bov question

[Squirrel]

Alright, I'm working on putting together my own turbo kit. I have a t25 on the way along with some other parts. I'm unsure of what to do about the bov. I plan on running 7lbs of boost so do I need to get a bov that has a spring that is slightly over 7lbs or are they adjustable. This seems like a kind of a stupid question but haven't found any info concerning this.

[themadscientist]

you will plumb a vacuum hose to the BOV which will apply boost to the back of the valve to keep it closed so any quality one will work.

[95_240sx]

you will plumb a vacuum hose to the BOV which will apply boost to the back of the valve to keep it closed so any quality one will work.

And then when you close the throttle plate (let off the throttle) it makes a vacuum in that vacuum hose and it draws open the spring and voila, the bov opens and make the neat whoosh sound.

Rick

[WDRacing]

Alright, I'm working on putting together my own turbo kit. I have a t25 on the way along with some other parts. I'm unsure of what to do about the bov. I plan on running 7lbs of boost so do I need to get a bov that has a spring that is slightly over 7lbs or are they adjustable. This seems like a kind of a stupid question but haven't found any info concerning this.

Not that this was your question, but a T25 is awfully small for a KADET.... You'll spool up really early, but it will become very constrictive over 4700 rpm or so....

WD

[Squirrel]

Where is the vacuum line run from. If it is after the compressor won't there still be boost going to the line after the throttle colses.

[WDRacing]

Any vacuum line from the intake will work....

[Squirrel]

Did you mean the intake before the compressor or after the compressor. The way I saw it if there was a line after the compressor it would always be pressurized even if the throttle body was open or closed and if it was before the compressor it would always be pulling a vacuum.

[Squirrel]

I also have decided to go with a t3/t04e. I had puchased the t25 simply because I got a steal on it. brand new with waste gate and bov for under 300. Plan to sell that on ebay. I had thought I would probably use it, I realized it was somewhat small when I purchased but couldn't turn it down. So if anyone is in the market for a t25 let me know.

[Squirrel]

one more thing, what are you guys running fuel pressure regulators. I had wanted to go with a boost referenced rising rate regualtor buth they are a little pricey. Would just a regular regulator with the pressure turned up be suitable for around 7psi of boost.

[themadscientist]

you want a vacuum line that sources from the intake manifold BEHIND the throttle body. When the throttle shuts the hose sees vacuum and allows the valve to open.

[DaveEEE]

Alright, I'm working on putting together my own turbo kit. I have a t25 on the way along with some other parts. I'm unsure of what to do about the bov. I plan on running 7lbs of boost so do I need to get a bov that has a spring that is slightly over 7lbs or are they adjustable. This seems like a kind of a stupid question but haven't found any info concerning this.

Okay wtf are you talking about? Did you mean WASTEGATE? Bov's do not have "springs that adjust for boost".....

If you mean wastegate, get a Tial 35mm... done.

If you meant bov, get an HKS SSQ... done.

dave

[Squirrel]

Alright it makes cimplete sense now. I have done a lot of research and never come across anything that talked about the functioning of blow off valves.

[toki]

ok. now someone said a T25 would be "restrictive" after 4700rpms now did you just mean that it would lack boost or it would physically constrict power somehow? Stupid question i'm sure, but, i am poor and realizing I probably wont have the money for a nice turbo setup when i get my 240 and i am thinking about strapping a t25 or t28 on with just the bare essentials to retard detonation and keep it running ya know?

[themadscientist]

Blow through a garden hose. Now blow through a straw, feel the difference? That is what a dinky turbo will do to the engine, start stressing parts and creating heat. Your boost will go to what you set it to go to but a small turbo will restrict the exhuast flow out of the engine and really cause problems. I don't have practical experience with the KA to suggest the proper turbo size but if it's too small keep the boost low because whatever you put in has to come out and you are setting up a self-perpetuating force to damage your engine.