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First of all, what car do you have? Speedster or Spyder? Manufacturer?

Ball joint beam or link-pin? Do you currently have 4 x 130mm bolt pattern, or 5 x 205mm? And if you have one do you want to convert to the other?

Swing axle or IRS in the back?

Do you currently have 4 wheel drum brakes? Do you want to do all 4 discs or front only?

How do you use the car? If you just cruise around, 4 wheel discs are unnecessary. Some spirited driving, just do front discs. If you drive REALLY hard, all 4 discs are a good idea.

According to Google, you are less than 100 miles from me. I can do the work. I'm a retired guy who loves tinkering with Speedsters, Spyders, dune buggies, 911s, and such. I'm an aircooled guy.

If you want to get in contact, send me a PM.

DPP(Dan Piperato Performance)

Last edited by DannyP

Danny asked the right questions - front discs don't present much in way of issues.  I did have to add 1/4" spacers so my 2L Porsche Fuchs would clear the calipers.  The rear is quite different as on a CMC the fender to wheel clearance is tight (mine is IRS and is even tighter on the driver's side - I still have OEM drums on rear).  Some rear brake kits claim to add zero to any increased offset - on mine a 1/4" increase would be too much. On a build with swing axle, you may have more room.

Last edited by WOLFGANG
@WOLFGANG posted:

I keep hoping for a really bad winter in NE so I can get a crew from there down here to sunny warm (ok 111 was a little too warm the other day) Florida!  Got BBQ, boiled peanuts, crawdads, grits and fried okra!

If you have accommodations better than a leather couch to sleep on, I could be in. Winter no longer bothers me, but 111F(and humid!) certainly does!

What about going from rear disc to drums on an IRS? Does that bring the rear wheels inward at all to help with the cmc driver side tightness?

Depends on what disc brake kit you have, some kits actually are zero offset. If you have clearance now, why do you need more? Wider tires? And if you got more, you might need to re-center the wheels, which you could do now(but only if your wheels are steel).

I don't know of a single soul who would go from discs to drums. None.

Last edited by DannyP

@WOLFGANG   Are you saying you're going to finish the speedster????

@DannyP  If you have accommodations better than a leather couch to sleep on, I could be in. Winter no longer bothers me, but 111F(and humid!) certainly does!  ...........That's because like me, Danny is retired and no longer has to work out in the bs cold weather !

Last edited by Alan Merklin

@Stan Galat Everything you say is true.

It is also possible today to have a calibrated(empty is empty and full is really full) gas gauge that doesn't wave at you like a wild ballet dancer when you hit bumps. Stepper motor gauges with built in hysteresis by Speedhut.

A low brake fluid warning light is unnecessary, if you actually monitor and check these things, like you're supposed to.

What I find beneficial is a sequential shift light, and definitely a rev limiter. Both modern conveniences that add to the fun factor, and take away some of the worry.

Last edited by DannyP

~71+ bugs had a brake light on the dash.  It indicated a failure in one of the hydraulic brake issue (assume bad 3 prong switch or loss of pressure like a leaky caliper, brake line, brake circuit, wheel cylinder).  It indeed could be installed in a speedster.  I forget how it works - it would come on when car was started and could be pressed while running to check brake circuit.

Image result for 1971 VW Bug Brake Dash Light. Size: 156 x 170. Source: www.bugcity.com

A bit of housekeeping: I got my first service call at 2:30 AM yesterday, and we've been buried for 3 weeks at work. I made the mistake of commenting on this thread before I read the entire thing. I deleted them both this afternoon because they weren't relevant to the discussion. I'd like to say I'm sorry, especially to @DannyP who took the time to reply to one of the comments.

To the business at hand: All of the advice has been solid, especially when Danny said:

@DannyP posted:

I don't know of a single soul who would go from discs to drums. None.

... with an addendum (which follows).

There have been a lot of advocates for rear drums over the years, with comments generally along the lines of "drums on the back are good enough". I understand the sentiment, but I don't agree. More braking power is always better. Always.

Something is important to note, however. Almost all of the commonly used disc brake packages are from EMPI or CB Performance, and these use the same front and rear calipers. It's a bad setup - the rear caliper bore is too big to be matched to the front. The net effect of this is that under hard braking, the rears will lock up before the fronts, which is less than ideal.

Henry at IM knew this for years, and his 4-lug setup was fully custom and used a hub from some economy car, a replaceable disc from something else, a rear caliper from a VW Golf, and a custom caliper bracket. The balance is mathematically perfect.

We had discussed the rear brake bias of my CB kit many years ago, and he had let me in on the "why" he did what he did, which was a powerful reason he built so many 4-lug cars - the brakes, as delivered worked beautifully.

Henry recently purchased a car he had built back in 2003 from the widow of a client who lived about an hour and a half up the road. It had the brakes I'm talking about. Henry and his daughter flew into Chicago, took a bus down to get the car, then drove to my house where we put it on the lift for some service work. He and June stayed the night with us before they left the next day to drive it back to Vancouver.

As an aside, I'd like to extend this invitation to pretty much anybody on this forum who needs a place to work on their car (and a home-cooked meal and nice bed) on your way from here to there. Flyover Country has a lot to recommend it - spend a few hours here, and you'll wonder what all the fuss on the coasts is all about.

Anyhow, while the car was on the lift, I looked at his setup and started thinking about the problem of mismatched brake components, and how little thought any of us really give to the most important component set on the car. We just assume that somebody smart put it all together.

As is often the case, this is just not true. Certain parts were used because they were available and cheap. AirKelwd, CoolStop, etc. are likely better engineered, but I've got no way of knowing. I'd trust that CSP brake systems are well engineered, because they are TÜV certified. Beyond that? I can tell you that the EMPI/CBP stuff is "homemade" in the worst sense of the word. By way of full disclosure - I run a CB kit, and it's "fine" for the way most people use their car. However, I don't like settling on "fine" - I aspire to do things "right".

I suppose one could use a proportioning valve in the rear brake line, but that seems like a Rube Goldberg "Radiator Springs" way to do things. I don't aspire to be Tow Mater.

The reason for this long/boring piece is to say that whereas most aftermarket disc kits are biased to the rear, that would never be the case with a front disc/rear drum setup which may be why a lot of guys want to run them. That's the nice thing I can think to say about them. I personally don't think the answer to the riddle lies in reducing the size of the rear brake, so much as increasing the size of the front caliper. I'd want to talk to somebody smarter than me, but I think the typical Varga rear caliper (with E-brake), matched to a 2 or 4 piston Wilwood front caliper would be a much better way to go. I'd still want to know what MC would be best to use. I'm not trusting the brain trust at EMPI to have done any actual math.

To conclude, I'm not interested in reducing braking power to get better balance. But better balance with more stopping power would be great.

Last edited by Stan Galat

I have Karmann Ghia front disc brakes.  I am wondering if they are any better than the front systems discussed here.

For some guys, Michael, KG front discs (as you know, a relatively inexpensive upgrade) are more than adequate.  More pad with bigger multi piston calipers and even vented discs aren't really going to change things much, other than empty your wallet.  Slowing down an 1800 lb. car with 2 occupants in a full panic stop from 75 or 80 mph isn't going to be a concern with stock KG discs and Type 1 drums in the back- once.

Now, start serious canyon crawling, road racing, parking lot slaloming, or any situation where you're on the brakes repeatedly and you're going to find your budget stuff's limitations pretty quickly.  Yeah, the more expensive equipment won't stop you much faster the first time, but what it will do is shed heat and keep pad (and fluid) temps down, and those features allow you to hit those brakes again, and again, and again!  And that's where the fun is...

@Tac422 posted:

If you change the front drums to disc, do you also need to change the master cylinder?

KG front discs will work with the original equipment late Beetle master cylinder- you just have to pull the residual valve out of the front section.  This worked with my Cal Look Beetle, even with Type 3 rear drums.  I may be wrong, but I don't think the Karmann Ghia mc is a bigger bore than the Beetle unit (someone please correct me if I'm wrong).  I haven't pulled apart a master cylinder in a while so I can't tell you if that trick is possible with today's replacement parts.

@Stan Galat posted:


There have been a lot of advocates for rear drums over the years, with comments generally along the lines of "drums on the back are good enough". I understand the sentiment, but I don't agree. More braking power is always better. Always.

Something is important to note, however. Almost all of the commonly used disc brake packages are from EMPI or CB Performance, and these use the same front and rear calipers. It's a bad setup - the rear caliper bore is too big to be matched to the front. The net effect of this is that under hard braking, the rears will lock up before the fronts, which is less than ideal...



The reason for this long/boring piece is to say that whereas most aftermarket disc kits are biased to the rear, that would never be the case with a front disc/rear drum setup which may be why a lot of guys want to run them. That's the nice thing I can think to say about them. I personally don't think the answer to the riddle lies in reducing the size of the rear brake, so much as increasing the size of the front caliper. I'd want to talk to somebody smarter than me, but I think the typical Varga rear caliper (with E-brake), matched to a 2 or 4 piston Wilwood front caliper would be a much better way to go. I'd still want to know what MC would be best to use. I'm not trusting the brain trust at EMPI to have done any actual math.

To conclude, I'm not interested in reducing braking power to get better balance. But better balance with more stopping power would be great.

Stan brings up some great points.  While discs front/drums back do work, you really limit yourself as to what you can do SAFELY.  Imagine you've heat soaked the brakes to almost their limit through 3 or 4 corners in a row (just playing a 'little bit'), you come around the next corner, there's wreckage everywhere and you have to stop NOW- will you make it or just become part of the mess?  As Stan says, "more braking power is always better.  Always."

Re the rears locking up before the fronts on the less expensive 4 wheel disc brake kits- I'm guessing that while this is the case with these kits in a lot of Speedsters (with the same wheel/tire size all the way around) a lot of VW owners, being Cal Look fans with smaller tires/narrower rims on the fronts with taller/wider tires on wider rims on the back probably find their brakes much more close to 'balanced' than most Speedster owners do.  As Stan mentioned in his post above (which I've since cut out for what reason I'm not sure of now) Henry has taken the time to figure out how to make the braking in his all disc brake cars much more balanced.

And Stan, your last statement- "I'm not interested in reducing braking power to get better balance.  But better balance with more stopping power would be great." really says it all.  Al

Last edited by ALB

Stan and Al are on the money here.

It's the repetitive heat soak that gets you in trouble. And brake balance is IMPORTANT too. The Airkewld kits can be had with 1,2, or 4 piston calipers in front, however the SAME Varga rear e-brake caliper comes with each kit. And we need an e-brake caliper on the street, don't we? I don't think there's a whole lot(none?) of engineering/calculation that was done there to be honest.

Back in the 60s, VW used a single circuit master with a 17mm bore. Then they changed to a dual-circuit 19mm. Later they used a 20.8mm dual circuit, which is the recommended size for 4 wheel discs.

But to what Stan was getting at, the sizing of the master cylinder(s), the brake pedal lever ratio, the sizing of the caliper pistons(and relation to pad size), and difference between F-R to get balance are all important. I never even questioned this when I bought my brakes, just bought the best braking available at the time. I lucked out, as mine worked out with a very good balance, no tendency to lock front or rear permaturely, and no tendency for the back of the car to come around either.

Drum brakes can work reliably, even in a racing situation, when sized appropriately. Formula Vee cars weigh less than 1100 pounds WITH DRIVER and work just fine. They are usually equipped with racing shoes and two separate master cylinders with a mechanical balance bar for bias. That's a far cry from a typical Speedster on the street, at typically TWICE that weight.

I wanted 4 wheel discs for two reasons: better and fade-free stopping, and not having to adjust brake shoes. I added braided flex lines for a harder and higher pedal. I also added more aggressive Wilwood front pads for higher temp resistance and better "bite". I think I've got a good package.

All braking systems should be able to lock all 4 wheels mechanically. It's the ease of doing so, coupled with repeatability and low maintenance. All discs cool better than drums(except for Porsche 356 aluminum-finned). Functioning front brake ducts(standard on V Spyders) are a nice feature. Easily do-able on almost any Speedster.

At the end of the day, the tire's contact patch and tread stick are the limiting factors of braking, besides driver skill.

@Stan Galat posted:

A bit of housekeeping: I got my first service call at 2:30 AM yesterday, and we've been buried for 3 weeks at work. I made the mistake of commenting on this thread before I read the entire thing. I deleted them both this afternoon because they weren't relevant to the discussion. I'd like to say I'm sorry, especially to @DannyP who took the time to reply to one of the comments.

To the business at hand: All of the advice has been solid, especially when Danny said:

... with an addendum (which follows).

There have been a lot of advocates for rear drums over the years, with comments generally along the lines of "drums on the back are good enough". I understand the sentiment, but I don't agree. More braking power is always better. Always.

Something is important to note, however. Almost all of the commonly used disc brake packages are from EMPI or CB Performance, and these use the same front and rear calipers. It's a bad setup - the rear caliper bore is too big to be matched to the front. The net effect of this is that under hard braking, the rears will lock up before the fronts, which is less than ideal.

Henry at IM knew this for years, and his 4-lug setup was fully custom and used a hub from some economy car, a replaceable disc from something else, a rear caliper from a VW Golf, and a custom caliper bracket. The balance is mathematically perfect.

We had discussed the rear brake bias of my CB kit many years ago, and he had let me in on the "why" he did what he did, which was a powerful reason he built so many 4-lug cars - the brakes, as delivered worked beautifully.

Henry recently purchased a car he had built back in 2003 from the widow of a client who lived about an hour and a half up the road. It had the brakes I'm talking about. Henry and his daughter flew into Chicago, took a bus down to get the car, then drove to my house where we put it on the lift for some service work. He and June stayed the night with us before they left the next day to drive it back to Vancouver.

As an aside, I'd like to extend this invitation to pretty much anybody on this forum who needs a place to work on their car (and a home-cooked meal and nice bed) on your way from here to there. Flyover Country has a lot to recommend it - spend a few hours here, and you'll wonder what all the fuss on the coasts is all about.

Anyhow, while the car was on the lift, I looked at his setup and started thinking about the problem of mismatched brake components, and how little thought any of us really give to the most important component set on the car. We just assume that somebody smart put it all together.

As is often the case, this is just not true. Certain parts were used because they were available and cheap. AirKelwd, CoolStop, etc. are likely better engineered, but I've got no way of knowing. I'd trust that CSP brake systems are well engineered, because they are TÜV certified. Beyond that? I can tell you that the EMPI/CBP stuff is "homemade" in the worst sense of the word. By way of full disclosure - I run a CB kit, and it's "fine" for the way most people use their car. However, I don't like settling on "fine" - I aspire to do things "right".

I suppose one could use a proportioning valve in the rear brake line, but that seems like a Rube Goldberg "Radiator Springs" way to do things. I don't aspire to be Tow Mater.

The reason for this long/boring piece is to say that whereas most aftermarket disc kits are biased to the rear, that would never be the case with a front disc/rear drum setup which may be why a lot of guys want to run them. That's the nice thing I can think to say about them. I personally don't think the answer to the riddle lies in reducing the size of the rear brake, so much as increasing the size of the front caliper. I'd want to talk to somebody smarter than me, but I think the typical Varga rear caliper (with E-brake), matched to a 2 or 4 piston Wilwood front caliper would be a much better way to go. I'd still want to know what MC would be best to use. I'm not trusting the brain trust at EMPI to have done any actual math.

To conclude, I'm not interested in reducing braking power to get better balance. But better balance with more stopping power would be great.

That car came with a hard top ... a very nice one to say the least.

BTW, on my build the master builder's secret sauce he calculated the pad surface area and the number of pistons in the calipers for both the front and the rear disc brakes to comply with a known car AFAIK.

I like the front disc conversion kits that include new spindles - vs the bolt on caliper mounting adapters.  Ones that have an available dust/water shield/back plate may be desirable too.  You might also want to consider kits with a lowered spindle (actual implemented by raising the spindle).  These drop the front 2-2 1/2" so you might have to use your beam adjuster to get height where you actually want it.  They do widen the front track but there is generally enough room in the front for 6' and down rims.  Some kits take different wheel bearings and tie rod ends depending on your year chassis.  Believe they all take longer rubber brake lines.

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