Boost/load targets on new 3port EBCS and turbo

[DLYDRVN]

Welp, the 'Hybrid' k04 I got back from Cherry Turbos is installed, car is now running and idling well and Cobb EBCS in 3port all seem to be working great. Slow as fack tho on super conservative tune. 14psi FTW.... I'm approaching about 50% of my original WGDC but still can't make boost/load targets.

I'm making around 1.6 load in an RPM range i've set 2.01. Boost holds steady at 14.1, well below 19psi target....

I was told a good general rule for 3port was to 1/2 WGDC, and for the larger compressor in this new k04 to reduce WGDC a bit as well. So I started around 1/4 of my original WGDC and worked up a bit last night and today, but approaching the 50% mark and wondering how safe it is to push harder.

Shouldn't be any other tables I need to adjust for these two mods? (EBCS and larger compressor

Might be time for me to pro tune. I'm loving learning from great people and reading and tweaking, but my head isn't good with the actual practice of tuning!

[loki]

Don't think lex is on this forum

[DLYDRVN]

Whoops! My bad. Edited.

[fywdyl]

What RPM range does this happen at? What happens when you run spring pressure (e.g. 0 WGDC)?

[DLYDRVN]

Its basically across the whole rpm range. I was running like almost 0wgdc when we did our first run and made ~9-10psi. Boost pressure and flow is rising as i increase the wgdc table. But im just now making 18.2 peak 17.1 hold psi on wgdc thats very close to what my original one was before these. Ive always been told you have to halve wgdc when you run 3 port on the ebcs. So im surprised that my numbers are low given how high i am now.

My current wgdc table is close to this one, (current is slightly lower numbers in the midrange)

[DLYDRVN]

Ill upload my last log when i get home tonight. Gonna try a boost leak test this weekend and see if im leaking anywhere but ive never had boost leaks before @20psi and ive got my share of practice taking the top end of my engine apart

[fywdyl]

Do you know what your spring pressure is suppose to be?

[DLYDRVN]

Stock k04 actuator still. So around 7-9 isnt it?

[fywdyl]

Yeah that's right then. Do a boost leak check to make sure.

[DLYDRVN]

Ill do that this weekend. SomeGuy thinks it could also be an issue with tapping my boost reference from the back of my bpv and not the port on the turbo housing. Possible that with my boost sender and that i may have too many taps from that boost/vac source or too much hose.

[DLYDRVN]

datalog8.csv

Here are the logs with the latest map.


And the VD results wot_407-hur_rev6_stg3.jpg

[DLYDRVN]

It's actually painful to see that torque number >_<

[SomeGuy]

Ill do that this weekend. SomeGuy thinks it could also be an issue with tapping my boost reference from the back of my bpv and not the port on the turbo housing. Possible that with my boost sender and that i may have too many taps from that boost/vac source or too much hose.

I re-thought that, it shouldn't matter...running 3 port you remove all pressure from the wastegate when at 100% WGDC so it (wastegate) will stay completely closed. Your tap would only matter if you were creeping. That said, it could be causing your bypass valve to open since you're venting the boost source that's supposed to keep it closed. That wouldn't show up in your trims or AFR and wouldn't show up with a boost leak test.

[DLYDRVN]

Ok.. This makes sense.. the BPV still chirps when i let off boost, but i guess it's still _making_ boost, jsut not ENOUGH... it's leaking more than fully open.

It's cobb's schematic, but maybe this weekend i'll go back to 2 port mode _first_... We may have made a fundamental mistake of doing two big mods at one time.. now we have to possible problem sources to hunt down.

[MajesticBlueNTO]

You should take the boost source for the EBCS from the turbo side and not at the bpv. One of the reasons is that there's up to a 2 psi drop across the intercooler.

[DLYDRVN]

Of course. That makes too much sense. So ill flip that and bring wgdc back down again and log and see whats up

[SomeGuy]

You should take the boost source for the EBCS from the turbo side and not at the bpv. One of the reasons is that there's up to a 2 psi drop across the intercooler.

It shouldn't make a difference for low boost though...in 3 port mode you are either shunting air to open the wastegate (decrease boost) or shunting air to the intake (increase boost)...essentially anyway, since we know the valve is proportioning the air between the two. In any case, at 100% WGDC target all air goes back to the intake meaning there's nothing to force the wastegate open at all and he should be able to make the maximum boost possible on the turbo. If he was having boost creep issues though, ie the wastegate can't open enough to bleed off air then the 2 psi would definitely make a difference.

Correct me if I'm wrong though, I always get the ebcs/wastegate/wgdc stuff mixed up in my head when it comes to what is practically happening.

[DLYDRVN]

Doesnt it work the other way round. Like the bpv, boost holds the wg closed to assist the spring. Otherwise spring pressure wouldnt be a thing since the waste gate itself is normally closed.

In this case i make low boost ok, but im atruggling to make anything above 14psi. Its really gotta work and build up to it to make 18.

[SomeGuy]

The wastegate actuator pushes the flapper open...the push is provided by pressurized air. The spring holds back ~7psi or whatever, and once there's more than that 7psi on the wastegate actuator it overcomes this spring and starts to force it open. This is why we bleed off air to the intake, keeping pressure off the wastegate actuator so it remains closed for longer.

[DLYDRVN]

So im still thinking my best plan for this weekend is to go back to 2port mode and make sure i can make boost targets on the new turbo. Then move the ebcs back in the mix next weekend.

[SomeGuy]

Yup, I agree that going back to the old style boost control is a good first step...I still think a boost leak test is in order though.

[DLYDRVN]

Worth a shot... but i can hold stable boost... it's just holding low. I'll flip back and start back at the 1/2 wgdc map... See what i make. and ramp up from there.

[DLYDRVN]

Ok. Went back to 2 port and found and fixed a small boost leak... And now, suddenly, im making 20.5psi and flowing 278g/s... Not sure if the boost leak was the only culprit. May attempt 3 port this afternoon and see how it goes

[DLYDRVN]