Blow Off Valve
 

Has enyone ever heard a blow off valve on a diesel truck? I figured if a car's turbo making 10psi sounded cool then a truck at 40psi would sound even better. Atleast give the ricers something to admire. I just got mine in and noticed there is a little more wireing involved that I would have thought but will try to get it all hooked up soon.

where did you get yours and what brand is it? i've been looking for one as i have a huge turbo bark problem and i know that would eliminate it....

couldnt one use somthing like whats on a semi air tank, only set for 45-50psi?

aftermarket units, my truck discharges loud enough as it is when i let off it.....

el cheapo http://www.hopupracing.com/kptwhobloffv.html

better http://www.hopupracing.com/tubloffvatys.html

good http://www.rallysportdirect.com/shop...lve-p-568.html

logan those are for gassers..... not for diesels..... those use a vaccum reference to open the valve. when the throttle blade closes it creates vaccume and opens the valve..... diesel's never create vaccume. even if you plumbed a valve into the vaccum pump you'd still have to have a boost pressure line ran to it to keep the BOV closed under boost...... it's perty complicated to get one of those to work on a diesel..... i'm prolly gonna do it but it's gonna take a crap ton of solonoids and relays and different hobbs switches to get right.....

bd makes one its called the turbo gaurd, thats made for diesels

true, it was late and i was tired and i didnt think anything about it being referenced to vaccum......

BOV

cute picture Whit.......

here is the BOV on Cummins Express truck

got it from bd. If you do want one make sure your intercooler pipe going into the intake manifold is metal. The 06's are plastic so I had to get one of them from BD also. I thought it would be a bit easier to install but there is a bit of wireing to do since it is activated by the position of the pedal and how much voltage at what position it is at. A bit more complicated than I thought.

hey wes would you mind telling me how that is plumbed? what size is it? and is that a BOV for when you let off of it or is that a Bleeder to not build up too much boost?

from what dave said it does not affect boost pressure. It only blows off when so much of the pedal is released. It is controlled by the volts and the position of the pedal. not sure about size but it will cover the palm of my hand.

This BOV is setup just to relieve pressure upon lifting of the pedal. It helps to minimize the surge conditions present when drive pressure drops.
The BOV is a 50mm TiAL

~Wes~

well if you don't mind me asking.... how is it plumbed? ie where does it get it's signal? (vaccum or boost?) you can pm me if you want to i am just trying to figure something out where i can be as cheap as possable.... thanks in advance Benjamin

Sorry, wasn't trying to be vague. It has a boost signal plumbes to the top of the valve with a small electric spool valve in between the boost source and the BOV diaphragm.

When the pedal is closed (depressed) the spool valve allows boost to the top of the BOV to hold it closed. When the pedal is released the spool valve opens and alows the top of theBOV diaphragm to vent to atmosphere. If boost is higher than the seat pressure of the spring in the top of the BOV then the plunger in the BOV will open and vent boost to atmosphere.

~Wes~

ah that makes sence.... that really simplifies my thought process on how to make something work.....

No prob. Any questions, then feel free to ask. I'm here to help in any way that I can.

can you explain the valving you used? i've been thinking of using the electric solonoids that came stock on RX7's to control something like that using a 5 pin relay. opening one valve when i leave idle to allow boost to see the bov and closing the other that would be vented to atmosphere at the same time.... then when i go back to idle position it'll close the boost line and open the vent to atmosphere to allow the bov to work.... all this being controlled my a microswitch..... i can draw it all out but it'll take me a sec or two.... can you follow my logic?

I follow. That should work just fine as long as the valve will handle the intended pressures.

ya that's been the only holdback as of now.... i guess i gould do some testing with just the valves before i go full scale.....

Let me know how your testing goes on those valves. Would give me one more option next time I build one.