Hi everyone,
I just registered to this site, and I understand that TDR might have more information. However, I am very against the fact that they want money to join their forums, so I came here instead. I probably won't get the attention in these forums, but any information is better then none at all.

Here is my question. I was standing around talking with one of my good friends tonight about my new truck. He has built a custom t3/t4 turbo setup on a volkswagen, and I was just BSing the turbo system design. (this is both the first diesel I have ever owned, and also the first turbo system.) We both went searching for the a blow off valve of some sort, and couldn't find it. So, he said "well hell, just go on one of the forums and ask about adding a blow off valve, then they can laugh at you." So, here I am, to be laughed at.

In the basics, I understand that a Diesel doesn't have any way to slap the motor shut from incoming boost, like a gas motor does. There is no throttle plate anywhere in the motor. I understand that, under this assumption, there should be no back pressure building up on the turbo.. However, I am more concerned about the momentary shifting when you are suddenly forcing the motor down to lower RPMS then your high RPM shift. By letting off the throttle, you might now be closing the motor off to incoming boost, but won't the motor be getting less fuel, which means it will be using less air, which means it will be creating a good amount of back pressure on the turbo itself? I have already heard the turbo "bark" at me a few times under high acceleration and suddenly releasing the pedal to make a shift.

My question is this, can I add a blow off valve in the tubing to help protect my turbo from un-needed turbo abuse? Bd performance makes an electronically controled unit: http://www.bd-power.com/ram/product.php?pn=BD%20TurboGuard&tt=ram but I was thinking of doing a manual one on the intact tubing.. I know this is going to sound silly, but part of the reason I want to do it is asthetic.. I love the sound of a Greddy Type S blow off valve, and I am jealous.. That might sound shallow... but hey.. some people like fender flares, some like moon visors, I like something that could help protect my motor while adding "style" at the same time.

So.. Can it be done? If it can be done, will the sudden releasing of the throttle and the motor winding down cause enough back pressure to actually activate the blow off valve? Anyone done it before?

Thanks in advance for any and all answers!!

Go register at Northwes Bombers

www.nwbombers.com

Ask a guy named Hoss.

he has the BD TIAL BOV.

Just for clarity, I do NOT want the BD system.. I want a manual, pressure activated blow off valve like the Greddy Type S... not an electronically controlled unit...

I will be registering for that site though! I live in Idaho, so it is kind of ironic I havn't found that site yet!

Thanks again!

Just for clarity, I do NOT want the BD system.. I want a manual, pressure activated blow off valve like the Greddy Type S... not an electronically controlled unit...

I will be registering for that site though! I live in Idaho, so it is kind of ironic I havn't found that site yet!

Thanks again!Pressure activated single action will not work on a Turbodiesel... we have no throttle plate for the boost overrun to 'back up' against. as well as no vacuum signal to reference from.

TDR is worth the $35 for the four publications they send out yearly in addition to the website.

Got Juice?: See, that was exactly what I was wondering about. I understand that there is no throttle plate to slap closed, which means I should not be experiencing any trubo bark.. But its still there! On an automatic tranny, I can see how the tranny might keep it in the power band long enough to never cause any back pressure.. But on a manual tranny (like mine) when you slam the clutch in during really hard acceleration, you are dropping the RPMS down instantly. Even though there is no throttle plate to slap closed, there is no way the motor can be using all of the excess air that the turbo is still generating.. I mean, it can't be forcing 21psi of boost into a motor that is under no throttle and at idle speed (while the clutch is in).. Wouldn't that cause enough pressure to activate a pre-set blow off valve? I'm not trying to do a "yes it is, no it isn't, yes it is, no it isn't" arguement, I'm just wondering if anyone has any actual experience with the idea.. or, is my theory so far off that it isn't even possible?

hoot: I gotta disagree... I'm a Classic Bronco fanatic to the core, and I write tech articles for websites and for magazines.. I have never asked anything for my information, and I would never ask anything from anyone for theirs... Look at this great site, for instance.

I don't know about the feasibility of putting a BOV on a diesel, but I would be interested in doing it as well if a way could be figured out.

Go to www.dieseltruckresource.com (http://www.dieseltruckresource.com) and register there. They're free, and Dodge-based. This is a great forum, but pretty scarce on Dodge info as it's a Chevy-oriented website.

I barked my turbo hundreds of times a day for years. Dont worry about it.

The reason it barks is because there is a lot of exhaust spinning it up. Then there is none. There is a lot of demand for fresh air then there is none(high rpms to low). You dont have the volume of exhaust to support the speed that the turbo is spinning. I have heard that barking is not good for turbos but my turbo went 150k(sold the truck) without a single issue. It was green from heat but still kickin.

Bovs are for gas engines. They have a throttle plate that closes blocking incoming air. Diesels get 100% of the air all the time. Forget the bov. Just remember if you arent barking your turbo. You arent driving hard enough.

150k is hardly a lot of miles for a Cummins... how about the guys with 800k+ on the clock?

Oh wait, they're out driving their trucks right now! :)

Im new to this site, normally Im at TDR, BUT, BOV, it is a good question. I mean, I have heard it on the rice burners and they do sound pretty cool, but, I also have heard a Blow Off on the Big Rigs when were at a stop and they take off, I can actually hear the Poof and they shift gears, can it actually be done on a regular diesel like ours and or automatics?

150k is hardly a lot of miles for a Cummins... how about the guys with 800k+ on the clock?

Oh wait, they're out driving their trucks right now! :)
Those guys arent barking their turbos 100s of times a day. The turbos are very reliable. Forget about the BOV. We dont need em.

I also have heard a Blow Off on the Big Rigs when were at a stop and they take off, I can actually hear the Poof and they shift gears, can it actually be done on a regular diesel like ours and or automatics?

big rigs do not have any blow off valves on them...

i have plans/ideas to make a standard BOV work on a diesel [stick or slushbox] but i haven't had the time/parts/money to make it work/work on the project...

big rigs do not have any blow off valves on them...

i have plans/ideas to make a standard BOV work on a diesel [stick or slushbox] but i haven't had the time/parts/money to make it work/work on the project...

that would be Airbrakes right?


oh and i bark my turbo all the time, its funny to see the look on the guy in the hondas face when it barks right next to his window