Boost Control Issues ATP GTX3071R IWG
25 March 2017, 10:27 PM
#1
Scooby Regular
Thread Starter
Boost Control Issues ATP GTX3071R IWG
2008 STI Hatchback
Have been battling some boost control issues on an ATP GTX3071R IWG and getting a bit frustrated. Car is being mapped remotely so tuner isn't able to see things first hand, just what i describe and what we see from the logs.
Engine is fully built with supporting fueling, exhaust and intake mods.
Solenoid is still stock, but I read the the 08+ solenoids are 60% stronger than previous models so not an instant need to switch to a 3 port for better boost control.
I checked all vac pipes and they are good. Boost pill has been drilled out to 1.1mm
So I then decided to check wastegate flapper movement was okay and free which initially appeared to the case. After some frustrating logging sessions and map revisions my tuner said I must have some mechanical issues. I hooked a pressure line up to my actuator and found it was barely opening.....after disconnected I found the flapper was stuck. Pulled it back towards the front of the car (closed) and it came unstuck and I had full free movement again. But after 4-5 open/closed cycles it jammed again. I wire brushed the exhaust housing which had some surface rust, sprayed some WD40 which worked wonders at reducing friction felt on the WG flapper arm, realigned the actuator arm to make sure it was pushing straight and readjusted the clevis angle. Put it all back on and back with the air line and this time I got full movement. Everything nice and smooth and repeated tests for around 15 mins to simulate use.
Took it out on the road and this time when doing logging runs in 2nd (21PSI), 3rd (21PSI) and 4th (20-21PSI), i had nice tidy boost control exactly where I would expect things to be , EXCEPT under one condition....if I go 100% throttle in 2nd (boost at 21PSI), snap into 3rd revs around 5500rpm and this time it over-boosts to 24PSI. Repeating the tests and it does the same. Now I am not discounting it being from the map, BUT if not any ideas what this could be....
- Is it the factory boost solenoid not reacting quick enough?
- Actuator is the stock Garrett 480009-0006 14-15PSI, 4-5 years old
- Is it a design issue with the ATP exhaust housing flapper port not being able to vent quick enough?
Am hoping maybe someone out there might have some insight.
__________________
ATP GTX3071R IWG|80mm MAF|3" intake pipe|FMIC|3" bellmouth DP, 3 inch full decat exhaust|Manley Conrods|Mahle Pistons|ACL Race bearings|ARP headbolts|Cosworth timing belt/tensioner|Cosworth oversize high pressure/high volume oil pump Cosworth HG|Mocal Oil Cooler
RCM unequal length mani and up-pipe|RCM 1000cc injectors|RCM Parallel Fuel Rails|RCM FPR|RCM Fuel Pump|RCM Air pump delete kit|JDM Manifold with TGV delete|Dual Custom oil catch cans|Exedy Hyper twin plate clutch
Have been battling some boost control issues on an ATP GTX3071R IWG and getting a bit frustrated. Car is being mapped remotely so tuner isn't able to see things first hand, just what i describe and what we see from the logs.
Engine is fully built with supporting fueling, exhaust and intake mods.
Solenoid is still stock, but I read the the 08+ solenoids are 60% stronger than previous models so not an instant need to switch to a 3 port for better boost control.
I checked all vac pipes and they are good. Boost pill has been drilled out to 1.1mm
So I then decided to check wastegate flapper movement was okay and free which initially appeared to the case. After some frustrating logging sessions and map revisions my tuner said I must have some mechanical issues. I hooked a pressure line up to my actuator and found it was barely opening.....after disconnected I found the flapper was stuck. Pulled it back towards the front of the car (closed) and it came unstuck and I had full free movement again. But after 4-5 open/closed cycles it jammed again. I wire brushed the exhaust housing which had some surface rust, sprayed some WD40 which worked wonders at reducing friction felt on the WG flapper arm, realigned the actuator arm to make sure it was pushing straight and readjusted the clevis angle. Put it all back on and back with the air line and this time I got full movement. Everything nice and smooth and repeated tests for around 15 mins to simulate use.
Took it out on the road and this time when doing logging runs in 2nd (21PSI), 3rd (21PSI) and 4th (20-21PSI), i had nice tidy boost control exactly where I would expect things to be , EXCEPT under one condition....if I go 100% throttle in 2nd (boost at 21PSI), snap into 3rd revs around 5500rpm and this time it over-boosts to 24PSI. Repeating the tests and it does the same. Now I am not discounting it being from the map, BUT if not any ideas what this could be....
- Is it the factory boost solenoid not reacting quick enough?
- Actuator is the stock Garrett 480009-0006 14-15PSI, 4-5 years old
- Is it a design issue with the ATP exhaust housing flapper port not being able to vent quick enough?
Am hoping maybe someone out there might have some insight.
__________________
ATP GTX3071R IWG|80mm MAF|3" intake pipe|FMIC|3" bellmouth DP, 3 inch full decat exhaust|Manley Conrods|Mahle Pistons|ACL Race bearings|ARP headbolts|Cosworth timing belt/tensioner|Cosworth oversize high pressure/high volume oil pump Cosworth HG|Mocal Oil Cooler
RCM unequal length mani and up-pipe|RCM 1000cc injectors|RCM Parallel Fuel Rails|RCM FPR|RCM Fuel Pump|RCM Air pump delete kit|JDM Manifold with TGV delete|Dual Custom oil catch cans|Exedy Hyper twin plate clutch
26 March 2017, 06:24 AM
#3
Scooby Regular
Thread Starter
Thanks for the reply. I wondered whether perhaps the actuator was tired and working slowly.
Had in mind to replace it with a Turbosmart IWG75 with a 11PSI spring. They aren't cheap but I like that they are fully modular. Anyone use one ?
http://www.turbosmartdirect.com/IWG75-Garrett-GT2860RS-Disco-Potato-7-PSI-Black.html
From what i read boost creep wise its common to Internal gates at higher power levels but I dont want the noise from an EWG. The WG flappper should already be ported in the ATP housing and have a large swing gate.
Had in mind to replace it with a Turbosmart IWG75 with a 11PSI spring. They aren't cheap but I like that they are fully modular. Anyone use one ?
http://www.turbosmartdirect.com/IWG75-Garrett-GT2860RS-Disco-Potato-7-PSI-Black.html
From what i read boost creep wise its common to Internal gates at higher power levels but I dont want the noise from an EWG. The WG flappper should already be ported in the ATP housing and have a large swing gate.
26 March 2017, 08:49 AM
#4
Thanks for the reply. I wondered whether perhaps the actuator was tired and working slowly.
Had in mind to replace it with a Turbosmart IWG75 with a 11PSI spring. They aren't cheap but I like that they are fully modular. Anyone use one ?
http://www.turbosmartdirect.com/IWG7...PSI-Black.html
From what i read boost creep wise its common to Internal gates at higher power levels but I dont want the noise from an EWG. The WG flappper should already be ported in the ATP housing and have a large swing gate.
Had in mind to replace it with a Turbosmart IWG75 with a 11PSI spring. They aren't cheap but I like that they are fully modular. Anyone use one ?
http://www.turbosmartdirect.com/IWG7...PSI-Black.html
From what i read boost creep wise its common to Internal gates at higher power levels but I dont want the noise from an EWG. The WG flappper should already be ported in the ATP housing and have a large swing gate.
Last edited by stonejedi; 26 March 2017 at 08:53 AM.
18 April 2017, 09:22 PM
#5
Scooby Regular
Thread Starter
Actuator changed , BCS as well but it looks like an issue with the turbo gate port size/porting. Well either that or the specific header/up pipe/turbo combination. Spool with this combo is slow slow 0.7bar at 3080rpm and 1.4 bar by 3800 in 4th gear.
2nd and 3rd gear is where I am having issues, when boost comes on, its strong and flows hard with a 3 inch inlet, but the ATP exhaust housing gate can't dump quick enough to stop an over boost beyond target 1.5bar and even with lots of wgdc fine tuning Its easy to hit 1.73 bar when I snap from 2nd gear to 3rd and stay at WOT which is more than I want to have on an EJ257 block that isn't pinned or sleeved.
Plus for the type of driving and use , I would prefer a turbo that is at 1.5 bar by 3200rpm and has good boost control without the need to run an EWG. Lots of people are quick to 'upgrade' their manifold and go with something like an RCM unequal length but you need to accept a 400-500rpm shift right in spool especially if you are running a FMIC. That combined with the fact that most wouldn't want to run more than 420-450bhp on these engines without being pinned/sleeved and you are prob better off with the stock manifold and a decent up pipe.
2nd and 3rd gear is where I am having issues, when boost comes on, its strong and flows hard with a 3 inch inlet, but the ATP exhaust housing gate can't dump quick enough to stop an over boost beyond target 1.5bar and even with lots of wgdc fine tuning Its easy to hit 1.73 bar when I snap from 2nd gear to 3rd and stay at WOT which is more than I want to have on an EJ257 block that isn't pinned or sleeved.
Plus for the type of driving and use , I would prefer a turbo that is at 1.5 bar by 3200rpm and has good boost control without the need to run an EWG. Lots of people are quick to 'upgrade' their manifold and go with something like an RCM unequal length but you need to accept a 400-500rpm shift right in spool especially if you are running a FMIC. That combined with the fact that most wouldn't want to run more than 420-450bhp on these engines without being pinned/sleeved and you are prob better off with the stock manifold and a decent up pipe.
Last edited by STI450; 18 April 2017 at 09:24 PM.