[Modified by cgtarga1, 3:56 PM 6/19/2002]

 

:confused:

 

Sorry, Corvettes don't have Jake Brakes. :crazy:

 

eh?

:confused:

 

Semi trucks have compression braking. Basically a valve that opens on the cylinder head that bleeds off compression. It slows the truck down quickly without touching the brakes. It's really loud too. These have been nicknamed "Jake brakes" for some reason. I'm sure this has nothing to do with what he's asking but it is about compression braking. :)

[Modified by jmr302, 4:52 PM 6/19/2002]

 

he's probably thinking about engine braking
http://www.howstuffworks.com/question134.htm

"They are called Jake Brakes because Jacobs Vehicle Systems is the original maker of this sort of braking system. "

 

Compression Braking: The use of large, heavy, fixed objects to stop a fast moving vehical, there by compressing it into an unrecognizable piece of scrap. A good example is the movie "Vanishing Point". :jester

 

Sorry about the smartazz reply to your post, cgtarga1. Got a serious question you'd like to repost?

 

:confused: :confused: :confused:

 

Sorry, I was referring to engine braking. I was under the impression that 'engine' braking was a result of overcoming compression, and that a car's compression ratio influenced the amount of engine braking. Maybe I'm wrong. If so please straighten me out. :yesnod:

We had a few of my wife's co-workers (bankers'bankerettes - don't ask :smash: ) over for dinner and it was suggested in a conversation that this was harmful for an engine.

My original question: I did not see how this was bad for a car and was asking if this is true, and if so why.

 

Lot's of "opinions" on this. I have heard claims that it causes excessive stress on an engine.

Prove it.

Learn how to do it correctly, it "ain't" rocket science. I downshift to maintain control of my vehicle when coming to stoplights, entering turns; any time the engine RPM's drop low enough to "lug" the engine, I shift to the next lower gear. If my Corvette were an automatic, I certainly would not put it in neutral and "coast" up to a stop light; why would I do it with my 6 speed?

If you drive in the mountainous areas of the west coast (California, Oregon, Washington, Arizona, Nevada, etc., etc. you will become familar with "compression braking" or you will overheat your brakes very quickly.

My opinion but I have 41 years of driving experience to back it up in many different vehicles with standard transmissions. I have replaced one clutch in that time but I have NEVER replaced a blown engine in any vehicle with a standard tranny. Downshifted every d**n one of them.

'92 LT1

Addendum:

After much discussion with a fellow employee (registered mechanical engineer in state of California), yes there is stress on the engine while downshifting, slightly more than going up through the gears. Stress... yes, but premature engine failure? Not hardly. He feels (as do I) most engines, high performance engines in particular, are designed with this in mind.

His and my recommendation? Down shift.... it sounds "cool".

:chevy


[Modified by Oly, 1:02 PM 6/20/2002]

 

I don't believe it's harmeful to the drive train if the gear change is done smoothly and within the correct RPM limits.

I too use it to some extent when slowing for a traffic light, on a steady downgrade to hold speed and before some "agressive" maneuving and that's with my A4 and a modified shifter that now has positive down-shift stops in all gears.

For me it's not a matter of wear to the brakes vs the engine; it's a matter of driving style and pleasure.

 

Ditto.