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Old 06-09-2021, 10:38 PM   #1
michav717
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Default Canít get rid of mysterious compressor surge. Twin scroll Efr7163 rotated

So I just finished my build and no matter what I do I canít seem to get rid of the compressor surge when I let off the throttle. I know it sounds really cool but Itís insanely loud and attracts way too much attention for a street car. I also have a buddy who has the same turbo setup and his doesnít surge. My tuner canít figure it out and heís one of the best out there. Iím making 530whp and 515tq on E85.
Iím trying to avoid going with a Bov on the piping since borg Warner designed this turbo to use the built in one.

Anyone have any idea what could be going on? Itís not the stock heads cause it does it at lower boost levels too. I just canít seem to get rid of the stututu. Lol

Here are some more details/mods about my car:

speed density tune
IAG Magnum short block
stock heads drilled out to 14mm
IAG TGV Deletes
ID 1300cc injectors with top feed conversion
Cosworth intake manifold (flipped)
Aeromotive a1000-6 fuel pressure regulator
Walbro 512 hellcat fuel pump (hardwired)
cobb 4 bar map sensor
cobb front mount intercooler with custom piping.
19mm phenolic spacers
Turbosmart Genv IWG75
IAG street AOS
Grimm speed lightweight crank pulley
cobb flex fuel kit
parallel fuel lines
Invidia Q300 exhaust
efr 7163 twin scroll full race kit
killer bee oil pickup
cyl 4 cooling mod
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Last edited by michav717; 06-09-2021 at 10:48 PM.
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Old 06-09-2021, 11:09 PM   #2
UltimatumPerformanc
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Quote:
Originally Posted by michav717 View Post
So I just finished my build and no matter what I do I canít seem to get rid of the compressor surge when I let off the throttle. I know it sounds really cool but Itís insanely loud and attracts way too much attention for a street car. I also have a buddy who has the same turbo setup and his doesnít surge. My tuner canít figure it out and heís one of the best out there. Iím making 530whp and 515tq on E85.
Iím trying to avoid going with a Bov on the piping since borg Warner designed this turbo to use the built in one.

Anyone have any idea what could be going on? Itís not the stock heads cause it does it at lower boost levels too. I just canít seem to get rid of the stututu. Lol

Here are some more details/mods about my car:

speed density tune
IAG Magnum short block
stock heads drilled out to 14mm
IAG TGV Deletes
ID 1300cc injectors with top feed conversion
Cosworth intake manifold (flipped)
Aeromotive a1000-6 fuel pressure regulator
Walbro 512 hellcat fuel pump (hardwired)
cobb 4 bar map sensor
cobb front mount intercooler with custom piping.
19mm phenolic spacers
Turbosmart Genv IWG75
IAG street AOS
Grimm speed lightweight crank pulley
cobb flex fuel kit
parallel fuel lines
Invidia Q300 exhaust
efr 7163 twin scroll full race kit
killer bee oil pickup
cyl 4 cooling mod
I do believe you have a internal issue with the bov spring if its a non vaccum system.
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Old 06-10-2021, 12:25 AM   #3
michav717
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The bov does have a vacuum line running to my intake manifold. Iím using the stiffer spring that they offer. I also today tried two other springs one a little lighter and one very light. I was still getting the compressor surge.
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Old 06-10-2021, 12:26 AM   #4
michav717
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I also completely put on a new replacement bov kit for the efr turbo.
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Old 06-10-2021, 03:27 AM   #5
alexmartynyuk
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Does it surge when letting off from full boost or just at lower boost or both?
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Old 06-10-2021, 12:07 PM   #6
michav717
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Both. If Iím in any sort of boost and I let go the throttle fully it will surge.
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Old 06-10-2021, 12:09 PM   #7
michav717
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Sometimes itís a little more snappy and shorter at full boost but a lot of the time itís the full stututu as well at full boost.
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Old 06-10-2021, 01:54 PM   #8
T-37
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Could it be a throttle body difference between yours and your friends? Throttle mapping, or cable vs DBW? Perhaps you need a softer throttle closing mapped in?

What is the pre turbo intake? Maybe just a quieter intake would solve it?

Edit: there are aftermarket BOV/BPVs designed to work with the BW housing as well, I believe Turbosmart and GFB both have them

https://gfb.com.au/products/blow-off...turbos-detail/

https://www.full-race.com/store/borg...-plumb-back-1/

Last edited by T-37; 06-10-2021 at 02:02 PM.
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Old 06-10-2021, 02:49 PM   #9
michav717
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Yea Iíve thought about using one of the aftermarket ones. Itís just that my bov now is already smushed up against my fender well. Guess its hammer time lmao
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Old 06-10-2021, 03:12 PM   #10
michav717
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I just talked to full race he says it might me my compressor housing? And that going to a bigger housing with a 3 inch inlet might help with the surge and going external bov. Does that make any sense to anyone?
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Old 06-10-2021, 04:27 PM   #11
Waddlz
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my 7163 has turbo flutter as well, and has for the 3 years I've ran it.

Even with the OEM BW BPV spring, and the Forge BPV I installed flutters.

I had a Tial BOV before I went to the BW recirc, and it fluttered as well and was much much louder with the 10 psi spring.
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Old 06-10-2021, 07:10 PM   #12
michav717
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I really need to figure this out cause it is a street car and you can hear the stututu within like a half mile radius And itís not the best ideas in Los Angeles to break literally everybodyís neck every time I shift with any boost. I had a dude scream at the top of his lungs the other day in the car next to me out of fear and probably the ringing in his ears lol.

Donít get me wrong tho if this was kosher around here I would love to keep it cause it sounds amazing

Last edited by michav717; 06-10-2021 at 07:24 PM.
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Old 06-10-2021, 08:54 PM   #13
Homemade WRX
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With how bad your making it out to be, and it seems that it only happens when you are coming off throttle (boost dump), I'd highly suspect the vacuum line has a pinch acting like a check valve and keeping the vacuum line pressurized.

If you're getting compressor surge with boost, then you're simply building too much pressure for the given mass flow (see surge line on compressor map). That is where the surge porting on the compressor housing comes into play, or the 'get a bigger compressor'. A lot of people run the 7163 on a 2.5, so I don't suspect this to be your issue. Shoot, guys run 6758's without issue.

Run a new vacuum line as a first check. Have you made sure the diaphragm/piston of the valve can move?
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Old 06-10-2021, 10:35 PM   #14
michav717
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I took the vacuum line and blew through it with my mouth and itís not obstructed at all to the manifold. Also Iíve completely replaced the bypass valve. I also made lighter springs and it still does it.

It is definitely closed throttle surge not the bad open throttle surge. So I
Know itís not the worst but I still canít really drive this on the street like this.
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Old 06-11-2021, 12:05 AM   #15
michav717
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If anyone wants to see the engine bay thereís pictures on my Instagram.
@loudfire_

Iím trying the turbo smart bpv tomorrow when I get it to see if it does anything..
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Old 06-11-2021, 12:18 PM   #16
Waddlz
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OP, just so I'm clear. are you talking about this noise?

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Old 06-12-2021, 02:07 AM   #17
alexmartynyuk
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Quote:
Originally Posted by T-37 View Post
Could it be a throttle body difference between yours and your friends? Throttle mapping, or cable vs DBW? Perhaps you need a softer throttle closing mapped in?

What is the pre turbo intake? Maybe just a quieter intake would solve it?

Edit: there are aftermarket BOV/BPVs designed to work with the BW housing as well, I believe Turbosmart and GFB both have them

https://gfb.com.au/products/blow-off...turbos-detail/

https://www.full-race.com/store/borg...-plumb-back-1/
Thats what i was trying to get at when i asked if it happens only when letting off after full boost or not.
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Old 06-13-2021, 04:20 AM   #18
michav717
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Quote:
Originally Posted by Waddlz View Post
OP, just so I'm clear. are you talking about this noise?

Efr 7163 Forge bpv flutter - YouTube
Yes, but about 10x louder when Iím on it. Like in the video the engine sounded louder than the surge. Where as my surge is about 3 times as loud as my exhaust.
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Old 06-13-2021, 04:22 AM   #19
michav717
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Originally Posted by alexmartynyuk View Post
Thats what i was trying to get at when i asked if it happens only when letting off after full boost or not.
So I got the turbo smart valve and itís even louder and happens at even lower boost levels now lol. It sounds even sicker but weíre going in the opposite direction lmao
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Old 06-13-2021, 10:39 AM   #20
alexmartynyuk
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Quote:
Originally Posted by michav717 View Post
So I got the turbo smart valve and itís even louder and happens at even lower boost levels now lol. It sounds even sicker but weíre going in the opposite direction lmao
What is your vacuum reading at idle and what spring is in the turbosmart?
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Old 06-16-2021, 07:47 PM   #21
michav717
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Quote:
Originally Posted by alexmartynyuk View Post
What is your vacuum reading at idle and what spring is in the turbosmart?
It is at about 19inHg at idle. In the turbosmart it is the factory stock orange/green spring.
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Old 06-17-2021, 01:30 PM   #22
Waddlz
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I dont see a problem then. Mad stustustu's is awesome.
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Old 06-18-2021, 12:55 PM   #23
michav717
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So is this how itís supposed to be?I just highly doubt that. I love the mad stututus I just donít want everyone whether youíre into cars or not look at me every time I shift gears in Los Angeles.
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Old 06-18-2021, 01:20 PM   #24
T-37
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You might need a quieter intake/airbox
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Old 06-19-2021, 02:25 AM   #25
michav717
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Quote:
Originally Posted by T-37 View Post
You might need a quieter intake/airbox
I wish it was that simple. Iím also on a speed density tune
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