help me cure my compressor surge!

[volkri25]

Attached is a short clip of my compressor surge in a low rpm 3rd gear pull. What can I do to cure it. Hits around 14psi and sticks to about 18-20psi. Lean it out? Adjust timing? Something has to work! Car specs are in profile if it matters.

 

[volkri25]

here is a high rpm wot pull. The lb/min are nearly double for around the same psi, but not double the rpm. Somehow have to make the turbo spool slower or creat more lbs/min at 3.5/4k rpm. Can either be done with tuning?


Timing is 10* higher during the high rpm throttle pull (15* compared to 5* at low rpm pull)

Also wideband is around 12.5 during high rpm pull and only 11.5 during the low rpm pull.

Not sure where to start though.


***the high rpm is a 2nd gear pull and therefore lower load, and the low rpm pull is 4th gear i believe and a little more load.)

 

[donniekak]

You could change your cam timing with the cam gears to bring the ve of the engine up in the trouble rpm range. You can also use an electronic boost controller, that controls boost by rpm.

 

[volkri25]

donnie I think you may be right on. Im pushing 16-17 lbs/min under heavy load 3-5 gear. I need to get it to at least 26 lb/min for my psi range of 16. I have a H1C. A HX35 only requires 23 lb/min. And I know theres a handful of people running a near identical mods list as me, so my guess is my cams have to much overlap. So with decreasing overlap and maybe adjusting the timing a little bit, to increase efficiency even more, I should be able to ale my problems.

Maybe this helps but I can not get my AIRFLOWPERREV to get to .25 like dsmlink recomends. The lowest I can get it is about .30 and thats with my VE in the high 30's The stock VE table has these values in the mid 50's. It seems like my cams have WAY to much overlap going on? I should be able to get to .25 airflowperrev but the mid 40's for 272 cams.

 

[Imback]

Your sd tables show's your in the 60's 50's no wonder you can't get .25airflowperrev.

 

[volkri25]

whats wrong with that?