Air Brakes or Jake Brake?

Has anyone ever considered installing a Jake Brake or air brake system in their TDI?

I think it would be both functional and hilarious. I would love to use it while coming down a steep grade.

Do you guys think it would even be possible?

Discuss.

On a ~2800lb car...not necessary. Jake brake? Not possible. Exhaust brake? Probably not possible unless you put in heavier valve springs. It would suck to smack a valve just for the sake of having fun.

Sounds like you need a truck.

Dustin said:

Has anyone ever considered installing a Jake Brake or air brake system in their TDI?

I think it would be both functional and hilarious. I would love to use it while coming down a steep grade.

Do you guys think it would even be possible?

Discuss.

Click to expand...

Fuh-get about it.

Air brake system would gain you nothing. If you just want the psst sound, get an air tank and fill it like a tire and hit a release valve when you want to "vent". I don't know why any sane person would want to do this. The only reason you might want air brakes is if you were towing a BIG trailer with air brakes installed. I would not want to try this with a sub two liter engine.

A "Jake Brake" type of engine brake would require major modifications to the cylinder head. Again, not worth the trouble. These require very different (and adjustable) valve timing.

Either dream on, or buy an old Semi Tractor to play with.

Have Fun!

Don

Put a 5th wheel on 'er, a gun rack, some nice pipe stacks.

Finally you could sit in the trucker's section at the diner!

Dustin said:

Do you guys think it would even be possible?

Click to expand...

Anything is possible if you have enough money. JSW is correct though, you would pretty much have to have an entirely new/re designed head built, which require the services of an engineering firm, auto-cad, machinists... It's pretty much an insane idea. As for airbrakes, that would require, at a minimum, the installation of an engine driven accessory air pump, which would require a completely new, cutom designed and made serpentine belt. Said compressor would rob power from your tdi resulting in lower economy. Beyond that, there's a myriad of plumbing required to route the air pressure.

Where did you get this idea, anyway? Oh wait, you got to drink the bong water...I get it. =)

Around here you need a licence endorsement to drive an air braked vehicle

Paul

Dustin said:

Has anyone ever considered installing a Jake Brake or air brake system in their TDI?

I think it would be both functional and hilarious. I would love to use it while coming down a steep grade.

Do you guys think it would even be possible?

Discuss.

Click to expand...

This is a totally comical post.... Isn't it?

does this guy understand the operating principals behind an airbrake or jake brake??

i'd love to be watching when he engages that!!!!

say hello steering wheel and good bye teeth

Oh, I don't know, nothing wrong with an innocent question. every time someone posts something like this it gives me an opportunity to increase my mechanical knowledge.

From the Jake brake site I got a rudimentary idea of how a Jake brake works. I think it would be great if TDI's had a Jake brake. I could get 200K miles on my brakes.

A Jake brake unloads the built up compression towards the top of the compression stroke causing the power stroke to not return any energy back into the 4 stroke process. If you could add an additional lobe for each exhaust valve and a way to cause it to unload the compression at deceleration it could be done. Of course, making it work would be interesting...............................................

Ol'Rattler said:

Oh, I don't know, nothing wrong with an innocent question. every time someone posts something like this it gives me an opportunity to increase my mechanical knowledge.

From the Jake brake site I got a rudimentary idea of how a Jake brake works. I think it would be great if TDI's had a Jake brake. I could get 200K miles on my brakes.

Click to expand...

There are actually number of different "compression release" and exhaust driven supplemental braking systems available for big trucks. The term "Jake Brake" has sorta become a generic name (like Kleenex) much to the displeasure of the Jacobs company. I believe that the decision was made (probably rightly) that the VWs do not weigh enough to require more than standard disc brakes. When you are trying to slow down 40,000+ lbs (like going down a long hill) you can burn through (or burn up) conventional brakes pretty quickly, whether air brakes or hydraulic brakes. My wife used to work for Jacobs, building prototypes for new models (many years ago). FL2AK is correct, anything is possible with enough money. That's the real question - how much extra price would you be willing to pay for better engine braking? A more complex cylinder head would be required, plus a whole new set of sensors, controllers, and actuators to make it work. This is worth the expense with heavy loads - not so much with a VW.

The biggest advantage of diesel engines is efficiency. One of the significant disadvantages is far less engine braking than an equivalent gasser would have (no throttle plate (air valve) to create suction). Therefore, you must use the regular brakes.

Have Fun!

Don

In a manual trans car it would appear we already have the pieces to make a compression brake. Banks is using the VNT vanes to increase backpressure and thus turning the engine into a compression brake.
I still don't see the benefit for our cars, except in cruise control, if it was written into the tune for the car, you could maintain your set cruise speed no matter how steep the downgrade.

Here's a link to the Banks Speed Brake
http://www.bankspower.com/products/show/323/3

Have fun with that.

O.C.TDI said:

In a manual trans car it would appear we already have the pieces to make a compression brake. Banks is using the VNT vanes to increase backpressure and thus turning the engine into a compression brake.
I still don't see the benefit for our cars, except in cruise control, if it was written into the tune for the car, you could maintain your set cruise speed no matter how steep the downgrade.

Click to expand...

That's actually an interesting idea. Engine braking a mere tune away. I wonder if closing the VNT vanes like that could cause any problems. If there was no harm in it - I wonder why it hasn't been tried already. As you stated, there are times when it could be useful.

IMHO, calling it a "compression brake" is a common error. It's really more of a "suction brake" (especially your excellent idea). Instead of using exhaust "back pressure", intake suction (like a gasser) is more useful (although they would both work together). The proper term for a "Jake brake" type system is a "compression release brake".

Have Fun!

Don

No doubt, something I could never afford to do, but I think that the ability of my throttle to actually provide engine braking has some merit.

I know that my TDI does completely cut the fuel under certain conditions. All that is needed is a way to unload the compression....................and of course the right tune to make it all work.

I guess the only time I would see this as a good thing is towing something. I haven't had any issues coming off the mountains so far. Just downshift and the engine holds me back. But that is without a trailer. If it was cheap enough and practical enough to use I would maybe get one.