# Brake upgrade options



## dbgtwill1 (Dec 11, 2007)

if ur having problems with vacum in power brakes when converting to ev you could use a 12v pump like blown moter racers use summit racing has these pumps cheap
p.s. if thats not what you need to know sorry but cant really understand question
luck 2 u
/dbgtwill1


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## houseoffubar (Nov 18, 2007)

mattW said:


> I'm planning to do a wiki topic on what to do to upgrade the brakes for an EV, this will obviously begin with vacuum pump options but may also include upgrading disks/pads etc. I don't really know much about them other than I will need to upgrade them and provide a vacuum for them but i generally learn best by teaching others so I'm learning/teaching in one go. So what do you have to do to the brakes when you are converting an electric car?


 MattW, I'm building from scratch, not converting, so I have a little more leeway in my brake selection. However, I wanted to mention a few ideas for increasing the effectiveness of your brakes for any EV needing more whoaa power. 
For heavier EV's there may just be no getting around using power brakes, but don't underestimate the your ability to increase the efficiency of non power brakes.

Increase the diameter of your brake rotors. Every inch of rotor diameter increases the brakes leverage to stop the vehicle. Many models of car/truck have larger brake discs available for sporting models. For some more pedestrian models look to bigger cars/trucks from the same manufacture. For example the Chevy s-10 has rather small rotors. I noticed while walking through the wrecking yard that the Chevy Astro van has big rotors, that appear to be able to be made to fit.

Install a smaller master cylinder. This obviously has limits to how far you can go, but a small change in the bore of the master cylinder will increase the power at the brakes, while using the same pedal effort ( with a proportion ant increase in pedal travel)

Install stainless steel braided brake lines. These will not increase the power of the brakes, but they will reduce excess pedal travel, by not expanding with the pressure of pressing on the brake. This can help reduce excess pedal travel from the install of the smaller master cylinder.

Buy high performance brake pads. High performance brake pads can have significantly more friction. This can be quite dramatic, although it comes at the expense of brake longevity, a small price to pay, in my opinion.
(Buy performance street pads, and not racing pads. Pads designed for track use require being "up to temperature" before developing full stopping power.

One last thing, I don't recommend going with tiny tires, and wheels, but If your tires are a little taller than your car was designed for, this is reducing your stopping power. 
Going with a SLIGHTLY smaller tire diameter will have a difference on how hard you must push the pedal.
None of these will change your world individually, but put together, can improve your braking, possibly enough to go without power brakes.


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## rankhornjp (Nov 26, 2007)

mattW said:


> I'm planning to do a wiki topic on what to do to upgrade the brakes for an EV, this will obviously begin with vacuum pump options but may also include upgrading disks/pads etc. I don't really know much about them other than I will need to upgrade them and provide a vacuum for them but i generally learn best by teaching others so I'm learning/teaching in one go. So what do you have to do to the brakes when you are converting an electric car?


Let me introduce myself, Im James, 28yrs old, from Georgia,USA. Ive been working on/modifying cars/trucks since i was 9, just started researching EVs, looking forward to learning alot.

Moving on.... Most 1-ton Diesel trucks have what they call a "hydrobooster" which uses pressure from the power steering pump to provide power brakes. I have used this system in smaller trucks with ICE and large cams (which reduces the vacuum available) and they work great. So, i was thinking IF you are going to have power steering anyway, it would be worth looking into, if nothing else it means you'll only have 1 acc. motor, providing both power steering and power brakes.


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## houseoffubar (Nov 18, 2007)

rankhornjp said:


> Let me introduce myself, Im James, 28yrs old, from Georgia,USA. Ive been working on/modifying cars/trucks since i was 9, just started researching EVs, looking forward to learning alot.
> 
> Moving on.... Most 1-ton Diesel trucks have what they call a "hydrobooster" which uses pressure from the power steering pump to provide power brakes. I have used this system in smaller trucks with ICE and large cams (which reduces the vacuum available) and they work great. So, i was thinking IF you are going to have power steering anyway, it would be worth looking into, if nothing else it means you'll only have 1 acc. motor, providing both power steering and power brakes.


 Good idea, You would have plenty of pressure, that's for sure. Eric


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## Coley (Jul 26, 2007)

A fellow commented a while back, about how much brake pressure you would have to use to push the pedal, if you don't use the P/B setup.

He thought the pressure in the system might damage the braking system because of the higher (foot) pressure.

I assured him that the pressure would be less, as the vac boost is much more than you can put into the systen without it.


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## rankhornjp (Nov 26, 2007)

houseoffubar said:


> Good idea, You would have plenty of pressure, that's for sure. Eric


They are a lot smaller in diameter, also. So that may help people who have a limited space problem.

http://www.stu-offroad.com/suspension/vanco/hboost-1.jpg

here's a pic of what one looks like.


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## houseoffubar (Nov 18, 2007)

Thats a clean little unit, Perhaps you could add that somewhere in the Wiki. It could be very useful for someone. Eric


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## rankhornjp (Nov 26, 2007)

houseoffubar said:


> Thats a clean little unit, Perhaps you could add that somewhere in the Wiki. It could be very useful for someone. Eric


I can do a little write-up with the picture, but I don't anything about a Wiki or how to add anything to one.


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## david85 (Nov 12, 2007)

rankhornjp said:


> I can do a little write-up with the picture, but I don't anything about a Wiki or how to add anything to one.


rankhornjp, I was going to bring this up, but looks like you are ahead of me. I'm not sure if newer cars use a hydroboost, but I know that some of the large diesel trucks you mention (we have 2 of them at our house) can be retrofitted to have the newer powerboost setup. It might be worth looking into which cars (if any) are also upgradeable with bolt on setups from the factory.


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## rankhornjp (Nov 26, 2007)

not sure about what boosters will fit which cars, best bet would be to measure your bolt pattern on the firewall and go look through junk yards until you find one that fits. You can always adjust petal throw and master cylinder bore size to fit your application. I did a google search and found this company:
http://hydratechbraking.com/products/universal/

This shows a universal kit, they also have limited vehicle specific applications.
Not cheap at all, but an option.


If you do the junkyard method, MUCH cheaper, look for 3/4 or 1 ton trucks. Not sure what year they started but I do know they've used them up to 2007 model trucks. Be sure to get the power steering pump with it, as you'll need the extra capacity.


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## mattW (Sep 14, 2007)

Ok I started a wiki topic about it, here it is: http://www.diyelectriccar.com/forums/showthread.php?p=16383#post16383
To edit all you need to do is click edit on the bottom right and then it is just like a normal forum post. I left room for you hydrobooster fans to write about them and it would be good for someone to add more detail to my quick uniformed vacuum pump description with maybe some links to some how to's or examples. Cheers


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## david85 (Nov 12, 2007)

rankhornjp said:


> not sure about what boosters will fit which cars, best bet would be to measure your bolt pattern on the firewall and go look through junk yards until you find one that fits. You can always adjust petal throw and master cylinder bore size to fit your application. I did a google search and found this company:
> http://hydratechbraking.com/products/universal/
> 
> This shows a universal kit, they also have limited vehicle specific applications.
> ...


 
For a new kit, thats not very expensive, the upgrade for my 1986 F250 would be in the $700 range, add another $300 for rear disc brake conversion (something that may also be worth exploring).

For the ford Fseries in north America, the model year was 1996 for the F450 to get the upgrade, for the GMC, I think 1993 3500 was the first year offered with hydroboost. Although both those trucks are usually at least 6000lbs empty in their smallest version, so not a very common conversion platform.


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## rankhornjp (Nov 26, 2007)

david85 said:


> For a new kit, thats not very expensive, the upgrade for my 1986 F250 would be in the $700 range, add another $300 for rear disc brake conversion (something that may also be worth exploring).
> 
> For the ford Fseries in north America, the model year was 1996 for the F450 to get the upgrade, for the GMC, I think 1993 3500 was the first year offered with hydroboost. Although both those trucks are usually at least 6000lbs empty in their smallest version, so not a very common conversion platform.


Ive used these for 4x4 trucks with huge tire 38in+, when the normal brakes just weren't holding up, usually for less that $200 in parts in the US.


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## RandyC (Dec 24, 2007)

The previously mentioned hydraulic booster system that runs off of power steering can also boost the pressure to the brakes, from the stock 300-600 PSI range to the 2000 PSI range. I found a company that has an electric hydraulic brake booster system. It has a small remotely mounted electric pump unit that uses the existing brake fluid to provide the boost simplifying the plumbing. Sorry the company name is in my other computer. I found them while researching electric power steering systems. I'm trying to get away from the continuously running hydraulic pump.


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## Alex Everett (Dec 26, 2007)

Kinda late on a reply to this thread but I have some info for you all.
Believe it or not there is an old racing trick that would apply to this thread. Us Hot Rodders have been doing this for years.

VENT YOUR BRAKES !!!!

This is actually easy to do. Drilling small holes in the surface area of the drum/rotor where the pad/shoe contacts the surface. Use a 1/4 inch drill bit and drill 3 to 5 holes diagonally across the surface. Usually in four places like on a clock face 12, 3, 6, and 9 O'clock positions. You then need to turn drums/rotors to remove any burrs left from drilling. Any brake repair shop can turn them for 10 to 15 dollars each. Best scenario is to start with brand new disks/rotors. 

When normal brakes are applied, there is a small build up of gasses as well as brake dust and heat that all are created between the pad/shoe and its mating surface (even worse in high humidity like rainy weather). Drilling these holes will vent the area of gas build up and allow it to easilly escape. This then allows greater contact of pad/shoe to drum/rotor thus decreasing the ammount of force needed to stop vehicle. 

It may not sound like much but this procerure can increase your braking capacity by about 25% and every little bit helps when dealing with weight issues.

I have done this procedure at least 20 times on street rod applications and will definatly do it on my E/V project Please feel free to p/m me for any questions as I am allways at your disposal. I will also be monitoring this thread closely.


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