While sleuthing around on options for LSDs for the Ital, I came across this lively discussion. I wish to post some of the comments on the Morris/Ital parts. Someone might find them interesting. Thank you to "Gareth T" for the contributions. Salty, yes, and probably got booted for it, but this is someone who was there.
https://www.triumphexp.com/forum/spitfire-and-gt6-forum.8/limited-slip-diff.710970/page-2
Robert Coates (RC): Where can I find a limited slip differential for Spitfires (a MK1 specifically)?
Bill Kea (BK): Only one I know about is Quaife and they are over $1,200.
Garret T (GT): Quaife are rubbish. They simply don't work. I've built LSDs for Spitfires for near 30 years inc the original salisbury fitted in the Le Mans car, inc ADU3B. (I used to have one in my road car). The only worthwhile LSD is a PLATE TYPE. There are 2 done in the UK now, (Tranx and Gripper), and another salisbury was remanufactured in Australia for the dolomite. The price is quite high, but sure as anything no-one would ever bring me to lower the price ever again. (You get fat thanks for helping people out, all they want is freebies!)
James King (JK): Mention made here of LSD options. http://www.triumphspitfire.com/substitute.html
Joe Curry (JC): I see he's BACK! Actually, Quaife is not all that bad. It's biggest problem is that it is torque biased and if one wheel is off the ground or axle breaks(offerning no resistance on one side) it won't go anywhere. There are other options as Gareth suggests. I guess it all comes down to what you intend to use it for. One option is welding the diff so that both wheels turn simultaneously. This is NOPT recommended for daily drivers.
Joe
P.S. Don't fall for "Phantom Grip". I tested one (thanks to GT6 Steve) and found that they are (as Gareth would put it) RUBBISH. I could not see any difference in that and and open diff.
GT: We tested the Quaife back to back against a Salisbury in our FIA championship winning car in 1993.
The German co didn't believe me when I could get their car 2-3 seconds a lap faster...
They said "PERFECT" car...German style!
Funnily enough when we changed from that crap Quaife to a good second hand Salisbury, the car made that 5 seconds a lap difference IN THE WET.
In the dry it was even faster.
I spent ages convincing them..."sigh"!
I also worked on the Le Mans TR2, and they also said I couldn't make it better German style again!
I managed to build in some castor, get proper feel into the steering, then the magazine that reviewed the car thought it was "b...marvellous".
Said they had never driven a TR2 that was so nice to drive....
Jerry Bryant (JB): I didn't see one advertised for spitfires They ran 980.00 US for other TR's
Andrew Mace (AM): What about the "Detroit Locker"? At one time, it was offered through the US Competition Parts program for Spitfires as well as other Triumphs. I don't know much about them or any other LS diff. so I don't know how it compared to the Salisbury unit, etc.
Kevin Allen (KA): The locker is a strange animal to drive. Robust and reliable but you have to drive them differently. They are an open diff off the throttle and when you go back to throttle they lock the rear wheels together like a welded diff or spool. SO you get a good turn in and when you go back to the throttle it points the nose out of the corner, very unsettling until you learn to drive it.
I always ran a locked diff in the race car, it is the right choice for a swing axle Spit. It tends towards corner entry understeer which helps the Spit with it's high rear roll center. Makes it where you can really hang the car on it's rear tires getting in and then when you go to throttle, you drive it off using your right foot to point the nose. Great fun and fast when you are HP limited.
RC: Where can I find any of these limited slip differentials? I have a welded differential in it right now. I am planning on using it for vintage racing but I also want to take it to autocrosses every now and then and a welded differential sucks for that. I have driven plate type differentials versus torsen style in the same vehicle and I found the torsen was better.
GT:
In reply to a post by Kma4444I "always ran a locked diff in the race car, it is the right choice for a swing axle Spit.."
WRONG choice.
With this style of driving you will ALWAYS be slower.
Initial turn-in is one of the great unsung advantages of the Triumph cars.
Blasting into the entry of a corner with the front wheels pointing extremes and understeering means you will also run into the dive/castor/chassis flex mess the car is known for on the DOWN SIDE.
If you like it, fair enough.
It's SLOWER, just like it is on a mini, which also had good initial turn in, but then shed loads of disappointing speed penalising understeer.
Fast initial turn in means you can come in, brake MUCH later, then get on the right lines without going all over the place.
Locked diffs are absolutely hopeless for this.
Carrying high speeds into the corner means higher exit speeds, even if you have to be "slow in, fast out".
"slithering" your way around corners is nonsense, maybe looks and feels good, but sux on the stopwatch.
If you ever did any karting, you would see fastest is CLEANEST, > usually least spectacular., and heck THEY have locked axles from the word go, so they understeer/oversteer like crazy!
Brake late, turn in, > slow in FAST out.
The heavier and faster car you drive, the MORE you have to observe it.
Try 500bhp behind you, & see how you get on with a "locked diff"!
The proof is, ALL the modern lightweight Jaguar E type boys now moved from Salisbury LSD plate type axles, to Modern multi plate type LSD with variable ramp angles.
The results are blistering fast, ESPECIALLY in the wet!
60-40
70-30
ramp angles are the BIZ.
Forget locked diffs, they belong to the museum or in the back of lightweight cart.
(NB, if you want a LSD it takes some time to make up, and you have to choose a ratio, not just mention "I would like one".)
KA: Yeah, of all the things I was called in the Spit, slow wasn't one of them.
In the ALMS Viper, we got the car from Canaska with a spool, it was the way we had to run it initially as we didn't have the $9k for the viscous one that Oreca was by then running. luckily, one fell off the truck at Daytona and we put it in the car at the track. It was magic and transformed the car.
My Trans-Am car had to run the locker or a spool, it had a locker in it when I got it and I hated it. I had planned on swapping to a spool and setting up around it and am convinced on that chassis it would have been faster. Recently I spent three weeks in Denmark and did a couple races in American GT1/ Trans-Am cars and that chassis worked very well with the locker. I would leave the lockers in those cars because they were very good.
My point, every car is different, every driver is different. I have run some 200+hp FWD cars with the Torsen and they were absolutely seamless. I also run one in my sportsracer that again is seamless, you never notice the diff at all. Again, blanket statements are as useless as arguing on the internet.
The OP wanted opinions and those are mine. My choice for what he is doing is keep the welded one for racing and get a good plate style or secondly the Quaife for autocross.
RC: Where can I find a Tran X differential for the Spitfire?
RC:
In reply to a post by yellowbookroad "Quaife are rubbish. They simply don't work."
May I ask why they don't work? From talking to a couple other people, I am getting the impression that helical style differentials are better for daily drivers but clutch types are better for track cars.
Steve Smith (SS): To say simply "They don't work" is too strong a condemnation. They work well within their limitations. As stated they are a torque biasing style of diff. And as said they will behave much like an open diff on ice or if a wheel is in the air.
It is still noticably better because of the biasing but NOT as effective as other types of LSD's. I have one in the GT6 and it was an improvement back in the day. I don't use it any more on the racer because of the issues noted. I'd have no qualms using it on a street car. IMHO...
GT: Tranx only make LSD for the larger Triumph axle (Dolomite/TR4 IRS).
Funny that most of the people contributing here have NEVER EVER tried a plate type axle in the Spitfire....so the comments here are about as valid as piloting a plane when all you have ever done is drive a bus.
I can assure you, having had the Salisbury in road cars for many years (ie including the issues of maintaining it), the Torsen design is complete crap, by comparison.
No proper locking action, no balancing the car on the throttle, no feel at the steering, and pointless in a car that lifts wheels.
(like all proper rally cars do)
The thing about a plate type LSD is that it's fully tuneable.
You can set it up tight, and the car will swop ends real quick just like you would with those utterly useless welded axles, or set it up nice and loose and it's innocuous.
Modern ones have different cam angles and progression settings.
Reading the stuff I saw here, it seems as though some people think they can drive.. Go figure!
Have you seen what they use on hillclimb cars?
Judd powered F3000 Single seaters? (Hewland transaxles)
Modified saloon cars on hillclimbs? (Viscous LSD)
Historic D type/E type/Aston Martin?
That stuff is all FAR quicker and more competitive than any old Triumph, yet in some weird way we get this story yet again about "all cars are different".
(yep we like to race really MEDIOCRE cars don't we!)
Yep there's slow ones, and there's fast ones.
You don't go fast by locking 2 of the rear wheels together, unless you driving a 65bhp, 250cc kart doing 18 000rpm....and believe me that's enough to scare the Sh..ts out of anyone!
JC: I see Gareth is now back to his usual tactics, trash everybody else's opinion to try and PROVE that his is the only one that is valid.
The fact here is that there are woefully few options for LSD in Spitfires. I have a Corvette Diff in Tiny Tim, so I think I actually can speak with a little authority regarding how plate type diffs perform. And they do well. I previously had a Quaife when I had the Spit Diff and it is less effective but not as much as Gareth would have you believe. My worst problems had more to do with having to push the dar off the course wnen something broke rather than turning in slower times.
I also tried a welded diff (challanging to get accustomed to, and a bear to maneuver around the pits), and the much publicised "Phantom Grip" which truly is "Phantom".. I could not tell any difference between that and an open diff.
And finally, Gareth, We really do have good Designers, Mechanics and Drivers here on this side of the pond. Europe does not have a monopoly on those things. Joe
Fox Trapper (FT): A locker is vastly different than a locked differential. I've driven both.
The welded or locked differential is nicely consistent, and once you figure out how to slip your rear tires, it turns well enough. Not fun to shove around in the shop or paddock. Certainly eats tires! Driveable on the street, but you will get tickets for spinning your wheels.
Then there is the locker, it's triggered locking of an otherwise open differential. The action is sudden and violent. Prone to throwing the car sideways if you are in a turn when it locks. Most lockers lock-up the differential when the driveshaft is under load (throttle on or engine braking), and when the axles are matching their spin. This means you're open differential going into a turn. But as the inside wheel lifts and starts to spin, the differential suddenly locks when the axles match spin, tending to break the rear end free when it happens. Lovely. Locking a rear wheel hard braking tends to result in the most remarkable pogosticking of the rear end of the car.
Of all the differentials I've tried, the locker is the one I like the least. Especially for street driving. Good on a drag strip I guess. Wonderful on rock crawlers. Manually lockable differentials are great for tractors.
One that I've come to like for street cars is the viscous differential. Don't know of one for a Spitfire, and I doubt it exists. They are a very mild clutch-pack limited slip differential. They work as an open differential until you start spinning a tire. Then it heats up, expands, and slightly engages the limited slip clutches, giving a bit of power to the non-spinning wheel. Very gentle, very mild action. But also quite effective, in a very mild manner. Sorta like aspirin for differentials.
GT: In reply to a post by spitlistI "see Gareth is now back to his usual tactics, trash everybody else's opinion to try and PROVE that his is the only one that is valid."
& "The fact here is that there are woefully few options for LSD in Spitfires. We really do have good Designers, Mechanics and Drivers here on this side of the pond. Europe does not have a monopoly on those things."
Unfortunately for you, I have been building these things for longer than anyone else, supplying modified salibury at a time when there was literally nothing else.
These won many many races and championships since 1982.
(which can we say will be 30 years ago next year)!
Sometime there are just people who KNOW what they are talking about, because they build them and test them....no trashing, - just happen to know what I'm on about!!
QED.
woefully few options? I think not.
There is a very nice plate type LSD available, but I'm not doing any more for people for peanuts.
The first ones I did were merely servicing the original SAH salisbury axle, which was a specially made version of the mini cooper salisbury, with a Triumph specially made casing.
Triumph had a few 100 of them done & SAH sold them.
They were all fitted in the Le Mans cars...one of which I have also since serviced.
The main weakness was the fact they HAD to be used in the early type axle with the early 15245 carrier bearings and the early small stub axles.
I found a tweak to make them last, using rolled spline stub axles instead of the early triumph ones which had machined spline ones.
I then moved these to using the Cooper S internal planet gears, which entailed making purpose made quarter shafts from EN24T.
This cost a bomb, and no-one as usual was prepared to pay.
It was the version I successfully used in my own race car with a 4.55:1 axle ratio.
This was again THE FIRST one made in the world, before anyone else discovered the Marina diesel van crownwheel & pinion combo.
I've since built units with the "gripper", which is a far more sophisticated piece of kit and gives much better progression than the Salisbury did, and uses CNC made parts.
Having said that I DO still use the original plate and 45 degree ramp XJS V12 type salisbury in my Jaguar, because I rather like the slightly harsher attack it gives when on the limit.
It is capable of handling 600bhp+ abuse, compared with the gripper, which doesn't have forged gears internally.
FYI I've seen loads of broken quaife units, and if you study the action, it's easy to see it's NOT a LSD, it doesn't even lock properly.
I just supplied a gripper for a friend in OZ with a saloon.
He had a quaife which also went BANG....
Merely fitting the plate type LSD he went about 2-3 secs a lap quicker & the cornering forces were so much higher he had to upgrade the brakes and brace up the front suspension.
If you are asking for design for an ancient British car made in Coventry UK, I'm afraid there's no other place where an LSD is made.
Dana (Aston/Jaguar/Land Rover) is also made in Birmingham.
This is hardly suprising is it?
Homer Simpson (HS): So in other words, there are woefully few options for an LSD for a Spitfire.
GT: Woeful? My goodness, have you ever tried to buy a LSD for any other older sports type cars?
Ford Escort?
Talbot Lotus?
Triumph Dolomite?
Alfa Romeo GTV6?
Fiat 131?
They really don't grow on trees, but the parts situation (particularly for modified parts) is incredibly good for such an ancient car as the Spitfire.
Let's look?
Forged pistons:- 5 manufacturers many IN STOCK
Modified camshafts AT LEAST 10 manufacturers many IN STOCK
Close ratio gearbox 2/3 specialists
Modified axles 3/4 specialists
Modified exhaust manifolds AT LEAST 6 on the market
Modified inlet manifolds for Webers AT LEAST 3 manufacturers
Modified or steel conrods AT LEAST 5 manufacturers many IN STOCK.
I simply can't accept it, that ONE manufacturer has deliberately made a LSD for the AUSTIN MARINA (for which there is zilch demand,but is identical to the Spitfire axle), and yet people are still moaning on that the parts situation is bad.
I mean that guy (TS) put his money where his mouth is, and did a good job!
Homer Simpson (HS): So in other words, there are woefully few options for an LSD for a Spitfire.
It's time to stop all that, and wake up.
Those Triumph sports cars are amazingly cheap, and the modified parts support is miles better than most other things in th world of 30+ years ago.
BK:
Do you have a clue how many Austin Marinas ever came to this country? Nobody here would have a clue that diff would fit a Sptifire. If the brilliant manufacturer of this LSD knows it fits Spitfires, why does'nt he market it as such? I don't think he would have such a tough time finding a dealer in the US and could probably move quite a few units.
GT:
In reply to a post by billspit "Do you have a clue how many Austin Marinas ever came to this country? "
It's got nothing to do with it.
In the UK we all call the stuff by its name in the wholesale and trade sector.
Gearbox spigot bearing "marina large".
diff pinion oil seal Marina POS. (it's even got an austin morris pt no)
syncro rings...MARINA syncros.....
The spitfire 1500 gearbox casing was originally made for the Marina and has an AUSTIN morris pt No, most of the good bits fitted in the later cars came from the MARINA, as it was mass produced.
We don't really give a hoot how many people want this kind of LSD in the states, it's not a question of marketing it's all about who has the bits, so you'll have to buy the a complete differential unit anyhow, (except possibly in Australia where they made cars anyhow, so have stocks of NOS stuff).
The Marina fortunately was the basis for the 3.63:1, 4.55, 4.11 cw & pinion, without which, many many things wouldn't be possible.
The mess Beans industries made of the remanufacturing processes is more the reason why mass produced stuff from Austin Morris didn't make it into the Triumph range & vice versa.
Those companies were all bust in 1980,so it's a miracle there's anything left 30 years on.
Take a trip down memory lane
Don't blame me, blame British Leyland & the beer!
"Beans Industries was sold to Standard Triumph in 1956 from where they became part of British Leyland.
By 1975 they were known as Beans Engineering and a management buyout followed in 1988. In 1991 they purchased Reliant, which went into receivership in 1991 and took Beans with them"
"Standards bought it with some of the MHF money and continued to use it as a foundry for Standard Triumph Product castings. A La William Haig "comment" regarding 14 pints a day, the Union at Tipton had negotiated an agreement with the company for 18 pints a day for each foundryman and the apprentices first job was to go to the pub in the morning at 7-30 to collect the first issue.
At the end of the week he popped along with the money to pay. It was always mild beer, a midland favourite, which with an SG of about 2.8 you could drink all day without getting pissed, indeed stopping for a pint with the lads before you went home for tea!
Summer temperatures in the foundry could get as high as 130f, in the winter of course it was a bloody marvelous place to work. It was a favourite with STI students and apprentices, for the above reason, but the union was always a little funny about allowing some of their precious allocation of the amber nectar down transient throats, as we were only there for a maximum of three months work experience, which, over the period, was around 1500 pints of their best Ansells Mild to their way of thinking!!"
RC: So I have a line on a used limited slip differential (hopefully clutch type but if it is helical whatever, it is cheap) but it is in a late rear end. Can I make it work in an early rear end?
SS: Dependant upon "early" Vs "late" the spline sizes may differ and not be interchangable. I don't know the changeover years.
AM: I'm not sure, either. There actually were at least two notable changes. Sometime in Mk3 Spitfire production, the inner axles got beefier. Then, beginning with MkIV production, all the input and output flanges got larger (not sure what else changed with that or what other internal changes happened or when).
Paul Mugford (PM): Hi, I'm pretty sure the change in the Mk3 output shafts comes at the diff unit numbered FC 120000. Below that number has the small output shafts. That number and above has the larger output shafts. Good luck,Paul
AM: That's it, Paul. But that was a bit after the Mk3 introduction!
PM: Andy, Yes, they left a fairly big gap in the serial number run and restarted at FC 120000. These are diff unit numbers. not commission numbers. Paul
GT:
In reply to a post by spitfire50Hi, "I'm pretty sure the change in the Mk3 output shafts comes at the diff unit numbered FC 120000. Below that number has the small output shafts."
The early axle with small axle shafts ALSO has a different crownwheel carrier, different sunwheels and cross pin.
At the end of the production they already changed to the rolled spline on the stub axle, and these don't break.
The sunwheel and planets also have smaller shims, which can't be used elsewhere.
Before that they had splines hobbed in with a standard v shaped root cutter.
These were also fitted to the Vitesse 1600, and break dead easy.
Those were the stub axles they originally fitted to the Le Mans cars, and the "SAH"/works Salisbury LSD.
One or 2 of those came in with snapped off stub axles stuck inside, and I had to rebuild them, extracting all the nasty fragments from the clutch packs and carrier bearing tunnel...Made a right old mess it did!
Steve McCurrey (SM): In looking for information on what type of limited slip is a best choice, I see that most are in the clutch/ plate type goove.
I have a Gleason Torson helical / front and rear/ in my 1983 Toyota 4x4 . Installed it at 17K miles , now 137K. Have run the Rubico trail in the Siera Mountains multipal time.
Works absolutly outstanding .At $590.00 for the GT6 is alittle spendy , but not $1300.00..
What about the Tration control metal spring plate that fit between the side gears. Looks like it puts preasure agenst the side gears, metal to metal , slip woud be just wearing the two surfaces down RIGHT ??? $350.00
Carter Shore (CS): This is a 5 year old Zombie thread, but I do recognize some currently active names on the postings, and the question is still relevant.
The Torsen LSD are good but not perfect.
I'm not aware of a current Torsen or Viscous diff available for the Spit/GT6.
I think the inexpensive LSD you describe ('Phantom Grip') is well named, as the 'Grip' part seems to be elusive or non-existent.
It is possible to swap an ex-Subaru/Nissan R160 or R180 diff into a Spit/GT6, and choose from 3 different LSD types, depending on what year and model of donor:
Clutch style, Torsen, or Viscous
Is your car a Spitfire or GT6?
Laurence Cochrane (LC): NOTHING WRONG WITH A TORSEN i have two Quaife and a Chinese Blackline ( Half the price of a Quaife ) Granted lift a wheel, loose drive. As Quaife themselves will tell you. Lifting a wheel SORT YOUR SUSPENSION. This is CORRECT.
CS: Lifting a Spit/GT6 drive wheel is uncommon but does occur.
As noted, this can be overcome with suspension refinement.
All LSD types have issues of one kind or another.
The recent Toyota GR16 Yaris employs an 'always active' electric wet clutch that permits the ECU to modulate the front/rear torque split.
A similar approach can be applied to left/right torque split.
(interested parties are advised to bring the BIG wallet)
Laurence, can you provide details on the Quaife & Blackline units?
LC: Carter Really not sure what you expect me to tell you. Replacing the centre unit with a Quaife Blackline really reinforces diff over the FAR WEAKER OE Item. Yes the little 1/4 shafts are still a factor. I have to say having given these diffs DOGS ABUSE over many years I have NEVER broken a 1/4 shaft. SKUDS SELF ! My EFI 2600 even endured on a daily basis FULL POWER tyre shredding donuts in the back yard at work. ( Proper donuts cannot be doine in a Gt with an open diff) Till my boss told me to refrain from it. THINK THAT IS WHAT HE SAID. The Torsen is REALLY PROGRESSIVE IN ACTION. Unlike plate diffs. No need to view the PUBLIC roads through the side windows WITH ABSOLOUTLY NO WARNING. More info look up Quaifes web site. The Backline is / was sold by Rally Design here in the UK again look their web site THEY SOLD A LOT OF THOSE. There are other brands of these badge engineered Quaife copies sold by other dealers Same thing different brand names.
Mike H (MH): I bit the bullet this summer (2022), replacing a welded gearset with a Quaife unit in my racing spit. I'm running 4.11 gears in a GT6 housing and it mostly bolted right in. I did have a problem getting the backlash set correctly, I had to grind 0.015 off the back side of a bearing race (Temkin) and put all the shims on the crown wheel side but I suspect that was more of an issue with the bearing not the Quaife.
Quaife Part number QDF8K , around $1,000 delivered to the US directly from Quaife. According to Quaife, it works as for all gearsets except the 3.27. That needs some machining done to clear the mounting bolts. The specs and description of the work is on the Quaife site.
Results: I've had solid back end race vehicles for 25+ years, from Gokarts, to F440 and then the welded rear Spit.
Big change in cornering, much fewer mid corner corrections, the car just flows through the turn. Downside, I sometimes get wheel hop on corner exit under acceleration. I dialed most of it out with tire pressure and shock setting changes but one of my off season projects was a new rear spring and reduced rear camber to get more contact with the track. I'll find out in the spring how much that helps.
Here's an in car example of the hop as I go enter then exit the hay bale chicane at the Put In Bay reunion race this summer. I think it's worse here because it's a concrete track but you can see the shuddering and vibration as I put the power down. Asphalt tracks were much smoother, maybe only hopped once or twice a session, here it was just about every lap, made it easier to catch on film. https://youtu.be/u8IBppef6Do
I'm interested in the blackline version, I want to build another one for my currently welded 3.89, for higher speed tracks. I'm going to the all Triumph Kastner Cup race at Road America (1st time there) next July so I have some time.
Stan Part(SP): Ran across a thread on bmw forum where someone disassembled a Blackline (Scroll down to the first post by booloveblankie). General impression is that it's a direct copy of a Quaife with some cosmetic machining areas where they cut corners and saved cost. Obviously this isn't the Triumph unit, but I suspect the same level of quality. For half the price, it's certainly worth giving it a shot. If it works nearly as well and only lasts half as long as a Quaife, you got your money's worth.
https://z4-forum.com/forum/viewtopic.php?t=102831
LC: I noticed that too the changes are purely cosmetic so as not to be a Quaife direct copy. Copyright law.
CS: Spit rear wheel hop is usually down to rear suspension compliance.
The rear spring has the job of taking the front/rear forces from the top end of the rear Vertical Link.
They are very stiff in that direction, but with racing tires, the forces are far greater that they were designed for.
All the forces resolve into the diff case, and so any diff bushing compliance will show itself here.
Urethane or solid diff bushings, as well as the bushings at the spring tips-to-vertical links can eliminate the compliance,
at the expense of NVH.
Kastner even went so far as to use Heim jointed links from the VL tops, through passages cut into the rear bulkhead
connecting to pivot brackets located in the cockpit floor behind the driver&passenger seats.
They of course ruled them illegal at the time, but Shelby later got away with the same trick to help locate the
live rear axle of the Shelby GT350. Different rules for sedans I guess.
