GT3071r slow spool w/EWG

[Xploder08]

Hey all!

I'm having some issues after a rebuild with building boost on a GT3071r. From what I've seen and read, this turbo should be hitting 20+ psi by 3800rpm's. I attempted several different adjustments ranging from EBCS configs, timing adjustments and WGDC with very little change.

For timing changes I read thru this:
Trouble shooting big turbo slow spool time

For EWG changes, I've tried 3 different spring setups... 14lb, 17lb and 21lb, currently running 17lb springs.

For EBCS changes I've read and tried all of the setups from here, currently I'm running the config from ATR:
Grimmspeed and EWG

I've also checked for boost leaks and exhaust leaks, both are in-check and none found.


I have a feeling that I'm hitting some kind of load limit, I'll attach a few logs and a ATR tune. I'm boost tuning in ATR, and I have set my load targets/limits to a value of 3. Also I will note that after changing the EWG to 17lb springs the wastegate hardly opens (just by listening for the screamer pipe). If anyone has some input I would greatly appreciate it!


MODS: Built bottom end (wiesco/manley/SP63 keyed crank), ATP GT3071r with mazda turbine side, no porting to head (all stock), steedspeed ext mani with turbosmart ultragate 38mm EWG, ported w/ no VTCS intake mani, 4" HTP intake, MAC poor man's EBCS, M2 downpipe.

[snailD]

thats definitely slow and not right. have you tried to bypass the boost controller yet and just run straight boost source to wastegate?

[Xploder08]

Originally Posted by snailD thats definitely slow and not right. have you tried to bypass the boost controller yet and just run straight boost source to wastegate?

Thanks for the suggestion! I haven't tried that config yet... I've thought about it but I was concerned with getting it wrong and nuclear detonating this new build... with EWG, just run the boost source to the bottom air port right? that way the diaphragm opens at x psi?

[fivefingerdeathpunch]

Originally Posted by Xploder08 Thanks for the suggestion! I haven't tried that config yet... I've thought about it but I was concerned with getting it wrong and nuclear detonating this new build... with EWG, just run the boost source to the bottom air port right? that way the diaphragm opens at x psi?

Yes sir. It should run only spring pressure that way

Do you have any catalytic converters?

[Xploder08]

Originally Posted by fivefingerdeathpunch Yes sir. It should run only spring pressure that way Do you have any catalytic converters?

The M2 dp is catless. I do have a stock catback though.


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[fivefingerdeathpunch]

Originally Posted by Xploder08 The M2 dp is catless. I do have a stock catback though. Sent from my iPhone using Tapatalk

I don't think this should matter, but you might try disconnecting the catback. If there is a lot of back pressure then it would slow the spool down but to do it that much would have to be a lot and I'm fairly certain people have made good power/spool on the stock catback. Maybe just check for blockages?

[Xploder08]

Here's a short log with the EBCS bypassed. Boost source directly to the bottom air port on the EWG.

I know the steedspeed mani's are not the best flow wise, but I thought they are worse up top... not down low.

[snailD]

you make more boost at 4k without the boost controller than with it...

did any of the different setup styles change your boost control at all? at this point it might be a good idea to borrow a controller from someone to test

[fivefingerdeathpunch]

Did you change to a 12psi spring? If so, do you have a log with the ebcs connected on the 12psi spring?

[Xploder08]

Sorry gents for the slow response... I ended up spending all weekend fighting diff mounts... never again will I fight this... By whole body is sore beyond all belief.

Originally Posted by snailD you make more boost at 4k without the boost controller than with it... did any of the different setup styles change your boost control at all? at this point it might be a good idea to borrow a controller from someone to test

Definitely going to try this route, I reached out to a few local Nator dewds and I might be able to get one tonight... However I'm prolly just going run to grimmspeed and/or MAP to grab one (since both are local to Minnesota!!)

Originally Posted by fivefingerdeathpunch Did you change to a 12psi spring? If so, do you have a log with the ebcs connected on the 12psi spring?

I do not, I only have 14/17/21 few a few combos in-between this. The log above I posted is the boost source connected directly into the bottom air port of the EWG.

[fivefingerdeathpunch]

I just don't think the EBCS is necessarily your problem. You are supposedly running on spring pressure but still not actually getting to spring pressure. That last log on only spring pressure you only hit 12psi and held that. I can only think that your spring setup is wrong or that you are having some other weird turbo issues that are causing you to not build boost

[Xploder08]

Originally Posted by fivefingerdeathpunch I just don't think the EBCS is necessarily your problem. You are supposedly running on spring pressure but still not actually getting to spring pressure. That last log on only spring pressure you only hit 12psi and held that. I can only think that your spring setup is wrong or that you are having some other weird turbo issues that are causing you to not build boost

Trust me, 17lb springs are installed. The only thing I can assume that would cause only 12psi max would be due to the boost source directly connected to the ewg would cause the diaphragm to open and bleed with any entering boost. If the ebcs isn't the issue, I'll just sell it or keep it for a backup.


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[fivefingerdeathpunch]

I wasn't questioning you, just talking out loud.

I don't see how that's possible. My understanding is that you are using the boost pressure from the boost source to counter the spring pressure. Once the boost source pressure is greater than the spring pressure, it opens the wastegate. It's quite simple and mechanical. If the boost pressure from the boost source drops below the spring pressure, the wastegate will close and allow all the exhaust gases to flow through to the turbine wheel.

This is why I'm confused. Maybe your EWG itself is just messed up? It'd have to be stuck open though in my mind. Stuck closed would cause all the exhaust gases to go to the turbine housing and would overboost. You don't have a leak at your ewg to turbine housing do you? exhaust gases escaping there could cause issues.

[Voltwings]

Check if the Fire ring is installed between the wastegate and manifold, you may be bleeding exhaust pressure out. @rfinkle2; had this issue didnt you?

[BigBoostMS3]

Originally Posted by Voltwings Check if the Fire ring is installed between the wastegate and manifold, you may be bleeding exhaust pressure out. @rfinkle2; had this issue didnt you?

I had this issue as well, it's pretty obvious because you have an exhaust leak all the time.

But that certainly would do it.

[Xploder08]

Thanks everyone for the suggestions, I've swapped out for a GS EBCS and stuck with the COBB suggestion for running a 3-port and EWG with pretty much the same results. I'll add some logs.

Originally Posted by fivefingerdeathpunch I wasn't questioning you, just talking out loud. I don't see how that's possible. My understanding is that you are using the boost pressure from the boost source to counter the spring pressure. Once the boost source pressure is greater than the spring pressure, it opens the wastegate. It's quite simple and mechanical. If the boost pressure from the boost source drops below the spring pressure, the wastegate will close and allow all the exhaust gases to flow through to the turbine wheel. This is why I'm confused. Maybe your EWG itself is just messed up? It'd have to be stuck open though in my mind. Stuck closed would cause all the exhaust gases to go to the turbine housing and would overboost. You don't have a leak at your ewg to turbine housing do you? exhaust gases escaping there could cause issues.

Sorry if I came off that way, just saying I knew what springs I had installed. It could be the EWG, but if it was... I would hear it be open at all times and not hit 17psi+ or not at all and overboost right?

Originally Posted by Voltwings Check if the Fire ring is installed between the wastegate and manifold, you may be bleeding exhaust pressure out. @rfinkle2; had this issue didnt you?

That "fire ring" is definitely there, it was a slight PITA to make sure since it slips out easily. I dont hear an exhaust leak from the engine bay.

Originally Posted by mituc The throttle plate is wide open, the timing is in check, AFRs don't bounce, and you shouldn't be getting so low boost in the 3kpm range even with zeroed VVT. So it's either your BPV recirculating like nuts or an exhaust leak pre-turbo. Or a rag in your intake.

Yeah... I'm just as confused dude. BPV could be it, but wouldnt that stop it from hitting 20+psi if it was bleeding boost? I can boost leak/exhaust leak test again, kinda at that point still.

Originally Posted by BigBoostMS3 I had this issue as well, it's pretty obvious because you have an exhaust leak all the time. But that certainly would do it.

Definitly dont hear/feel a leak, and no carbon/black soot buildup anywhere near the mani/EWG.

[mituc]

The throttle plate is wide open, the timing is in check, AFRs don't bounce, and you shouldn't be getting so low boost in the 3kpm range even with zeroed VVT.

So it's either your BPV recirculating like nuts or an exhaust leak pre-turbo. Or a rag in your intake.

[mituc]

Can you try to adjust the wastegate actuator arm length? Maybe it is not closing when the EBCS is at high/max duty cycle.

[Xploder08]

Originally Posted by mituc Can you try to adjust the wastegate actuator arm length? Maybe it is not closing when the EBCS is at high/max duty cycle.

EWG not IWG. I bought this turbo with the IWG flapper welded shut.... Actually now that you mention this... I wonder if those welds broke and is causing the IWG flapper to open....... Hmmmmm

[skoski17]

Originally Posted by Xploder08 EWG not IWG. I bought this turbo with the IWG flapper welded shut.... Actually now that you mention this... I wonder if those welds broke and is causing the IWG flapper to open....... Hmmmmm

Post pics of the welds if you can, I'm very interested in what the outcome of all of this is. I'm currently dealing with slow spool as well. PS, being a welder myself... you are brave buying something someone else welded unless said person is a certified welder and knows what he/she is doing. Don't mean to sound like a Richard or anything.

[Xploder08]

Originally Posted by skoski17 Post pics of the welds if you can, I'm very interested in what the outcome of all of this is. I'm currently dealing with slow spool as well. PS, being a welder myself... you are brave buying something someone else welded unless said person is a certified welder and knows what he/she is doing. Don't mean to sound like a Richard or anything.

For sure. I got it with low miles (claimed 1k). I do believe it to be slightly true since it was free of usage... IE lack of carbon buildup and scuff marks. I'll definitely get some pics since the welds are on the outside of the housing and not the flapper itself. Let's hope this is it! I'll also run some more seafoam and triple check exhaust leaks from the mani-turbo gasket.


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