Compressor Surge at 20-23psi WOT

[SolidBoostTSi]

Alright, I think it's my turn to ask for help....
profile is current and up to date,

I was doing some 3rd gear pulls @ 20psi and things were fine...
then, after things got situated I turned it up a little more and it feels like I hit the surge limit of the turbo. It oscillates from 20-23 psi and i can't make a clean pull.
the turbo is an Internally gated SCM6152SP "surgeported" but the damn thing is surging...
It never did this with my SCM50 so it concerns me
1st gear, ok
2nd gear, ok
3rd geear, not so ok

any help would be great especially from experienced DSM'ers !

 

[CanadianTSi]

If it is true Compressor surge then you can either slow the spool or increase the VE of your motor.

If you have an EBC try playing with the gain to slow spool slightly.

 

[andymoraitis]

In addition to what Tyler mentioned, I would contact PTE and see what they have to say since I'd hate to slow the spool on a large turbo to fix a surge issue. I wonder if perhaps and E cover wouldn't help although that may play hell with your IAT's.

 

[SolidBoostTSi]

this is probably my fault, but did I mention I had the Surge ported S cover? From what I understand, Surging at WOT occurs when the VE is Exceeded? - I beg to differ.... like the Flow rate of the Turbo is higher than the ability of the engine to ingest A/F. As far as raising volumetric efficiency, I don't know what else to do? I'm out of ideas...

 

[CanadianTSi]

Yes, the Turbo is trying to shove more air into the motor than it can handle so the air is backing up and slamming into the compressor wheel.

 

[Reese92tsi]

If you have adjustable cam gears you could try adjusting them, or maybe you could switch to a bigger turbine housing.

 

[andymoraitis]

If you have adjustable cam gears you could try adjusting them, or maybe you could switch to a bigger turbine housing.

There is no larger cover for that setup than the S with surge ports.

 

[Reese92tsi]

I said turbine housing. He could get an adapter plate and run a larger t3 turbine housing. It would lag more but it would help his surge issues and make more power.

 

[oldman]

I said turbine housing. He could get an adapter plate and run a larger t3 turbine housing. It would lag more but it would help his surge issues and make more power.

I agree, most compressor surge occurs when a "too efficient" turbo is paired up with a "too small/inefficient" "bolt on housing".

 

[SolidBoostTSi]

as arrogant and much of a candy ass as I am, It does make sense after oldman explained it. Another anomoly* happens to be that the surging went away....? I was making some pulls this wonderfull christmas eve and barely any surging. Could it be a fluke? or because it was cold out last night and this morning I managed to pull 24psi cleanly. But here's another problem I'm pegged at 10.0 A/F from 3200 - 7000K rpm. I know it's better too rich than too lean but at the AFC Hi settings set at -7 throughout 3.2K - 7.0K it kinda worries me, I'm still on 780's and I'm probably gonnat hit over 90% injector duty cycle soon. sigh.......

 

[oldman]

Well I do see serveral problems with your setup after reading your profile which can account for your rich conditions.

1. FPR overrun.

2. 780cc compensated via piggy back systems.

 

[andymoraitis]

I said turbine housing. He could get an adapter plate and run a larger t3 turbine housing. It would lag more but it would help his surge issues and make more power.

My bad. Sorry about that.

 

[CanadianTSi]

2. 780cc compensated via piggy back systems.

He has a Chip...

Keep leaning it out until you get to 11.0:1

 

[biglady112]

My E cover SCM6176 surges horribly at 18-28psi. This is at 6000ft above sea level though. My motor is all stock. From the non-turbo throttle body, 1G intake, 2G head and 6 bolt bottom end. But, the moment I hit 30psi in my mirage, it magically disappeared. Now I am living life at 36psi and no hint of surge what so ever. But, I am only flowing 53lbs/min. The altitude is hurting me a lot, as well as my stock setup. But, 53lbs/min up here is a big deal. At least on my little turbo. Maybe turn the boost up a little more, it helped me. Mine I know for a fact is from surpassing my VE.

Steven

 

[GVR4592]

You should just put that in your signature, it would be one less sentence to type every time you post.

 

[biglady112]

Was that to me Luke?

Steven

 

[91-gsx]

I have a stock engine, no cams and no smim. I will be putting a turbonetics t3 manifold on it along with a .63 a/r sc6152 with the SP cover(ported 4"). Should I be concerned about surge with this setup? Damn this thread has me worried now....
later

 

[94Jettameowpsst]

Not hijacking this thread but what does surging feel like? I just turned the boost up on my massive evo 3 from 19 to about 26-27 via boost gauge and it pulls HARD *on pump btw* no knock, but it bucks at higher rpm sometimes when im full throttle, its not a significant buck like fuel cut, but it does buck indeed.

 

[CanadianTSi]

Its a bucking accompanied by a like chh-chhh-chh sound or something there abouts.

 

[94Jettameowpsst]

Yep, im surging. I wasnt sure what it was but it makes the car run like poop.
I ran a 35 r on my old 1g with no problems like this, but then again i had a acufab tb, ported head, cams etc....im rockin a 2g now with stock head, tb, cams, and intake mani. Looks like i have an excuse to upgrade some things or atleast put my cams in

Btw, thanks for the imput!