How strong is a R180?

[johnymd]

The gearing on my red lexus v8 powered car is all wrong so I need to swap the diff for a higher ratio. The one currently in the car is a 3.9 and I would like to go as high as possible to get the cruising revs down. This car is primarily going to be a GT so the more relaxed the drive the better. I could go for a R200 3.54 but that will only make a small different to the revs at a given speed. I do have a 3.36 R180 and a spare R180 quaif so I'm considering this as an option. I know the open R180 could be an issue with spider gear problems so replacing this with the quaif should cure this.

Anyone have some real world experience of R180 diff problems?

 

[jonbills]

I’ve got a 3.36 R200 John, swap for a 3.9?

 

[Fairlineguy]

I'm also kind of trying also to get my head around the ideal diff ratio for a modified car.
With the RB and a 3.9 diff .(I think from memory in 5th at about 80mph she is around 3000rpm.)Which in away isn't to high .
Thing is the car is light there's a lot of power and you kind of find you are up into 5th and can drive every Where in it.

 

[johnymd]

Yeah, 80 is around 3.2k with mine but when you consider power is starting to drop off by 5800 I really want it to be reving in the mid 2k's at 80mph. Incidentally if I check the ecu data it tells me that the original car was doing over 100mph at just over 3.2k.

 

[johnymd]

Jon - I didn't know they made a 3.36 r200. My r200 3.9 has a nismo plate diff in it so will be keeping it for another car.

 

[Alphabettispaghetti]

they're fitted to high torque subaru engines,where they generate traction, I don't think strength is an issue?

 

[IbanezDan51]

You using the auto box Johny? If so the 3.36 will be better suited. Had a 3.54 in my old V8 car but was running the 6 speed manual. Probably would have been better with a 3.7 tbh - 1st gear nearly 60mph though was fun!

 

[Nigel Brook]

they're fitted to high torque subaru engines,where they generate traction, I don't think strength is an issue?

Yes but the Subaru shares its power with 4 wheels not 2.

 

[Alphabettispaghetti]

Yes but the Subaru shares its power with 4 wheels not 2.

It does, however due to the grip the drivetrain produces it puts a lot of stress on it, also think of some of the massive torque figures they produce, the extra weight, the r180 on them is considered a 'big diff'.

 

[AliK]

Mr Johny,

Firstly, top man for getting a piece of your back-side into the Le Mans race!!!

You know far better than me that torque, harshness and wheel spin kill diffs.

I read somewhere that an R200 is rated at 300lbft (I'm sure Albrecht will correct me if wrong) so your r180 will be less, but by how much? And what "shock" loading can it handle!?

I read here that R180 is not recommended to exceed 250lbft ....

http://forums.hybridz.org/topic/126544-r180-limits-and-failures/#comment-1182681

Some other answers somewhere between this thread ....

https://www.zcar.com/forum/10-70-83...-can-r180-r200-differentia.html#/topics/37512


And this one ....

http://forums.hybridz.org/topic/49194-differential-cv-lsd-hp-torque-r160-r180-r200-r230-diff-

 

[SeanDezart]

The R180 is underrated imho and there has been as much hype over 'must have 'R200s' as there's been on 'close-ratio' 280ZX boxes being the best also......bigger is best in Trump-land.

Alan (not Albrecht or The Count) can tell you how extensively the R180 was used.

I'm fitting one to my L31 in complete confidence.

 

[johnymd]

Thanks for all the response. The links to the hybrid threads makes good reading. It would appear that the spider gears are the main limitation so the quaif should alleviate that. The auto box and guibo joint should reduce the shock loading. The box changes into second as soon as the car starts moving and is in 5th by 20mph.

 

[Ian]

I read somewhere that an R200 is rated at 300lbft

lol at this, I am running 490lbft through mine. Others running much more, you might not be wrong, but it can sure handle much more than that.

 

[AliK]

lol at this, I am running 490lbft through mine. Others running much more, you might not be wrong, but it can sure handle much more than that.

That's interesting, I know the drifters have been pumping serious twist through them but can't seem to find anything definitive on tinter.

I wonder if Nissan would be willing to give specs?

What engine are you running to produce that monstrous torque? That even eclipses my 340lbft Diesel which I thought was pretty punchy!

 

[johnymd]

Are these "rated" figures for an open diff. I'm sure once you put an LSD in there the numbers change.

 

[Alphabettispaghetti]

Are these "rated" figures for an open diff. I'm sure once you put an LSD in there the numbers change.

I think that’s a key point. Lots of r160 lsds running a lot of torque without issue. R160 lsd’s are cheap also.

 

[Alphabettispaghetti]

Are these "rated" figures for an open diff. I'm sure once you put an LSD in there the numbers change.

I think that’s a key point. Lots of r160 lsds running a lot of torque without issue. R160 lsd’s are cheap also.

 

[Alphabettispaghetti]

Are these "rated" figures for an open diff. I'm sure once you put an LSD in there the numbers change.

I think that’s a key point. Lots of r160 lsds running a lot of torque without issue. R160 lsd’s are cheap also.

 

[AliK]

I think that’s a key point. Lots of r160 lsds running a lot of torque without issue. R160 lsd’s are cheap also.

And probably lighter!?

 

[tmr]

I have only ever run a 180 LSD diff in my car with no problems using both slicks and modern radial race tyres. It has survived Sprinting, Hill climbing and Circuit use without any problems. The main advantage over a 200 as far as I was concerned was it's weight, actually had more issues with the drive shafts than the diff