Autocrossers and Road Racers what Differential?
01-31-2007, 12:34 PM
#1
Autocrossers and Road Racers what Differential?
It's time for me to upgrade my differential. The oem VLSD is dead, It works when it wants to work. A NISMO 1.5 way is what I think I'm going to get. I have a Central 20 3.9 FD waiting to be installed so I would like to do this all at once. I use my car for autox, road racing, and drift. Are the clunking noises clutch types make too harsh for daily driving? I wanted to get an idea of what you guys were using and why? Thanks.
Bradley
Bradley
Last edited by BloMyS14; 01-31-2007 at 12:37 PM.
01-31-2007, 01:07 PM
#2
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I'm using a nismo for road racing. I don't have any autox experience in the Z but I would think that the nismo might be a little too strong for tight courses. The noise and abruptness don't bother me because I think the benefits outweight the drawbacks. Having said that, if I didn't track the car, I would never go with a clutch type differential.
01-31-2007, 01:18 PM
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I've tried all the settings and think that med or low is the best. Again fluid choice plays a big part. Extra slip additive makes it much smoother without noticeable loss in effectiveness. Stickier tires also make it run smoother. I've got balding t1-s's for the street and the diff is getting louder and louder as the tires get worse. I just switched over to my R comps and strangely enough, it is better behaved. Sport compact car has a couple articles on the Z that say the same.
I would be curious to try a carbon lsd as well..
I would be curious to try a carbon lsd as well..
01-31-2007, 02:12 PM
#5
I've got a Cusco RS clutch diff and it's fine for daily driving. It uses springs instead of all discs to make the engagement smoother and it is pretty quite with good diff fluid.
Mine is on 1.5 way with 60% lock. I auto-x and track my car, love the diff. A quiter but pricier diff is the ATS carbon, I hear that one is completely quite.
Mine is on 1.5 way with 60% lock. I auto-x and track my car, love the diff. A quiter but pricier diff is the ATS carbon, I hear that one is completely quite.
01-31-2007, 06:08 PM
#7
+1 Cusco RS.
mine has been with me to HPDEs and Drft events.. 60% lock. it's definately a great piece to have. its not noisy at all... i've riden in a Cusco RS at 80% lock on the street and it still feels good. not too much clunking.. i highly recommend it with either the nismo finned diff cover or DIY diff pump/cooler for heavy track events.
mine has been with me to HPDEs and Drft events.. 60% lock. it's definately a great piece to have. its not noisy at all... i've riden in a Cusco RS at 80% lock on the street and it still feels good. not too much clunking.. i highly recommend it with either the nismo finned diff cover or DIY diff pump/cooler for heavy track events.
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02-01-2007, 05:37 AM
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I have the Nismo 1.5 on the lowest setting, and the Central 20 gears. This setup kicks butt for autocross. I noticed the diff behaves very differently depending on what tires you run on the street. If you don't have a lot of traction, your tires will give before the diff and chirp, set off the VDC/SLIP bells and whistles, etc. I also noticed that a nuetral or toed out rear suspension will make the car feel like its trying to push you off the road. Ice? Forget it. You're not going anywhere.
But once the car gets out on course, it's a thing of beauty, even on a very tight autocross. The gears are great for an NA car, esp. on an autocross. You can short shift into second and third and stay in the torque band the whole time. On the track, no complaints. I hit higher speeds than I did with the regular gears. For drifting, I'm not sure how much I like the gears. I'm still learning though. The diff is great for drifting, though. Big difference between the VLSD and the clutch type. Smooth as butter.
But once the car gets out on course, it's a thing of beauty, even on a very tight autocross. The gears are great for an NA car, esp. on an autocross. You can short shift into second and third and stay in the torque band the whole time. On the track, no complaints. I hit higher speeds than I did with the regular gears. For drifting, I'm not sure how much I like the gears. I'm still learning though. The diff is great for drifting, though. Big difference between the VLSD and the clutch type. Smooth as butter.
02-01-2007, 07:21 AM
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Guys - I had the same questions and concerns as you did until I went to the Rolex 24hrs at Daytona and talked to the teams there. Along with the Playboy 350Z team and others have all switch to a Gear type LSD due to heating issues with a clutch type. Many of the teams had a problem with cooling of the differential even with a cooler with a clutch type and had to rebuild them often. So many teams have gone to a gear type and actually removed the cooling and stopped having to rebuild the diff. The only problem with the gear type is that if you lift the inside wheel, it works like an open diff. They got around that problem by tunning the suspension so this doesn't occur.
Therefore I have ordered a Quaife for my car, and hope to have it installed before Road Atlanta in March.
Therefore I have ordered a Quaife for my car, and hope to have it installed before Road Atlanta in March.
02-01-2007, 07:45 AM
#11
Read this.
That's all S-Tune. R-Tune adds a clever, adjustable clutch-type limited slip. The NISMO limited slip can be set up as a two-way (works under acceleration and engine braking) or 1.5-way (same thing, but it's not as strong under engine braking). We recommend 1.5-way. The pre-load on the clutch packs is also adjustable by removing the right-hand stub axle and stuffing a 19mm socket in the hole. The three settings give a breakaway torque of 50, 69, or 101 lb-ft.
If you disassemble the differential, of course, you could also lower the breakaway torque even more by re-arranging the 10 clutch plates on each side of the diff so that some of them are inactive. NISMO doesn't officially state this, but it doesn't have to, that's just how clutch-type diffs work. The NISMO diff is also stronger than the stock one, since it transmits torque through four pinion gears instead of the stock diff's two.
We don't know how the diff in our car was set up, but whatever it was, it was too tight for the street. On the track, where you brake, turn, and accelerate through every corner in the same smooth, predictable fashion, a tight limited slip can be good. Drive a narrow, twisty mountain road at night, though, and you won't be laying into the gas at the apex and holding it down all the way to the next corner. Not with 249 hp at the wheels. Instead, you tend to feed in and out of the gas as you try to stay between the yellow line and the white one and figure out when this damn corner is going to end.
Rolling on and off the throttle like this makes the rear wheels lock together and release every time, which makes the front tires push and then grab with every move of your right foot. That makes you look like a swervy monkey. Don't believe us? Look at the skidpad results. The S-Tune car, which uses the loose factory limited slip, pulled an impressive 0.98g. The R-Tune Z, with exactly the same suspension, but the NISMO diff, pulled "only" 0.95.
I'll never buy the Nismo unit.
That's all S-Tune. R-Tune adds a clever, adjustable clutch-type limited slip. The NISMO limited slip can be set up as a two-way (works under acceleration and engine braking) or 1.5-way (same thing, but it's not as strong under engine braking). We recommend 1.5-way. The pre-load on the clutch packs is also adjustable by removing the right-hand stub axle and stuffing a 19mm socket in the hole. The three settings give a breakaway torque of 50, 69, or 101 lb-ft.
If you disassemble the differential, of course, you could also lower the breakaway torque even more by re-arranging the 10 clutch plates on each side of the diff so that some of them are inactive. NISMO doesn't officially state this, but it doesn't have to, that's just how clutch-type diffs work. The NISMO diff is also stronger than the stock one, since it transmits torque through four pinion gears instead of the stock diff's two.
We don't know how the diff in our car was set up, but whatever it was, it was too tight for the street. On the track, where you brake, turn, and accelerate through every corner in the same smooth, predictable fashion, a tight limited slip can be good. Drive a narrow, twisty mountain road at night, though, and you won't be laying into the gas at the apex and holding it down all the way to the next corner. Not with 249 hp at the wheels. Instead, you tend to feed in and out of the gas as you try to stay between the yellow line and the white one and figure out when this damn corner is going to end.
Rolling on and off the throttle like this makes the rear wheels lock together and release every time, which makes the front tires push and then grab with every move of your right foot. That makes you look like a swervy monkey. Don't believe us? Look at the skidpad results. The S-Tune car, which uses the loose factory limited slip, pulled an impressive 0.98g. The R-Tune Z, with exactly the same suspension, but the NISMO diff, pulled "only" 0.95.
I'll never buy the Nismo unit.
02-01-2007, 09:13 AM
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I'm running a quaife as well, and it works like it should. I've been to a few trackdays only though and done no auto-x or competition with it.
To touch on the heating issue, my diff still heats up to the point where it pukes oil through the breather so i need to make some sort of catch bottle for it.
It does not need to be rebuilt though and it has a lifetime warranty. Even if you through 1000HP at it and it fails, they'll fix it.
To touch on the heating issue, my diff still heats up to the point where it pukes oil through the breather so i need to make some sort of catch bottle for it.
It does not need to be rebuilt though and it has a lifetime warranty. Even if you through 1000HP at it and it fails, they'll fix it.
02-01-2007, 11:20 AM
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Originally Posted by mistico
I'm running a quaife as well, and it works like it should. I've been to a few trackdays only though and done no auto-x or competition with it.
To touch on the heating issue, my diff still heats up to the point where it pukes oil through the breather so i need to make some sort of catch bottle for it.
It does not need to be rebuilt though and it has a lifetime warranty. Even if you through 1000HP at it and it fails, they'll fix it.
To touch on the heating issue, my diff still heats up to the point where it pukes oil through the breather so i need to make some sort of catch bottle for it.
It does not need to be rebuilt though and it has a lifetime warranty. Even if you through 1000HP at it and it fails, they'll fix it.
Mocal makes a pump and Heat Exchanger for the differential. You will just need to get the plumbing and wiring and install it.
02-01-2007, 01:17 PM
#16
A Quaife will generate a lot of heat from the shear forces of the gears. Running a Quaife and Nissan Motorsports clutch pack LSD in an R180 behind my 240Z showed no difference in temps (300+ degrees) in a 45 minute race. Running a good Tilton pump, an oversized Mocal oil cooler, and ducting air to the cooler kept the temps around 200 degrees in the same type of race.
IMHO... the Quaife is the best one. I was amazed at how well it can put power down IF the car's suspension is adjusted to work with the unit - at least 1 second per lap faster around WSIR in my experience. Unfortunately, I can't afford the $1,400 a Quaife costs so I purchased a Nismo R-Tune LSD. It will do for a couple years.
IMHO... the Quaife is the best one. I was amazed at how well it can put power down IF the car's suspension is adjusted to work with the unit - at least 1 second per lap faster around WSIR in my experience. Unfortunately, I can't afford the $1,400 a Quaife costs so I purchased a Nismo R-Tune LSD. It will do for a couple years.
02-02-2007, 04:45 AM
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Betamotorsports - I get about 50% saying that you need to cool a gear type and the other 50% saying you don't. Did you take actual temps of your diff when you ran a gear type LSD?
02-02-2007, 05:42 AM
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We run a Kazz 1.5 way set to aprox 80% lock-up on our SCCA T2 car. It works great, never had any problems with it. Provides excellent traction. It does make all kinds of noise at parking lot speeds...
I have never had a problem with it in a race, but we are only on track for about 40 minutes at a time. I would definately install a diff cooler with this set-up if you are doing longer sessions.
I have never had a problem with it in a race, but we are only on track for about 40 minutes at a time. I would definately install a diff cooler with this set-up if you are doing longer sessions.
02-02-2007, 07:18 AM
#19
Betamotorsports - I get about 50% saying that you need to cool a gear type and the other 50% saying you don't. Did you take actual temps of your diff when you ran a gear type LSD?