GTR Gearbox Poll

[SkylineMannen]

Have in my car when a swedish reporter from a famus motor show test drived the car for a hole day and miss shifted from 2nd to 3rd gear always, burned the synkronosations on the 3rd gear alot and brokend (in half) the inner cone!

Yeah, this morning at 0500 was the work complete in the garage whit all things new included the gear on 3rd and all synkros @ 4th gear allsow so now still it when to se if it is working pleasent for tonight final in street / Drag event here in sweden!

But overall about getrags to the bnr34, Always heard it is bullet proof etc etc but is is really BullS**t! Maybe it can survive better whit less power!?! Next thing to do is a crossmission!


Only my tought´s!

Regards Klaus!

[gavman]

i had heard that the getrag wasn't as strong as the previous five-speeder

[Piggaz]

Have got a brand new R33 GTR late model gearbox that is 6000 kms old behind a 2.8 litre with twin GT - RS's holding up fine. So far has run a 11.2 @ 130 MPH

[Smokey 1]

OS GIKEN 12345, mint thanks

[icydude]

Originally Posted by Floyd

I remember reading somewhere that the Toyota 6speed R160 getrag box is the same as the R34 getrag, perhaps there's someone who can confirm this, or tell me I'm wrong?

yes the r160 uses many of the same components.

contact toyota for rebuild pieces.

[tokes]

I just don't get how the toyota V160 can be so bulletproof and the GTR one seems to tear apart. A guy on supraforums just posted his dyno of 1400 RWHP and 1000 RWTQ through a stock 6-speed, and people on here are breaking them at less than 1/2 the power!

[Terry & Jane]

Morning all,

I've been looking for hours trying to find the gearbox and diff oil capacities , can anyone please help?

Did quite a bit of reading on such matters last night and Redline's 75W90 NS sounds excellent for gearboxes with problems. They leave out the friction modifiers added for LS diffs so the synchros come to equal speed more quickly, got to be worth a try

By the way my box is not good into 2nd and sometimes 3rd, gets a bit better when things warm up

[icydude]

Originally Posted by tokes

I just don't get how the toyota V160 can be so bulletproof and the GTR one seems to tear apart. A guy on supraforums just posted his dyno of 1400 RWHP and 1000 RWTQ through a stock 6-speed, and people on here are breaking them at less than 1/2 the power!

The only thing in my head that could cause this would be the additional torsional stresses of having a transfer case hanging off the side at the back. then on top of that not being constant. If you have ever seen the chain running in there you would see it is made for immense power. Something makes me think the hydro clutch plates locking and unlocking would cause huge stress on the case.


The reason that 3rd usually kills itself in 5 speed boxes is from case flex when the helical gears climb themselves to death. that is if you dont shift hard and destroy it that way prematurely.

[Chris Wilson]

Originally Posted by tokes

I just don't get how the toyota V160 can be so bulletproof and the GTR one seems to tear apart. A guy on supraforums just posted his dyno of 1400 RWHP and 1000 RWTQ through a stock 6-speed, and people on here are breaking them at less than 1/2 the power!

Can you tell bullshit when you find it? 1000 lbs ft torque is enough to tear up the CWP, the propshaft and the gearbox in a MKIV Supra. The reason the similar internals in the box box of the MKIV Supra twin turbo survive better is the car is very traction limited. The torque in actual driving can't build very high, the rear tyres just lose traction. In a 4WD GTR, with more weight, and a LOT better traction, the torque will build, and overstress the internals even more. The transmission is good, but does anyone HONESTLY believe Getrag over engineered the thing to take 1000 ft lbs of torque? It's madness to even consider this as realistic. It's a strong box, but nothing special, the gear centreline spacing and tooth width alone is enough for anyone with transmission knowledge to see that it will have fairly modest limitations over its design torque / rpm curve. It's got helical teeth, which will give immense end thrusts at 1000 ft lbs, Jeez, I can't be bothered continuing, the stuff the Yanks on the US Supraforums site come up with is just an insult to the intelligence of anyone who does the maths...

[icydude]

also have the r160 and the r161.

there are two variations with different ratios.



and traction has nothing to do with it, that supra just ran 1400whp through it's getrag with traction.

[tokes]

Originally Posted by Chris Wilson

Can you tell bullshit when you find it? 1000 lbs ft torque is enough to tear up the CWP, the propshaft and the gearbox in a MKIV Supra. The reason the similar internals in the box box of the MKIV Supra twin turbo survive better is the car is very traction limited. The torque in actual driving can't build very high, the rear tyres just lose traction. In a 4WD GTR, with more weight, and a LOT better traction, the torque will build, and overstress the internals even more. The transmission is good, but does anyone HONESTLY believe Getrag over engineered the thing to take 1000 ft lbs of torque? It's madness to even consider this as realistic. It's a strong box, but nothing special, the gear centreline spacing and tooth width alone is enough for anyone with transmission knowledge to see that it will have fairly modest limitations over its design torque / rpm curve. It's got helical teeth, which will give immense end thrusts at 1000 ft lbs, Jeez, I can't be bothered continuing, the stuff the Yanks on the US Supraforums site come up with is just an insult to the intelligence of anyone who does the maths...

Yeah, those damn fools coming up with dyno charts.



Guys on that site have been 8's at over 170 MPH, and going 1.30 second 60-foot times on drag slicks. Don't think you're getting much better traction than that just because of the AWD.

I guess what damien is saying is starting to make a lightbulb go off in my head. Supercharged cars will tear the snout off the crankshaft pulling ~150 HP worth of power off the end to drive a supercharger. I'm sure that chain puts similar loads on the internals of the gearbox to drive the front wheels in a GTR, causes some case flex, and pop go the internals. I wish there were some cheaper way to do it, but by the time you have something like a billet case made you're at the cost of a sequential box that isn't going to fail.

[gavman]

[quote=tokes;761224]

Guys on that site have been 8's at over 170 MPH, and going 1.30 second 60-foot times on drag slicks.

is that with the standard gearbox?

[tokes]

[quote=gavman;761347]

Originally Posted by tokes

Guys on that site have been 8's at over 170 MPH, and going 1.30 second 60-foot times on drag slicks.

is that with the standard gearbox?

Yep. The most anyone does with it is rebuild it with new OEM synchros. All most of them run is a scatter shield, triple plate clutch, and good fluid. Stock box, stock driveshaft.

[Nicolas Kiesa]

Ive got a little crunch going into 4th anything above 8500 rpm from 3rd with my R34.

Ive read all of the thread now and my thoughts and experiences with the Getrag 6speed is, its actual gear wheel strenght is as tough as the Supra Getrag but our syncros wear faster.

Ive done some 15 quarter passes sub 11's and my best is 10,36 on stock box runing full weight.Mishifting will kill anything but the actual gears will last a long long time.

I will try the Redline lightweight and see, if it works Ill let ya'll know.

Nicolas K
KISMO

[porridge]

I had issues with worn synchro's for 4th gear
Redline super light weight shock proof fixed this issue perfectly

however I have heard from some people that this stuff eventually kills your gearbox, but I've had no issues so far