Help needed with ecoboost boost issue

[Vell !]

So I recently installed an NX2 turbo upgrade onto my ecoboost, the issue is when I accelerate boost starts to build to around 15-18psi but then falls back down to 0-2psi while I’m still accelerating. I’ve done a smoke boost leak test and found a small boost leak, I fixed it but still have the same issue any help would be greatly appreciated

Sponsored

 

[SnowFox]

Is it happening suddenly? Are you between gears? Does it start to build boost again immediately after the drop? Few more details needed.

 

[Vell !]

Is it happening suddenly? Are you between gears? Does it start to build boost again immediately after the drop? Few more details needed.

Yes it just drops completely not instantly of course but close to. It drops during gear and it sometimes goes up like 1psi after a shift

 

[K4fxd]

My SWAG would be the wastegate spring not holding.

 

[Vell !]

My SWAG would be the wastegate spring not holding.

Would I need to add more preload ?

 

[K4fxd]

I think the spring itself is toast. Hits the limit then cannot close till the turbo spools down.

Adding pre-load should raise the pressure where it fails. This assumes my diagnosis is correct.

 

[Buldawg76]

Did the NX2 come with its own wastegate actuator or did you install an aftermarket one. Are there any codes being set also. The more info we get the better we can help. Did you get a tune for the bigger turbo, so the PCM knows what it has to work with.

BD

 

[Vell !]

Did the NX2 come with its own wastegate actuator or did you install an aftermarket one. Are there any codes being set also. The more info we get the better we can help. Did you get a tune for the bigger turbo, so the PCM knows what it has to work with.

BD

Yes the NX2 came with its own waste gate, I’m using that one right now. No codes as of right now. I did get a tune for the NX2 from Ryan martin at EMS tuning. I also have supporting mods such as charge pipes and an upgraded intercooler. Please let me know if you need more information

 

[Buldawg76]

I would contact Ryan and see if he wants some logs of when it happens since he may need to adjust something in the tune or can give you more info on what it could be. It does sound like the wastegate is either getting stuck open or not operating properly. Could just be a faulty wastegate actuator.

BD

 

[Vell !]

Is it happening suddenly? Are you between gears? Does it start to build boost again immediately after the drop? Few more details needed.

After some more test drives yes the psi tends to rise again after shifting but only for a little bit before falling again

 

[K4fxd]

After some more test drives yes the psi tends to rise again after shifting but only for a little bit before falling again

Sounds like the wastegate spring is not working properly. Add some pre load see if the PSI where it fails rises. I'm no turbo expert but this is the reason big power turbo guys use compressed air as a waste gate spring

 

[Buldawg76]

Sounds like the wastegate spring is not working properly. Add some pre load see if the PSI where it fails rises. I'm no turbo expert but this is the reason big power turbo guys use compressed air as a waste gate spring

They actually use CO2 not compressed air I believe but it's the same reason as you stated as to why. Some may use compressed air also. I know I shoot PCP airguns so have a compressor capable of filling an SCBA fireman's tank to 4500 psi here at home, it's not breathable air.


What bypass valve are you using, still stock BPV or do you have an aftermarket valve and is it still in recirculate back to intake tube or vent to atmosphere, if VTA do you hear it venting when boost drops off. It could be the BPV/BOV is not holding the boost since the NX2 will increase the volume of boost air over the stock turbo. It does not necessarily make higher boost but just more volume of boost so can show other items that become a weak point in the system. Stock BPV is known to bleed boost at steady throttle settings at highway speeds so may not be able to control the larger volume of boost air at certain RPMs.

Again, you should discuss issue with tuner first since I assume you have done some data logs to fine tune with revisions, if not then that may be required to correct the issue.

BD

 

[K4fxd]

They actually use CO2 not compressed air

Same difference. It's a compressed gas.


He said he is using the wastegate that came with the turbo

 

[S550HPP]

Silly, but disconnect battery for few min....

 

[Buldawg76]

Same difference. It's a compressed gas.


He said he is using the wastegate that came with the turbo

No not really since CO2 does not contain moisture of any measurable amounts and is considered a clean gas whereas compressed air from a compressor that is not filtered and contains a high quality desiccant media will contain quite a bit of moisture from the heat of compressing it and other oil/petroleum contaminate from the compressor, if it is compressed by a compressor like a scuba shop or medical supply uses that is considered breathable air. Fire houses either have their own high quality breathable air compressors or use medical supply companies to fill their tanks. Your local compressed gas supply house that sells CO2, acetylenes, argon, oxygen gases etc. do not use filters to remove the moisture from plain compressed air so that the moisture in it can lead to corrosion of metal parts of the blow off valves and associated parts. I have a multi layered molecular sieve filter on my high pressure compressor to remove 90% of moisture from the 4500 psi air I compress for my air guns.

I realized he is using the NX2 wastegate that came with the turbo, I was asking about the bypass/blow off valve for the hot side charge pipe since if it is not capable of holding the boost in that could also be an issue with it dropping boost at high rpm if the valve is blowing off before he lets off the throttle.

BD

Sponsored