho 60' times suffer a little but i'm not into drag racing at all.

I'm not so sure about that. it's a nice street box, but lots of serious 34 GTRs I know of switch back to the 33/32 type boxes for any track or drag use.

edit: see snowmans post above...

[NoFX_Hardcore]

Yeah mate a standard box should handle 300kw no problems. It's all about how you drive it I guess. Apparently the R33 gearboxes were supposed to be slightly stronger than R32's? Anyone confirm?

[Angus Smart]

I'm not so sure about that. it's a nice street box, but lots of serious 34 GTRs I know of switch back to the 33/32 type boxes for any track or drag use.

edit: see snowmans post above...

Yerrp this is true, tho there are some big hp 34's that still run the box too.

tho then again mines got nismo goodies inside it.

[Piggaz]

Series 3.5 R33 GTR boxes have better synchro's.

3200 from just jap

[sh@un]

series 3.5?

that's a new one...

[Dohmar]

Series 3.5 R33 GTR boxes have better synchro's.

3200 from just jap

would like to know more dude, i know nowt about about synchros but thats where my problem lies atm.... theyre 18 yrs old, shagged and i need a good shift up to 300 kw....

-D

[Mr. Keets]

Greenline are doing a special on OS Giken 5 speed kits at the moment.

[sloutch]

Series 3.5 R33 GTR boxes have better synchro's.

3200 from just jap

I think he meant the 1999 R33.5 GTRs that came out 1 month before the R34 GTR came out.

[Beer Baron]

Yerrp this is true, tho there are some big hp 34's that still run the box too.

tho then again mines got nismo goodies inside it.

the 'nismo goodies' is just an upgraded input shaft. the stock getrag shaft has been known to twist especially when you have decent power and a hard core clutch. so nismo when they desinged a clutch kit added an upgraded input shaft to it. you get the input shaft when you buy a nismo 34 GTR clutch. but it doesn't do anything for the strength of the gears or the ratios, or the synchros. it's just one short little shaft that send power into the front of the box that is changed over. I would say whoever was using the box before you was using a nismo clutch with it hence the reason it had the input shaft in there from the clutch kit.

[GTS4WD]

Save yourself a bucketload of money and drop in a second hand GTR box.

GTR boxes should not be rooted with only 220kw.. Rb20 boxes shit themselfs and do in bearings and strip gears at that power, not GTR boxes

Perhaps previous owener just abused it?

How do you drive it? Heal and toe? Double clutch?

thats my 2c

Edited June 4, 2008 by GTS4WD

[GTS4WD]

Greenline are doing a special on OS Giken 5 speed kits at the moment.

How much?

Just gears or complete boxes?

[Mr. Keets]

discussion of my rebuild here

Greenline

you get 5 gears and the strengthened input shaft but you need a butt load of Nissan parts synchros gaskets seals etc. Or you can go the 3 speed kit...no input shaft

[Dohmar]

Save yourself a bucketload of money and drop in a second hand GTR box.

GTR boxes should not be rooted with only 220kw.. Rb20 boxes shit themselfs and do in bearings and strip gears at that power, not GTR boxes

Perhaps previous owener just abused it?

How do you drive it? Heal and toe? Double clutch?

thats my 2c

I do a little bit of heel/toe when going around a corner but really not much. I just drive around the city and try not to draw attention to myself. I've never double clutched (dont know anything about it). The previous owner did abuse the shite out of the box which is why they had the redline shockproof gunk in it. Its mainly the synchros which are rooted, the gears themselves feel really good. Just shifting into gear after acceleration can cause the grind... if I let the engine rev down to 3-4 it usually slips in OK but anything above 4k is grind city... Im mainly just curious cause the extra power I want to draw later on when I get turbos replaced. I don't think I need the OSG kit at all, and if the stock GTR boxes are as ballsy as their reputation leads me to believe, then I should be ok. Bear in mind its an 18 yr old gearbox which has undoubtably been thrashed out by its previous owner... thats the way I look at it at least. So if I can get a decent 2nd hand box I should be ok.... otherwise its synchro+thrust bearing replacement (which is probably more expensive?)

Not too sure really...

-D

[GTS4WD]

Well second hand GTR boxes can be found for about $1200

So I guess you got your answer

[ferni]

A lot to do with the clutch. Get a solid centre POS clutch that will break your gearbox, get a cushion center clutch that wont send shocks through the gearbox and its much harder to break.

R33 GTR Series 3 gearboxes have a bit stronger syncros. You can buy them brand new from justjap or nissan for about 3.2k. Or stick a 2nd hand 32/33 GTR box in for a grand or so.

[Dohmar]

A lot to do with the clutch. Get a solid centre POS clutch that will break your gearbox, get a cushion center clutch that wont send shocks through the gearbox and its much harder to break.

R33 GTR Series 3 gearboxes have a bit stronger syncros. You can buy them brand new from justjap or nissan for about 3.2k. Or stick a 2nd hand 32/33 GTR box in for a grand or so.

Yeah I got a 6puk Jim Berry clutch on its way for when I do fit the replacement box... with my old box, would it be worth selling as a shagged box to someone or getting it fixed incase I stuff up the replacement? Going to go with a stock 32 box, cant really afford 3.2k

-D