external wastegate before and after tuning

SoflaSTI · Jan 13, 2009

neverendingmods said:
It's normal. Mine does it too. Did it more so on stock turbo in 4-6th gear. 3 tuners have tuned my car with same wastegate and it always sounds the same. It is normal. It is the sound of rapid open/closing to give a steady boost.

yup thats exactly how it was explain to me. Thanks for all the help guys. Thats why i come here. Im sure this information will be helpful for anyone else to.
Best regards
-Roman

flatthump · Jan 13, 2009

That's what you get with an EBC.

WolfPlayer · Jan 13, 2009

I am self tuned and have tuned mine to do the same thing. It is caused by boost coming on very quickly and very strongly - and the wastegate constantly adjusting (EBC) and fighting against the huge rise in preturbo exhaust pressure. Thus, it will happen the most in the higher gears because you can build boost stupid quick. This is easily stopped (or curtailed) by tuning for a slower spool. Additionally, higher AVCS settings appear to increase this phenomena because you are feeding so much air through the motor and against that wastegate (on a WOT spool).

A lot of tuners will fight me on this by saying - "no man, it is caused by having WGDCs that are too high for the target boost setting". To a degree, I agree. That being said, we do not have per gear WGDC compensation. Thus, it's all a balance. I tuned my car for optimum performance in 3rd/4th. Thus, 5th and 6th are going to require less WGDC. The ECU tries to use the specified WGDC that I tuned for 3rd/4th and, therefore, it will overshoot the boost target and flutter away. I am ok with that, because I use WOT in 3rd and 4th more often.

Long story short: Fast spool + increased load (higher gears) + more aggressive AVCS + crappy VF39 IWG and actuator + no per gear WGDC compensation + tuned for lower gears (4th) = easy flutter.

Clear as mud?

If not, let me make it muddier

The ECU also has turbo dynamics that increase the amount at which WGDC is applied or taken away. This can also attribute issues to the flutter. But, again, it is about balance. We really need per gear compensations in our cars.

t

SoflaSTI · Jan 13, 2009

WolfPlayer said:
I am self tuned and have tuned mine to do the same thing. It is caused by boost coming on very quickly and very strongly - and the wastegate constantly adjusting (EBC) and fighting against the huge rise in preturbo exhaust pressure. Thus, it will happen the most in the higher gears because you can build boost stupid quick. This is easily stopped (or curtailed) by tuning for a slower spool. Additionally, higher AVCS settings appear to increase this phenomena because you are feeding so much air through the motor and against that wastegate (on a WOT spool).

A lot of tuners will fight me on this by saying - "no man, it is caused by having WGDCs that are too high for the target boost setting". To a degree, I agree. That being said, we do not have per gear WGDC compensation. Thus, it's all a balance. I tuned my car for optimum performance in 3rd/4th. Thus, 5th and 6th are going to require less WGDC. The ECU tries to use the specified WGDC that I tuned for 3rd/4th and, therefore, it will overshoot the boost target and flutter away. I am ok with that, because I use WOT in 3rd and 4th more often.

Long story short: Fast spool + increased load (higher gears) + more aggressive AVCS + crappy VF39 IWG and actuator + no per gear WGDC compensation + tuned for lower gears (4th) = easy flutter.

Clear as mud?

If not, let me make it muddier The ECU also has turbo dynamics that increase the amount at which WGDC is applied or taken away. This can also attribute issues to the flutter. But, again, it is about balance. We really need per gear compensations in our cars.

t

did i ever mention your a extremely intelligent man??
Thanks bro :tup: that will clear up a lot of questions.

lacrosseks29 · Jan 15, 2009

WolfPlayer said:
I am self tuned and have tuned mine to do the same thing. It is caused by boost coming on very quickly and very strongly - and the wastegate constantly adjusting (EBC) and fighting against the huge rise in preturbo exhaust pressure. Thus, it will happen the most in the higher gears because you can build boost stupid quick. This is easily stopped (or curtailed) by tuning for a slower spool. Additionally, higher AVCS settings appear to increase this phenomena because you are feeding so much air through the motor and against that wastegate (on a WOT spool).

A lot of tuners will fight me on this by saying - "no man, it is caused by having WGDCs that are too high for the target boost setting". To a degree, I agree. That being said, we do not have per gear WGDC compensation. Thus, it's all a balance. I tuned my car for optimum performance in 3rd/4th. Thus, 5th and 6th are going to require less WGDC. The ECU tries to use the specified WGDC that I tuned for 3rd/4th and, therefore, it will overshoot the boost target and flutter away. I am ok with that, because I use WOT in 3rd and 4th more often.

Long story short: Fast spool + increased load (higher gears) + more aggressive AVCS + crappy VF39 IWG and actuator + no per gear WGDC compensation + tuned for lower gears (4th) = easy flutter.

Clear as mud?

If not, let me make it muddier The ECU also has turbo dynamics that increase the amount at which WGDC is applied or taken away. This can also attribute issues to the flutter. But, again, it is about balance. We really need per gear compensations in our cars.

t

so does that so called, "Flutter hurt your car or turbo in anyway?"

neverendingmods · Jan 15, 2009

lacrosseks29 said:
so does that so called, "Flutter hurt your car or turbo in anyway?"

No, it is helping not overshoot target boost. Over shooting target boost is bad for the car.

evil06sti · Jan 17, 2009

mine is doing the same thing........ but i know mine is also doing it cause of the super lite spring in my synapse 50mm.....

LittleBlueGT · Jan 17, 2009

Wolfman is right.

The sound of the flutter is actually the result of the boost overshooting the target by a small amount.

In all reality you should post up a log so that we can be sure that you are not overboosting by too much.

CharlesC · Jan 17, 2009

The EWG in my car. Idk if that will help or not

SoflaSTI · Jan 17, 2009

CharlesC said:
The EWG in my car. Idk if that will help or not

hey boss mine sounds just like that man.

my boost setup btw is
forge bpv
prodrive ebcs
ewg 44mm .9lb spring

flatthump · Jan 17, 2009

What is your boost target and when exactly do you first hear the EWG open in relation to your boost level?

SoflaSTI · Jan 18, 2009

22psi tapers to 18psi. Holds boost like a mofo, turner said the ewg is prolly one of the best setups on the sti compared to its internal design. Anyway, im sure its has the same ups in other cars asell.

strider327 · Nov 10, 2009

I know this thread was created long ago, however I wanted to share my experience with my external wastegate. When I first had my external wastegate setup I was on a manual boost controller tuned at EQ Tuning. The response was very fast and the wastegate was very consistant and opened quickly and strong...no fluttering or anything out of the ordinary. However when I got retuned and installed a 3 port boost solenoid, I started getting the fluttering at very low to partial throttle but at full throttle no flutter. Hope this helps.

external wastegate before and after tuning

SoflaSTI

flatthump

WolfPlayer

SoflaSTI

lacrosseks29

neverendingmods

evil06sti

LittleBlueGT

CharlesC

SoflaSTI

flatthump

SoflaSTI

strider327

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