Pop off valve?

[JTroiano]

I don't know if any body has asked this quistion but here it goes. Would a pop off valve help a 5spd diesel stay spooled up between shifts? I know they are vacuum operated and we don't have vacuum but if some one could rig one up would it make a difference? The other thing is there is no throttle plate so it shouldn't make a difference but it sure sounds like the turbo is spooling down pretty quick when I let off the go pedal. It would be a great benifit if it worked. Any input would be great.

Jon

 

[Evan A. Beck]

Originally posted by JTroiano

... when I let off the go pedal...

Solution... Don't let off the go pedal.



BOMB ON

 

[joesoot]

Wasn't someone working on a BOV for our trucks?

 

[CumminsAholic]

If I'm thinking about what you're talking about Joe, I'm sure somebody was woking on it. I have that problem with my auto. If I let off really fast at high boost, it'll try to spin the turbo backwards. I know someone was working on a valve to fix that, but nothing has come up about their progress yet. There is a solution, like Evan said, don't let off, or in my case don't let off so fast. I'm getting better now, but I still let off too fast on ocassion. Hopefully whoever was working on this will read this and share their findings.

Corey

 

[Todd T]

I just use my high idler.



it is set for 1300RPM's and I can usually keep it at 1500-1700 between shifts

 

[Briar Hopper]

KwikSpool 12cm2 keeps boost up

I've noticed that having the 12cm2 housing on my Hx40 keeps the boost up, it doesn't hardly fall below 10 psi when I shift, it's fantastic. Give Kurt a call, and get one of these for yourself !

 

[roadranger]

Originally posted by JTroiano

I know they are vacuum operated and we don't have vacuum but if some one could rig one up would it make a difference?

No vacuum? There's a vacuum pump by the power steering pump, and all of the heating/AC system,

and the power brakes works by vacuum.

 

[Mopar-muscle]

would a pop off valve keep the turbo spooled up ??



as far as the brakes comment , depends on the year , i don't know when the switch was made but my 2000 ( as far as i have seen 97 - 2001. 5 ) have a hydro boost power brakes system connect to the power steering system . the vacuum pump is used to control the ducts in the ventilation system as far as i can tell .

 

[JTroiano]

I guess the real quistion is, what slows the turbo down in our diesels? Is it the exaust or the intake? On a gas car the throttle plate slams shut when you let off the gas to shift and that stops the air flow dead in its tracks causing the turbo to rapidly spool down. With the Dodge having a vacuum pump is good but the way a pop off valve works is that on a gas car under heavy acceleration there is no vacuum at the intake so the valve stays closed and then when the throttle closes there is vacuum and then it opens. So it is sort of like a switch for the pop off valve. When the valve opens it vents the boost to the atmosphere so the turbo doesn't have to push the stopped air in the intake and as soon as you hit the throttle the vacuum goes away and the car is getting the boost again. So the vacuum pump on the truck is always making vacuum and so the valve would always be open but you could put a micro switch on the throttle that would activate a VSV (vacuum switching valve) to apply or remove vacuum to the pop off valve. Hope this isn't to long. I just don't know if it is worth the effort to build. I'm also not talking about staying at 10 psi I want to keep the boost up around 30 psi. I'm hitting 40 when shifting and when it drops to 10 it still takes that split second to pick back up.

Jon