Lacking boost controll

[TomkST]

Hi guys, doing some troubleshooting here, me and my tuner have been working together to try and find a solution to what seems like lacking boost control on my s280 powered car, we have tried a variety of map styles with little success. The car seems to get to about 20 psi of boost and starts to fluctuate heavily to the point where it’s nearly undriveable. We have checked wastegate routing, I have put a new boost control solenoid on the car, I have done everything in terms of blow off valve testing from 25mm recirculating valve to no bov at all. I have even made adjustments to wastegate preload to see if it makes any difference which lead to limited success. Just wondering if anybody has had this issue as well and what was done to resolve it?

 

[Dpro]

Hi guys, doing some troubleshooting here, me and my tuner have been working together to try and find a solution to what seems like lacking boost control on my s280 powered car, we have tried a variety of map styles with little success. The car seems to get to about 20 psi of boost and starts to fluctuate heavily to the point where it’s nearly undriveable. We have checked wastegate routing, I have put a new boost control solenoid on the car, I have done everything in terms of blow off valve testing from 25mm recirculating valve to no bov at all. I have even made adjustments to wastegate preload to see if it makes any difference which lead to limited success. Just wondering if anybody has had this issue as well and what was done to resolve it?

interesting what are you doing for tuning? I know stateside with use COBB AP’s with tunes by tuners that know the setups. I know a lot of us over here running S280‘s use the turbosmart 14lb solenoid. It seems to work real well. You adjust preload to 14lbs( about 4mm’s on the screw) or above and it holds boost like no tomorrow. I also use a turbosmart plum back EV on my car for recirculating blowoff.

 

[Dialcaliper]

interesting what are you doing for tuning? I know stateside with use COBB AP’s with tunes by tuners that know the setups. I know a lot of us over here running S280‘s use the turbosmart 14lb solenoid. It seems to work real well. You adjust preload to 14lbs( about 4mm’s on the screw) or above and it holds boost like no tomorrow. I also use a turbosmart plum back EV on my car for recirculating blowoff.

Just noticing what looks like a slight mixup here between the “boost control solenoid” (the electric valve that controls flow to the wastegate actuator) and the wastegate actuator itself. The turbosmart 11 or 14psi actuators is a replacement for the stock wastegate actuator (not the solenoid) with a stiffer spring, vs the stock actuator’s spring that opens when pressure reaches 6psi.

Using the stock wastegate actuator on a bigger turbo like the S280 is making the solenoid work harder using only boost pressure. With less spring holding the flapper shut, it can blow open, leak or flutter resulting in loss of stable boost control when trying to operate at higher boost levels.

The opposite can happen if the wastegate actuator is too stiff or the wastegate opening too small - “boost creep” where the wastegate can’t open enough to limit boost to the target level.

 

[Dpro]

Just noticing what looks like a slight mixup here between the “boost control solenoid” (the electric valve that controls flow to the wastegate actuator) and the wastegate actuator itself. The turbosmart 11 or 14psi actuators is a replacement for the stock wastegate actuator (not the solenoid) with a stiffer spring, vs the stock actuator’s spring that opens when pressure reaches 6psi.

Using the stock wastegate actuator on a bigger turbo like the S280 is making the solenoid work harder using only boost pressure. With less spring holding the flapper shut, it can blow open, leak or flutter resulting in loss of stable boost control when trying to operate at higher boost levels.

The opposite can happen if the wastegate actuator is too stiff or the wastegate opening too small - “boost creep” where the wastegate can’t open enough to limit boost to the target level.

Their wording led me to use the word solenoid because I figured they were talking about the wastegate actuator which technically does the same thing in a solenoid as a solenoid actuate movement. Like in a starter the solenoid actuates the starter motor to engage with flywheel.
It’s also why I mentioned adjusting by 4mm to get it set for proper use on the S280 . I am fully aware of everything you are starting people in cther countries do not always use the exact terminology we do . For instance we call a trunk a trunk and in the UK they call it a boot.

 

[TomkST]

Just noticing what looks like a slight mixup here between the “boost control solenoid” (the electric valve that controls flow to the wastegate actuator) and the wastegate actuator itself. The turbosmart 11 or 14psi actuators is a replacement for the stock wastegate actuator (not the solenoid) with a stiffer spring, vs the stock actuator’s spring that opens when pressure reaches 6psi.

Using the stock wastegate actuator on a bigger turbo like the S280 is making the solenoid work harder using only boost pressure. With less spring holding the flapper shut, it can blow open, leak or flutter resulting in loss of stable boost control when trying to operate at higher boost levels.

The opposite can happen if the wastegate actuator is too stiff or the wastegate opening too small - “boost creep” where the wastegate can’t open enough to limit boost to the target level.

This makes sense, and i do know that, it is using the wastegate actuator that the 280 comes with, I'm with laird performance for tuning, which is a renowned tuner in the UK as there are none in Aus, he has never had issues with the stock actuator and has actually told me on this occasion to not change it (although i think i might do to be honest as it makes no sense for such a small wastegate to control such high boost (27 psi)) I'm thinking at this point that the actual circuit for the boost control solenoid (not the wastegate actuator) might be faulty and have a slight resistance in it as it is a resistance-based circuit. I have sourced an engine loom from another car so i plan to swap it in to test it out (my car is a track car so being off the road is nothing new haha)