SX366 really this laggy?

whitneyj

whitneyj

still in pieces
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Jan 31, 2012
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Truck is a 2004 5.9, 50% over, Airdog 4G, 2nd gen manifold ported, Edge Juice w/ Attitude (unlocked 6th tune) and the turbo is a 66/71/13ss with the turbine housing port matched to the manifold. It doesn't start to light until 2000rpm and is slow to build to ~42psi before I run out of rpm's. I don't have any boost leaks nor exhaust leaks that I can tell. I'm using steel gaskets with exhaust manifold studs, new T3 gasket with new G8 hardware (it's what I had otherwise it would be G5) but I am pushing oil from between the intermediate housing and the turbine housing. I'm running an AN #10 drainline but there's a few bents in it to get around things and I have a feeling that's being too restrictive and not letting the oil drain fast enough. Regardless, there isn't any soot anywhere however I haven't done a load test with someone brave enough to be under the hood checking...

Am I missing something? Turbo is relatively tight however there was a large crack between the volutes inside the turbo, not where it mounts. I've had Holsets like this but there wasn't any noticeable issues with lag with those. I'm going to put a 3/4" pipe drain with hose to the block to confirm the oil leak goes away and if it does then I'm out of ideas and will probably be on the lookout for a 62 or 63...

Is an SX366 really this laggy on a CR with light fueling mods?
 
whitneyj said:
Truck is a 2004 5.9, 50% over, Airdog 4G, 2nd gen manifold ported, Edge Juice w/ Attitude (unlocked 6th tune) and the turbo is a 66/71/13ss with the turbine housing port matched to the manifold. It doesn't start to light until 2000rpm and is slow to build to ~42psi before I run out of rpm's. I don't have any boost leaks nor exhaust leaks that I can tell. I'm using steel gaskets with exhaust manifold studs, new T3 gasket with new G8 hardware (it's what I had otherwise it would be G5) but I am pushing oil from between the intermediate housing and the turbine housing. I'm running an AN #10 drainline but there's a few bents in it to get around things and I have a feeling that's being too restrictive and not letting the oil drain fast enough. Regardless, there isn't any soot anywhere however I haven't done a load test with someone brave enough to be under the hood checking...

Am I missing something? Turbo is relatively tight however there was a large crack between the volutes inside the turbo, not where it mounts. I've had Holsets like this but there wasn't any noticeable issues with lag with those. I'm going to put a 3/4" pipe drain with hose to the block to confirm the oil leak goes away and if it does then I'm out of ideas and will probably be on the lookout for a 62 or 63...

Is an SX366 really this laggy on a CR with light fueling mods?
Click to expand...


Years ago it was commonly stated that the 13ss housing wasn’t friendly to spool up. Unfortunately, I never tested one due to this. S4s spool better then you are describing. Also with 10an return lines and no issues. The 62 or 64 if identically paired turbines, should yield near same results with no other changes.
 
TheHammer said:
Years ago it was commonly stated that the 13ss housing wasn’t friendly to spool up. Unfortunately, I never tested one due to this. S4s spool better then you are describing. Also with 10an return lines and no issues. The 62 or 64 if identically paired turbines, should yield near same results with no other changes.
Click to expand...


Sounds like I may be buying another turbo from the sounds of it then.... dang... must be why it was so cheap.
 
Sounds like you have an automatic truck, a 12 cm exhaust housing will suit you better. A T3 is definitely the way to go for the 5.9CR.

I wouldn't put the lag issue entirely on the turbo. The tuning method you're using was barely fit for a stock truck 15 years ago. You'd be better off to find someone near you to tune your truck with HPTuner and get the truck dialed in.
 
RD TRCTR said:
Sounds like you have an automatic truck, a 12 cm exhaust housing will suit you better. A T3 is definitely the way to go for the 5.9CR.

I wouldn't put the lag issue entirely on the turbo. The tuning method you're using was barely fit for a stock truck 15 years ago. You'd be better off to find someone near you to tune your truck with HPTuner and get the truck dialed in.
Click to expand...


It's an auto, stock, correct. I should've put that in my first post...

It is a T3, using a factory 2nd gen manifold, and I figured 13cm was close enough to not make this big of a difference. Maybe I'll look around for 12cm turbine housing and see how that spools first, but I have my eye on II's 330 Thunder at this point.

I didn't think the tuner would be ideal but once at operating temp it's an absolute smoke show (preboost turned to 5/5) until the turbo is fully lit at 2400+rpm. I have thought about someone with HP tuners or EFI live. Maybe I'll research that more, but if this turbo is known for being a slow spooler than I'll probably swap it out for something more streetable first and then consider better tuning. My background is pretty exclusive to mechanical diesels so I'm not 100% sure what I should expect from the turbo with better tuning or how it’ll react....


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I have an agp .76, for a 71turbine, but I believe that’s t4 and everything else I have is for a 74 or 80 turbine.
 
Or a cam change. I was running a 62 with Edge Juice on my '02. Once I finally swapped cams I wished that I had have done that on day one.
 
4x4dually said:
Or a cam change. I was running a 62 with Edge Juice on my '02. Once I finally swapped cams I wished that I had have done that on day one.
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I thought about that too but it’s my only vehicle currently if I go the cam route there’s a laundry list of things I’ll do. Wish I could but that’ll have to wait until I freshen things up in a few years. But good to know.

Just to confirm, with your 62 the Juice wouldn’t spin it hard enough or fast enough?


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I’m sure this has been talked about too but I can’t figure out what keywords to use to confirm. If I take a 68mm exhaust wheel/shaft ($100) then I can use a .70A/R turbine housing. Would that just lead to lots of surging and a waste of $700 and a few hours?


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TheHammer said:
I have an agp .76, for a 71turbine, but I believe that’s t4 and everything else I have is for a 74 or 80 turbine.
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I passed on an S363SX-E because it was T4. Didn’t want to buy another manifold or deal with the slower spooling. Kicking myself now...


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whitneyj said:
I passed on an S363SX-E because it was T4. Didn’t want to buy another manifold or deal with the slower spooling. Kicking myself now...


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Click to expand...

I’d build you a 68/76stock appearing charger for not much more then what that wheel/housing you stated. Had one on an 04 hot street class sled truck all summer and it never placed outside of 5th and it’s still alive and tight, as are the several others.
 
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I ran the same charger on an old 12v truck, came on the truck when I bought it, HTT 66/71/13ss.

I thought it spooled very quick for its size, don't remember exactly what rpm, but well before 2000.
Truck ran strong
 
I liked the 13SS housing I had on a 65mm turbine wheel, didn't notice slower spool up than the 12cm.
 
You could add a Smarty tuner to the Edge box for more aggressive fueling at lower RPMs. I ran a 66mm on my 2003 auto for a long time. It did lag, but I learned to lock out OD until it was lit.
I ditched the Edge Juice that came with the truck because I wanted reliable gauges instead of the digital format.
 
So what I’m reading is I have more of a tuning issue than anything right now, maybe too large of a man exhaust wheel..... I’ve read on a few 65 and 68mm exhaust wheels on the 66 compressor wheel but everyone said they surge badly unless you have a 14cm turbine housing.

You know, before I bought this turbo I thought I had don’t enough research to know I wanted it... doh ??*♂️??*♂️

So let’s say that I change the drain line back to a 7/8” Jose like what comes from the factory and I’ll still pushing oil between the turbine housing and intermediate (core) housing. That could be where I’m losing spooling due to exhaust leak right? If it’s able to push oil (which is an issue unto itself) but that also means gasses are able to get out that way too. What would cause the exhaust gas leak between the core and turbine? Red RTV a fix for that?

I’m either going with the Phatshaft 62 or putting a 68/76mm exhaust wheel and housing in this thing....


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Your oil drain issue isn't your problem with spool.
Tuning issue.
 
Get set up with a tuner to get it dialed in with HP tuners. I did one a couple weeks back with 400 67.7/87/.90, and it drive very well.
 
whitneyj said:
Truck is a 2004 5.9, 50% over, Airdog 4G, 2nd gen manifold ported, Edge Juice w/ Attitude (unlocked 6th tune) and the turbo is a 66/71/13ss with the turbine housing port matched to the manifold. It doesn't start to light until 2000rpm and is slow to build to ~42psi before I run out of rpm's. I don't have any boost leaks nor exhaust leaks that I can tell. I'm using steel gaskets with exhaust manifold studs, new T3 gasket with new G8 hardware (it's what I had otherwise it would be G5) but I am pushing oil from between the intermediate housing and the turbine housing. I'm running an AN #10 drainline but there's a few bents in it to get around things and I have a feeling that's being too restrictive and not letting the oil drain fast enough. Regardless, there isn't any soot anywhere however I haven't done a load test with someone brave enough to be under the hood checking...

Am I missing something? Turbo is relatively tight however there was a large crack between the volutes inside the turbo, not where it mounts. I've had Holsets like this but there wasn't any noticeable issues with lag with those. I'm going to put a 3/4" pipe drain with hose to the block to confirm the oil leak goes away and if it does then I'm out of ideas and will probably be on the lookout for a 62 or 63...

Is an SX366 really this laggy on a CR with light fueling mods?
Click to expand...
Learn from my mistakes; it's the 71 turbine. Aside from the turbine housing size, I've found that the 71 wheel itself is incredibly free flowing to the point where it isn't "grabbing" enough energy from the exhaust and makes things laggy. The 68 wasn't popular yet at the time, but that's what I should have had for that turbo. It was a 66/71/14.
 
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