R200 diff

[Mr260z]

So I've found an r200 longnose clutched LSD 4.375

Around $1200.00 then it will cost around $150.00 freight .

 

So is that the right price?

Will it fit ? Think it was last in a 1600?

 

And will my zed be revving of its tits at 100kmh?

I'm not likely to race the car but it's not really gonna be a highway cruiser either.

I just want a little more of zed feeling!!

[dat2kman]

They're good.

Prob out of a DR30 skyline, will have 2x spacer plates, ( not full complement of plates)

You can get 2.1mm thick ones from Isuzu/Rodeo utes

Stock plates are 1.95 thick.

[Zedman240®]

Price is about right and yes, it will be revving on the freeway. Great at taking off but once you hit 100, be prepared to rev.

 

Jason, which year model Rodeo's are the clutch discs from?

[Riceburner]

I got my 4.37 fitted today, according to my calcs with 225/50/16 wheels (rolling dia of 24.858267" which is the same as standard) and a 0.833 fifth my car will do 3346rpm at 110kph. Or 3057 at 100kph.

 

The same wheel size with the standard L series 0.859 fifth gear will see you doing 3450rpm at 110kph. At 100 kph you should be doing 3153rpm.

 

The acceleration is awesome! 

[Mr260z]

Thanks guys , I reckon I'd be happy with those kinda revs at 100kph

Looks like decision time 

[Pedro]

IMO: If you are a highway runner (110km/hr) you really want a 3.9 if you have the 260z box. 4.11 is ok, but buzz's a bit. 4.6 is very racey, like track racey;

 

 

[Mr260z]

I took the zed for another drive this arvo and I reckon 4.375 might be a bit too low. I'm not real keen now on over 3000 revs at 100 kph when I really think about it .

I definitely want a bit more up and go .

Biggest problem I guess is I don't know what gearbox I'm running or what diff ratio I've got now but I'm pretty sure it would be a 3.54 or maybe even 3.3 . It currently sits a little over 2000rpm at 100kph

So maybe a 3.7 will keep me happy enough aswell as lightening flywheel a bit and maybe exhaust aswell.

Any help will be appreciated. I'm a real novice when it comes to mods.

Thanks Joel

[d3c0y]

OK here's my 2c worth.

 

 

I run a 4.44 in my car and it's a borderline race car and i couldn't live with the highway RPM it was going to be doing, so I put an RB 0.75 ratio 5th gear in it.

 

 

My suggestion is to run a 3.9 ratio Subaru STi R180 LSD. The whole setup will be cheaper to buy than the diff you are looking at and you will have a much newer diff. The 3.9 is relatively easy to get as far as STi R180s go and has the SureTrak torque sensing centre. It's bolt in; all you need is an R180 mustache bar and wolf creek side axles, which should all up coming in under $1300. The R180 is lighter too.

 

 

I have some neat spreadsheets that plot your gear ratios on a graph so if you give me your tyre size i can tell you the RPM at 100kph.

 

 

For a 225/50/16 (I have to read these off a graph that just has 1000rpm increments):

 

 

3.9 ~ 2750rpm @ 100kph  3100rpm @ 110kph

4.11 ~ 2900rpm @ 100kph  3300rpm @ 110kph

4.375 ~ 3200rpm @ 100kph 3500rpm @ 110kph

 

 

Also for interest's sake, I put in some ratios that gave me a little over 2000 rpm at 100kph and it would need to be way down around the 3.0:1 ratio (about 2200rpm). If it is indeed that tall, it's going to be very sucky. Going up to a 3.9 will make a massive difference to the way it drives.

 

 

Pic is of my Kameari CR box and is just for reference. The day I rev out 5th in my car is going to be an exciting one.

 

 

As usual, my conversion is documented on my facebook page Garage San Maru, link below.

[dat2kman]

So, with that 0.75 fifth gear, the RPM drop/reduction on upchange from 4 to 5 is quite massive, compared to rpm drops, in every other gear on upchange.

Be a bit un-inspiring!

[Mr260z]

Well tyre size I'm running are 205/55/16

I'll have to confirm again because I'm 2nd guessing myself but I'm definately in the low 2000 rpm at 100 in 5th

I've gone through all receipts and I found one for the gearbox at around $3000.00 back in 1997 but no info on what the box was or if it had been converted from auto? Ofcourse that may not be the same box in it now.

If I do in fact have a diff running 3.3 or something then I'd probably be happy with a 3.7diff for the difference it would make and they are a lot cheaper and easier to get.

So what's the easiest way to check the ratio in the diff?

How would I work out what gearbox I have?

[d3c0y]

So, with that 0.75 fifth gear, the RPM drop/reduction on upchange from 4 to 5 is quite massive, compared to rpm drops, in every other gear on upchange.

Be a bit un-inspiring!

 

 

Yeah but it wont be completely shit to drive around for the 75% of this car's life, not to mention I couldn't drive it out to warwick or any out lying events without wearing the crap out of the engine and using a ton of fuel. Red line 4th to 5th will drop in back to 5900rpm at 205kph so its fair in the meat of the power band and there wont be many tracks that will need more than 205kph. 5th gear can be for the PI main straight. What would you suggest I should have done Jason? If it's crap, i'll just send it back to PMC to stick a 0.83 on it I guess?

[d3c0y]

Well tyre size I'm running are 205/55/16

I'll have to confirm again because I'm 2nd guessing myself but I'm definately in the low 2000 rpm at 100 in 5th

I've gone through all receipts and I found one for the gearbox at around $3000.00 back in 1997 but no info on what the box was or if it had been converted from auto? Ofcourse that may not be the same box in it now.

If I do in fact have a diff running 3.3 or something then I'd probably be happy with a 3.7diff for the difference it would make and they are a lot cheaper and easier to get.

So what's the easiest way to check the ratio in the diff?

How would I work out what gearbox I have?

 

 

So you don't care about having an LSD? Were you just getting that other diff for ratio?

 

 

 

You drive train isn't that much of a mystery though:

 

 

RPM = (mph x ratio of diff x ratio of gear x 336)/tire diameter

 

 

So if we assume you have:

 

 

- 3.5 ratio diff (R200 auto 260z) because long nose diffs to my knowledge didn't come in ratios below 3.5

- 0.75 ratio fifth gear (because your RPMs are so low)

- 60mph

- Tyre diameter of 24.96"

 

 

Guess what you get? 2120rpm

 

 

Most zed boxes have similar ratios and in 1997 probably not going to be an RB box. Maybe an FJ? Either way some type of 71C probably FJ turbo. Get under the car and take some pics of it. Does it have a stock gear stick or a big fat one, could be an RB30E box.

 

 

So that 4.3 diff is going to give you around 2650rpm at 60mph pretty much the same as my setup, or get a GC8 STi v6 mechanical R180 that is 4.44 with 4 clutch plates and no spacers for slightly better acceleration.

 

 

 

In relation to my previous post, your tyre combo has the same OD as the 225 i used so no difference there.

 

 

To tell the diff ratio, pull the hat off the diff and there are numbers stamped on the crown wheel which is the ratio. You can also spin the tail shaft one revolution and count how much the wheels spin. Not really important anymore though is it.

 

 

/Case closed

[dat2kman]

That .75, and the .83 fifth are only 18mm wide, compared to 20mm wide for rest of them, in the RB boxes,

An upchange 4-5 with your Torque Monsta, may he a bit too harsh on the .75, by having a S13/S14 Sylvia .83, the lesser rpm drop will not be as severe on the drivetrain engagement on upchange.

 

It's still gonna be a fun ride on any trip!

[dat2kman]

 

So you don't care about having an LSD? Were you just getting that other diff for ratio?

 

 

 

You drive train isn't that much of a mystery though:

 

 

RPM = (mph x ratio of diff x ratio of gear x 336)/tire diameter

 

 

So if we assume you have:

 

 

- 3.5 ratio diff (R200 auto 260z) because long nose diffs to my knowledge didn't come in ratios below 3.5

- 0.75 ratio fifth gear (because your RPMs are so low)

- 60mph

- Tyre diameter of 24.96"

 

 

Guess what you get? 2120rpm

 

 

Most zed boxes have similar ratios and in 1997 probably not going to be an RB box. Maybe an FJ? Either way some type of 71C probably FJ turbo. Get under the car and take some pics of it. Does it have a stock gear stick or a big fat one, could be an RB30E box.

 

 

So that 4.3 diff is going to give you around 2650rpm at 60mph pretty much the same as my setup, or get a GC8 STi v6 mechanical R180 that is 4.44 with 4 clutch plates and no spacers for slightly better acceleration.

 

 

 

In relation to my previous post, your tyre combo has the same OD as the 225 i used so no difference there.

 

 

To tell the diff ratio, pull the hat off the diff and there are numbers stamped on the crown wheel which is the ratio. You can also spin the tail shaft one revolution and count how much the wheels spin. Not really important anymore though is it.

 

 

/Case closed

Use 4th gear, that will be a known 1:1 ratio.

As decoy says, it could be anything for 5th! And be inaccurate on calcs.

You then have your known figures,

Tyre size,

Fourth gear,

Engine rpm

Indicated speed.

Re--jig the formula to give you a diff ratio.

 

From there, with the now known diff ratio, and at same indicated speed, select fifth ( unknown) note new lowerrpm,

Rejig the formula, to then calc put to give you your fifth gear ratio.

 

Having an observer in the car to make note at what speed is what rpm's, a rather good idea!

[Mr260z]

 

So you don't care about having an LSD? Were you just getting that other diff for ratio?

 

 

 

You drive train isn't that much of a mystery though:

 

 

RPM = (mph x ratio of diff x ratio of gear x 336)/tire

 

So if we assume you have:

 

 

- 3.5 ratio diff (R200 auto 260z) because long nose diffs to my knowledge didn't come in ratios below 3.5

- 0.75 ratio fifth gear (because your RPMs are so low)

- 60mph

- Tyre diameter of 24.96"

 

 

Guess what you get? 2120rpm

 

 

Most zed boxes have similar ratios and in 1997 probably not going to be an RB box. Maybe an FJ? Either way some type of 71C probably FJ turbo. Get under the car and take some pics of it. Does it have a stock gear stick or a big fat one, could be an RB30E box.

 

 

So that 4.3 diff is going to give you around 2650rpm at 60mph pretty much the same as my setup, or get a GC8 STi v6 mechanical R180 that is 4.44 with 4 clutch plates and no spacers for slightly better acceleration.

 

 

 

In relation to my previous post, your tyre combo has the same OD as the 225 i used so no difference there.

 

 

To tell the diff ratio, pull the hat off the diff and there are numbers stamped on the crown wheel which is the ratio. You can also spin the tail shaft one revolution and count how much the wheels spin. Not really important anymore though is it.

 

 

/Case closed

 

Yeah LSD is really just a bonus . If I do have the 0.75 5th which seems likely , then the 4.375 could be good.

I'll do a road test and check it out.

I really appreciate the advice guys

[Mr260z]

Ok so I got it a bit wrong I'm actually doing 2400ish at 100kph and doesn't seem a big jump from 4th to 5th so is a 3.5 a fair assumption then.

Anyway thanks guys looks like I'll be going with a 3.9lsd