Why you need a LSD if you like cornering!

[CSG David]

Originally Posted by diss7

Quite simple really, you need it that tight for drifting in the wet, when you're giving it very little beans before wanting both wheels to engage. Having it that tight on decel means it feint drifts like a boss.

If I'm super smooth and slow during a slow maneuver than I can stop it engaging, but its so slow often I don't bother and just let if bounce/bind.

Also remember that no matter how tight the diff is, you can always use it like an open diff by pressing the clutch in. I'll often do that say if I need to make a u-turn, I just get enough momentum to do it without power.

Every drift car and most of my rwd street cars ive run Nisbro diffs. (NZ Slang for a welded diff) They're good because they always work, unlike a torsen. (My torsen was already getting lazy after 2 drift days) But the 2 way gives me the compromise I wanted, basically all the good things of a locker, but with some small areas where it performs like an open.

I don't disagree that I run it tighter than what would be ideal for circuit. I wouldn't even run a 2 way for a circuit car. I'd be much more inclined to run such a loose decel setting that I might as well run a 1 way. But my point from my previous post still stands, that if its so loose that it NEVER binds/engages on the street, then its probably too loose.

Welded diffs are great. It's actually one of the best modifications I did to a 240SX at one point. It's funny driving around grocery store parking lots though because one tire is constantly creating noise.

[diss7]

Originally Posted by CSG David

Welded diffs are great. It's actually one of the best modifications I did to a 240SX at one point. It's funny driving around grocery store parking lots though because one tire is constantly creating noise.

Two things:

Some people are working to a budget. I certainly was when I had my first couple of silvias. Spending $1500 on a mechanical LSD was the last thing I was going to buy, when I could weld it up for effectively nothing.

Having my welded diff chirping around a car park was a small compromise in my eyes, for the realiability and predictabilty it gave while using it for drifting.

[CSG David]

Originally Posted by diss7

Two things:

Some people are working to a budget. I certainly was when I had my first couple of silvias. Spending $1500 on a mechanical LSD was the last thing I was going to buy, when I could weld it up for effectively nothing.

Having my welded diff chirping around a car park was a small compromise in my eyes, for the realiability and predictabilty it gave while using it for drifting.

In that sense, you're right. It was probably the best modification you can do for virtually nothing. I paid $50 for my S14 diff, welded it, cut some wood bushings, drilled them out and boom..."solid" bushings for the S13.

However, comparing that to a mechanical clutch type LSD was a very nice experience as well. While Torsen works great for what it does, I do desire more at times, hence the recommendation of the clutch type LSD.

[ZDan]

Tight diff in general requires more rear roll stiffness to counter the understeer, which unloads the inside rear more, which requires still more diff tightness! Can be kind of a vicious circle.
I remember pushing a friend's ITS 240Z with a "Kennesaw locker" (welded diff) in the pits, when he cranked in a little steering, the car just stopped! This cannot be good for handling, thought I...
Point: there's more than one way. I don't think a tight clutchtype diff is necessarily necessary for putting the power down at the track. Some approaches and some driver preferences will lead that way though.

[CSG David]

Originally Posted by ZDan

Tight diff in general requires more rear roll stiffness to counter the understeer, which unloads the inside rear more, which requires still more diff tightness! Can be kind of a vicious circle.
I remember pushing a friend's ITS 240Z with a "Kennesaw locker" (welded diff) in the pits, when he cranked in a little steering, the car just stopped! This cannot be good for handling, thought I...
Point: there's more than one way. I don't think a tight clutchtype diff is necessarily necessary for putting the power down at the track. Some approaches and some driver preferences will lead that way though.

It's always in preference. The way you drive a windy course with a welded diff is definitely going to be different compared to an open one and a LSD setup. It's really assimilating to the car's abilities in order to extract the most out of it.

In this case, we have actual data that proves the settings we were looking for worked exactly as intended. The OTS settings in the past locked up a little harder than what we wanted.

[diss7]

I did do some circuit days with mine prior to the 2 way.

I'm no CSG level driver (not a dig, I'm not) but I noticed almost straight away the 'auto-lsd' type aid the car has. Definitely not good for corner exit speed.

A few of us in NZ have 2 ways now, and what becomes apparent when you go from a torsen equipped car to a mechanical equipped car, is how much more the mechanical equipped car seems to spring out of corners better. Where as in realty, its the torsen equipped cars that are being held back by the car.

[ZDan]

Originally Posted by CSG David

It's always in preference. The way you drive a windy course with a welded diff is definitely going to be different compared to an open one and a LSD setup. It's really assimilating to the car's abilities in order to extract the most out of it.

In this case, we have actual data that proves the settings we were looking for worked exactly as intended. The OTS settings in the past locked up a little harder than what we wanted.

Which brings up another point: OTS (Off-The-Shelf) solutions are not likely to ideally suit every driver. It's not as simple a problem as "Stock Torsen sucks, I got Brand X clutch type and it's the bomb". For most people who track these cars, I think they're gonna be better off at least trying to optimize setup around the stock diff and spend that $1500 on track time and tires/brake pads instead. With experience they might have a better idea how to spec a diff to their liking if the stock Torsen isn't working for them. For someone like myself, I bet my preferences would lead to a setup that would work with the stock Torsen LSD.

[CSG David]

Originally Posted by ZDan

Which brings up another point: OTS (Off-The-Shelf) solutions are not likely to ideally suit every driver. It's not as simple a problem as "Stock Torsen sucks, I got Brand X clutch type and it's the bomb". For most people who track these cars, I think they're gonna be better off at least trying to optimize setup around the stock diff and spend that $1500 on track time and tires/brake pads instead. With experience they might have a better idea how to spec a diff to their liking if the stock Torsen isn't working for them. For someone like myself, I bet my preferences would lead to a setup that would work with the stock Torsen LSD.

That is a point that is very important to make. @CSG Mike presented data we derived on a track that utilizes mechanical grip more than grip obtained from aero. In stating this, we wanted to see a CSG configured diff put through its paces to find out how well the LSD was performing. Data is important to validate claims, statements, and proving theories. In either case, I believe these conversations with you and @diss7 show that our goal and points are, at the very least, communicated. Every setup is a specialized setup, but it definitely shows that the differential does improve performance when done properly.

[diss7]

Realistically, having a CSG spec'd diff is a golden opportunity for most. Because its going to be based off real world data, using the good drivers and this car.

Its a not brainer to get it if you..
Are a circuit guy
Not really sure how to set a diff up (most poeple don't)
Don't have the time/money/desire to pull the diff out and try different settings (almost NO one does)

If I was going to focus on circuit I would buy a pre specced CSG diff, purely for the R&D put into it's settings.

[7thgear]

how much would an autocross spec dif differ from a circuit type, I wonder?


would one aim to have more lockup for easier rotation by throttle?

[Calum]

After reading Mikes first post my only question was, 'why aren't you trying to load up the unloaded tire to prevent the wheel spin instead of ****ing around with the diff? CSG already has the ability to adjust rear roll stiffness.'

Of course, my question has already been answered in that it comes down to personal preference. But along the way I've learned yet more about the artistic side of suspension setup. Thanks guys!

[ZDan]

Originally Posted by 7thgear

would one aim to have more lockup for easier rotation by throttle?

No, more lockup => more understeer off the gas, more understeer on the gas.

Which is one reason I'm kind of philosophically opposed to tightening up the diff. You're adding work to the tires that is trying to make the car go straight. My approach would be to try to make the car work with as little diff preload/tightness/lockup as possible.

[diss7]

Originally Posted by ZDan

No, more lockup => more understeer off the gas, more understeer on the gas.

Which is one reason I'm kind of philosophically opposed to tightening up the diff. You're adding work to the tires that is trying to make the car go straight. My approach would be to try to make the car work with as little diff preload/tightness/lockup as possible.

Heading into apex, yes I agree with you, hence why I said I'd go loose 1.5way, or possibly just 1 way.

But past apex, you want to get the power down, and being able to do that is more important than a little more push understeer at that point; because more often than not you'll be able to accomodate it.

[CSG David]

With a low powered car, you'll spend a lot of time trail braking to rotate the car and get on the gas as long as possible. Many times the car may be experiencing a slip angle and potentially lifting a wheel just enough so the contact on the pavement is not as well loaded as it should be. In these times, data has shown that a true clutch type LSD has allowed us to grip and power through those corners. The experiences we've had with the Torsen is that you get times when the engine suddenly just revs up kind of awkwardly indicating a certain level of slip. Usually these places are off-camber corners or sudden uphill/downhill drops that cause an off balance of weight transfer. With the proper suspension setup, the wheel still maintains contact with the pavement, but it's still not as loaded as it should be. We say proper because many well known setups have notorious pictures of cars 3-wheelin' or 2-wheelin' through these corners.

With that said, driving with a 2-way, 1.5-way, and 1-way all require a slightly different driving style and setup. You can almost say that the 2-way and welded diff setups require you to "drive harder" while feeling incredibly stable. It's actually a pretty cool feeling if you get the car to dance properly.