full throttle compressor surge?

[slow1gentsi]

I can not figure this problem out for the life of me I have tried every thing I can think of and nothing seems to help. so like the title says I believe I am getting compressor surge under full throttle. so the symtomes started when I installed my speed density I went out do some driving to start dialing in my ve tables and I noticed that when I floored the car the boost guage needle would start jumping around even when floored.

So is it compressor surge or BOV flutter and is it possible a boost leak could be causing this to happen.

And the weird thing is it was driving absolutely perfect the night before So I'm lost

any input is appreciated thanks

 

[talonryder]

You seem to have a good guess or on the right track. What psi are you running and what kind of BOV do you have? Also, do you have a boost controller? Best question i guess first would be how badly is the boost gauge needle jumping from what to what psi? Is the gauge a mechanical or electric gauge? What brand? Sorry for tons of questions but it helps us figure your problem.

I would do a boost leak test to what your turbo is been pushing and see if your BOV is opening or such. I had an issue like that awhile back and only after so much psi, i was seeing my boost gauge jumping around. It turned out that after 16psi, my BOV would open and close.

It can be many other things but the boost leak test is always the first thing to do when a boost/performance issue starts. It can also be your wastegate premature opening or horrible fuel trims, exc.

 

[donniekak]

td05h 20g's surge. Going sd may have allowed you the quicker spool that causes surge. My 20g surges horribly below 4,000 rpm's, unless i keep boost under 20 psi. For now i use an ebc for daily driving, with a contoured boost map to avoid surge. When i run a straight 30 psi, i just don't floor it below 4,000 rpm's.

 

[slow1gentsi]

well I am running waste gate spring pressure 1bar on a external tial 38mm no boost controller at all, BOV is a forged motor sports vta, the boost guage is a glow shift mechanical style I wonder if a boost leak before or after would make a difference in this matter. the car feels a little shaky when floored but their is no bucking with the car with this problem. thanks thoe for the input.

td05h 20g's surge. Going sd may have allowed you the quicker spool that causes surge. My 20g surges horribly below 4,000 rpm's, unless i keep boost under 20 psi. For now i use an ebc for daily driving, with a contoured boost map to avoid surge. When i run a straight 30 psi, i just don't floor it below 4,000 rpm's.

what do you mean by a contoured boost map?

 

[donniekak]

what do you mean by a contoured boost map?

My boost settings go from 10psi at 3500 rpms, to 26 at 4500 rpms.