I have heard of this phrase used when discussing Turbos on our trucks. What is this?

 

A wastegate is a valve in the exhaust housing of the turbo that allows exhaust gas to bypass (or waste) around the turbine. When boost reaches a certain level, the valve opens to reduce the amount of exhaust going through the turbine, which slows the turbine down. The wastegate is used to limit the boost produced by the turbo to prevent damage to the engine and/or turbo.

 

Great site to bookmark.
www.howstuffworks.com

Turbocharger Options

The Wastegate
Most automotive turbochargers have a wastegate, which allows the use of a smaller turbocharger to reduce lag while preventing it from spinning too quickly at high engine speeds. The wastegate is a valve that allows the exhaust to bypass the turbine blades. The wastegate senses the boost pressure. If the pressure gets too high, it could be an indicator that the turbine is spinning too quickly, so the wastegate bypasses some of the exhaust around the turbine blades, allowing the blades to slow down.

 

A local cummins guru gave me a little elbow to put in between my WG and Turbo it is a sort of pop off valve he also gave me a professional looking sheet of paper that said cummins and eveything and how to use it I think he got it with his high end box. well in fine print it said wont work on '01 and '02 automatics I cant beleave it a free upgrade and I get boned
my WG dont have a rubber hose to the TURBO it has a steel line and its connected by a non removeable compression type fitting
I gave it back and was thinking about it and I thought that....
the waste gate didnt let any boost go untill it reached the level its set to pop off so It woundt do me any good to have it any way because the only way I can get my waste gate to open is if I get on a hill .....stop.......mash the brake.....and floor it ....when I'm all spooled up I release the gas and brake at the same time and it sounds sooooooooooooooooo coooooooooooooool like a supercharged 5 motor pulling tractor getting under the turbo's ...... it takes a couple tries at first it goes chhettly...hetty...heeretly...hhlly....hilllyy.... ..tty...t.t...t..t..... choooooo... just like that.
that was my under standing in how it worked then it was explained that when your boost builds up the waste gate releaves some pressure anyway. reguardles if you have mods or not ..............OK OK so I didnt know

NOW my question is........can I crimp the steel line between my turbo and WG so I wont lose any boost Im pretty stock so I have no worry about blowing my turbo

 

Yes, you can in theory.

If you don't have a boost fooler (built into most fueling/timing boxes) they your truck will "defuel" if it sees more than 22-24psi boost, so it won't help much.

My truck, being still stock, I can get the wastegate to open on a hill no problem.
Watching the boost guage, it builds and builds until it hits 19-20psi, then just stops, and the truck just doesn't want to go up the hill any faster.

I don't think what you're describing is the wastegate opening,
rather you "barking" or "huffing" your turbo, which is bad.
Basically it stops compressing the air, so that air needs to go somewhere,
and starts coming back out of the turbo, making the blades slow down rather fast which makes that "whoosh" you hear.

You most likely won't be able to overspin the turbo on a stock truck, but with the wastegate blocked shut, you would be able to get it past its effenciency point, when it actually starts heating the air, and hot air is bad, cooool air is good.

confuse you enough yet?


phox

 

PHOX,

The sound I hear while "huffing" in your words kind of confuses me how can a stock turbo build up enough boost to compress the air enough to have the air go back up threw the fins with out the waste gate opening to releave the extra boost pressure??
IS my wastegate not opening like it should??

 

The wastegate works on the exhaust, the only way it affects boost is by letting some exhaust bypass the turbine to slow the turbo down and lower the boost.

When you let off the gas with all that boost built up, the engine speed drops immediately but the turbo keeps spinning. All that air the turbo is cramming in the intake has no place to go but back out through the turbo, making the noises you hear. This also causes the turbo to slow down really fast which puts a lot of stress on the shaft. Do it enough times and the shaft will twist off.

or still ?

 

but they should have a waste gate on both sides if the fins to prevent people like me from tareing up there trucks when they dont know what there doing

Can you hear a stock turbos waste gate open ?? all I hear is a lot of whisle ...If you can hear it open what would you have to do to get it to open to the point you could tell with no boost gauge??if I just mash the throttle on a hill all i hear is whisle.

 

You won't hear the wastegate open. I can tell when mine opens because the boost stops going up and the pyro starts climbing faster. Truck keeps pulling though.

No sense in adding more complexity to solve a problem that can easily be avoided by driving sensibly.

 

gottcha
but Im sure on semi's you can hear there wastegate open I figgered you could hear ours a little if it wasnt for all the whisle.
thanks

And your right ,but driving sensibly would probly cure 99 percent of the problems here @ DTR and I would have to find some friends somewhere else

 

The truck I drive at work isn't quite a semi, but the only way I can tell that the wastegate has opened is that the boost stops climbing. No sound change at all.