R180 vs R200

[red_dog007]

Is LSD worth it?

I am thinking that I might just get a R180 instead of a R200. You can get the same gear ratios on a R180 to an R200 and from what I hear, save 60lbs~70lbs from an R200. They are also a ton cheaper.

I can see the advantages of having a LSD, but will it make THAT much of a difference compared to the extra cost and added weight?

[sublime5225]

LSD means better burn outs! No, but in all seriousness, i have the R200 installed in mine and i have to say that i feel more power to my car and smoother feeling when i shift.

[red_dog007]

Smoother feeling when you shift? How does that happen?

Also, wouldn't a 3.9 R180 give the same kind of power as a 3.9 R200?

The LSD though, wouldn't that minimize the power differences from each tire, so the tires are more so pushing the same kind of power compared to a non-LSD? Also help with a more uniformed tire tread loss for the back two tires?

I think that I am getting my differentials confused.

R180 vs R200 3.9 in a straight away, would you be able to tell a difference? What about cornering and even fuel economy?

[beandip]

the difference between the two diffs is only 25 lbs. gear ratio is gear ratio period. Makes no difference in performance which diff is used other than the little extra weight being moved. The R-200 is a stronger unit this is the main reason to make a change. I made the change to the r-200 because I wanted the 3.70 ratio. LSD just makes both wheels drive. The slip part is when you go around a corner it allows one wheel to turn less than the other. On a straight away they all will feel the same in the same gear ratio. Cornering or fuel consumption will be also dictated by the gearing not the different pumpkins. LSD on a corner if the power is applied will lock the diff and could cause the rear end to slide out. Actually slower on a road coarse or auto X

[red_dog007]

Oh, only 25lbs? I wonder where the hell I got 60/70 then.

hmmm.... Will have to sit on this one.

Think the extra dollars are well worth the R200?

[jmortensen]

LSD on a corner if the power is applied will lock the diff and could cause the rear end to slide out. Actually slower on a road coarse or auto X

LSD is MUCH faster on a road course or at an autox because you can apply the power much earlier and get forward drive instead of just spinning the inside wheel. It's a night and day difference. I know no autoxer or track junky who doesn't have an LSD or welded diff. Spinning that inside tire is the slow way around.

[Mr Camouflage]

Oh, only 25lbs? I wonder where the hell I got 60/70 then.

hmmm.... Will have to sit on this one.

Think the extra dollars are well worth the R200?

No I dont. If you dont have a heavily modified (powerful) engine, and only drive on the street, stick with what you have got.

If you do auto X then a R180 LSD would help you there as you can power out of corners with both wheels. With and open diff, if one wheel starts slipping you are wasting power.

Swapping from an open R180 to an open R200 seems like a waste, unless you happen to have an unused one laying around.

[John Coffey]

A 3.90 ratio R180 diff is pretty rare here in the US and most folks who own one are racers. That gear worked out very well for a number of specific east and west coast race tracks for those folks racing a 240Z in SCCA's ITS class. 3.70 ratio R180s are more common. I sold one last year with a brand new LSD installed for $650.

Typical transaction prices for a R180 3.90 is around $250. With a good, recently rebuilt LSD installed the price is around $750 - when you can find one that someone is willing to sell. R200s with 3.90 gears and an open diff sell for $100. With a LSD they are around $500.

And, if you can afford it, buy one with a LSD. Its the single best thing you can do for the handling of your 240Z.