Boost overshooting target
 

Im basically at the end of my tether with this car now adter £10k+ being spent on it in the last couple of months.. the cars had a full rebuild to a 2.1 stroker with a few goodies like FPR, parallel fuel rails 1000cc injectors 340lph fuel pump etc etc its running the link g4+ with a link 4 bar map sensor.. the car was run in at 1500. Its went for its remap where it produced 470 on a mdx321v however once in a while it overboosts and cuts power on WOT.. i took it back to the mapper where he tweaked it and all seemed fine then one week later it did it again on WOT. It even did it on the low boost setting. Then i got the turbo sent to turbo Dynamics where they gave it a full overhaul with a new actuator etc and got it tweak mapped again. Picked it up today and surprise surprise on the way home it overboosted again.. it will probably do it 20% of the time when on WOT. Is it fuel surge? A vacum leak? Any thoughts would be appreciated

Boost solenoid sticking, what type you using

2 port or 3 port solenoid

3 port solenoid

cold weather and wot at low revs can cause over boosting , the chap who mapped my 2 litre put a compensation into the map to stop it from happening , don’t know if that helps

I would echo the above , I had a previous car mapped in the summer and come the winter time or cold mornings my target boot would over shoot and hit fuel cut ECU over boost.
If you don't already have or use one then a dedicated boost controller may be a good option if the ECU is not able to cope.

The link ecu should be set to closed loop boost control

same as mines

same boost level all year round

Are you maffless?
What are your high and low boost map set to and how much are you overshooting boost by?
Not sure about link but on esl and running maffless you use a IAT sensor and adjust fuel&timing compensation tables for high intake temps,heat soak etc.
I've know mappers pretend to fit the sensor(actually wire it up totally wrong)and not even attempt to adjust the tables.
Your fuel cut maybe down to det?

Yes running mafless and overshooting by about 0.2/3 bar
it mainly does it on low fuel ie. under 1/4 tank. When it has a full tank or anything over 1/2 it does it much less. Could it be my fuel pressure regulator as this is the only item that i didnt renew in my build as everything else was new

i’m still thinking a map issue , if it’s been mapped when the weather was warm it will drive different boost wise when it’s cold , as per my above comment as i had it in mine , it’s not a good sign to have it happening as not good for your engine

Who mapped it?

I would think a change in barometric pressure would affect boost but this only swings around 0.1bar so not a lot really,you should have headroom on the boost limit to cover this?
On mine running mafless the baro is set at a constant as the map sensor is used to calculate load,so a change in atmospheric pressure won't affect the boost at all.
Not very technical and is only as I see it so could be way off the mark!