Wastegate Explained.

[turbolover]

Yup if not turbo engine don't need la.Not enough air anyway.Just like never eat how to fart or burp!
bbbbuuuuurrrrrpppp!

 

[Mivec559]

Bro, no offence but I respect your 'foreman' friend for giving you that answer....
I wonder which workshop hired him hehehe.....

And no, you don't need them. You won't even have to think of it... :)
(until you turbocharge your engine of course...)

hahas..ur answers is includes the turbo or without the turbo?? :hmmmm:
i need d answer in without the turbo lo..
but nvm that..anyways.. cheers :proud:

Yup if not turbo engine don't need la.Not enough air anyway.Just like never eat how to fart or burp!
bbbbuuuuurrrrrpppp!

thx for the info pal..

 

[speed2horizon]

hahas..ur answers is includes the turbo or without the turbo?? :hmmmm:
i need d answer in without the turbo lo..
but nvm that..anyways.. cheers :proud:





thx for the info pal..

Ok, make it this way. MIVEC, VTEC, VVTI etc anything to do with Valve/lift variability is just a cam system.... Only Force induction can create positive pressure for BOV to blow off

 

[yashiofactory]

Yeah turbolover ur r right.......anyway speed2horizon ur car really powerfull nowdays hah....heheheheh....i heard from my paparazi :wavey:

 

[speed2horizon]

Yeah turbolover ur r right.......anyway speed2horizon ur car really powerfull nowdays hah....heheheheh....i heard from my paparazi :wavey:

Aiks!!!! Sure boh...?? Ok lar, for daily driving... Just nice for time being... But long time neva see bro... Apamacam..? Everyything ok..?

 

[teo1957]

Hi sifus,

Now let us differentiate BOV's, diverter and bypass valves. First, a blow off valve (seen top right) is common to high performance applications in that it provides the least bit of compromise. A BOV essentially releases this pressure straight out into the atmosphere. Quite often you will find that these units take on particular shapes, making them resemble musical instruments. I guess some people out there really like to flaunt their gadgets. Just wait ti'll you see how much they impress the ol' 5-0. Aside from this legal dilemma, the second problem you encounter with BOV's is that the mass air flow sensor will cause the engine management system to "think" that the air will go into the engine and in turn will release an appropriate amount of fuel for it. However, a BOV system will vent this air out before it gets to the injectors causing your mixture to run lean. In turn, this will result in unburned fuel to escape into the exhaust system. This is why you often see flames and hear those "pop's" in rally cars. It is unburned fuel exploding in the exhaust system. Doesn't take a genius to figure out that this is not the smartest application for the day to day car. For this reason, reasonable tuners will usually employ a bypass or a diverter valve (see left). These units essentially redirect this pressure back behind the compressor causing the net flow of air to remain constant. This in turn slows the turbine down gradually and allows the air flow sensor to work appropriately.

http://www.streetracersonline.com/articles/turbo/bov.php

1. Mitsubishi turbo engines such as the 6A12 from the Galant Eterna and the 4G63 from the Evos use Karman Vortex AFM.

2. Does this mean that it is better for Mitsubishi engines with Karman Vortex AFM to use diverter/dump valves/bypass valves, rather than blow off valves?

3. Diverter/dump valves/bypass valves are not common in Malaysia (or at least for me). Where can I get it installed?

 

[jinkl]

Hi sifus,



1. Mitsubishi turbo engines such as the 6A12 from the Galant Eterna and the 4G63 from the Evos use Karman Vortex AFM.

2. Does this mean that it is better for Mitsubishi engines with Karman Vortex AFM to use diverter/dump valves/bypass valves, rather than blow off valves?

3. Diverter/dump valves/bypass valves are not common in Malaysia (or at least for me). Where can I get it installed?

yes , its recommended to fit in a reroute kit , SSQV has a reroute kit , greddy type-s standard can be used as well as greddy type-r and type-rs but addition adapters needed

 

[teo1957]

yes , its recommended to fit in a reroute kit , SSQV has a reroute kit , greddy type-s standard can be used as well as greddy type-r and type-rs but addition adapters needed

1. Thanks for the prompt reply bro.

2. Now I have a question that's been bugging me: Karman Vortex AFM reads air intake before the amount of air is fed into the compressor. Say the reading for the amount of air is A.

3. The ECU then will assign the approriate amount of fuel for the A (the amount of air). Say the reading for the amount of fuel is F.

4. A + F = optimal air and fuel mixture (as determined by the ECU).

5. However, the BOV releases excess amount of air into the atmosphere. This causes the amount of air fed into the compressor, to be less than A. Say the reduced amount of air now is A2, and the excess amount of air released by the BOV is B.

6. A - B = A2, A2 < A.

7. A2 + F = less air, more fuel (too rich)?

8. Now if we use the rerouting kit, or the diverter/dump valve/bypass valve, the excess amount of air will be redirected to the hose before the compressor. Does this mean that the amount of air, that will be fed into the compressor, will turn from A2 to become A again?

9. B + A2 = A?

10. Does this mean that the effect of using the rerouting kit, or the diverter/dump valve/bypass valve, is the same as not using a BOV at all?

 

[speed2horizon]

1. Thanks for the prompt reply bro.

2. Now I have a question that's been bugging me: Karman Vortex AFM reads air intake before the amount of air is fed into the compressor. Say the reading for the amount of air is A.

3. The ECU then will assign the approriate amount of fuel for the A (the amount of air). Say the reading for the amount of fuel is F.

4. A + F = optimal air and fuel mixture (as determined by the ECU).

5. However, the BOV releases excess amount of air into the atmosphere. This causes the amount of air fed into the compressor, to be less than A. Say the reduced amount of air now is A2, and the excess amount of air released by the BOV is B.

6. A - B = A2, A2 < A.

7. A2 + F = less air, more fuel (too rich)?

TOO RICH

8. Now if we use the rerouting kit, or the diverter/dump valve/bypass valve, the excess amount of air will be redirected to the hose before the compressor. Does this mean that the amount of air, that will be fed into the compressor, will turn from A2 to become A again?

YEAH... SOMETHING LIKE THAT...

9. B + A2 = A?

YES...

10. Does this mean that the effect of using the rerouting kit, or the diverter/dump valve/bypass valve, is the same as not using a BOV at all?[

If U ARE looking at IT IN TERMS OF TOTAL AIR VOLUME, THEN YES...

WELL, MITSUBISHI OR MOST OF THE TURBO ENGINE THAT USES MAF, IS BUILT IN WITH A PLASTIC BYPASS VALVE. HOWEVER, THE BYPASS VALVE DOESN:T LAST AND LEAKS MOST OF THE TIME. So, AN AFTERMARKET BYPASS VALVE OR REROUTED BOV IS JUST A REPLACEMENT OF THE STOCK BYPASS.

WELL, OF COURSE WHEN U REROUTE, IT DOESN;T SOUND THAT LOUD ANYMORE. OR MAYBE U WON;T EVEN HEAR IT.

AND I DUN QUITE UNDERSTAND WITH UR "NOT USING BOV AT ALL" STATEMENT. U STILL NEED A BOV OR BOV TO REPLEASE THE PRESSURE FROM THE INTERCOOLER PIPING WHEN THE THROTTLE CLOSES, IT'S EITHER TO THE ATMOSPHERE OR BACK TO THE SYSTEM TO PREVENT TURBO SURGE

/B]

happy boosting

 

[teo1957]

10. Does this mean that the effect of using the rerouting kit, or the diverter/dump valve/bypass valve, is the same as not using a BOV at all?

If U ARE looking at IT IN TERMS OF TOTAL AIR VOLUME, THEN YES...

WELL, MITSUBISHI OR MOST OF THE TURBO ENGINE THAT USES MAF, IS BUILT IN WITH A PLASTIC BYPASS VALVE. HOWEVER, THE BYPASS VALVE DOESN:T LAST AND LEAKS MOST OF THE TIME. So, AN AFTERMARKET BYPASS VALVE OR REROUTED BOV IS JUST A REPLACEMENT OF THE STOCK BYPASS.

Totally agree bro, the use of the stock bypass valve is to ensure the total volume of air is the same as what was calculated by the AFM.

Now the next question.

The stock bypass valve (or 'blow-in' valve as many people call it) channels air from the piping in-between AFM-compressor to the piping in-between I/C-throttle body.

Now, the air in-between AFM-compressor is uncompressed.

The air in-between I/C-throttle body however, is compressed.

Why channel uncompressed air to a piping full of compressed air? Doesn't that defeat the purpose of having a turbo?

 

[jinkl]

Totally agree bro, the use of the stock bypass valve is to ensure the total volume of air is the same as what was calculated by the AFM.

Now the next question.

The stock bypass valve (or 'blow-in' valve as many people call it) channels air from the piping in-between AFM-compressor to the piping in-between I/C-throttle body.

Now, the air in-between AFM-compressor is uncompressed.

The air in-between I/C-throttle body however, is compressed.

Why channel uncompressed air to a piping full of compressed air? Doesn't that defeat the purpose of having a turbo?

when u let go ur throthle, ur throthle plate closes , ur boost goes to vacuum, the excess air needs to be vented out to atmo or reroute back to compressor inlet, if you do not let the air out, where can it go ? u have already closed ur throthle plate , hehe

thts the reason u need a blow off or bypass valve
diffrence between stock bypass valve and greddy or etc is that
the aftermarket ones hold more higher boost
stock plastic ones will start leaking out above 0.8~bar

 

[teo1957]

when u let go ur throthle, ur throthle plate closes , ur boost goes to vacuum, the excess air needs to be vented out to atmo or reroute back to compressor inlet, if you do not let the air out, where can it go ? u have already closed ur throthle plate , hehe

That's what I read in Wikipedia too.

Now the problem with Evos is, the Wiki theory doesn't seem to apply:
1. Wiki says BOV sits in-between the throttle plate and the turbine? Where's the intercooler and the compressor?
2. In Evos, the stock bypass valve sits in-between the AFM, and the compressor.

Now, if the purpose of the BOV is to take care of the compressor fin, shouldn't it be placed somewhere near the compressor fin?

If we put the BOV after the compressor, and before the I/C, there's no throttle plate there. The throttle plate is placed after the I/C.

If we put the BOV before the compressor, and after the AFM, there's no compressed air at all.

Bump:

Image from Garrett.

1. Stock bypass valve is placed at 1. There's no compressed air there.
2. Stock bypass valve reroutes uncompressed air to 4, which contains compressed air.
3. If we place BOV at 2 (near compressor fin, contains compressed air), there's no throttle plate there.

 

[jinkl]

That's what I read in Wikipedia too.

Now the problem with Evos is, the Wiki theory doesn't seem to apply:
1. Wiki says BOV sits in-between the throttle plate and the turbine? Where's the intercooler and the compressor?
2. In Evos, the stock bypass valve sits in-between the AFM, and the compressor.

Now, if the purpose of the BOV is to take care of the compressor fin, shouldn't it be placed somewhere near the compressor fin?

If we put the BOV after the compressor, and before the I/C, there's no throttle plate there. The throttle plate is placed after the I/C.

If we put the BOV before the compressor, and after the AFM, there's no compressed air at all.

Bump:

Image from Garrett.

1. Stock bypass valve is placed at 1. There's no compressed air there.
2. Stock bypass valve reroutes uncompressed air to 4, which contains compressed air.
3. If we place BOV at 2 (near compressor fin, contains compressed air), there's no throttle plate there.

nah, u got it wrong
BOV and also bypassvalve sits in the same place , before TB, after Intercooler/Turbo compressor
even in the evo's , it sits in between TB and Intercooler/Turbo Compressor

ur picture below, u can place ur BOV anywhere between 2 and 4, u can even weld it on ur intercooler

 

[teo1957]

nah, u got it wrong
BOV and also bypassvalve sits in the same place , before TB, after Intercooler/Turbo compressor
even in the evo's , it sits in between TB and Intercooler/Turbo Compressor

ur picture below, u can place ur BOV anywhere between 2 and 4, u can even weld it on ur intercooler

1. Evo 7 bypass valve sits between TB and I/C;
2. Evo 1 bypass valve sits between AFM and compressor (see attached pic).

Now Garrett states that 'BOV should be installed between the compressor discharge and the throttle body, preferably downstream of the charge air cooler (if equipped)'. This statement completely contradicts Mitsubishi's action of placing bypass valve between AFM-compressor in the earlier Evos.

Garrett doesn't sell BOVs.

 

[jinkl]

1. Evo 7 bypass valve sits between TB and I/C;
2. Evo 1 bypass valve sits between AFM and compressor (see attached pic).

Now Garrett states that 'BOV should be installed between the compressor discharge and the throttle body, preferably downstream of the charge air cooler (if equipped)'. This statement completely contradicts Mitsubishi's action of placing bypass valve between AFM-compressor in the earlier Evos.

Garrett doesn't sell BOVs.

no laa brooo, adui
if u see ur picture properly, the bottom of the bypass valve connects to the intercooler piping
the top part where air comes out from the bypassvalve is rerouted back to turbo compressor inlet

nah hw a stock bypass looks like, the bottom part goes to intercooler piping, sideways one goes to AFM, thts wht we call "re-reroute"

this is a picture if the bypassvalve is replaced with a greddy

Bump: nah attached a evo , it also connects it outlet of the valve to AFM, same as older evo
garrett is correct :D