Alright, first question.

When is a turbo timer necessary? when your turbo is glowing cherry red after a good drive? Can having too hot of a system and then shutting off your car right away cause serious damage that a turbo timer eliminates?

Second question

I finally have grasped the wastegate. There are a few things i am confused about.
1. Does the wastegate valve open away from the diaphram, or towards?
2. If it opens towards the diaphram, can high exhaust manifold pressure cause the wastegate to open before the intake boost pressure does? If it opens away from the diaphram, ignore this question
3. What are the benefits of having the wastegate actuator on the intake near the turbine housing and not near the throttle body? My book explains it, but I don't understand. It says there are benefits and disadvantages to both.. im not to sure why.

Bear with me im learning, and learning fast

Reted if your reading this, please, if you have nothing nice to say, don't say anything at all



thank you.

Not expecting answers to every question, but by all means, if you have two cents of info to throw towards this, please do.

 

yes, prolongs life. Oil can break down at those high temps.



internal/external wg?

internal- puck is forced shut by exhaust and pulled open by the actuator

external- valve is pulled away from exhaust and exhaust gas is pushing open.

no idea what your try'n to say for point 3

edit: are you talk'n about about a bov. That would be hot side/cold side benifits

 

Well with point 3, im trying to say that every wastegate needs boost pressure to activate, so putting that source near the turbing outlet or near the throttle body has its advantages/disadvantages.

with point number 2, does the PSI inside the exhaust manifold prematurley open up the wastegate?

thx

 

Depends on what your looking for.

Before the ic the pressure drop would mean the wg would actuate before the tb version.

but the tb version would set it to the correct pressure as that is what the engine would see and boost guage.

so a 8lb spring could open as low as 7psi (engine) if you had a drop of 1psi from your ic.

external is the only one with exhaust pushing agains it and no it won't. There is a path of lesser resistance (aka turbo).

 

Alright, I now understand how a wastegate fully works. Thanks.

How do you guys route your external wastegates? do you feed it back into the exhuast system, or do you just have a pipe that lets it vent under the car?

When it vents, is it really loud if you just put it to a straight pipe?

 

i was thinking about that more and i think before the tb would have a faster reaction to pressure changes thus helping the control (shorter distance). Most all turbos have a nipple for the wg on the compressor housing.

you can dump or recirc. Yes it's loud.

 

I bet, especially when your reaching your maximum desired boost level and leaving it, the wastegate will always be open and the noise must be pretty crazy.

thanks for answering my questions btw

 

All the internal, flapper-door style wastegates that I have seen would also be pushed open by the exhaust pressure. Having the exhaust pressure hold a wastegate shut seems like an odd design.

-Max

 

hehee your right.

been a while since i ported an internal.