4 Wheel disc brake experience anyone?

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Donald-Giovanoni
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Joined: Tue Jun 26, 2012 5:00 am

4 Wheel disc brake experience anyone?

Post by Donald-Giovanoni »

I am thinking of converting my Manx to 4 wheel disc brakes from CIP1.  Will anyone share their experience with 4 wheel disc brakes on a 80" wheelbase buggy?  Is brake bias an issue?
Thanks,
Don




ManxManiac
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4 Wheel disc brake experience anyone?

Post by ManxManiac »

Hey Don, I've never run disc brakes "myself" on a f/g buggy, but I do know several that do & I've driven several with disc brakes. Many years ago, a couple friends & I built about a dozen sets of custom made 4 whl disc brakes that worked great. They were used on street cars & Baja Bugs & a few sandrails on the rear. IMO, most of the factory made sets available work quite well. 
I have found that if you run dual master cylinders with an adjustable balance/bias bar, you can really dial them in to perfection. 
If you run a dual circuit m/c, I advise installing an adjustable brake proportioning/bias valve in the front system & adjust it so under hard or panic braking, the fronts just barely want to lock. That way you get maximum braking in the front to help keep it straight & stop as quick as possible. 

On our buggy Xena, I have Type 3 rears & Type 1 fronts & under really hard braking the fronts will lock, so I need to install an adjustable proportioning valve in the front on mine too.


I drove a friend's "street buggy" with a Turbo 2332cc & it had extra large 4 whl disc brakes that would stop you on a dime & tip you a dollar... of course the tires make a difference too.
At least with discs, you don't have to adjust them.
A friend built a set of discs for the rear of his f/g buggy & still runs stock drum brakes on the front & once he installed a proportioning valve in the front & got it adjusted properly, they work great.
Good luck & keep us posted.

Michael Cates
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Original Meyers Manx "Xena"
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Tom-Szwajkos
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Re: 4 Wheel disc brake experience anyone?

Post by Tom-Szwajkos »

I run VW calipers and discs on the link pin front end, drilled out for the Chevy five bolt pattern. I purchased rotors that did not have any bolt holes since it is difficult to drill the four bolt out to match the Chevy pattern. Since my transaxle is Corvair, I have Ford Explorer solid rotors, modified to the Chevy bolt pattern and VW calipers using custom made brackets. I also installed a proportioning valve, Chevy Camaro dual master cylinder and one way valves. You need the one way pressure valves if the master cylinder reservoir is mounted lower than the calipers. You can utilize the VW dual master cylinder, I just chose the Chevy master cylinder because the Hadley conversion kit utilized a single master cylinder originally. You mount the one way valves on each line coming out of the master cylinder before they split to each wheel. I have a very firm brake pedal and when I hit the brake pedal this Manx stops quickly. The proportioning valve is the key to the Manx stopping straight and true. Don't install rear disc brakes without it. I also installed custom emergency brake cable that was shortened to fit the Manx. If you want to go high tech, you can utilize the new rear wheel brake calipers that are designed for an electric parking brake. No cables required! The proportioning valves and one way valves can be purchased from Summit Racing or Speedway Motors. You will also need adapters for the brake lines to fit the one way valves and the proportioning valve too. Since you have everything apart you might as well install flexible steel braided brake lines to the calipers. These are also readily available in various lengths. If you have any questions, please let me know.
langan
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Re: 4 Wheel disc brake experience anyone?

Post by langan »

I have the proportion valve in the rear as suggested on Samba. Seams strange all my other cars always installed on fronts. Did the braided and surge valves too. I have only driven on shake down drives. If no rain I will try locking up brakes and let you know
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enesset
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Re: 4 Wheel disc brake experience anyone?

Post by enesset »

I wanted to ask the collective. Is there anyone in addition to Air Kewld that I should be talking with?

I know they are street/lower-rod focused. I'm building my Manx for Baja/NORRA and just want to make sure I "leave no stone unturned".

Thanks for any thoughts/advice people have on recommendations for "brake specialists".

p.s. I'm starting from scratch and am interested in 4-wheel disc with proportioning valve.
Tom-Kathleen
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Re: 4 Wheel disc brake experience anyone?

Post by Tom-Kathleen »

We have the AC Industries front http://www.socalautoparts.com/product_i ... 05-p-13590 and rear http://www.socalautoparts.com/product_i ... 05-p-13544 on our Manx. They work well, but they do not "bolt on". There was "massaging" on both ends and the brake pads were junk and had to be replaced right away. After all that, they work well. I like the zero offset on both ends and the stock spindles for the front. The other issue we had was one of the rotors had the splines strip on the way to Big Bear. That may have been the fault of using the old style nut without the flange. Since changing to the flanged nut, things have been OK. Tom
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GotManx
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Re: 4 Wheel disc brake experience anyone?

Post by GotManx »

I think for running NORRA you probably want to go with something that is more off-road proven. I run CNC brakes http://www.cncbrakes.com/ on my Manxter and Aussie Brad is happy with the Jamar brakes http://www.jamarperformance.com/ on his Manxter. Off Road Warehouse, Kartek, McKenzies are good sources and a great place to compare.
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jsturtlebuggy
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Re: 4 Wheel disc brake experience anyone?

Post by jsturtlebuggy »

I am using Kartek ProAm disc brakes in the front and Jamar in the rear. Also I am using a CNC brake pedal setup that uses two master cylinders with a balance bar to adjust brake bias.
The wide 5 bolt patterns for wheels is very common in off road racing still.

Like what Jon is saying you need to use parts that made for and have been tested for off road racing. They are of higher quality and lighter in weight then the disc sold for street use. The less weight you have on the suspension the is easier on the shocks controlling it.
If you are starting out with new suspension parts, think about using a MicroStub setup for the rear suspension. With them you can use a longer CV axle for more travel. The Empi stub axles (to replace stock stub axles) that are being sold for replacements to use 930 CV joints have been breaking even on the street.


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Joseph
Manx Club #1095
Having fun with Buggies since 1970
Worked in VWs in shops since 1970
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enesset
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Re: 4 Wheel disc brake experience anyone?

Post by enesset »

Guys, this type of insight/feedback is exactly what I need.

BTW, I am running a BJ Front end with Thing Spindles.

I am going to ask another "noob" question.

You mention micro-stubs, if I am understanding correctly... those are typically 3x3?....3" longer and 3" wider. If I want to stay at the standard length/width so my Manx doesn't look overly goofy, is there a "robust" provider of standard length "plug and play" non-additional-fab-needed rather than using refurbished OEM IRS suspension?

I'm going to spend a very serious amount of $$$ on my engine/tranny (Strictly Foreign) so my thought was to keep OEM suspension/trailing-arms/etc now and then I can spend more big money to upgrade in the future?
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GotManx
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Re: 4 Wheel disc brake experience anyone?

Post by GotManx »

Micro stubs are typically on a 3x3 trailing arm, but you can also get a 5-1600 arm that is stock width and 1" longer which would fit great on a Manx.
http://www.kartek.com/parts/1600-micro- ... -pair.html (Sorry they don't have the picture)

They are a little pricy, but it is one less thing to worry about running down Baja.

Another problem is that the disk brake setups are different for a VW bearing and a micro stub. So if you buy brakes now for the stock arms and then convert later to micro stubs, you are buying new brakes also.

I know it's easy to spend other peoples money, but at least you know what is out there to help with your decision.
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enesset
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Re: 4 Wheel disc brake experience anyone?

Post by enesset »

Again guys, thanks so much for this insight, I really appreciate it.

I'm going to digest on this but I'm thinking since my intent is for "vintage" and since Bruce went all the way to La Paz on a standard setup perhaps on this Manx for right now I will as well. More to come and this is going to be a great "sticky" historical thread to help people making the same type of "build decisions".

I'm very grateful -- Eric
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jsturtlebuggy
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Re: 4 Wheel disc brake experience anyone?

Post by jsturtlebuggy »

I guess it would be good to know what you are really wanting to do with the buggy.
What size engine are you going to be using?
What transaxle are you going to use?
How much suspension travel are you going to have in the front and rear?
How fast do you plan on traveling over rough terrain?

As Jon pointed out you can get rear IRS trailing arms that use the micro stub bearing in 1in longer than stock in two types. There is the one for the 5/1600 class that has modified mounts for clearance to not hit the stock VW body and there is the ones for 1-2/1600 class that have stock mounting points since there no steel body to hit.
One reason for the 1in longer arms is to allow for clearance between the long torsion bars (26-9/16") and a 31in tire and it allow for more suspension travel.
A micro stub set up is what you will find on a Chevy 4x4 with independent front ends. The aftermarket has made stub axle to use these hubs and bolt on CV joints in the Porsche 930 size and others. It a simple design, uses 3 bolt to hold it to trailing arms and are very strong.
Even Empi has a setup they are selling. I have no idea of quality of them.

I am using Empi CV axles and their 930 race prepped CV with good success on my Manxter Dual Sport.

When Bruce made his record run, he did not have to contend with a torn up race course from higher horsepower long travel vehicles start in front of him.
Joseph
Manx Club #1095
Having fun with Buggies since 1970
Worked in VWs in shops since 1970
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enesset
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Re: 4 Wheel disc brake experience anyone?

Post by enesset »

Guys, #1, I love this site and its SUPER helpful. I want to keep this thread about brakes so I created another thread called "Suspension and Torsion Bar 101" http://www.manxclub.com/forum/viewtopic.php?f=81&t=3814

Your comment about Bruce not having Walker Evans, Robby Gordon and the McMillans, & Herbst boys tearing up the trail in front at NORRA is a very good point. We even talk about that with our early bronco's (EB's) running 33's.

For my Manx, ideally I would like to chase or race it once a year especially as long as my EB buddies go down to baja (this is my 5th year in a row). Other than that, a toy, street, hollister and maybe pismo.

The thought process on why I'm leaning towards "wimping out" and going OEM is its easy to replace/repair run standard plug-and-go parts and shocks? My thought was if I'm down in Baja and blow something up, wont replace/repair be cheaper/faster/easier if OEM?

I like how robust the Micro-Stub route looks...... but don't I need to find someone to weld on some mounting brackets for shocks....or...does anyone know a manufacturer of the +1 length that has the mounting bracket pre-installed?

Finally to bring this back to a brakes discussion, I'm thinking I will go the four wheel disc Jamar route, with wilwood proportioning valve and perhaps I will go 5x205's for simplicity sake.
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enesset
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Re: 4 Wheel disc brake experience anyone?

Post by enesset »

Update: I just ordered the Jamar front disc set up from Moore parts.

The 2-man team I'm talking with to build the +1 swing arm and brake set are still working with each other....as I understand it, bus stubs/hubs and then a caliper setup that still uses cable emergency brake....perhaps he mentioned "Varga"...? Anyone have thoughts on that generally or Varga specifically?

More to come as this progresses....
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