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Old 03-11-2021, 12:44 PM   #1
putrio
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Default WGDC Question

I did a stupid and bought a poorly sized turbo, and I'm working to get it spooling a bit faster.

I've read most of the posts regarding WGDC questions, and one person mentioned logging these things during boost tuning:

-Manifold Pressure (aka boost)
-Target Boost
-Max WGDC
-Turbo Dynamics Continuous
-Boost Error

I've been logging, but not all of those values, so I'll do some more logging this afternoon. My current tune has a max PSI of ~26, but my WGDC is at highest 71% before it gets to the target pressure. Should the WGDC be 100% or close until it reaches my target PSI? My brain is telling me I wouldn't want the EBCS to open the wastegate at all until it's close to target.

Side note....how many people have two turbos and swap them for the occasion? If I bought a smaller faster spooling turbo that could be plumbed the exact same way it'd be a somewhat easy job to swap 'em as desired.
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Old 03-11-2021, 01:06 PM   #2
kopele
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You can set it at 100% but you risk overboosting past your target, because it takes some time for WGDC to affect boost level. You'll want to start lowering WGDC before you reach your target.
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Old 03-15-2021, 11:30 AM   #3
putrio
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Well....time for a new clutch. I thought it (the stock clutch) would be more of an issue in lower gears but on boost in 3rd and 4th has some really weird RPM surging...I was hoping to do that upgrade last because I really don't relish the idea of pulling the engine again. Boo.
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Old 03-15-2021, 12:35 PM   #4
Chi_San
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Smaller, faster spooling turbo? You mean, like a TD04? Full boost at 2,250RPM, runs out of breath at around 4,000RPM? Yeah, living that dream.

Which turbo did you get?

There are hardware things you can (or, could) do to get faster spool. One is a TBE, another is delete the uppipe cat. Get a better turbo inlet, go with a smaller intercooler, and run silicone hoses everywhere.

One you can't do anymore, apparently, is delete the TGV's. >_> MFG, what a lame BS mess this is...
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Old 03-15-2021, 01:01 PM   #5
putrio
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Let's just say the turbo is far too big...and I should have listened to others saying I'd enjoy a fast spooling turbo a lot more.

I had to replace the short block a couple of years back soooo....in the process of doing that I did a bunch of other stuff and have been working on it bits at a time...

Secondary air pump delete
TGV Delete
Upgraded fuel pump
1500CC DW injectors
DW Rails
DW FPR
new fuel lines
closed deck block with forged internals and 14mm head studs
Full turbo back exhaust
Grimmspeed uppipe
AEM CAI
Torque Solutions 3" Turbo Inlet (ffffff that was a bi*** to install)
TiAL 44mm wastegate with dump tube (venting to atmosphere)
I can't think of any more.

Still to do in a general order...
Clutch/flywheel
FMIC
Go Rotated
spare turbo, maybe GTX3071 or 3076
Head Work
equal length headers
air oil separator depending on community feedback and research
flex fuel sensor install somewhere in this list
Suspension mods
exhaust work to plumb ewg into downpipe....
Paint job

.....it's a GTX3576R. F. Me. Scary acceleration once it hits but holy f it spools slow. Queue the community laughing :-p

Last edited by putrio; 03-15-2021 at 01:09 PM.
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Old 04-18-2021, 09:50 PM   #6
cproo12
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I think you'll find this video helpful:


70% WGDC at full boost should be fine (7:20)
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Old 04-18-2021, 10:22 PM   #7
K3rm1tth3fr0g
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I have a GTX 3576 Gen 2 spoolinator kit going on my car soon and from everything I can see the 3576 on a 2.5L should pretty good with AVCS and proper tuning.

Are you rotated?

Is it an ATP or stock housing turbo?

Gen 1 or gen 2 3576?

And if you're running a 3576 on unported stock headers you are in for a tough time.

If you want it to spool well and you want to keep the same turbo do the following:

Find a GOOD tuner who knows what he or she is doing and ask them to tune your car with spool in mind.

Buy Killer B or equivalent headers or port your headers

Switch your oem style hotside for a properly sized (A/R) hotside compatible with a quality rotated kit. I suggest a V-band style kit.

Run ethanol!

Last edited by K3rm1tth3fr0g; 04-19-2021 at 05:36 PM.
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Old 04-19-2021, 09:47 AM   #8
GeoNV
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there's some great discussions on this on the Romraider forums. I know for me- I improved my turbo spool about 500 rpm by playing around with my AVCS timing. I'm still in the process of tuning everything, but pretty big differences. the thing I ran into next was compressor surge when coming on boost- so I've had to reduce my WGDC where that was happening which makes my boost curve less of a cliff you climb and more of a curve. But my torque curve looks way better than it did before tuning it. some other tricks to improve spool I've read are playing with your AFR to be a bit leaner (say 12-13:1)when building boost to get the exhaust a little hotter. but really so many things are inter-related that it's a challenge to say "do this" to get better spool. it's more like "experiment with these five variables".
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