Has anyone used pop valves like they use on pulling tractors between the ic and the intake instead of a waste gate? how do they work? Are these also called external waste gates? How many times can they be opened without before they wear out? Just a thought. Non-waste gated turbo upgrades are so much cheaper. Feel free to shoot it down!

 

you mean a blow off valve?

i think they can be used until the parts wear out which should be a long time away.

 

if its a blow off valve your going to need a vaccum source to run it i beleive. but if its an external wastegate then you should be able to rig it up

 

I've seen them made outta pipe, bolt, spring, and a piece of flat plate fully adjustable. A good friend of mine has his built that way outta stainless for his pull truck, works like a champ. I don't see why it wouldn't work on the street if it was setup right. You probably just give several people some ideas.

 

I figured there has got to be a better way than getting a wg housing, b/c the non-wg housings are so much cheaper. I wonder if a blow of valve would sound too much like a ricer tho. What's the difference between a blow-off valve and an external wastegate?

 

wastegate is what prevents the turbo from overboosting. if it is set to open at xx boost. any more boost above that will be sent into the atmosphere.

A blow off valve aka pop off valve, is there to prevent turbo bark between shifts. Its a bit different on our diesels, since there is no throttle plate.. but on a gasser when you let off the gas and the plate closes, all that compressed air coming from the IC has no where to go but back to the turbo. The BOV vents that into the atmosphere instead so once you accel again, air if free to flow to the engine rather than try to compete against the air trying to come back.

on my CTD, i actually run BD's electronic BOV (you can you tube it) but it still hasnt been tuned.. i hate electronics.

 

Using a BOV to control boost pressure is a good way to blow up the turbo. When the BOV opens it unloads the compressor. In a normal BOV install this is the whole point, it keeps the compressor from stalling when the turbine stops making power. If you open the BOV under load to bleed boost off, the load on the turbine and compressor will be reduced and turbo RPM will go WAY up. The first thing to explode is usually the compressor wheel...

 

Cool. So why do the ricers run them? And what is an external wastegate?

 

I don't think you understood my point, a BOV installed they way they normally are will not blow up the turbo. When the engine is not under load, the turbine is not making any power - the turbo is basically "coasting" so there is no danger of overspeeding the turbo when the boost is dumped. It just lets the turbo "coast" more freely. Does that make more sense?

Now switching to gasser talk: The purpose of a BOV is to unload the compressor when you close the throttle, it keeps the compressor from stalling when all the air piles up against the throttle plate. There is much less lag between shifts with a BOV installed than without.

OK, back to stuff that applies to diesels: An external wastegate is a valve that is plumbed in before the turbine (usually on the manifold) that dumps exhaust when boost reaches a preset point. It's just like an internal wastegate except they usually are capable of flowing much more exhaust (very important for gassers that can't stand lots of boost) and they are designed to be easily adjustable. On diesels they are sometimes used to control the bottom turbo on a set of twins.

"Wasting" exhaust before the turbine is the way boost should be controlled. When you take exhaust away from the turbine, the turbine makes less power and can't spin the compressor as fast, so there is less boost.

All clear now?

 

i guess since im some 'noob' with 10 posts my post gets ignored huh?


w/e

 

Says "25" as of this post.

Don't take it like that, some folks need several explanations from multiple posters before they grasp a concept. Yours was a good post, maybe the OP just didn't get it the first time.

 

If it had, it was not on intent. we sometime get "TUNNEL VISION" trying to make our points. I have done it too.

 

Sorry, guess I misunderstood. I get it now. Thanks guys.

 

s'okay just pokin around. no offense taken.. and didnt intend on any, that why i included the smiley smiley.

:highfive:

 

i tried to use 1/4" pipe sized pressure relief valves like on an air compressor tank to relieve boost. It was a dumb idea. They didn't flow enough to make a dent in boost pressure. I got a wastegated housing now with a manual boost controller and everything is under control.