SR20 surging issues bugging the Eff out of me

[lilnev11]

To no helpful prevail I did try the search bar but couldn't find any one with similar problems as me.

So, I just traded my bike for an s14 with a blacktop SR. I'm kinda familiar with boost but by no means any kind of expert. here goes it. It will surge pretty often if I'm in the range of -10in to about 3-4psi I snap off the throttle I'll get some hefty surging. The TurboXS BOV that's on it right now will wiggle on the flange but still blows off as it should. I don't think there's any kind of leaks all though the signs are there. It'll idle between 1200-1600 after warming up. builds boost fine all the way up to 12psi. I tried spraying brake clean at any possible leak points & had no change in the idle. What im most confused by is why it's surging under vacuum.

[blkvrtswp]

What exactly is your definition of "surge"? 1200rpm is too high for an idle unless you have cams or some reason to be so high. Should be 750-800.

[lilnev11]

I don't know why my idle's so high I was figuring that could be playing a factor. compressor surge or the bark. chakukukuk when throttle plate shuts & boost isn't vented. I softened the spring a bit but that doesn't answer my question as to the vacuum.

I've come to you guys for help. Yes i'm new to the site. Please keep the bashing to a minimum hahaha I just want my car to run right & ive read on previous post some guys on here can be pretty ruthless.

[blkvrtswp]

Some BOVs make the chuka chuka sound, try tightening the spring too. The sound may change. Watch some youtube videos of other SRs to see what they sound like.

On a stock SR turbo with a BOV, "compressor surge" is nothing to be concerned about. Just make sure your BOV is actually working and the vac line is connected to the correct place and enjoy the noises!

[lilnev11]

Some BOVs make the chuka chuka sound, try tightening the spring too. The sound may change. Watch some youtube videos of other SRs to see what they sound like.

On a stock SR turbo with a BOV, "compressor surge" is nothing to be concerned about. Just make sure your BOV is actually working and the vac line is connected to the correct place and enjoy the noises!



I've tried tightening & loosening the spring tonight. Not much change. I'm 100% it's surge cause I can snap the throttle from under the hood and hear it straight from the turbo. There also seems to be a bit of delay between closing throttle and the bov relieving pressure. But would that still relate my problems under vacuum?

[lilnev11]

& I've heard that go both ways. Some say the surging doesn't effect the turbo some say its detrimental. Personally I think stopping a ball bearing turbo mid free spin isn't good. And yes it is a t28r

[JF_OverBoosted]

Is it adjustable? If it is try loosening it.
if not possibly just a bad BOV?
goodluck!

[RedtopTech]

double check the vacuum diagram. make sure youre on the correct tb nipple

[ultimateirving]

It's the iacv. Take off ur manifold and remove the iacv. Clean it thoroughly. And reset the idle properly

[DJ 21o3]

Check the vacuum lines first. That was the issue my car had but it is now fixed. It blows off fine with enough boost but under 5psi, i still get surge.

[Drifter_85]

I'm having the same problem. The setup on my car didn't even have a bov so I installed one. If the spring is loose it works perfect but after the engine warms up it will fluctuate but if I tighten the spring idle goes back to normal but with it tight it will surge at low boost or even no boost and at a little higher boost it will surge for a second before the bov opens but on full boost no surge at all. I kinda like it so I don't worry about it

[Ka-t in progress]

Where is your bov mounted? After the maf or before?

[Drifter_85]

My maf is on the intake to the turbo. In stock location

[Ka-t in progress]

But where is your bov mounted at? Is it after the maf or before it. Trying to see if it is a recirc set up or draw thru

[cotbu]

Clueless much? If the bov fluctuates, there's a vacuum leak, this could even be seen in the tachometer. Although the vacuum fluxing at idle and rpm bouncing could be from cts, etc. So you have to eliminate things, Do a vacuum boost leak test, pull codes, check timing etc. Recirculating the bov will hide this issue, but won't cause big issues, if you allow the controlled leak to occur. Unless the leak is big or fluctuation is caused by cts, a faulty cts, can fail on its own either sensing overcool, or overheat. Wiring or even be disconnected. This post could get long just describing the possible symptoms, so ill stop.
Do you have iacv coolant lines hooked up?
It could be numerous things, goodluck though

Sent from my Highly Tune Galaxy S3.4!!!

[steve shadows]

I suggest checking timing with a timing light before anything else. If timing is off it will feel like there is little power then a lot all of a sudden when there shouldn't be any lag etc.