Hey guys, not sure if surge is the right word but i searched it and came up with no results so perhaps there is a better term to describe this but here goes.

Im running the Cobb AP with ets intake, and initially things were pretty smooth, but now regardless of my map choice (as none specifically meet the ETS intake) when I hit the power band my boost surges back and fourth between 26-20 it seemed like it was overboosting and cutting the boost then quickly trying to overboost again and correct rapidly.. but with a stage one map I overboost sometimes 26 - 27 or so if i use a LWG map to correct this i peak at about 20-22 on a stage 2 LWG map i usually peak at about 26 in first two gears but then 24-23 in the upper gears.. I was wondering if perhapse my wastegate was the issue? sounds like a lot of flutter.

Mods AP - ETS intake - Buschur UICP - (still runnning the factroy boost control pill in line)

I can log if someone would like though i dont know what format to put it in so others can view it when attached.

Thanks
-J

 

i've got a fairly similair issue, i've got only the ets intake and when i first started flashing the maps i got overboost like your numbers. i ran the sf 93 oct stage 1 for awhile and noticed alot of knock and overboost. tried the LWG map and was boosting about that 20-22 you're seeing. i switched over to the SF 91 oct stage 2 map and things seem to be alot better now. my knock was reduced to almost nothing (few .3 .7 and 1's in sub 140 load) and i dont seem to be overboosting much if at all now. i may hit a spike of 25.3ish every now and then seems to be more so towards after i've only been driving for a little bit but after that i dont hit to much over 24.4 when entering WOT.

so if i was you i would try out either the stage 1 or stage 2 91 oct SF map and see if it helps you like it helped me

 

Thanks for the info stetson, ill definately give that a try today.. though it is 92 degrees here haha.. I just tried the AMS 93 LWG stg 2 but havent gone wot with it yet to see how its acting but ill probably try the 91 octane solution with the stg 1 sf..
your running 93 still i assume?

 

dont run the ams map, its maf housing is not the same size as ours, stick with the cobb sf maps.

and yes im still running 93 oct gas with the 91 oct map. that 93 oct map just makes me knock alot for some reason.

 

The up and down is probably just a correction factor that is too large combined with too much BWGDC for your car. You can also try adjusting the error correction in access tuner if that option is available.

 

Yeah I stayed away from the AMS maps initally because of this fact, but i never got around to swapping my maps yesterday and the AMS map is actually runnnig good, little to no knock, minimal trim corrections, and steady boost at 24-24.7 no surging with smooth power delivery up to redline..

I still want to try the 91 SF map and see how that goes but its tough becuase the X hasnt operated this smooth in some time..

FOST, thanks for the insight.. which factors were your refering to in terms of correction adjustment? and what is the B is B wastegate duty cycle? noob question im sure but I just got up.

Thanks guys

 

Check your UICP connections. There may be a leak somewhere. I was having similar fluctuation with boost and retightened the connections on my APT UICP which fixed the problem.

 

what map are you running? i may try and log my car with that map and see how well it likes it

 

BEC = Boost Error correction
BWGDC = Base wastegate duty cycle

I'm not sure what their equivalent names are in access tuner.

 

In ATR:

BEC = Turbo Dynamics
BWGDC = Fine Wastegate Duty Cycle

 

^ this... plus the intake probably offset the maf based load and since you don't have a map designed for the intake your load calc (one of the three main inputs for load based boost control, the other two being rpm and tps) you are more than likely hitting an error correction loop.

You need to retune the boost control setup and or the maf scale tables.