low speed turbo surge

have you ever noticed turbo stall or surge at low speeds? we did a twin turbo on a sv6 3.6 holden, during normal driving the car makes the chirping noises as it gets to 100 kpa area, slightly above or below this area it is good. also have you had any experience with tuning these motors with hp tuners? it is the e77 ecu.

I've had very limited experience with running turbos into surge as it is relatively rare if you're using a reasonable matched turbo for the engine. I recall many years ago I tuned a Mitsubishi EVO that was fitted with a hybrid turbo and if you lugged along at 2000-3000 rpm and accelerated, it would surge. At higher rpm it wasn't a problem. The symptoms are generally what you described.

I've tuned a couple of SV^'s on HP Tuners but in stock form there's almost nothing to gain until you do some hardware mods so we didn't deal with many. From my memory the definition for that particular PCM is quite limited too which isn't ideal if you're doing something serious like a turbo conversion. I will say that it's been a good few years since I ran one on a dyno though so it's possible HP Tuners now offer a more complete definition.

thanks for your reply and ongoing help. to give an update we changed the injectors and tune and seen to have managed to tune out that low down surge at 100kpa. we do get very good hp from the sv6 now but it is very hard going with the limited tables available, all the tables are load based and many only starting at 70% upwards, also a pain is that the sv6 does not have a map sensor.