Waste gates on Diesels

[KEVINL]

I showed my friend who built alot of turbo systems for Gas powered vehicles my GT4094R setup he was concerned about no wastegate. I told him it wasn't neccesary because it would produce boost till it ran out of extra fuel to burn. He said that is not the way to do it.

So my question is what is the purpose of a wastegate on a Diesel. It seems to me like unless you are overfueling the motor it would serve no purpose.

I know the HTT has one but I am not sure why it would be neccesary

The stock IHI doesn't seem like it would need one with stock fueling

 

[Iceman56]

Well you either have to have a wastegate or variable vane, and they both limit boost right

 

[Josh2002cc]

Well you either have to have a wastegate or variable vane, and they both limit boost right

Why do you HAVE to have a wastegate if you do not have a variable vane turbo?

 

[Iceman56]

Why do you HAVE to have a wastegate if you do not have a variable vane turbo?

I don't know I am asking

 

[Big Block 88]

No, that is what I am askin

 

[MAXLLY]

I understand it like a 6 year old... so i explain it like that.:rofl:

When we spin the charger to fast it makes to much heat, in an effort to slow it down we release pressure somewhere between the exhaust valve and the turbine. This pressure is released with a wastegate, customarily we gate it at the ped. Some people may feel differntly about this.

 

[Iceman56]

I understand it like a 6 year old... so i explain it like that.:rofl:

LOL Thank you that is how I need everything explained to me about Duramax's

 

[TrentNell]

I understand it like a 6 year old... so i explain it like that.:rofl:

When we spin the charger to fast it makes to much heat, in an effort to slow it down we release pressure somewhere between the exhaust valve and the turbine. This pressure is released with a wastegate, customarily we gate it at the ped. Some people may feel differntly about this.

x2 but to further explain if you never hit that point and are not exceeding the map of the turbo the gate will never do anything , like my turbo starts to run off its map at 45 psi if i remember right so my gate is set to 44 psi ( wich i never make over 42) so i can protect my turbo from overspeeding and to keep my drive pressures from going through the roof . but it is a tool that you set to protect your equipment or to suite your needs like limmiting boost , drive pressure, ect but by no meens is nescecery . but a good idea imop

 

[bullfrogjohnson]

x2 but to further explain if you never hit that point and are not exceeding the map of the turbo the gate will never do anything , like my turbo starts to run off its map at 45 psi if i remember right so my gate is set to 44 psi ( wich i never make over 42) so i can protect my turbo from overspeeding and to keep my drive pressures from going through the roof . but it is a tool that you set to protect your equipment or to suite your needs like limmiting boost , drive pressure, ect but by no meens is nescecery . but a good idea imop

Nicely put

 

[MAXLLY]

I understand it like a 6 year old... so i explain it like that.:rofl:

LOL Thank you that is how I need everything explained to me about Duramax's

if i offended anybody, sorry. It just seems real simple like that.

However it ain't really that easy. If you wanna know if you need one... check drive pressure against boost pressure and intake tempeture.

Efficiency is key, low boost, low heat, easier to make power. You aren't fighting against diminishing returns. ie intake is hot, density is down, shove more air at it to make up the difference.

I ain't the pro take this with a grain of salt.

OOPS- DOUBLE POST SORRY

 

[Iceman56]

So the garret 4094 does not have a wastegate? And it is not VV? Isn't this kinda dangerous tell you get it tuned right like yours is Trentell

 

[KEVINL]

My thought is you are not going to get enough fuel on a stock single CP3 for it to become a problem but what do I know.

Alot of guys are running these turbos and I have not heard the absense of a waste gate being a problem

If it was I would think dialing back the tune would be better than overfueling and just wastegating it

 

[hondarider552]

So the garret 4094 does not have a wastegate? And it is not VV? Isn't this kinda dangerous tell you get it tuned right like yours is Trentell

Correct the 4094 doesnt have one, and its not variable.

 

[TrentNell]

most people with a single cp3 would not have near enough fuel to send a 4094 off its map . the best thing is to monitor boost and know what the limmit of your turbo is if you are exceeding the max boost you either need to gate it or cut back your fuel or you run a risk of over speeding it or really high drive pressure .

 

[McRat]

We aren't running gates on Casper, and the boost stays steady 62psi with both chargers still in their maps. If you aren't going to run the charger off it's map, then a gate won't do you any good, since you will clamp it shut to get more power out of it.

 

[super diesel]

If you aren't going to run the charger off it's map, then a gate won't do you any good, since you will clamp it shut to get more power out of it.

Correct. This is why drive pressure gauges and turbo speed sensors are a good thing. This will tell you where in the map the turbo is. When the drive pressures get out of hand or the turbo is way past the RPMs it's effective at, then this is where a waste gate is useful.

 

[Iceman56]

Okay guys thanks for the info staring to understand it now

 

[2wd_Sled_Puller]

I can promise you one thing. You will never here no one say i would be faster if i didnt have my waste gate. IMHO they are cheap insurance and i will always have a gate. Even if the turbo i buy dont have one i will put a external gate on it. 50 psi is all i wanna pull with even a build motor