zenoise

iTrader: (8)

When in fifth gear ONLY ON FULL THROTTLE in low rpms to medium rpm I am getting a very weird noise. Its like a quick "tsss" "tsss" tsss" noisebut very short and its repetitive until higher rpms. Its definetly an air noise, like an air release noise. Could it be my Wastegate acting up?? I dont get it if im going through gears from fourth to fifth in WOT. Only if im starting in fifth and going WOT from low rpms. I have
grimmspeed ebc
ETC intake
EVO 9 bov
other mods but shouldnt matter

I have no idea but it gets annoying and when it starts it seems like my knock sensor starts but that could be a phantom knock. I DONT KNOW

ANy help
thank youi

evoVIImoneypit

I personally don't know but could it be a boost leak?

adriano_917

iTrader: (14)

https://www.evolutionm.net/forums/04...er-please.html

Clessy

Its surge compression. If you dont fix this you're gonna kill your car. If you've got a adjustable bov like a greddy you might just be able to fix the surge by tighting up your bov.

Compression surge kills turbos and engines.

sho669

iTrader: (34)

Downshift

/thread

Ev0ikon

iTrader: (18)

Don't ever do that again!
Like previous guy said. Down shift. We could close this thread now.

zenoise

iTrader: (8)

Ok, thank u. I always lift or downshift when i hear it. But is there anyway or anything i can do to get rid of this???
I am planning on upgrading to and fp green or red this winter with some cams. Hoping that should fix it

zenoise

iTrader: (8)

I have an evo 9 bov on my evo 8. my setup is mostly stock besides intake and exhaust. I have a grimmspeed Ecu boost controller and a prosport boost gauge with an omni 4 map sensor.
So why would i have surge and what could i do to fix it???

Ev0ikon

iTrader: (18)

If you are not down-shifting the only other fix is to sell your car.
Adding larger turbo will only make it worse.
Is this your first turbo car?

dsmx17

Assuming larger will spool slower than current stock turbo, the problem will not get worse. Compressor surge = flow@given rpm VS VE of the engine itself, IE: if the stock turbo is trying to spool from low rpm in 5th gear, the load is great enough to do so....it just cannot be pumped through the engine at such a low rpm and backs up into the compressor wheel causing the flutter sound you mentioned.

Ev0ikon

iTrader: (18)

This is true in theory!
However, in my limited dealing with cars after upgrading to larger turbos I see this phenomenon more pronouced. I could not explain it even with increased VE after headworks and such.

zenoise

iTrader: (8)

Absolutely not. Ive owned plenty turbo cars.
Saab Turbo (highschool)
Eclipse GsT
Nissan 300zx Twin turbo
Present Evo 8

Ive never had this problem before, and only did I hear this when and after I installed my grimmspeed Boost controller and got my tune from 4wstuning. I Know enough to downshift or not to accelerate full throttle in fifth low rpm. But I was just asking if theres a way to fix this or upgrade something to fix it so it wouldnt happen anymore.
So some low mile cars( mine has 30k on it) just get compressor surge and then your engine is just screwed is what your saying???
If this is common with evos and the advice or thing to do is to downshift thats all i need to know.
I just Never had this with any other TURBO CAR I DID own. Even my problem having mess of a car 300zx twin turbo didnt have this issue.

But I love my Evo and will not sell it. Just wondered if there was a fix. But if the only thing to do is downshift ill just do that. Easy enough.

turbohaulic

I personally think its the Grimmspeed EBC. Search and Research this noise and you will find that everyone with the Grimmspeed EBC has this same problem\issue. I still havent really found out where the tsssssst tsssst tssssst noise is coming from but I believe one of the three ports on the EBC is not in use as if it was on say a Subaru (installation instructions) where all 3 ports are in use. I always figure its coming from port 1 and you can hear it releasing pressure to stop from over boosting?

That's just my take. Maybe someone has to ask someone at Grimmspeed why this noise is always present after installing their product and ARE WE LOOSING POWER BECAUSE OF IT?

I think the Evo 8 that I have is not using port 1 to release the air back into the intake. This may be the tssssssss tssssss tssssss sound we are hearing. I'm not a professional but reading what Grimmspeed has to say about installation and the sounds we are hearing may be the answer.
Know your car. Downshift as everyone says. You as I both know if I drive my car right I never hear this sound.

My question is... Who installed your Grimmspeed EBC and did they read the directions and tell you what it does?

Check this out. Installation directions from Grimmspeed. The 1st port on EVO 8 is not used. Is this the air bleeding from the unit to keep from overboosting? There are pictures that I did not post with this so look them up yourself.

B. Technical Background
A BCS is a binary device – i.e. it is either on (energized), or off. In the context of the Mitsubishi device, when the BCS is energized, air is allowed to pass through the device, while when it is off, the air flow is cut.
There are two modes of boost controller operation, at least in this context: “bleed” mode, which is the mode that the stock BCS operates in, and “interrupt” mode, which is the mode that a 3-port BCS can operate in. Note that a 3-port BCS can also operate in “bleed” mode, depending on how it is connected.
Despite being digital in nature, these devices perform a very analog-like task, which is to control the boost level. In order to do so, the ECU opens and closes the solenoid at varying speeds, from 0 Hz (closed) to (effectively) ∞ Hz (open).
C. 2-Port Operation (Stock) Review
The stock solenoid is part of the stock bleed-based boost control system. See figure 1. When the solenoid is off (closed), pressurized air from the compressor is fed straight into the wastegate control. Any increase in compressor pressure beyond the rated pressure of the wastegate control results in the wastegate being opened, preventing buildup of boost.
When energized (opened), air is allowed to bleed off the compressor-to-wastegate line by way of a “T” connector (in stock vehicles, this air is vented back into the intake post-MAF). This prevents the wastegate from seeing the full compressor pressure, allowing boost to build.
While the stock system operates adequately, it can lead to problems at higher-than-stock boost levels. Since the bleed system is sized for the stock turbo at stock boost levels, it is typically incapable of correctly metering air at higher boost, allowing the wastegate to see pressure and open before intended. Additionally, since the wastegate is never completely cut off from seeing compressor pressure, it can open at low boost levels and inhibit boost buildup. Ideally, the wastegate should remain entirely closed for fastest boost buildup (as all exhaust is then forced through the turbine).
Figure 2: Pneumatic schematic for the GrimmSpeed Boost Control Solenoid
D. 3-Port Operation and Installation
A 3-port solenoid does away with the bleed-based system, explicitly shunting air from the compressor to the wastegate, or compressor to vent (or back into the intake, OEM-style). Drawbacks of the bleed-based system are thus eliminated, with the wastegate seeing literally no pressure when the solenoid is energized, to seeing all of the compressor pressure when the solenoid is de-energized.
Now able to explicitly control the opening and closing of the wastegate, the ECU is able to control boost with greater precision and reduced response time.
Installation for EVO 8 and 9:

1. Remove factory airbox. Locate boost control solenoid on driver side frame rail. Unbolt factory solenoid. Unplug the electrical connector and vacuum lines.
2. Install GrimmSpeed bracket and solenoid while reusing the factory bolt.

3. Hook up vacuum lines. See Figure 2. Port 3 connects to a high pressure boost source (there is a vacuum nipple on the turbo compressor outlet). Port 2 connects to the internal wastegate actuator vacuum nipple and Port 1 should be routed back to the intake (where the factory BCS mounts). It is recommended that a plastic zip tie is used to secure vacuum lines. The electrical is plug and play with the supplied connector. Tuning: WGDC controls the actuator / turbo. Tuning to the WGDC is required (approx 30% reduction in WGDC)


Installation for EVO X:

1. Locate BCS bracket just below the brake master cylinder. Unplug the electrical connectors and vacuum lines. Unbolt factory solenoid bracket. There are two bolts that hold the bracket down. See picture.

2. Remove both factory solenoids from bracket. Reinstall factory solenoid with the black connector on the bottom of the bracket. You will not be reinstalling the factory solenoid with the brown connector. Install GrimmSpeed bracket and solenoid above this solenoid using supplied hardware. See picture.

3. Connect electrical connectors. The GrimmSpeed BCS utilizes the plug that the factory solenoid with the brown connector used. You must connect the black solenoid back to oem solenoid to avoid a check engine light although no vacuum lines will be connected to it.

4. Hook up vacuum lines to the GrimmSpeed BCS. You will be removing the 2 factory vacuum tees. See Figure 2. Port 3 connects to a high pressure boost source (there is a vacuum nipple on the turbo compressor outlet). Port 2 connects to the internal wastegate actuator vacuum nipple and Port 1 should be routed back to the intake (where the factory BCS mounts). It is recommended that a plastic zip tie is used to secure vacuum lines. The electrical is plug and play with the supplied connector. Tuning: WGDC controls the actuator / turbo. Tuning to the WGDC is required (approx 30% reduction in WGDC)

E. External Wastegate(EWG) Installation
Hook up vacuum lines. See Figure 3. Port 3 connects to a high-pressure boost source (there is a vacuum nipple on the turbo compressor outlet). Port 2 connects to the bottom port on the external wastegate. The factory restrictor pill should be removed for operation. It is recommended that a plastic zip tie is used to secure vacuum lines. The electrical is plug and play with the supplied connector.

Figure 3. Pneumatic schematic for the GrimmSpeed Boost Control Solenoid with EWG

Subaru:
Port 1 connects to a high-pressure boost source (there is a vacuum nipple on the turbo compressor outlet) and the bottom port on the external wastegate, you will need to use the factory “T” to connect . Port 2 connects to the top port on the external wastegate. The factory restrictor pill should be removed for operation. It is recommended that a plastic zip tie is used to secure vacuum lines. The electrical is plug and play with the supplied connector.

Ev0ikon

iTrader: (18)

Excellent post turboholic!
I have a Grimmspeed unit and I will put this to a test when I have some free time this week.

zenoise

iTrader: (8)

So what i dont understand is that in the installation for an evo 8 it sayz all 3 ports are used but ur saying only 2getting ports or used??
Another point is that is in tuning 30%he decrease needs to be made to the wastegate. Maybr my tuner didnt do this?
In the end im guessing i should just call grimmspreed and ask them a crap ton of questions.
i always was skeptical in thinking this was compressor surge as this only happened directly after my ebc install and tune.