Wastegate questions

[redmption]

I dont know much about this but I am trying to learn as much as I can about increasing boost on my MSP. Do the boost controllers keep the wastegate from opening at the 7psi mark on the MSP or do you have to buy a new wastegate which will hold more psi? Which is recommended for the MSP, an electric or manual?

 

[chdesign]

Boost controllers will only raise pressure. They work in conjuction with your stock wastegate. A manual one will work fine and keep you from tampering with it too much and possible blowing yoru motor. An electric one gives the option to adjust the level from inside the cabin.....if you are one to mess with things alot I woudl advise a Manual one as your boot isn't something you want to be messing with too much especially with the MSP.

 

[Dexter]

id probably just get like a turbo XS dual stage manual boost controller

 

[redmption]

so how do you keep the waste gate closed until like 9psi? does the controlled do that or do you have to get a new waste gate?

 

[BoOsTiN]

ok, this is not a very technical answer....
The wastegate is set to open at 7#'s or pressure. The 7#'s is the only thing opening the wastegate. Most boost controllers bleed off a small amount of pressure going to the wastegate. So you set your controller for 9#'s. The engine is seeing 9#'s but the line going to the wastegate has the boost controller inline bleeding off 3 #'s. So the wastegate is opening at what it thinks is 7#'s but is actually 9. Does this make any sense or am i just confusing people? I think i just confused myself.
Either manual or electronic works fine. Depends on your budget.
Electronic is nice because of options they have like HI/LOW boost settings. 6 could be the LOW setting and 9 could be the HI.

 

[BoOsTiN]

Keith@FP says it best......
(quote)
A wastegate is a diaphragm that opens a valve. That's all. The MSP one is set to open at around 7 psi. It's triggered by a signal line - a hose that's connected to the turbo output. The pressure pushes on the diaphragm and opens the wastegate, dumping exhaust gas. On some wastegate designs, it's possible to change the springs to change the boost setting.

A boost controller takes that signal line and bleeds off some of the air. This means that the wastegate will still open when it gets 7 psi of pressure, but the turbo might be producing 12 psi at this point and the controller is dumping 5 psi. Make sense? The closer your mechanical boost (set by the wastegate) and your boost target (from the controller), the easier it will be to control boost.

Notice that I haven't mentioned manual or electronic boost controllers, or integral or external wastegates. Makes NO difference. An integral wastegate can allow you to run massive amounts of boost if everything is set up correctly. Electronic boost controllers allow you to spool up more quickly because of the way they spill off the extra pressure, but that's it.

 

[redmption]

Okay Ive read that befroe and thats where I get confused. If the turbo is pushing out 12psi but your are losing 5 of it because of the waste gate then dont you still get 7psi and the whole point of increasing the boost is lost?

 

[BoOsTiN]

Ok.. not really.
the turbos pumping out 12#s.
Everything is pressurized to 12#s.
Only 1 small vacuum line is leading the the wastegate.
This is the only line that is "losing" boost.
Because that one line is losing boost , it takes more pressure to open the wastegate.
This vacuum line is small enough that its not just spewing out tons of air.
Think of a waterhose that has a small hole in it. Turn on the water and it shoots out the nozzle. At the same time it is also leaking out the small hole. Just because the small hole is there doesnt mean you lose all water going to the nozzle.
I duno. Hope that helped. I know how it works I just cant explain it properly.