Hi All,

I'm getting again what I think it's compressor surging with my GT3071 anti-surge ported.

Accelerating WOT from 3200 to 4000 in 4th and 5th gear, I get the annoying wosh wosh wosh noise, and the car stumbles a bit, so definitely is surging.

As i read, this kind of compressor surging (WOT from low rpm, longer gears, during spool up to max pressure 1.80 bar) can be caused by a too retarded ignition timing in the spool up region, that causes a too fast pressure rise:
is this correct ?

This is my ignition map, any advice is really appreciated.
For example, is it correct that from 3000 to 4000 I have less advance that over 4000?



Thank you.

 

what type of engine management are you running?

 

Hi, Motec M400
Does it make a difference ?

 

Nope, was just asking.

 

ive been having a problem with the static ignition timing retarding and it definatley makes comp surge worse. Im running a 3582 with out a ported front cover. Have a look at the dyno sheet, the only difference between these two runs are the static timing retarded alot, something like 6 or 8 degrees, it spooled the turbo a bit faster but lost a lot of power and comp surge is worse.

 

Very interesting, thanks