TURBO EXPERITISE: TWO questions: 1. Difference... 2. Disconnected..

just got my 1992 no to long ago. I got too amitt, mr2 turbo are my favorite. but n e ways i just learnin about the mr2 turbo now and i want more info about it.

1. I wanna noe wat is the difference between a Waste gate(or i think (ABV) and a blow-off valve(BOV)? do i need both of them to get the squeeling sound or or just one. and tell me which and consider im on a tight buget.

2. I was experimenting on the waste gate or ABV by disconnecting the hoses that was conneced to it. i was driving and i got that sound i wanted but i dont noe if thats a good or bad thing. (i just started disconnection yesturday night) Is there a way i can keep that sound going or i need to coneect everything back?

Without seeing what you did I can't tell you how bad what you did is going to be in the long run, however, if you believe yourself to be more wise than the Toyota engineers whom originally designed the vehicle, by all means keep it the way you have it...otherwise I would suggest reversing what you have done.

Read some of the other posts in this forum to understand wastegates and BOV's as this topic has been done to death.

Wastegates

More on wastegates

Some BOV stuff

BOV's and Wastegates are completely different.

You don't know what the difference is between a BOV and a wastegate, and you just decided to play around with your car not knowing what might happen? Especially experimenting on an MR2 TURBO...

I am just totally speechless...

Some terminology

which is better Im guessing the wastegate

There is no better or worse, a BOV and a wastegate are 2 different things!

thats right im sorry im still learning about turbo and how it works but I know there are 2 types of Bov's

thats right im sorry im still learning about turbo and how it works but I know there are 2 types of Bov's

You are correct there ARE 2 types of these, one is called the blow off valve and the other is called the bypass valve.

A blow off valve releases the pressure (or "boost") to the outside of the car, making the familiar "pssht" noise.

A bypass valve releases pressure onto the compressor turbine of the turbo, keeping it spinning. It makes no noise (not that I know of)

You are correct there ARE 2 types of these, one is called the blow off valve and the other is called the bypass valve.

A blow off valve releases the pressure (or "boost") to the outside of the car, making the familiar "pssht" noise.

A bypass valve releases pressure onto the compressor turbine of the turbo, keeping it spinning. It makes no noise (not that I know of)
A bypass valve does make noise, it's just more stifled than the open-air BOV. If your car uses a metered air system, you MUST run the recirculating bypass valve or your engine will run rich every time you shift.

Parts of a turbo:

Here's a quick guide on the parts of a turbo. I took these pics of my busted T3.

Here's the entire turbocharger assembly, including the stock exhaust elbow w/ built-in wastegate.
http://files.automotiveforums.com/gallery/watermark.php?file=/500/30794turboangle.jpg


Here are the main parts of a turbocharger (picture is looking at the bottom of the turbo):
http://files.automotiveforums.com/gallery/watermark.php?file=/503/30794wg_numbered.jpg
1)The compressor housing, this is where the air from the air filter/intake is compressed blown into the intake manifold.

2)The center section; this is what supports the turbo shaft, which is what the compressor and turbine wheels spin on. Depending on the model of turbo, it may be either oil or water/oil cooled. This one is both oil and water cooled. 2a is the fitting for the oil return line, 2b is the fitting for the coolant return line. Directly opposite these 2 fittings are their respective feed lines.

3) Turbine/exhaust housing, this bolts to the exhaust manifold so that the engine's exhaust spins the turbine blades (which are attached to the compressor blades via the center shaft).

4) This is the exhaust elbow. On this specific turbo, the wastegate is built in to the elbow. The exhaust downpipe attaches here.

5) Wastegate diaphragm. A vacuum line from the boost controller attaches to the diaphragm, which opens and closes the wastegate to control how fast the turbo spins.


http://files.automotiveforums.com/gallery/watermark.php?file=/503/30794turbine.jpg
This is the exhaust housing with the elbow removed. You can see the turbine wheel here (note the broken blade at the 12:00 position- oops!) and the small round wastegate opening at the bottom left.

http://files.automotiveforums.com/gallery/watermark.php?file=/500/30794wg_inside.jpg
This is the inside of the exhaust elbow, the round piece is the "door" to the wastegate. When the diaphragm closes it, it forces the exhaust to flow through the exhaust housing and spool the turbo. When the set boost level is reached, the boost controller opens the wastegate door and the exhaust flows through it instead, bypassing the turbine.

http://files.automotiveforums.com/gallery/watermark.php?file=/503/30794air.jpg
Finally, here is the compressor (air) side with the housing removed. The exhaust housing can be removed the same way.

A hybrid turbo (T3/T4) is where a smaller T3 exhaust housing and wheel (blades) are used along with a larger T4 compressor housing and wheel. The larger T4 compressor side allows greater airflow with reduced heat (as the air doesn't have to be compressed as much as with a smaller compressor). The smaller, lighter T3 exhaust side provides faster spoolup than a larger exhaust wheel would, such as on a regular T4.

how did your t3 get busted????

how did your t3 get busted????
Beat the hell out of me. I had driven up to Seattle on vacation, while I'm up there, I making a turn through an intersection and BANG. Had to limp it over to the nearby Ford dealer and had a turbo overnighted up to the dealership so they could replace it. Turned into a very expensive trip.

well if where not for your accident you would not have these pics for teaching people like myself the turbo stuff

well if where not for your accident you would not have these pics for teaching people like myself the turbo stuff
:iceslolan werd.

is any of it still good??

The housings, elbow, wastegate all are fine. It just needs new bearings/seals/wheels.

I have a question about oil lines how does that work with turbo??

Turbochargers oil supply is pressure fed and gravity drained.

now the oil is needed for the turbines right the reason why engines need oil same purpose???

Yep, lubrication and cooling, although the cooling property is lesser in a water cooled turbocharger.

when you say water do you mean antifreeze??

Yes, water cooled is just a term used for it.

how long do the bearings last??? would they wear out over time???

Watercooling is mainly used to cool the turbocharger after the engine is shut down when the oil stops to circulate.

The bearings in a turbocharger are usually hydrodynamic, that means that they are floating on a oil film so the wear on the bearings is low. However, if you don't service it properly, or regulary shuts down the car with a red hot turbo they and the piston ring seal in the turbocharger can take damage.

uh oh so how would you service it take it to pep boys or something??

Watercooling is mainly used to cool the turbocharger after the engine is shut down when the oil stops to circulate.
How is the water going to continue circulating if the engine is off and the water pump isn't spinning? :sly:

uh oh so how would you service it take it to pep boys or something??
Service = change the engine oil frequently.

How is the water going to continue circulating if the engine is off and the water pump isn't spinning? :sly:
Hot water and vapor goes up, cold water down. As long there is a temperature difference water will flow. Cold coolant is taken from a low place, in low in the turbocharger and out on a higher place like the cylinder head. The design of the cooling system and placement of the turbocharger is important if this shall work.

so in other words the turbo needs to be above the water pump???

so in other words the turbo needs to be above the water pump???
http://www.egarrett.com/about_garrett/faq.jsp