Help with 944 conversion on late Type 3 (with way too much power...)

[Shad Laws]

Hello-

I have a 1972 Type 3 Fastback. Very soon, it will have the most advanced Type 4 engine on the planet, giving at least 350hp of naturally-aspirated, gasoline-powered insanity. The four-wheel discs I have right now won't do! :-)

I have purchased a set of 16x7 ET55 and 16x9 ET70 993 rims (the 70mm offset in the rear will prove to be helpful!), and now need help to figure out which 944 brakes I should use to go with them :-). Because of my job, you may have guessed that I have access to a machine tool or two, so I'm not afraid of a little light machining.

For those that don't know, a late Type 3 has a rear suspension setup that is essentially the same as a late IRS Type 1 (uses the dual spring plates like an early IRS Type 1 - a PAIN to work on!). The front suspension is different. The rotors and calipers look *almost* like bug items, but are the same as a 1970-72 Porsche 914. The spindles are designed to take larger calipers (common 3" bolt spacing) and the same bearings&seals that a late Type 1 uses.

I'll be keeping stock steel trailing arms in a vain attempt to keep my fenders from hating me for my wide stance :-).

Question 1: finding 4-pot parts is proving to be a pain here in Chicagoland (where Chicago PartWerks is all we really have). Do you think it's worth the expense of scouring for them, or just get the 1-pot setup, get pagid carbon-kevlar pads, cryo the rotors, get stainless brake lines, and be happy? Personally, I'm leaning toward option two right now... I *think* (but am open to correction) that it'd also be more compatible with my stock Type 3 MC (19mm cylinders, similar to early 911). This is going to be my agressively-driven daily driver and an occasional autocross car, not a competition track car.

Question 2: knowing that I need to pull off the spring plates to do a rear suspension readjustment anyway, would swapping in adjustable springplates be easy and/or useful? If yes, what donor vehicle do I need to look for?

Question 3: I don't know exactly what the front brake conversion is going to entail. Does anybody have any words of advice on the late T3 spindles?

Thanks in advance for your help!

Take care,

[vujade]

Shad

an easy way to do the front disc conversion is to machine off the braking surface of your rotor until it looks like a hub. Then redrill it for the Porsche pattern if it isnt already. then you can use 944 rotors with your VW hubs, now all you have to do is make a caliper mount.

A few here on GL.com have done it this way on a beetle & super beetle, so I dont see why it wouldnt work on a Type 3 also.


BTW.... how are you gonna fit 9" wheels on the rear of a type 3?

[Shad Laws]

Hello-

an easy way to do the front disc conversion is to machine off the braking surface of your rotor until it looks like a hub. Then redrill it for the Porsche pattern if it isnt already. then you can use 944 rotors with your VW hubs, now all you have to do is make a caliper mount.

A few here on GL.com have done it this way on a beetle & super beetle, so I dont see why it wouldnt work on a Type 3 also.

Interesting... I'll definately keep that option in mind. Thanks!


BTW.... how are you gonna fit 9" wheels on the rear of a type 3?

Very carefully...

No, seriously, it won't be easy. *If* I've measured correctly, then I should be clearing the spring plates okay. The problem is the fenders. I have a trick up my sleeve here... If you unbolt the bottom of the T3 rear fender, the fender flies in the air like a wing. Now, if you put the forward-most bolt right back in where it should be, but then put spacers underneath the other bolts... hmm... I'm not 100% sure it'll work, but I think between that and killing the lip of the fender I just *might* make it.

Take care,

[vujade]

I sure that it will be a very tight fit.
I had 195/50/15 on the back of my notch years ago
and it was very close.
I have seen guys use 7.5" wheels on a type 3 at that was tight.

[Sandeep]

Shad,

For the rear brakes, you could start with a 944 single piston setup with 282mm x 20mm rotors, all bolt on using 944 NA ebrake components. This will increase the rear width by 22mm per side.

From here, you could add an early Boxster monobloc 4 piston caliper with appropriate machining (radial mount, not axial mount like a 944 turbo rear). This caliper will work with a 282mm x 20mm rotor, and you have to machine an adapter to mount the caliper.

Next step would be a 944 turbo rear rotor (299mm x 24mm) with a matching 4 piston Brembo caliper. This will bolt on as well, but you will have to remove the adapter you built for the Boxster monobloc previously.

After the 22mm width increase per side, If you have to fit a spacer of 13mm more, You can fit a 930 rear rotor (309mm x 28mm) with a 944 turbo front caliper mounted on the rear, like I have done. I'm using this setup with 993 Biturbo fronts (322mm x 32mm) on a BJ front end with CB dropped spindles. I needed the 35mm to get the 18x10 wheel off of the springplate.

I'm not too sure of a front setup as I only have experience with the 993 Biturbo setup.

Hope you can use this info.

Sandeep

[Pillow]

Hey Shad,

Sandeep offers the best advice for an top notch brake system, but I think you would be fine with a single pot early setup. If you need more later you are really not at a loss because you can upgrade quite easily later.

The trick to the early "basic" brakes is SS lines, good fluid, and most importantly use EBS Green pads or Hawk units. I know Tire Rack has them at a reasonable price which is probably lower than the Porsche exclusive places..? The EBS Green pads rock!

If you are tracking the car I would setup to the 4 pot brakes, but for street/auto-x I think the basic system will be fine.

As for the front the early 944/911 hubs can be machined to fit almost anything. Check out the tech article here or in the Keith Sueme book. I think 911 dual piston calipers could be used here as well. The 911 ealry 944 front rotors are the same. Never tried it myself though.

Even if you go full 944 early there are numerous easy bolt on big Brembo kits available, but pricey.

Good Luck,

[Alex]

Here is some advice I got from someone that sells Porsche brake kits for Beetles.....
Stick to original brake pads. Aftermarket brake pads are too hard for a lightweight car like the beetle. I was told that you will achive better braking with the orignals.

You have serveral MC choices....stock, Kerscher (I think it is a Daimler one) 944 with brake balancer for the rear and early 911 which was mentioned in this forum already.

The only advantage to go with the late style hub is that the disk mounts from the front and not from the back. If the internals of the hub are identical to the pre 87 hub then you can do the machining as outlined in my article. (Sandeep...those pics in my article need to re-uploaded. You can hardly read the measurements. Will send you the pics tomorrow).

The machining outlined will compensate somewhat fir the track increase in the front. The inner bearing will be a stock VW one and the outer the Porsche 944 bearing with a bearing spacer that needs to be machined. Get cross drilled rotors with original pads.....I would be surprised if you wear those off anyways with the T3 even with your HP numbers in a couple of years.

Alex

[Shad Laws]

Hello-

Thanks for all of your replies!

I think, for the time being, here is my plan: I'll get all 1-pot non-turbo 944 parts. I'll add to the equation some ATE blue fluid, some Porterfield R4S carbon-kevlar pads ("S" means street, in this case), and braided SS brake hoses. The more I think about it, the more I realize that this should be fine for now. And, if upgrading does itch at me later, Sandeep's post will come in quite handy :-).

I don't think that having carbon-kevlar pads will be a problem for me. I don't have an 1800lb beetle... I have a heavy Type 3. I took a stock late T3 (which is heavier to start), added a heavier engine, heavier transmission, a gas heater system, an A/C system, a complex dry sump and oil cooling system, and a stereo. I weigh probably 2500-2700lb... just like a 944.

Next question: the master cylinder... I have a stock Type 3 master cylinder. In specification, it is similar to an early 911 - 19mm front and rear cylinders with a little more travel before bottoming out than a stock T1. Given that I'll be using larger pistons in the discs but also using SS hoses, do you think I'll be okay? Also, because I'm keeping a parallel master cylinder (as opposed to an aftermarket one with a bigger front cylinder than rear, like a 21mm and 19mm setup), do you think that I can get away without a proportioning valve?

Thanks!

Take care,

[Shad Laws]

Hello-

One last question: hub seals. I'll be doing the conversion that machines down 944 hubs (will have less track width than if I machined VW rotors). This needs VW inner bearings and 944 outer bearings. What kind of dust seals do I need?

Thanks!

Take care,

[Alex]

Inner dust seal is the beetle one and the outer is the Porsche cap which you need to get a nice square hole in for the speedo. Drill a small hole and use a square screw driver and hammer it in.

Easiest way to get a square hole.

Alex

[chigger]

All the following is for a T3 with the 4 bolts hubs. As far as I know the late models and early models 4 bolt brakes are the same.
The front and rear torsion bars are indexable just like the rears on a beetle. If I remember correctly one the bottom tube on a T3 has a torsion bar. The top just has a bar to hold it together.
The rear should be the same as a bug except the later ones had a larger torsion bar for the greater weight. If you need to upgrade to a larger diameter see Adrian's tech article on suspension.
The early 944 brakes with the steel arms will bolt right up. They only require an adapter for the emergency brake cable. I forget who sells one. The later brakes and turbo brakes rotors are considerable heavier and thicker. The rear caliper is nice as it bolts right up.
If you go with the single pots you will need the 944 MC as they require more fluid than four pots to engage the rotor.
Ah! The fronts. As far as I know the front rotor and caliper is the same as a Ghia. I know this as I am running the rotor and caliper off a T3 on Ghia spindles on my bug. I have also made two sets of brakes for other people using all Ghia parts and they look identical. The spindles are not interchangable with the bug. The CSP vented rotor should bolt right up to the T3 spindle. This matches the early 944 rotor in the rear. The biggest problem will be making an adapter for the caliper for the front. The machining will be quite tricky. It was a lot simplier for me to use a drum brake spindle. You might be able to do it by drilling the backing plate holes and tapping them to 8mm then using them to secure the adapter after you have cut off the mount for the stock calipers. Getting the proper dimensions was a bear.
This is some of what you will need to adapt the early brakes to the T3. The other posts above also apply. I upgraded to Wilwood four pots from the start so if I ran up the HP I wouldn't have to upgrade the brakes again.
Hope it helps.

[Shad Laws]

Hello-

Inner dust seal is the beetle one and the outer is the Porsche cap which you need to get a nice square hole in for the speedo. Drill a small hole and use a square screw driver and hammer it in.

Thanks for the info!

I just got back from Part Werks in Chicago. I made sure that the hubs I took had caps in them :-). Also, one of them has a square hole in it for the stock speedo cable... I wonder if it's the same size...

Take care,

[Shad Laws]

Hello-

All the following is for a T3 with the 4 bolts hubs. As far as I know the late models and early models 4 bolt brakes are the same.

The rears are the same. The 1971-1973 fronts are very different. They use the same bearings, but a different rotor, calipers, backing plate, etc. The parts are the same as a 1970-72 Porsche 914 or 1969-72 411/412 - they use 42mm pistons in the calipers (which have a much more common 3" bolt spacing).


The front and rear torsion bars are indexable just like the rears on a beetle.

Yes indeed. It makes front suspension adjustment much more fun :-).

If I remember correctly one the bottom tube on a T3 has a torsion bar. The top just has a bar to hold it together.

Actually, the T3 has _three_ torsion bars in the front beam. The bottom tube has two of them, and one end of each is fixed to the tube. These act as the main "spring" for each wheel. The third torsion bar is in the top tube and goes from one wheel to the other. It acts as a built in "anti-sway bar." Very convenient.

The rear should be the same as a bug except the later ones had a larger torsion bar for the greater weight.

Only Squarebacks, IIRC.

The early 944 brakes with the steel arms will bolt right up. They only require an adapter for the emergency brake cable. I forget who sells one.

I got some from Alex (thanks, Alex!).

If you go with the single pots you will need the 944 MC as they require more fluid than four pots to engage the rotor.

Really? 1-pots take _more_ than 4-pots? I'd have thought that it'd be the other way around...

I'm also using stainless steel brake lines, so I hope that they help to compensate for the bigger brakes and make my MC adequate. If not, I'll swap it out later.


Ah! The fronts. As far as I know the front rotor and caliper is the same as a Ghia.

Ghia is 40mm piston with ~2.25" bolt spacing, as is pre-71 T3. This bolt spacing is the same as only a few odd rear caliper pieces from other makes. But 71-73 is different - 42mm piston with 3" spacing. The 3" spacing is _very_ common, so there are quite a few caliper swaps from other cars (like BMW) that become possible.


[B]The biggest problem will be making an adapter for the caliper for the front. The machining will be quite tricky.

I'm not afraid of machine work...

I just measured - the 944 fronts use a 3" bolt spacing, too. This is a good thing! It *may* be even easier than I was expecting!

Thanks for the help!

Take care,

[Wally]

Hi Shad,
Since you discussed the front upper sway bar in the thread, you may know that the upper - sway- bar of a squareback is larger in diameter, so get one of those if you can. Then again, you may already have thought of that.
Anyway, good luck and show us sone pics when you're done please.
How is the big block developing?
Walter

[Shad Laws]

Hello-

Since you discussed the front upper sway bar in the thread, you may know that the upper - sway- bar of a squareback is larger in diameter, so get one of those if you can.

Apparently I'm backwards... I thought it was the rear torsion bar of the late squareback that was bigger...

Then again, you may already have thought of that.

No, but I added another anti-sway bar (ala T1 style) below the beam. I also added a rear anti-sway bar intended for an IRS T1.

Anyway, good luck and show us sone pics when you're done please.

I will! I'll find out in the next couple days (today I have other fish to fry), but I *think* I need NO adapter to make the front caliper fit. The bolts look like they are in the same place as the late T3... :-) I *think* that all I'll need is change the offset by removing material from a face or adding a spacer. Here I thought that doing a late T3 was going to be a PITA because I couldn't find reference to anyone else who has done it, but it might be much, much easier...

How is the big block developing?

Quite well! The 350hp+ 2720cc engine should be done in approximately 2-3 months. The 220hp 2615cc engine is still in there right now, and still pulls just as strong as the day it was built (forever proving that big bore T4 is possible if cast iron cylinders are avoided) - it'll be grafted into Charles's '72 squareback with an automatic transmission!

Take care,