My T4 build

I had a transaxle made at Rancho that they calla pro-suby, I think. Custom ratios, and I had it set up to run a 3.88 because I put a Peloquin Torsen diff in it and that won't fit on a 3.44. New Rhino reinforced case, Weddle gears, etc. No rebuilt or used parts, IRS set-up for bus axle stubs. The target was reliable when used with 200 torquey horsepower. (200 will be optomistic, but let's build in a margin of safety.) I think a similar tranaxle would cost around $7,000 now.

In one of our earlier transaxle technical throw downs I put together a comparison of that transaxle with the one Stan built for his car with a 3.44 and a clutch type LSD, taking into account the different tire sizes we're running. I've attached the chart for both and a comparison of the speed in gear charts. Have fun!

Great stuff

@JMM (Michael)- Whoa, the 2 are pretty similar!

My Spyder had to have a 3.88 R&P because I wanted an LSD. It definitely needs one. I keep telling myself that I’m not going to drive this car in anger. We’ll see but I really want the 3.44 for higher shift points and leisurely highway driving.  I know I could get the same result using creative gearing and a 3.88 with an LSD. But it will be simpler and cheaper with the 3.44 and no LSD.

BTW. Exhaust by Tiger. This guy is an artist.

Well I don’t have an LSD but neither am I the most aggressive driver so I see little need for it in a cruiser.  In a spyder definitely, I would think your traction would suffer immensely without it.

My first Spyder did not have an LSD.  When I went around corners I could jam the accelerator at the apex and the inside tire would spin and smoke.  It was a lot of fun but not real fast.  If I tried that nonsense in my current spyder I'd be stopped and facing backward.  Or maybe in a ditch.

I don't have a Torsen diff. I also don't need one.

What you need is a properly set up swing axle with about 3 or so degrees negative camber per side, limiting straps so it can't go positive, sticky tires, and a proper anti-sway bar in the front that keeps the entire chassis flatter.

With all that, the inside rear tire never gets light enough to lose traction. 

Danny when we were at the Smo a couple of years ago you laid down 100 feet of rubber in a straight line with both tires. Never seen that in a non LSD car. You sure you don’t have a quaife hiding in that tranny?

Yes. I built the trans. 100% positive. It's a standard Super Diff from 2002. Originally it was installed by Trans West(now defunct).

"Poor man's posi"

@550 Phil posted:

Danny when we were at the Smo a couple of years ago you laid down 100 feet of rubber in a straight line with both tires. Never seen that in a non LSD car. You sure you don’t have a quaife hiding in that tranny?

@Stan Galat posted:

"Poor man's posi"

By way of explanation:

From a 2006 post on TheSamba:

"The Poorman's _(sic) posi shims will tighten the side gears to the spiders by taking the clearance away. Yea, it will give you the "posi" effect a little.

The wear is not really there since the open diff will only work the spiders when you loose _(sic) traction on one wheel. This is when it spins the spiders over the side gears. But so long as both wheels track at the same, the spiders stay put and the both axles roll as a unit.

All it is sticking the correct thickness shim in there between the "C" clip and side gear."

Lots and lots of people don't run any toque-bias or plate-type LSD and still lay down two strips of rubber.

Berg makes a kit for Swing Axle transmissions. I'm not sure any of this is useful information for an IRS car, but you asked how Danny laid down two strips of rubber in an open diff car.

I did not buy the Berg kit.

I did buy the Weddle side gear shim kit though. It consists of 2 shims each in a range of thicknesses. I merely installed the side gears and used the kit to obtain factory clearance for the side gears. The factory spec is 0.002-0.008".

What you're trying to do is eliminate the hammering of the side gears to the spider gears when installed too loose.

I did not make them tight as Berg's kit and instructions say to do. Which IMHO makes for more wear and metal filings floating around. Not a big deal when you rebuild often at the drag strip. But for a road car, no thanks.

That's exactly what most guys do, Danny. It seems like the nice part of the Berg kit is the steel thrust plate, but I'm not a transaxle guy, so what do I know? Berg was a drag-racer, which is STILL how most hi-po parts are marketed. A guy could buy the Berg kit and set it up a bit looser than recommended, but on the tight side of VW spec.

Back to the transaxle in question, I'd get a TBD for IRS if I were spending $5K+ on a box for a $15k+ engine... but that's just me.

Back in the day, we used to say "if you want to run with the big dogs, you need to pee in the tall weeds". A 2.6L T4 is definitely a big dog.

You do you, Phil.

I think the quaife in my Spyder is an LSD. But I’m also assuming that an LSD and a TBD serve the same function, to supply power to both wheels.

@550 Phil posted:

I think the quaife in my Spyder is an LSD. But I’m also assuming that an LSD and a TBD serve the same function, to supply power to both wheels.

Your Quaife is a TBD, and yes — but they do it in 2 different ways.

I think this is mine.

So for a standard friction-spring type limited slip diff, it's a ZF for VW. They were made and installed in Beetles, but I don't think many or any ever got here originally. Most friction type are 20-40% limited slip.   

TBD(torque biasing differentials) use sun and planetary gears to bias the torque to where the traction IS. Some say 0%-100%, most say 1%-99%.

Either way, they are made by Peloquin, Quaife and Paul Guard of Guard Transmissions.

I wish everyone used the correct terms, cuts down on confusion(Not picking on you, Phil. The advertisers).

I don’t know but this is my original receipt from Rancho. He didn’t believe in email at the time.

Again... if it's a Quafe, it's a Torque Biasing Differential.

That is a different thing than a Limited Slip Differential, even though the guys writing ad copy or catalog pages don't know the difference. Many people use the terms interchangeably, but technically they are not the same thing.

To put it in terms you may be more clear with, I tell people I take a Celebrex most days, even though it's really Celecoxib. It's the same thing, but it's not.

A LSD wears out (my ZF LSD needs rebuilt by... somebody). A TBD has no springs or clutch plates and so lasts effectively forever. There's no shame in having a TBD -- just like there's not a lot to be gained in taking a namebrand scrip for most people.

I understand that mechanically they are 2 different things but I don’t think that the average Joe understands that. I had never heard the term Torque Biasing Differential until you used it in this thread. When I ordered my Spyder from Rancho in 2016 I told them I wanted a LSD. And I figured that‘s what I received. A highly technical person might care and correct someone if they called a TBD a LSD but to a doc like me it just seems like semantics. I guess that’s why Rancho never corrected me. They knew what I wanted.

LSD=prohibited substance

@550 Phil,  we had this same conversation 2.5 years ago!  

https://www.speedsterowners.co...1#684750432129164211

If anyone is interested what it looks like inside a Torsen differential, check out the ad by Paul Guard.  These things are really sweet, but unfortunately he doesn't produce a model for Type 1 IRS, swing axle only.

Torsen Differential

I like to educate myself. Don't be average Joe. Be educated.

And if you care about describing things by their proper names(like I do):

https://www.planet-9.com/threads/lsd-vs-tbd.15040/

The best explanation is response #1, by none other than Paul Guard of Guard Transmission. I think he knows what he's talking about, he BUILDS this stuff. You know, for a living.

The simplest explanation I've got:

If there are springs and friction discs or plates, it's a limited slip.

If there are planetary gears, it's torque biasing.

@LI-Rick posted:

@550 Phil,  we had this same conversation 2.5 years ago!  

https://www.speedsterowners.co...1#684750432129164211

HA HA. Yup it’s deja vu all over again.

I’m ok being an average Joe when it comes to cars. Medicine. Not so much.

@550 Phil posted:

I’m ok being an average Joe when it comes to cars. Medicine. Not so much.

I want to know as much as I can about everything I care about.

YMMV

That’s the spirit Stan.  

@550 Phil posted:

I’m ok being an average Joe when it comes to cars. Medicine. Not so much.

That reminds me of Ralph Salzer, an orthopedic Surgeon and regular member of the car club in Beaufort, SC.  He was always bemoaning his lack of auto mechanic abilities compared to other people in the club, and yet, when he needed to do something on one of his cars he often relied on his surgical skills to "Git R Dun"!  

Like the time he made a new air plenum for the heater in his Dodge Hot Rod - Out of light fiberglass leg cast material.  Something he used all the time, especially on younger patients, just re-purposed a bit.  

You medical people are pretty resourceful.....

I guess the only thing I know a lot about is my profession. Hell I was in school until I was 31. I guess it was beat into my head. But I do know a little about lots of things. 50’s Porsches. WW2 weapons. Craft beer. Virginia wines. And I did ride motorcycles for 46 years before I almost killed myself. Oh, and recently I’m learning to cook. So why do I need to know everything there is to know about these cars when I have you guys?

@550 Phil posted:

So why do I need to know everything there is to know about these cars when I have you guys?

Because some of us are just apes with tools.

And others of us have been cooking for years.

Ooo Phil I like those…

In order of appearance:

1990 Browning High Power 9mm personally my favorite gun to shoot  

1936 German Luger P08 9mm WW2 gun

1945 Spanish Astra 600 9mm. Was in process on being shipped to Germany when the shipment was captured by the Americans.

1944 German P38 9mm WW2 gun

1945 American M1 Carbine 30 cal WW2 rifle

1944 Spanish Astra 300 380 WW2 gun used by the Germans

I belong to a local range and I shoot and clean all of these guns. I hate Nazis but I love their guns. Like 50s Porsches they are art.

Getting really close now.

Dude.

Exactly. I wouldn't want to pay the bill on this one(but it will be worth it).

I hope so. It’s been a long time coming. Bought those 1989 48 Dellortos (new in the original box from Italy) in 1999 and have been storing them for 25 years. I’ve been waiting to build a massive T4. The time is now. I think the 2000 IM Conv D I bought will make a good home. Antique carburetors in an antique car for an antique owner. I’ve paid my dues and I deserve this car. At least that’s what I tell my wife.

Perfect, Phil!!!!

"I’ve paid my dues and I deserve this car. At least that’s what I tell my wife."

Mine, too.

My last job almost killed me.  After fighting my way back to health for over two years, my car was my reward, even if it took a few more years to finish it.  It's a trophy car in more ways than one.