R33 Feels Very Slow Lately

[KLA33E]

Hi all! As topic reads I am an owner of a 95' Skyline R33 Gtst. Bought it 'bout a year ago, was and still is fairly stock. mods so far is:
* 3' turboback exaust
* Greddy profec b boost controller
* apexi filter

Also changed the coilpacks and plugs not too long ago.

So anyway to my problem. Always since i bought the car it has had the famous flutter sound (off throttle) which bothered me some, and the old owner had the Ebc set at 1bar
(14.5 psi) in high mode which I know is to much for the stock turbo to handle.
Experienced what I Belive was R&R at a point when the Ebc was set to only 0.75bar. (11 psi)
Been driving with the Ebc controller off for some time now, no more retarded timing. So with the controller switched off I get 0.64-0.67 bar.
(9.5 psi)

I decided to inspect the BOV to see if I could find the cause of the flutter, suspected it would be blocked, I was right. There was a metal plate in the shape of the gasket in between with some red goo around. Removed it and replaced with a new gasket and went for a drive, now the BOV opens and air gets released, though I could hear a high pitch whistle sound around 2500 rpm with 1/3 throttle applied. Boost still went to 0.64 bar.

Now more recently though the car feels really slow when I go full throttle it's holding back, like I was towing somebody kind of that feel. It dosen't missfire or anything just dosen't have that punchy acceleration anymore, but when cruising on the motorway
and I give it some gas in higher gears it pulls fairly good but boost only goes strong up to 0.44-0.46 bar. I can push it so it reaches 0.52 but thats not until 6000+rpm!

Can it be a boost leak? or clutch maybye?

Any advice would be much appreciated!

Cheers!

Edited July 26, 2015 by KLA33E

[Nanogrip]

Good thing you removed that metal plate blocking your BOV. For your issue, it could be your boost solenoid not opening (you have EBC), BOV leaking, leaking somewhere. Or maybe you were used to having your car with higher boost, and now it is in a normal range.

[tridentt150v]

Did u set the plug gap to 0.8???, at 14 psi the spark would be struggling at bigger gaps. But prob not so much at 10psi.

Also wondering if your BOV is partially stuck open?

[KLA33E]

Did u set the plug gap to 0.8???, at 14 psi the spark would be struggling at bigger gaps. But prob not so much at 10psi.

Also wondering if your BOV is partially stuck open?

Hello! Yes the plug gap is actually 0.7mm, they regap them from factory (also checked this). As for the BOV I think that might be the case actually. Sometimes I think I can hear it bleed off when still on throttle.

I have Ordered a new Turbosmart Plumb back BOV. (BPV) to see if it will help.

Btw i've heard that the original Nissan one does bleed off a little at throttle to recive a more linear powerband. Do you know if thats true?

Edited August 3, 2015 by KLA33E

[Ben C34]

True that original bov bleeds off boost.

There's a hole in it.

[KLA33E]

True that original bov bleeds off boost.

There's a hole in it.

Ok, Thanks! I noticed that small hole when I took it of but didn't know what it's purpose was.

[tridentt150v]

but the factory hole is not the problem of cause