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GTX2860R GENII boost creep ideas?

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W. Mansfield
#1
I have a DHM GTX360R setup, and have found a concern that i haven't an idea to fix. When tuning via spring pressure (17) i hold pressure at 17 till 5-5500 rpm and then it creeps up to ~20.5 by the time I shift. With open DP it will creep to ~18.5. i have a DHM catless DP, external TIAL 38mm WG, and a CP-e Nexus catback. Anyone have any ideas? I've removed the whole exhaust and checked for blockage and found nothing. Maybe the WG for this setup is to small? Newer to "BT" cars so still learning.
 


OP
FiST0187
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Thread Starter #3
Have you done a boost leak test up to the psi you are hitting?
I'm going to play dumb and ask what you mean. We are running a tune ATM that forces the boost to operate at EWG spring pressure so it should be ~17ish till redline. I just don't know if anyone with this kit has had a similar experience or if maybe the system flows beyond what the EWG can support.
 


OP
FiST0187
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Thread Starter #6
I would boost leak test all your intercooler+piping and make sure your MAP sensor is tightened all the way down.

You need to make sure the car is set up properly because if you have a big boost leak it will cause boost control issues.

How to boost leak test:
https://www.youtube.com/watch?v=atretf9u-Mc
I'm not having issues holding boost though. If I was leaking boost or not hitting my peak I could understand that. Not saying your wrong just not seeing the need or how it would point to my problem.
 


kivnul

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#7
I always thought the wastegate spring PSI is the pressure needed to start opening the wastegate and that the wastegate will keep opening up further as the pressure is increased. I do not think the amount of opening is linear (I.E. it will not open wide enough to keep the PSI at 17 all the time)
 


Last edited:
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132
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Location
Mississauga
#8
You wouldn't have an issue holding boost at 17psi with a bigger turbo lol... The boost leak will make it so you can't control the boost effectively.
The EWG should support north of 400hp, you have other issues you need to find.

Do some logs and post them, we can see more info from that.

You should always boost leak test a new set up IMHO, even a small leak that doesn't affect peak boost will have huge effects spool time and responsiveness.

Also, how is your EBC routed? you on 3 port?
 


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#9
I always thought the wastegate spring PSI is the pressure needed to start opening the wastegate and that the wastegate will keep opening up further as the pressure is increased. I do not think the amount of opening is linear (I.E. it will not open wide enough to keep the PSI at 17 all the time)
Not correct, a 17psi spring will allow the waste gate to open at 17psi to vent excess gases to maintain that pressure.
 


OP
FiST0187
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Thread Starter #10
You wouldn't have an issue holding boost at 17psi with a bigger turbo lol... The boost leak will make it so you can't control the boost effectively.
The EWG should support north of 400hp, you have other issues you need to find.

Do some logs and post them, we can see more info from that.

You should always boost leak test a new set up IMHO, even a small leak that doesn't affect peak boost will have huge effects spool time and responsiveness.

Also, how is your EBC routed? you on 3 port?
Currently using the factory boost solenoid as described in the kits instructions. I have a ATP boost tap at the coupler on the compressor side leading to the inlet on the solenoid. The solenoid has one VTA nipple and the third nipple is routed to the lower nipple on the EWG with the top one VTA. I followed the 3 year olds drawing that came with DHM's kit lol. Here are some logs from last week i think. 9 and 11 are with my exhaust on. the slight dips are due to road conditions, and log 1 is open DP. Let me know if that works.
https://drive.google.com/drive/folders/1-wvt4buju7JGSOgZbJQ3Wn9ELUJPclVV?usp=sharing
 


koozy

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#11
get rid of the ATP boost tap, it's mickey mouse. I have a DHM360R Gen 2 kit and can confirm that if there's a boost leak, boost psi can shoot up. My set up holds a steady 17psi through 7,500 rpms on the base spring without creeping.
 


OP
FiST0187
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Thread Starter #12
I would boost leak test all your intercooler+piping and make sure your MAP sensor is tightened all the way down.

You need to make sure the car is set up properly because if you have a big boost leak it will cause boost control issues.

How to boost leak test:
https://www.youtube.com/watch?v=atretf9u-Mc
get rid of the ATP boost tap, it's mickey mouse. I have a DHM360R Gen 2 kit and can confirm that if there's a boost leak, boost psi can shoot up. My set up holds a steady 17psi through 7,500 rpms on the base spring without creeping.
Where did you get your boost reference for the EWG? My understanding is it should not be from the map tap supplied and the turbo didn't arrive with a tapped compressor housing.
 


OP
FiST0187
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Thread Starter #13
Regardless though sounds like I need to get a boost leak test done and see where that goes. Thanks for the help.
 


koozy

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#14
Where did you get your boost reference for the EWG? My understanding is it should not be from the map tap supplied and the turbo didn't arrive with a tapped compressor housing.
Turbosmart MAP Tap and routing according to this diagram.

 


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Mississauga
#15
Hunt down a boost leak from one of those connections that may house a sensor or control the EWG. The best boost source for the EBC waste gaste port is something see's accurate/constant boost levels with the shortest routing. Intercoolers can sometimes cause a pressure drop so using a source before that gives the best pressurized flow for waste gate control. After the intercooler works but the response time will be slower.

Just so you know I am not getting any of this info from my Fiesta ST "build/bolt on", I have a Big turbo Mazdaspeed6 that had every issue under the sun while tuning so I am pulling my knowledge from my experience. I had some boost control issues that took 2 months to find... bad MAP sensor and a bolt that was too long so it was a boost leak (but only leaked @ 28psi) and sensor issue.
 


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Location
Beltsville
#16
A few things id suggest:

Routing your external wastegate in 3 port mode so that the top and bottom of the wastegate are both hooked up to the boost control solenoid. This offers much better control, most of the time. if you PM me I can find a diagram for you. Its usually a little better to run a boost port directly from the turbo. I usually drill and tap an NPT fitting on the outlet of the turbo. You can also do it the same way as the ATP kits and run a fitting in the silicone at the outlet. I try not to run wastegates on manifold pressure as you can have the effect of the throttle closing and manifold vacuum.

As many people have said, check for boost leaks. In a closed loop system a leak can throw everything off.

Try routing a boost source straight to the bottom of the wastegate, just for testing. By eliminating the electronic solenoid, you can make sure everything mechanically is working correctly.

Larger AR exhaust housing. As you have more mass airflow, the pressure in the manifold increases and even the wide open wastegate isnt enough to quell the pressure and slow down the turbo.

adding a cat to the downpipe. More backpressure.

make sure the fire ring is installed on the wastegate (manifold side). However, you would most likely have LESS boost if this wasnt installed as the wastegate will always be venting a little but this is always good to check.

open wastegate test. I have done this a few times on cars with creep issues. Use shop air and a pressure regulator and put 20ish psi to the bottom of the wastegate and do a pull (need a dyno for this). See what kind of boost it hits with the wastegate wide open. This will show if the system has the ability to properly control boost.

Double check your logs and make sure the WGDC is at zero all the time. If the WGDC compensation mode setting is not right (assuming your using cobb) the closed loop system will add WGDC.

Put a lighter spring in the wastegate. With a 3 port EBCS setup you can run alot of boost on a pretty light spring.

MAC 3 port boost control solenoid. I always use these on external wastegate setups. They can flow more and react faster than most stock valves. Boost control wiring is always pretty easy. Theres 2 wires and the polarity doesnt matter.
 


OP
FiST0187
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Thread Starter #17
Hunt down a boost leak from one of those connections that may house a sensor or control the EWG. The best boost source for the EBC waste gaste port is something see's accurate/constant boost levels with the shortest routing. Intercoolers can sometimes cause a pressure drop so using a source before that gives the best pressurized flow for waste gate control. After the intercooler works but the response time will be slower.

Just so you know I am not getting any of this info from my Fiesta ST "build/bolt on", I have a Big turbo Mazdaspeed6 that had every issue under the sun while tuning so I am pulling my knowledge from my experience. I had some boost control issues that took 2 months to find... bad MAP sensor and a bolt that was too long so it was a boost leak (but only leaked @ 28psi) and sensor issue.
I'm not doubting you and I didn't even look to see what you have or have not done. Anyways I'm in process of making a tester. First one didn't currently properly and blew the top off lol. Starting there for now. Thanks
 


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Mississauga
#18
I'm not doubting you and I didn't even look to see what you have or have not done. Anyways I'm in process of making a tester. First one didn't currently properly and blew the top off lol. Starting there for now. Thanks
Have fun, I didn't think you doubted me so I was giving you some words of comfort because issues come up when you modify a car.
 


OP
FiST0187
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Thread Starter #19
Have fun, I didn't think you doubted me so I was giving you some words of comfort because issues come up when you modify a car.
Hey out of curiosity do you know what size the coupler is at the TB?
 


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