This has probably been raised before but why are locked diffs usable in the XFR and UFR? In reality they would be no use on tarmac as FWD cars would be too heavy, the steering of Minis with LSDs was said to be heavier than that of Camaros when Car and Car Conversions did a test of 70s BTCC cars.

You mean the steering would be too heavy or the cars are too heavy for locked diffs?

Quote from ajp71 :

was said to be heavier than that of Camaros

Camaro's handle pretty good! Any FWD car cannot compare with the handling of a Camaro!

Quote from wheel4hummer :

Camaro's handle pretty good! Any FWD car cannot compare with the handling of a Camaro!

LOL what Camaro have you been driving?? My 2000 V6 (which handles better than the V8's just due to less weight over the front axle) is a decent handler, but my VW Scirocco with blown shocks and 175-75-13 tires (and no power steering) could out-handle it without any trouble at all! I could probably drive it one-handed (shifting and all) and do better than I could with both hands on the Camaro. There's a reason why almost all Camaro's end up on the drag strip, that's about all they can do well.

And, I use the locked diff a lot on most of my UFR setups, it helps the car pull out of turns with more throttle and keeps from burning the tires up. I've heard of auto-X and rally Volkswagens that use 85% or more LSD in the front for exactly the same reason.

Brendan

Quote from Lord_Verminaard :

LOL what Camaro have you been driving?? My 2000 V6

This was back in the '70s British Saloon Car Championship, when Camaros really were big and wouldn't stand a chance at outhandling a Mini , the Minis were running with an LSD and with the very short driveshafts this made the car have very heavy steering.

I'd doubt you'd use such high diff settings for circuit racing, but the real reason a locked diff wouldn't even be considered for RX in a Mini is the steering on tarmac would be impossibly heavy.

I think handling and cornering are two different things altogether. The Camaro, for what it's capable of, is an excellent handling car. When it get out of shape it's very easy to correct. (Given that it's one of the models with enough throttle response.) My Fiero does not handle as well as the Camaros do, but will out corner any of the ones I owned. (Box stock.)

I've only driven a Scirroco once or twice. I would probably have to agree, from memory, that the Scirroco corners better at low and medium speeds. But I'd take a Camaro before that any day. Because of the handling.

Oh yeah, on topic: Diffs confuse the crap out of me. I just keep flinging numbers until I can keep the thing on the road. An improvement for me would be to put a * next to the diff type that I don't need to understand to drive.

[edit] Driven a highschool GFs mini a few times. Great handler.

Diffs aren't that complicated really. For instance I was burning up one of my rear tyres in the FXR, increasing the power locking by 5% made it go away because when that tyre was the inside tyre, it was spinning under power. So instead of making the car more oversteery as you would expect, it helped put the power down. I tried adding another 20% and then both tyres get fried as you are sliding out all the time.

Obviously FWDs are a different story, but then you don't actually want to race them do you?

Quote from Slartibartfast :

The Camaro, for what it's capable of, is an excellent handling car.

I don't think we're talking on the same wavelength here, I'm talking about 1970s Camaros with ridiculous amounts of power, but no grip, they would certainly be handful to drive (http://www.tplusplus.de/muscle/taimg/ta70_6.jpg)

oops... No, I've never owned, or driven, one of those. They sure look cool though.

Bob, learned that last night or the night before. I was in the RX7y GTR thing at Aston Nat and was getting wheelspin in the slow corners. A guy suggested more power side lock. Worked like a charm. The different types are a brain clot for me too. Hard to feel what they are doing.

I certainly don't want to race FWD. Or do anything in FWD. But my league is running a series... and I love racing with them.... and Gimpster made a setup that isn't too frustrating. Still, it's too much to ask two wheels to do. And my right foot acts all funny...

Quote from Slartibartfast :

The different types are a brain clot for me too. Hard to feel what they are doing.

Have a look at Bob's setup guide (http://myweb.tiscali.co.uk/thefloatingwidget/lfs_guide.html)

Basically an open diff will keep putting power to the wheel with the most torque (therefore increasing the speed differential between the wheels) so this is a non-starter in powerful cars and you never need to run one in LFS.

A locked diff is the two drive shafts welded together, this gives better traction for drag racing and maybe things like ice racing, but on tarmac a locked diff will be ripped to pieces so it's a non-starter in LFS.

An LSD is the best option, it comes using either a system of clutches or a liquid system. They are the best option to use where you can (which is all cars in LFS), maybe they shouldn't be allowed in all cars seeing as you can't use them in all racing series?

Thanks for the info. A real help in your printed message and the link... why on earth have I never before clicked the link in Bob's signature?

Quote from ajp71 :

Basically an open diff will keep putting power to the wheel with the most torque (therefore increasing the speed differential between the wheels) so this is a non-starter in powerful cars and you never need to run one in LFS.

Read again. An open diff cannot transfer torque, both wheels will always get an equal amount. This is bad because
a) due to weight transfer, when you go to accelerate out of a corner, you won't have equal grip on both tyres, so can't make optimal use of the grip available
b) because of a you will spin the inside wheel first... then once the wheel is spinning, it's resistance drops dramatically, which limits the amount of torque that can be sent to it... since the open diff can't transfer torque, the wheel with plenty of grip gets less torque too... end result, you torch your inside wheel but don't actually speed up

Quote from Slartibartfast :

Thanks for the info. A real help in your printed message and the link... why on earth have I never before clicked the link in Bob's signature?

Don't worry, nobody clicks on links in signatures, some don't even read them. Makes you wonder why we bother with them at all really...

The RWD GT is fastest with a locked diff. The Lx4 is very driveable with a locked diff too. So its not just the UFR/XFR

Right now the clutch pack lock without any preload is very disapointing for me.

Quote from Slartibartfast :

I've only driven a Scirroco once or twice. I would probably have to agree, from memory, that the Scirroco corners better at low and medium speeds. But I'd take a Camaro before that any day. Because of the handling.

I loved my Scirocco BTW, it's 1 'r' and 3 'c' .

I'm not a fan of camaros, at all, but i understand they are pretty decent
handling cars. I'd still choose a Scirocco over a camaro, anytime. Much
lighter, uses much less gas and can easily be as fast unless you really
NEED to have 1000hp to go fast in a straightline for 1/4mile (cause we all
know how usefull THAT is..) Heck i'd take any 240sx/300z, Miata or BMW
before even touching a camaro.

Reminds me, i had a 'race' with an old 84ish camaro the other day and i
was an even match with my 1988 325ix, thats an inline6 with 170hp btw.
What engine do you camaro guys think he had ? It had a tailpipe on
each side (2 in total) a bit like Mustangs have sometimes.


Ah yeah, the locked diffs, sure, why not, i'd like to have all diffs available in all
cars if only for testing purposes. It's always fun to be able to use 'real world'
to understand how things work/relate.

@fonnybone
The 325ix is one of the rare BMW's using a viscous lock for the rear instead of cluch pack. You know why ?

Quote from Fonnybone :

I loved my Scirocco BTW, it's 1 'r' and 3 'c' .

Reminds me, i had a 'race' with an old 84ish camaro the other day and i
was an even match with my 1988 325ix, thats an inline6 with 170hp btw.
What engine do you camaro guys think he had ? It had a tailpipe on
each side (2 in total) a bit like Mustangs have sometimes.

In 84, the Z28 had the 350 V8 with a Quadra-jet (or Quadra-junk) carbed engine. Due to GM not having a clue how to deal with emissions, it made about 200 hp at 5000 rpm stock. Yea, real POS. :P I think that was before the Camaro started coming with the 2.8 V6 and the RS engine was the 305 carbed engine with something like 160 hp. They didnt start using fuel-injection until about 86 with the Camaros, and then they started making more power again, something like 230 or so.

Funny thing, my 2000 Camaro has the 3800 V6, I've done a lot of modifications and it will run with the older LT1 Z28's and is capable of getting 36 mpg on the highway. Still, my poor old 84 Scirocco is more fun to drive, blown shocks and all. She's not stock though, either. Has headers, full exhaust, no cat, Audi TB with ported intake manifold. Stock factory limited slip and the "4k" close-ratio transmission. I bet it would give my Camaro a run for it's money. I had a couple of guys in a Prelude scratching their heads because they just got spanked stoplight to stoplight in some funny looking old Volkswagen. :P

I'm trying to sell my Camaro, as the VW is going to get all of the attention here soon.

Brendan

Quote from Lord_Verminaard :

In 84, the Z28 had the 350 V8 with a Quadra-jet (or Quadra-junk) carbed engine. Due to GM not having a clue how to deal with emissions, it made about 200 hp at 5000 rpm stock. Yea, real POS. :P I think that was before the Camaro started coming with the 2.8 V6 and the RS engine was the 305 carbed engine with something like 160 hp. They didnt start using fuel-injection until about 86 with the Camaros, and then they started making more power again, something like 230 or so.

Actually, i meant to say i found it 'fast' for a 'stock' 84ish camaro, i'm
not very knowledgeable in GM engines, but i know a GM 350 can be tuned at
will with just about millions of parts from just about any part store in america.
In other words, his camaro looked 'tuned', it was a ghetto beater, but it had
too very long and shiny tailpipes (the only clean thing on the car!) and you could hear the engine VERY well...

anyways, i don't find my bimmer that slow, sure with the awd and extra
weight, it can only do 0-60 in 7.8 or so, but it can still manage the 1/4 mile
in a bit under 16 seconds. Looking at a 1988 car book i see the camaro had
2 350ci engines, a 170hp and 215hp versions and TADA, the 215hp version
does 0-60 in about 7.7 and tops around 220kmh, so i guess that's the engine
he had then.

Quote from Lord_Verminaard :

I had a couple of guys in a Prelude scratching their heads because they just got spanked stoplight to stoplight in some funny looking old Volkswagen. :P

Had the same thing happen against an Integra...a friend of mine in a '99
Cavalier Z24 was also surprised that my 'rocco could hold his Z24 of the line,
100lbs of torque might seem low, but it's only pulling 975kg

Quote from M.Mos :

@funnybone
The 325ix is one of the rare BMW's using a viscous lock for the rear instead of cluch pack. You know why ?

Well, i bought it just because it's rare, period. I always loved those cars as a
kid and still can't believe i have one when i go outside and see it. It's my
baby She's so purty...she's a bit lowered too and with the OEM ground
effects and BBS mags, she's a blast from the past.

The differentials surprised me too. From what i understand, a rear viscous diff
is standard issue on ALL 's' (sport) BMWs at the time. The 325ix basically has
a 325is rear end and viscous clutch-pack (see where the confusion begins..).
The transfer case actually uses a viscous clutch to connect the front and
rear, so it's also considered a viscous differential. It's the same system used
in the bigger 5 series of the time. The tranfer case gives a bias Front/Rear of
37/63 %.

Here's a link about the 325ix differentials:
http://www.garlington.biz/Ray/BMW/325ixDriveTrain.htm

The car feels extremely solid in turns and can accelerate to insane speeds
from the apex on, it's incredebly 'grippy' and that's with winter tires...i can
feel the viscous work as the handling gradually gets tighter and the open
front diff seems to make it pull itself out of any turn.

My friend with a '99 Audi A4 was surprised himself, his car has a Quattro
(II ?!) system which we recently learned is a TORSEN center diff with an
electronic locking diff, EDL both front and rear. The Quattro system is 'locked'
at low speeds, or something like that. It's a bit more understeery than my
325ix, but he's getting an S4 suspension installed as we speak and a few
other mods here and there...so we'll see how that helps.

Plenty of great images of just about all parts !!
http://www.realoem.com/bmw/par ... 81000&hg=26&fg=10

Taken from the above link, these are the 3 'diffs' in my car.
Front diff:
http://www.realoem.com/bmw/sho ... _0185&hg=31&fg=15
Tranfer case
http://www.realoem.com/bmw/sho ... _0003&hg=27&fg=05
Rear diff:
http://www.realoem.com/bmw/sho ... _0105&hg=33&fg=15

Sorry, no locked diff there...

Quote from Fonnybone :

It's my
baby She's so purty...she's a bit lowered too and with the OEM ground
effects and BBS mags, she's a blast from the past.

Hell yeah e30 is one of the finest series BMW ever made So keep your baby in a good shape, watch the usual points where a E30 wants to corrode and you will have a great car for a long time But i belive canadian winters will hurt her bad :weeping:

Quote :

The differentials surprised me too. From what i understand, a rear viscous diff
is standard issue on ALL 's' (sport) BMWs at the time. The 325ix basically has
a 325is rear end and viscous clutch-pack (see where the confusion begins..).

Thats exacly the point Afaik only the ix had a viscous lock. All others had a fixed passive clutch lock with 25% lock.

Quote from M.Mos :

Afaik only the ix had a viscous lock. All others had a fixed passive clutch lock with 25% lock.

You seem to be a bimmer man so i'll give you the benefit of the doubt,
i'm not sure, i always heard it was the same rear end, diff included. I
assumed that non awd e30 had either an open diff or the viscous/clutch
diff as in my 325ix. In that first link i posted, you can read this though :

"The application of viscous clutch technology in the rear drive unit provides several advantages:
1. automatic and continuous rear wheel locking according to varying road surface conditions
2. quieter, softer engagement which rseults in less strain, wear and noise.
3. gentler lock/unlock action enhances front axle steering control"

I guess the choice might have to do with 'balancing' the awd. Reading that
stuff again i realise that the drivetrain doesn't accumulate any trapped stress,
meaning i could hit a patch of dry while the 3 other wheels are spinning and
the viscous couplings will 'absorb' it or something. I must admit i didn't go into
the details much hehe.

I'm really refering more to personality when I say handling. The 240sx is a sweet handler and cornerer. The 300z that my brother owns is fairly good around corners, but it is not a neutral car with a tendancy toward understeer at all speeds and crazy snap oversteer. I've never liked stock BMWs. Have driven a few, don't like the roll. Not sure what it is. But they don't feel responsive to me.

The Camaro is very easy to read. The correct models also have gobs of power. My favorite feeling when driving is that of a direct link from the engine to the rear wheels. I'd rather all my cars have a chain straight to the back axle. Any bit of lag drives me nuts. (I can't drive an automatic to save my life.) Maybe it is the diffs that came in my favorite Camaros that did that.

Do Sciroccos do 160mph? If so, how are they in a drift at that speed? I'm not saying they aren't worth having, even more so than a Camaro. I'm just saying the Camaro has it's charms. And RWD is really the only truly romantic and responsive drive system, as god intended.

As far as street racing goes, well... I've blown off so many really nice Porsches, BMWs, Audis, Vipers... and not just in a Camaro, and NEVER in a straight line. Mountains only for me. Datsun 510s, Mazda RX7, Toyota Celica, Isuzu Troopers, Pontiac Fiero, Datsun 620s, Chevy Nova, Galaxy 500, I've even embarrased a few folks who thought they were racing in my VW Bus. (Downhill usually.) I've driven some very nice Porsches and Ferraris and the like. Let me just say that on the public road, the car is rarely the reason for the result of the race.

Quote from Bob Smith :

Obviously FWDs are a different story, but then you don't actually want to race them do you?

why not, a fwd car can be really fun to drive.

Quote from Tomi :

why not, a fwd car can be really fun to drive.

Certainly can. All you do is make it RWD and give it more power, and you're away

Quote from tristancliffe :

Certainly can. All you do is make it RWD and give it more power, and you're away

narrow minded. A real driver don't need this

Quote from Tomi :

narrow minded. A real driver don't need this

He was joking.

Of course FWDs are perfectly raceable, but many (including myself) don't like the handling.

Also it's no secret FWDs by nature have low power handling.