Rear drum brakes?

[Chip]

So I kinda just figured out that the rear brakes are drum style and not disc style. While I was getting my X5 at the BMW dealership serviced (oil change), I was talking to the service guy about the difference between disc and drums brakes. Basically, he said your X5 comes with Disc brakes because they are much superior to drum brakes.

So, I don't know a lot about car modifications, but can I get a shop to change out the brakes on my Hybrid to disc rear brakes? Would this affect the charging of the IMA battery?

The brakes aren't bad, they are good, but they are definitely not like my X5's.

Thanks in advance!

[Chase]

Im sure it's possible to swap using EX parts... be a pioneer and let us know.

[GoHuskies]

I'd research on how the car regains energy via braking. Friction from braking in turn turns the electric motor and enables it to charge the battery. Not sure if it's drawn from front or rear. No idea if changing out the brakes will affect the system either. Couldn't find an answer on wiki either.

CleanMPG, An authoritative source on fuel economy and hypermiling

I'd head over there ask pose the question in general forums. Pretty knowledgeable folk.

[BigT]

In my opinion you wouldn't see enough benifit from the disc brakes to be worth the cost/time/effort.

Disc brakes offer several advantages over drum. Then are simpler (less moving parts), offer much better heat dissapation, and far less fading when they do heat up.

Drum brakes are generally cheaper, they can offer the same stopping force with much less effort, and with a much smaller cylinder.

Disc brakes are the obvious choice in high performance situations where you will be using the brakes a lot, or very hard and want minimum heat buildup and fade. On larger vehicles where cargo/towing comes into play they can also be useful for when you have to stop a load and heat can build up fast.

On your car you aren't likely to push the brakes to their limit very often. When trying to get good fuel mileage it is best to push the brakes as little as possible. This cost/benifit likely why Honda put drum brakes on the Hybrid to begin with. The amount of benifit you would get from upgrading would likely be minimal if any. Probably not worth the trouble.

However, if you want to do it for looks, brake feel, or just because then go for it. The only thing that really matters is if it's worth it to you.

[w00t692]

Not one person mentioned you'd also destroy your front/rear braking bias that the car has when stock. The ABS can only compensate so much before it doesn't know what to do in an emergency braking situation.

The best thing to do is upgrade the pads in the drum brake and front brake. You'll get increased performance from this.

[asndragonboii]

Originally Posted by GoHuskies

I'd research on how the car regains energy via braking. Friction from braking in turn turns the electric motor and enables it to charge the battery. Not sure if it's drawn from front or rear. No idea if changing out the brakes will affect the system either. Couldn't find an answer on wiki either.

CleanMPG, An authoritative source on fuel economy and hypermiling

I'd head over there ask pose the question in general forums. Pretty knowledgeable folk.

Regenerative braking doesnt necessarily mean the battery charges when you brake. It basically means it charges whenever youre slowing down or youre not on the throttle.

[GoHuskies]

Originally Posted by asndragonboii

Regenerative braking doesnt necessarily mean the battery charges when you brake. It basically means it charges whenever youre slowing down or youre not on the throttle.

Only while slowing down, if the peddle is held flat the car just coasts with fuel cutoff still engaged. It's a fuel saving technique called a glide. Only a complete release of pressure allows regen braking.

Now that I think of it I have no idea even how the regen braking works, wether part of the mechanical brakes or friction applied somewhere else. Wiki or Honda websites are of no help.

[SuperJay]

Originally Posted by GoHuskies

Only while slowing down, if the peddle is held flat the car just coasts with fuel cutoff still engaged. It's a fuel saving technique called a glide. Only a complete release of pressure allows regen braking.

Now that I think of it I have no idea even how the regen braking works, wether part of the mechanical brakes or friction applied somewhere else. Wiki or Honda websites are of no help.

not true, I get charging while going uphill (4% grade) at 85mph. It charges when it has a chance, and doesn't need all the power from the gas motor.

[splew]

Yeah good luck. LX owners have contemplated a drum to disc swap only to come to find it would cost around $1000 and would require an ass load of work.

Until someone comes out with a conversion kit there is no practical way to do a drum to disc swap.

[Chase]

^ even with parts from a Smashed EX?

[splew]

Originally Posted by Chase

^ even with parts from a Smashed EX?

I suppose you could just yank the whole rear suspension and have every thing you need and more. IDK how much that would cost though.

I don't know if I would want to replace the perfectly good stock parts on my car with ones I found in a salvage yard though. Especially something as important as the brakes.

[SuperJay]

you would have to replace the master cylinder too. otherwise the proportions would be WAY off

[splew]

Originally Posted by SuperJay

you would have to replace the master cylinder too. otherwise the proportions would be WAY off

I think EBD controls the proportioning, and I think the EX and LX master cylinders have the same part number.

[Chip]

Thanks for all the input guys!

Guess this mod is too much work and money, and really, just not worth all the effort! Thanks again!

[Chase]

wait a few years when Ex's start piling up in junk yards... Then it will be cost effective..

[bengteck]

There’s few consideration to ponder upon if you wish to touch such modification, namely if it’s for aesthetic or performance. Both have its good reason for the conversion.

Just like a normal civic, they upgraded their disk with a bigger size rotor to achieve their specific requirement. So via upgrading from drum to disk just another form of upgrade most will do for their ride if you can just forget about you driving a hybrid.

For aesthetic reason, it’s due to rim change to alloy and it’s fully visible.

For performance, it will definitely improve on handling when you require tackling the corners at high speed as back end tends to slip at that speed.

For me it’s due to both reasons I opted to change them but no luck yet for a used set as I’ve set a budget on the upgrade.

The only costly items will the new knuckle replacement as it must change to accept the brake assembly as the current ones do not support them.

As for those still wondering on the Assist/Regenerative Control at deceleration work, here’s how.

During deceleration the IMA motor driven by the wheels function as a generator. It charges the battery module by generating electrical energy. This is done by converting the kinetic energy of the vehicle during braking from the front wheels into electric energy that is stored in the IMA battery. When the battery module is full, regenerative stops to prevent overcharge of the battery.

[SuperJay]

Originally Posted by splew

I think EBD controls the proportioning, and I think the EX and LX master cylinders have the same part number.

what about the hybrid though? is it the same master as the LX? I've been wanting to change to rear disc for some time now.

Also, I think I can weld a mount onto the existing arm without changin the entire rear linkage. do you know anything about this? is it possible?

[splew]

Originally Posted by SuperJay

what about the hybrid though? is it the same master as the LX? I've been wanting to change to rear disc for some time now.

Also, I think I can weld a mount onto the existing arm without changin the entire rear linkage. do you know anything about this? is it possible?

I'm pretty sure the hybrid has the same brakes as the DX/LX, 10.3 inch discs up front and 8 inch drums in back, so I think the master cylinder is the same.

As far as I know you would have to replace the knuckle and possibly other suspension parts for a swap. You would also need the hubs, lines and obviously the calipers, pads and rotors from an EX. I wouldn't recommend welding on suspension parts. Even if you are an expert welder, welding still sets up the possibility of corrosion. Failure of suspension parts will cause a serious accident, so I don't think it's a good idea. I think the best bet is just to go to a salvage yard and pull the entire (undamaged) rear suspension from a wrecked EX. That way you should have everything you need.

[SuperJay]

thanks for the advice. I'll get around to it eventually. When I get to it, I'll be sure to post build pics.

[r18lx]

^ nice i need to see this!