If you are going to ignore the answers people give you then why ask questions? It is your bov that is too tight.

 

When you say when you let off the throttle a little do you mean you still have it down most of the way but not full throttle? If so you are making full boost at partial throttle and this is causing compressor surge because you are reducing the efficiency of your engine where it is passing the surge line. When full boosting you should be at full throttle. If it happens when you fully let off the throttle then it is the BOV being too tight.

 

Thanks Batty200, yes its happen when "Let off the throttle a little do you mean you still have it down most of the way but not full throttle? If so you are making full boost at partial throttle and this is causing compressor surge because you are reducing the efficiency of your engine where it is passing the surge line"So what should i do to overcome the surge? Doing full throttle (full boosting) for few km's while on highway during high speed?

The problem does not happen when i fully let of throttle while full wot.

 

Hi Guys,
i managed to get this video on Youtube about Compressor surge but my question is :
How to solve this problem???

Ive changed to Turbosmart Race Port BOV but its still the same! When part throttle my engine will judder and the boost meter will go haywire....

When WOT ive no problem at all but when i lift off the throttle a little the problem comes immediately...

What should i do?
Ive tried stiffen my BOV spring but its still the same!
Today ive tried using few spring rate on the BOV by blowing air into it and the result as follow
1) Softest spring which comes with the Turbosmart race port bov = The piston will start to lift just only when the pressure reached -0.1bar

2) Medium spring rate = The piston will start to lift just only when the pressure reached -0.45bar

The history is, when im on the lowest spring rate, i encounter insufficient spring pressure as the bov piston will lift partial or full when the vacum pressure is moderate to high.
So, ive tried by using dual springs to make the bov stiffer and the lift goes away but the massive juddering (Compressor surge) while half throttle still happen!

Which spring rate do i need to use?

http://www.youtube.com/all_comments?v=RIC4MOq5w9s

 

which compressor cover is on the 3076?

 

It doesnt matter if your bpv bov is open at idle. Infact it does give good drivability. Use thespring rate that allows it to open without surge and disregard trying to keep it closed at idle. You realize that the intercooler is under pressure vs the manifold. So for most bov the combination of air in the uicp and vac should be operating your bov. Applying throttle should use boost and spring to hold it shut, closing the throttle should just negate the spring enough to unseat it a little. My .02.. and how i set my type s which works awesome.

 

Ar60

 

Hi do you mean i need a softer spring or a stiffer spring?
Ive tried the softest & hardest spring rates but the juddering is still there when partial lift off...

When on the softest spring, it cant sustain the pressure when on higher RPM and the bov piston will open prematurely...

Any idea to solve this problem???

 

Tial. Or stock ix bpv. Try something else. Tuning drivability is a pita. I think a proper tial would be your best bet.

 

Have tested few springs tension on my Turbosmart (tightest to softest) & increase & decrease Sard RD2D spring tension but still ive the jerking/juddering while partial lift off throttle...

What is happening??? Its seems like Compressor Surge but i cant solve it!!!

Help....

When on soft = Premature opening on the Bov piston
When on Stiffest = Premature opening gone but engine still judder/jerking massively when partial lift off...Tried using 2nd & 3rd gear slowly rev the rpm and the piston open everytime the rpm hits 6,000rpm.

 

Finally, tested with the Profec B II b/c off and boosting at 1.3 bar (WG spring rate pressure) instead of 1.6 bar and the judder goes away. No more massive judder at high rev lift off or partial lift off...

So, i believed all the springs that ive tested on my Turbosmart race port bov is still not stiff enough.
Am i right???

 

Anyone???