R34 GT-Four questions...

[GTSBoy]

The thing is, he has the 4.1 ratio in the engine, and that is the harder one to change.  Makes sense to keep that and put a new 4.1 centre in the rear, no?

[admS15]

Yes that does make sense, just giving my feedback as I've used both ratios and op was asking about the 4.3 ratio. Anyways, carry on.

[Steve85]

My car has 4.3s. It's too short for my liking. My car tops out at 270kph at racetracks (not the road before you all jump in).
It's ok on the road (twisties and freeway alike), but if you have anything north of 400whp its probably not a great plan.

If I could be bothered/have the money I'd get them shortened.

[KiwiRS4T]

1 hour ago, Steve85 said:

My car has 4.3s. It's too short for my liking. My car tops out at 270kph at racetracks (not the road before you all jump in).
It's ok on the road (twisties and freeway alike), but if you have anything north of 400whp its probably not a great plan.

If I could be bothered/have the money I'd get them shortened.

Yes especially as OP is not building a track car. Open road cruising at 3000 rev/min will soon become tiresome...even 4.1 is about 2700. Look for a complete GTR rear end ( I found one for $1200) and then you get the LSD, the axles, alloy hubs and 2 pot brakes.

[R34GTRSilver]

14 hours ago, admS15 said:

1st to 3rd is quite snappy. With 420whp, traction is a bit of an issue. If you can get it to grip, it goes like a rocket. 4th, the speed just keeps piling on.

You won't notice too much of a difference vs 4.11 other than a little quicker through the gears and a couple hundred higher rpm at cruising speed in 5th.

Yeah sounds great, thanks for the heads up.

I'm looking forward to the 4.3 as when i typed it online, it seems a fair few people have tried to convert 4.1 to 4.3 so must be for good reason.

My car will never see a track anyway, i strictly drive road only and the odd beating on a dual or motorway but nothing serious.

Traction will be because your running the stock 1 wheel spinning diff still aren't you?

If i put the super Q 1.5 way in the back, being 4wd it should grip better than a stock GTR shouldn't it?

Thanks

[admS15]

I have a kaaz lsd but im only rwd. Good tyres help. You won't have any issues with 4wd unless you have some rediculous amount of horsepower.

[R34GTRSilver]

Arr i see, sorry thought you were 4wd..  slightly lost track of who has what in these comments.

Do you have the normal Kaaz or the WPC treated super Q in yours?

And yeah tyre's do help, the super Q transformed my GTT. I have 295 35 18 PS2's on the rear which are good but i think there's still room for improvement with the supersports or the PS4S if i could get hold of them sizes.. there supposed to be mega sticky even in crap conditions.

Yeah the 4wd is the only reason iv bought this car so i can put the power down much better and use it more 

My GTT isn't worth taking out unless its a dry sunny day and the roads are better.. too much rain and greasy roads because of buses, so if it gets moist.. full boost is pointless on rwd

My M5 has a great mech LSD diff in it and they bring the torque in later so they let you put some power down before all hell brakes lose. 

 

[admS15]

Just an older normal kaaz. I run 265 yoko ad08r, they're not enough. R specs or proper drag radials get the power down much better.

[GTSBoy]

2 hours ago, R34GTRSilver said:

it seems a fair few people have tried to convert 4.1 to 4.3 so must be for good reason.

I told you why.  Almost always for drag.

Turbo cars on the road are almost always better with taller diff ratios.

[Steve85]

3 hours ago, GTSBoy said:

Almost always for drag.

 Turbo cars on the road are almost always better with taller diff ratios.

100%. The last owner of mine built it for drag purposes. I'm sure of it. 

I'm busy trying to make it a more useful road car. 

My advice would be stick with the 4.1s you'll be better off in the long run, especially if you go chasing power.
But as with all things. It's your car, you do you.

[R34GTRSilver]

I have a lot to do before I decide what ratio but I might try 4.3 first,

If i’m not happy I will just change to 4.1

There’s always stock for a GTR diff and rear shafts so il be fine if I need to get hold of them 

[GTSBoy]

It's engine out to change the front diff.  Just sayin'.....

[R34GTRSilver]

Okay il bear that in mind 

cheers 

[KiwiRS4T]

Guarantee you'll bang your head against a wall and say "why didn't I listen" if you go with 4.3!

[R34GTRSilver]

I have about 4 months to decide so il consider the 4.1 

 

If I go 4.1, Which would be the best diff to go for from the GTR’s? An R33?

 

[Steve85]

I have about 4 months to decide so il consider the 4.1 
 
If I go 4.1, Which would be the best diff to go for from the GTR’s? An R33?
 

I have Cusco diffs in mine. They're tight as anything. 1 way in the front and 1.5 in the back. They seem to do the job well.

[GTSBoy]

The consensus is that the best front diff is Quaiffe and the best rear diff is either another Quaiffe (for a streeter) or a Nismo pro.

There are always votes for the other brands, as per Steve above, and they are valid.  But I have a soft spot for how nicely helical diffs drive compared to tight mechanicals.

[R34GTRSilver]

13 hours ago, Steve85 said:

14 hours ago, R34GTRSilver said:

I have about 4 months to decide so il consider the 4.1 
 
If I go 4.1, Which would be the best diff to go for from the GTR’s? An R33?
 

I have Cusco diffs in mine. They're tight as anything. 1 way in the front and 1.5 in the back. They seem to do the job well.

Okay thanks, so for say the front diff, i can order an R33 GTR front diff and itll go in my 4.1 from the NEO Turbo 4wd engine or do i need to go for a stagea front 4wd diff fitment?

Rear isn't a problem as iv seen many options for that

Its the front that seems confusing.

The engine i'm buying is just down as an RB25DET Neo 4wd.. doesn't say if its from an R34 or Stagea.. I take it both diffs for the front are the same for them, just not sure if the GTR front diff internals will go in there

[R34GTRSilver]

10 hours ago, GTSBoy said:

The consensus is that the best front diff is Quaiffe and the best rear diff is either another Quaiffe (for a streeter) or a Nismo pro.

There are always votes for the other brands, as per Steve above, and they are valid.  But I have a soft spot for how nicely helical diffs drive compared to tight mechanicals.

Iv heard of Quaiffe but don't know much about them. I take it they specialize in Helical diff's.

I was going to leave the front diff stock to begin with anyway whether its 4.1 or 4.3, but the Rear i was going to upgrade 100% 

Il have a look at the Quaiffes and have a read up

[Steve85]

45 minutes ago, R34GTRSilver said:

Okay thanks, so for say the front diff, i can order an R33 GTR front diff and itll go in my 4.1 from the NEO Turbo 4wd engine or do i need to go for a stagea front 4wd diff fitment?

Rear isn't a problem as iv seen many options for that

Its the front that seems confusing.

The engine i'm buying is just down as an RB25DET Neo 4wd.. doesn't say if its from an R34 or Stagea.. I take it both diffs for the front are the same for them, just not sure if the GTR front diff internals will go in there

The truth here is i don't actually know if the GT-4 is the same mechanical setup at as GTR. 
This is where my knowledge starts to run out. At the risk of being an internet jerk, see if you can search here for the data. 

Surely someone else has done something similar before. (crosses fingers on ambiguous advice).