What Diffs Will Fit What?

[lows_13]

I'm looking to buy a spare diff in housing for my R32 GTS-T and re-build it,

then swap it out with my old one.

My car doesn't have ABS, will non-ABS and ABS types interchange?

Whats diffs will fit into the R32?

Will R33, S14, etc fit in?

Edited May 30, 2007 by lows_13

[Cubes]

The issue is the diff ratio..

I've tried... I'm now back with the 4.363:1 ratio.

With the 4.11 or 4.08 you'll notice less response and slightly increased lag. Increased lag, strange yes but its what it feels like. The motor spends more time trying to accelerate through the rpm that doesn't generate boost. Once on boost it looses that hard snap turbo mid range feel the 4.3:1 ratio gives.

The S13 5bolt is a direct bolt up and runs a 4.08:1 ratio.

The R33 5bolt 4.11:1 also bolts up but requires a few little bodgy mods.

[BHDave]

Whats the dodgy mod? swap rear end and make up some sleeves for the front bolt holes or is there more to it?

S13 non abs will be the simplest alternative if you want a ratio change at the same time. ABS diffs are longer so you also need the abs rear half of the tail shaft to suit. Luckily non abs is a lot more common in s13's and r32's.

Interesting to hear your thoughts on the longer diff ratios cubes. I'd have thought the 3l would benefit from some 4.11's. I'm considering a set for mine and i only have a 2.5.

[Cubes]

Dave, first gear was much improved as it felt usable instead of simply buzzing up but for second and third there was a noticable loss in response; generally it felt slower getting out of corners and was slightly slower on rolling accelerations (against a mates car).

If I could keep the current second and third ratio's and throw in a longer first gear the 4.3:1 ratio would be perfect.

Gary (SK) did tell me to stick with the 4.3's but I refused to listen. lol

Its also interesting to note UAS went for a 4.3:1 R200 in their 300zx track car.

[lows_13]

Is the R32 GTS-T type the only one which a 4.3 ratio?

What about a S14 diff?

[CEF11E]

S14 diff is 4.1

[Habler]

so... off the topic off stock diffs... can you swap 2 ways out of 32's/silvias into 33's etc or even swap the whole housing?

Or is it a matter of after market diffs only fit into what they are in? sorry im just a bit confused of what i should do diff wise for my r33.

I think i want to upgrade to either 2 way or 1.5 but paying for a new diff is a bit pricey and i have not seen too many second hand r33 mech diffs popping up. So wondering if i can fit anything else in there?

Also...can you pop a GTR diff in there or is this pointless and has no real gains?

Sorry to sound stupid but still trying to get my head around the diff area.

Also looked into shimming on here and d1NZ but...such mixed results and what starts off costing 10 bucks can end up costing you a lot more in time and effort if it ends up not working or wearing out in two weeks.

[Cubes]

It 'may' work out cheaper to source a second hand 300zxt 87-89 CLSD long nose R200 and throw the center in to your short nose housing. Not 100% certain its possible but I have heard of the blokes in the US doing the same thing with their 240sx's. (S13's). So it should work. 29spline 12mm ring gear bolts so it should just bolt in.

[CEF11E]

If you are after a cheap 1, 1.5 or 2 way give sss automotive a call. the guys there are pretty good and will not sell you crap. they will sell a centre or complete housing with 1/2 shafts from $600 to $900. depending on what they have.

[lows_13]

Is the R32 GTS-T the only one to have a 4.3 ratio?

[Habler]

ok did a bit more research. Is there anyway to tell easily if you have alsd or vlsd... as from what i read alsd are shithouse and seem like a lot of hard work to get rid of. I havnt ever noticed a light on my dash when spinning the wheels (slip light) so i suspect i dont have one.

Im preety sure my car doesnt single spin ridiculousy but when sliding it, you really need to give it a shitload to get it to lock up properly which sometimes annoying.

Has anyone here replaced there standard diff with a 1.5 way or two..if so do you notice a freakin huge difference? is the 33 diff just that shit?

[Cubes]

I've found a good little test for the VLSD is....

Wait for a little wet weather.. Pull out of a side street turning left briskly (no clutch dumps etc) and if the diff is fairly nackered it will spin up the left wheel. If its fine it will send the car sideways.

For near stock power levels (up to 200rwkw) I've found the VLSDS to handle the power not to badly.

BUT drop a 3ltr in it and its all over; the vlsd hub simply can't hold the torque and power delivery harshness of the 3ltr.

I've compared J30 R200 VLSD (vg30det) to the 29spline GTST vlsd and the J30's viscous hub is meatier. I've seen one hold just over 300rwkw from an rb25det that went on to run a low 11sec pass with slicks.

The J30 vlsd runs the same 6 bolt half shafts as the gtr; so a good cheap option for some one upgrading their rear end slowly.

[ZENNON]

i was under the impression manual r32 gtsts had 4.111 diff ratio (and Autos had 4.36)

[Cubes]

Definitely not the case.

[Abo Bob]

I fully respect your opinions pretty much always cubes but I just can't believe that you could be slower when already moving with a taller diff. Or increased lag and decreased response for that matter.

Just for a second, divorce from your mind what it felt like and think about it logically.

Compare your boost threshold in 1st gear to that of 4th gear. Boost comes on earlier in 4th. Now that's a big obvious difference but apply it in a much smaller difference - the difference between your two diff ratios. Why would it go the opposite way?

[CEF11E]

I have had a 4.3:1 and a 4.08:1 in my R32 with big turbo and can give a bit of feedback..

my 0 - 100 went up when i fitted the 4.08:1 as the rate of acceleration was slower but each gear was taller. the car did not feel any slower but i lost 1/2 a second.

Over the 1/4 mile this would probably be a lot less as the taller gears would produce more load and keep you on boost slightly longer

but for road use the 4.3:1 suits the R32

[Cubes]

I fully respect your opinions pretty much always cubes but I just can't believe that you could be slower when already moving with a taller diff. Or increased lag and decreased response for that matter.

Just for a second, divorce from your mind what it felt like and think about it logically.

Compare your boost threshold in 1st gear to that of 4th gear. Boost comes on earlier in 4th. Now that's a big obvious difference but apply it in a much smaller difference - the difference between your two diff ratios. Why would it go the opposite way?

Bob,

Ever played with ratio's? I'm assuming not otherwise you wouldn't have made the above post.

I've played with ratio's in a TE cortina (first car) and my last a VS 5ltr 5speed.

Both had improved pickup/response in gear acceleration with a lower (numberically higher) diff ratio.

There's no difference here.

There's a VERY good reason a lot of the on the ball GTR owners snap up the GTS4 4.375:1 final ratio's given half a chance.

The reason I tried a longer ratio is to help control wheel spin through first gear and make it usable; as it is even with a good diff if I plant it I hardly move; it instantly boosts and hits the limiter. The longer ratio was absolutely perfect in first gear but I didn't like the 'seat of the pants feel' in second and third gear. It just wasn't as punchy.

It wasn't all 'seat of the pants' either. A good mate of mine that I've had plenty of rolling accelerations against had a bit of a play with the new ratio.

I knew it 'felt' slower but to my surprise I no longer had that instant lunge away when putting the foot down. Prior I would lunge away hard and then slowly walk away.

With the longer diff it only started slowly walking away towards the end of the gear.

Corner exit sitting behind him it really felt as if I had to give it a hell of a lot more to stick up behind him. Prior it felt effortless and allowed slight short shifting. Needless to say the diff was out the next day and the 4.3 thrown back in.

With regards to the increased lag... There was no increased in lag vs rpm but it gave the feeling of increased lag as when accelerating at very low rpm it didn't accelerate as quick (even if it was only slightly) through the rpm where it makes little boost.

The theory behind it.... piston speed vs road speed. Its all relative.

Drop a longer ratio in and at any given speed in any gear compared to the higher diff piston speed is less. As a result so is torque and power, for that road speed.

Hope that makes sense.

I'm not the only one with this opinion. When I mentioned dropping a taller ratio in to the R32 RB30DET Sydneykid essentially stated.... Your silly, I've been there done that and always stepped back to the 4.3:1 ratio.

So on the cards.. Better tyres and smoother boost curve in first gear.

[Abo Bob]

I have so ner. Not in a turbo car though.

Off the line the shorter ratio will always (bar uncontrollable wheelspin) be quicker but at certain speeds the short ratio will pick up quicker and at other speeds the longer ratio will be quicker. Using the most extreme example to illustrate. Let's say about 80km/h in 2nd gear rolling race. The 2 cars are identical but one has a short diff and the other a longer one.

Both cars boot it. The shorter diffed car moves ahead as it is putting out more power due to being higher in the rev range but in a very short time it hits redline and has to change gear. When it does so the longer diffed car still has more rpm to go and surges ahead.

Now it depends entirely on where the race ends as to who wins. If it ends while the longer diffed car is in the top part of each gear it will win but if it ends while it's in the lower part of the gear it will lose.

So my conclusion is that shorter ratios get you off the line quicker but it all depends on the length of the race. If instead of a quarter mile it was 3 miles who would win?

[Cubes]

The longer diff'd car would.

For me it was bout the driving experience and how I drive.

You are correct about the longer diff'd car surging ahead when the short diff'd car changes gear but what about when the longer diff'd car changes gear? The shorter diff'd car then surges ahead, and on it goes.. The problem is its much harder to catch and pass a car once its already pulled its speed up.

[ZENNON]

So what is the diff ratio for a manual stock HCR32?