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Wasn't sure where this should go so I just put it in here. So I'm driving and my buddy was like get it up to like 5k rpm and I'm gonna turn the car off and when I do hold the gas pedal down. So I did, It sounds like a jake brake if you do that. I guess it is jsut that you can hear the valves opening and stuff with the throttle open. Is that good for the car? Just thought it was kinds cool.
 

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why the hell would you do that?
that could potentially be one of the most idiotic things i have ever heard!
congrats!
 

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Lol it wasn't my idea. I guess he figured it out or something. I haven't done it since.
 

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I don't doubt it
 

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i think his name says it all..................
 

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Discussion Starter #8
Firstly, it wasn't my idea. I had no clue what the hell he was doing. Secondly, I haven't done it since cause I don't wanna **** up my car.
 

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why the hell would anyone want to do this???

THis is almost as dumb as one of our friends who goes out on the highway and keeps the car in 3rd gear red lining to "clean" the cylinders.

Some people need a good smack over the head. But it is your car afterall so as you wish, i just hope u dont do this to someone elses car.

BTW im not sure why it would be bad for the car, but certainly the instant drop from 5000rpm could damage some valves and even jump timing if the belt is bad enough.

I wouldnt try it again if i were u, ive never even had my car to 5k, let alone stop it at 5k.
 

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spaz_boy31 said:
Wasn't sure where this should go so I just put it in here. So I'm driving and my buddy was like get it up to like 5k rpm and I'm gonna turn the car off and when I do hold the gas pedal down. So I did, It sounds like a jake brake if you do that. I guess it is jsut that you can hear the valves opening and stuff with the throttle open. Is that good for the car? Just thought it was kinds cool.
STAMPED.
 

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Discussion Starter #11
We did it once. I haven't done it again since, and don't intend on doing it again.
 

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Because I want to join the thrashing...

If I told you to jump off a bridge, would you do it? I mean it wouldn't be your idea either so I guess you would do it.

Also, it is only good to the engine if you do that during cold startup. So wait until it gets below freezing before you try that again.
 

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Couldn't resist...
The Jake Brake takes its name from the manufacturer who invented the most common implementation of the technology, the Jacobs Company.

The Jake brake is an add-on engine brake for diesel engines. Big semi trailers, the 18 wheel trucks that move everything we use, can weigh as much as 80,000 pounds. Stopping them or slowing them down results in a great deal of wear on the brakes, which have to be replaced frequently. The Jake brake, as an engine system, causes no wear and tear and can help slow the truck before the wheel brakes need to be applied. Its primary use is on long downhill grades where the wheel brakes would otherwise have to be frequently pumped to keep the truck from gaining dangerous speed.

When the driver presses a button in the cab to activate the device, two things happen. First, the switch excites the engine brakes' solenoids. By itself, this would help only a little but it is necessary for the second step. What happens inside of the engine goes roughly like this.

As a four-stroke internal combustion engine, each piston in a diesel normally moves up and down twice in each cycle. For the nit-pickers out there, there are many two-stroke diesel trucks on the road as well. The process begins when the fuel and air valves are closed and the piston moves upward. This compresses the air in the cylinder to as much as 25 times atmospheric pressure. This is much higher compression than a gasoline engine (typically ten times atmospheric pressure) and results in the air getting very hot, about 900 degrees Fahrenheit. At this time fuel is sprayed into the superheated air which immediately begins burning. The second stroke, the power stroke, is the downward movement of the piston as fuel burns. The third stroke is an upward movement with the exhaust valve open to clear out the combustion products while the fourth stroke refills the cylinder with air.

The Jake brake completely changes all this, redefining what the valves do as each piston moves up and down. With the fuel flow terminated, the upward moving first stroke still compresses the air to very high pressure. As we said above, this transfers mechanical energy into heat as the air becomes highly compressed. If nothing else were done, most of this energy would be recovered, except for frictional losses, as the cylinder moved back down and the compressed air expanded. The Jake brake, however, opens the exhaust valve just as the air reaches maximum compression, dumping all of that energy in an almost instantaneous explosive release. The result is a very effective slowing of the vehicle as mechanical energy is converted to heat and then dumped. The Jake brake effectively transforms the internal combustion engine into an air compressor.

It has only one drawback: it is very noisy. You may have heard a semi use the Jake brake without realizing what it was. Sometimes when a truck is approaching a stop sign or stop light it suddenly emits a load roar, very much like a large lawnmower, for five or ten seconds. It is the noise that is causing many towns to ban the use of the Jake brake. Even though tests have shown the decibel level to be about as loud as a large lawnmower, at night or early morning the low frequencies seem to carry a long distance and are very noticeable.

Because it extends the life of wheel brakes and saves money, trucking companies generally lobby against the bans and some towns are compromising by allowing the Jake brake to be used in daylight hours. Yet more and more signs, with the words Jake Brake and the international symbol for "banned", are certain to appear. Since the primary use of the Jake brake is to slow the truck on long downhill grades, the technology will continue to be widely adopted for use on the open road.
Didn't the steering lock,too?
 

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spaz_boy31 said:
We did it once. I haven't done it again since, and don't intend on doing it again.
Similiarlly,a friend and I took a non-aerobatic rated Cesna and did a REAL sloppy "loop" at 5,000agl to see if we could! (more of an inverted stall, but still a rush!!)
After finding out that there are only four bolts holding on the empannage-horizontal and vertical stabilizers- we never did that again!
 

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Okay here come my two cents. First although it’s a kinda pointless thing to do, I would be beyond surprised if this of all the things that are done to an engine would damage it. When you shut it off all that happens is that it’s getting no spark or gas, so it’s just going to be blowing out compressed air into the exhaust. And I don’t think it would wind down any faster then it does when you are doing a spirited acceleration and suddenly have to let off the gas, and it immediately upshifts into overdrive. I’m sure this has happened to a lot of us and we didn’t really think twice about it…well other then thinking that people should anticipate spirited accelerations and not pull out in front of you…


linuxglobal said:
I wouldnt try it again if i were u, ive never even had my car to 5k, let alone stop it at 5k.
Now this is something that I am astounded by. Not meant to be argumentative or anything, but do you really never push your car at all? If so, you’re the guy I want to buy a used car from! I personally love the thrust you get out of at least the 1g 3.5 in especially second gear once you get to about 5k rpms too much to keep the rpm’s under the 5 grand mark. It reminds me why I bought it in the first place, and makes me confused as to why anyone bought a Taurus or Lumina back in the mid to late 90’s.
(Note: I would never do this if I didn’t religiously use premium fluids in it, and never let it’s synthetic oil see over 3000 miles, and generally at least once every couple weeks go over the car with a fine tooth comb to make sure nothing is worn or damaged.)
 

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alarkyokie said:
Similiarlly,a friend and I took a non-aerobatic rated Cesna and did a REAL sloppy "loop" at 5,000agl to see if we could! (more of an inverted stall, but still a rush!!)
After finding out that there are only four bolts holding on the empannage-horizontal and vertical stabilizers- we never did that again!
Ok, and we all thought that the guy was crazy for trying to "break" his Intrepid...now while it may not have been smart, we have been shown just how stupid people can actually get. THAT is the stupidest thing I have ever heard.

You're just lucky you weren't over Manhattan when you did that.
 

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Gigamight said:
You're just lucky you weren't over Manhattan when you did that.
You're right!
But I would NEVER be over, or even close to Manhattan!
Flew over it at 32,000, but it was an AF pilot...
That's as close to NYC as I'd ever want to be!
 

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I'm pretty sure I know what the "instigator" was trying to do...Back in the days of carburetors, if you turned the key off while decelerating it would kill the ignition only. The result would be an exhaust system loaded with unburned fuel(exagerrated if you manually downshifted the car causing the engine to wind up). When the key was turned back to run the unburned fuel would explode causing a huge bang and if you were lucky enough, an exploded muffler. I have done this a few times back in the day...scares the **** out of tailgaters... The only problem with this scenario is the bonehead telling spaz what to do doesn't realize the modern EFI cars interrupt the fuel also so there will be no fuel in the pipe and no BANG. I doubt trying will do any harm...unless he somehow overrevs it...
 
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