Trying to Solve Fuel cut - at wits end - this one will stump you

ArmandoP

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Nov 4, 2006
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hereis the for sale thread http://www.supramania.com/forums/showthread.php?t=32113 and quoted
The wastegate hole has been ported to eliminate the boost creep problem these turbos have, and it is fixed. This turbo has between 2000-2500 miles on it.

in this thread he was able to keep it at 10psi with the same actuator and same style downpipe. apparently held 10psi and would "surge"
http://www.supramania.com/forums/showthread.php?t=24990

and here is the thread where he solved the "boost creep" problem.
http://www.supramania.com/forums/showthread.php?t=24782
quoted
Opened the ID of the hole up to 1 inch and problem solved!!!

these are the threads I was aware of.

ALSO, remember the car had a FC issue before I replaced the turbo, I think the more flow just exacerbated the problem. (that word doesnt mean what some of you think it means...)

I dont think chris jipped me, so now Im even more confused with this damned car. ugh. should have stuck with MR2s and flapper door AFMs, LOL.
 

ArmandoP

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Nov 4, 2006
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funny you should mention that
coonskincap.jpg



Im waiting on it to cool down so I can pull the WG clip.
 

GrimJack

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I am really starting to wonder if you are actually outflowing the Lexus AFM. I'd love to have some way to measure how much power you're putting down before hitting fuel cut.

As I recall, previously this turbo was matched up to a standalone, so fuel cut could be tuned out. Same here, I'm running a MAFT Pro.

The completely open wastegate test might rule this out - if you are still hitting fuel cut with the wastegate open, there is something rotten in Denmark.
 

Boost Lee

Bee Doo Bee Doo Bee Doo
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Sep 13, 2006
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Oh gawly this thread has an assload full of suggestions. ;)

Flapper door AFMs, Oh yes. Do it. :biglaugh:

Armando - Only running in a dark room with a blindfold,

But you should pull the 4" exhaust we fabbed up for you, and try a 3" or even open downpipe and see how she behaves.
Scientifically speaking, I don't think this would solve the problem...But the problem did begin after the 4" install. :)

How much longer are you going to be out at the "shop", A? :biglaugh:
Maybe I'll swing by...
 

ArmandoP

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Nov 4, 2006
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Boost Lee;1008673 said:
Oh gawly this thread has an assload full of suggestions. ;)

Flapper door AFMs, Oh yes. Do it. :biglaugh:

Armando - Only running in a dark room with a blindfold,

But you should pull the 4" exhaust we fabbed up for you, and try a 3" or even open downpipe and see how she behaves.
Scientifically speaking, I don't think this would solve the problem...But the problem did begin after the 4" install. :)

How much longer are you going to be out at the "shop", A? :biglaugh:
Maybe I'll swing by...


about another hour or so, come on by. am I the only one here who has a 5000 sq ft shop? :D

NOW HEAR THIS! THE FLAPPING WASTEGATE TEST HAS REVEALED THE PROBLEM! STAY TUNED WHILE I WRITE IT UP!
 

ArmandoP

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GrimJack;1008670 said:
I am really starting to wonder if you are actually outflowing the Lexus AFM. I'd love to have some way to measure how much power you're putting down before hitting fuel cut.

As I recall, previously this turbo was matched up to a standalone, so fuel cut could be tuned out. Same here, I'm running a MAFT Pro.

The completely open wastegate test might rule this out - if you are still hitting fuel cut with the wastegate open, there is something rotten in Denmark.


I would love to measure that too. honestly my first goal is to see what ti does without a boost controller and then turn it up a bit from there. stay tuned.
 

ArmandoP

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Nov 4, 2006
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The Flapping Wastegate Test

Ok, so I burned the hell out of myself again to get the wastegate clip off... and lost it in the process.... here goes.

first notes; "god this thing is loud even with the muffler on the wastegate pipe." and "why does it sound broken?" (wastegate flapper flapping)

dramatic version
driving impression.
pull out of complex, 3/4 throttle, no boost anywhere in sight. shift at 4500rpm. get out onto the street and floor it in second no boost no boost... 4500rpm, whats this???? boost?????? WTF? thats UNPOSSIBLE! let off. go under bridge as quietly as possible to avoid the popo... floor it in second again. wait, 5psi, 10psi, 14psi WHAT????? FUELCUT! rinse and repeat. does it every time at 14-15psi, even without a wastegate hooked up. just does it at a higher rpm without the WG.

non dramatic version.
REALLY slow spool. no boost till after 4700 rpm, then the freaking thing takes off and by 5600 its at 14psi slamming into fuelcut with the wastegate flapper flapping.
moral of the story... turbonetics backhousings and wastegates suck. tell me if Im wrong.

that or possibly the wastegate and downpipe are not getting along for scavenging reasons or some other obscure reason? (does the wastegate port require scavenging of any sort?)

after pulling into the warehouse I left the car running and reached down there with a pair of needlenose and moved the wastegate flapper door back and forth with zero resistance while it was running, so there goes that expansion of the metals theory.
 

ArmandoP

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Nov 4, 2006
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Boost Lee;1008673 said:
But you should pull the 4" exhaust we fabbed up for you, and try a 3" or even open downpipe and see how she behaves.
Scientifically speaking, I don't think this would solve the problem...But the problem did begin after the 4" install. :)

you just want to install it on your car while Im not looking. That exhaust is not coming off the car while youre in the same vicinity cause I know it will dissappear when I turn my back. hehehe
 

Nick M

Black Rifles Matter
Sep 9, 2005
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ArmandoP;1008709 said:
[moral of the story... turbonetics backhousings and wastegates suck. tell me if Im wrong.

You aren't the first person I have seen write something non-friendly about Turbonetics.
 

ArmandoP

Supramania Contributor
Nov 4, 2006
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anyone know if the lipp turbine housings will fit onto the turbonetics cartridge? damn, this is gonna suck. Im thinking out loud here, but is there an "easier" was to convert this thing to external gate than the hassle Im thinking of?
 

GrimJack

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Actually, I think they do fit.

Or you can take off the wastegate and the rear housing, buy a conventional rear housing and a new tubular manifold, and bolt an external wastegate to it.

I'm amazed that you're still building boost. Mine won't do that - I tried, when I put it on the first time, I didn't put enough pressure on the wastegate rod, and couldn't build any boost at all. There isn't a blockage in the wastegate section of the DDP, right?
 

Doward

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Jan 11, 2006
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Check for blockage after the wastegate.

Honestly, you shouldn't have suddenly started building boost. That's telling me that your wastegate section is not flowing enough air.

I suggest one of 2 things:

a) Get a fuel controller of some sort, tune it so that you can run the 14-16psi I think you'll end up running

b) You need a better way of getting rid of the wastegate gases before they 'clog up' and force the exhaust through the turbine of the turbo.
 

Poodles

I play with fire
Jul 22, 2006
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+1 ^^

Boost creep is common with the DDP's because they don't scavenge as well, so it's not helping issues...

I'd try a 3inch elbow and normal DP and see if it went away... or a recir. DDP might work as well...
 

ArmandoP

Supramania Contributor
Nov 4, 2006
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AWESOME! I get to use my sawzall! muffler comes off today or tommorrow. if that down work im getting an sp61 gt kit. this problem WILL be fixed by next friday damnit.