Another T4 thread

superpsd · Jun 7, 2017

Did you ever inquire about the gated housing. Did it look like the housing and actuator would have clearance bolts s to a T4 mount? And it was for the smaller S300SXE turbine wheel?

mikeeg02 · Jun 7, 2017

KCTurbos said:
Just curious how many guys are running a mechanical drive pressure gauge? And seeing what the turbo actual does.
I have done a TON of testing on the 6.0 and the results were pretty surprising. With a 364.5 74/.91 you can throw that 1:1 ratio out the window once you get up around 2900rpms. By 4000rpms it runs about 2:1 with 38psi of boost and 75psi of EBP (it reads higher on the street than the dyno)

But my question still stands. Does anyone monitor these turbos on a 7.3 using an actual drive pressure gauge and have any data?

I do. Green is back pressure. Red is boost.

1:1 up to 40 psi. 366sxe, 1.0 housing.

IIRC this run went up to 3k rpms (55-100 mph).

https://www.youtube.com/watch?v=OAdEvM3WVf8

This was in drive (not OD) 1800 rpm - 3500 rpm.

https://www.youtube.com/watch?v=m_vcp-AlOIA

KCTurbos · Jun 8, 2017

mikeeg02 said:
I do. Green is back pressure. Red is boost.

1:1 up to 40 psi. 366sxe, 1.0 housing.

IIRC this run went up to 3k rpms (55-100 mph).

https://www.youtube.com/watch?v=OAdEvM3WVf8

This was in drive (not OD) 1800 rpm - 3500 rpm.

https://www.youtube.com/watch?v=m_vcp-AlOIA

very cool. Thanks. I imagine with a 1.0 housing I would see better, The 6.0 is a dog with that big of a housing. We prefer the .83 and .91 housings.

If you went up to 4200rpms you might also see similar EBP to what I was running, but I know most 7.3 guys don't run the rpms out that far.

I know we are "theorizing" a little about wastegates. What I would want to do is run that similar setup with a 1:1 ratio all the way up to 40psi and then bleed off the excess pressure through the wastegate. I have notice on my truck (once again a 6.0) that as EBP climbs up faster than boost, the byproduct is that boost really starts to fall off.

For example I ran am s362sxe with .83t4 and 68 turbine. It would build a solid 1:1 ratio at 2800rpms at 45psi of boost. But by 4000rpms it would be at 25psi of boost and 75psi of EBP. Every turbo I have tried has the boost "fall off" even though when studying the compressor maps it should be able to maintain about 35-40psi of boost. I wonder if it is just from the turbine housing choking out so bad?

KCTurbos · Jun 8, 2017

superpsd said:
Did you ever inquire about the gated housing. Did it look like the housing and actuator would have clearance bolts s to a T4 mount? And it was for the smaller S300SXE turbine wheel?

I am about to be testing a some of these... I can post up some pictures if you like.

I am building a custom turbo for my 6.0 race truck.

s369sxe with a billet aluminum dual ball bearing center section. I am going to try a .83 t4 divided housing that actually gates BOTH volutes. It is a really tight fit. I am going to test it against a .91 and 1.0 non-gated housing back to back and see what it does to EBP, Boost, HP, and tq. I am hoping to have a monster street truck that makes 700-800hp on fuel only and can spray up to 900hp... but I am pretty picky with how my truck spools.

Swaan · Jun 8, 2017

superpsd said:
Did you ever inquire about the gated housing. Did it look like the housing and actuator would have clearance bolts s to a T4 mount? And it was for the smaller S300SXE turbine wheel?

Never did test it. It looked like it would fit .
They made the housing for both 68 and 74 wheel. Just got to tell them what wheel you have. It was gated on both volutes also.

Swaan · Jun 8, 2017

mikeeg02 said:
I do. Green is back pressure. Red is boost.

1:1 up to 40 psi. 366sxe, 1.0 housing.

IIRC this run went up to 3k rpms (55-100 mph).

https://www.youtube.com/watch?v=OAdEvM3WVf8

This was in drive (not OD) 1800 rpm - 3500 rpm.

https://www.youtube.com/watch?v=m_vcp-AlOIA

Makes sense. The 366 has the bigger 74 turbine , that's why you were 1to1 up to 40psi.
Mine was up to 35psi with the smaller 68 tubine.

superpsd · Jun 8, 2017

Swaan said:
Never did test it. It looked like it would fit .
They made the housing for both 68 and 74 wheel. Just got to tell them what wheel you have. It was gated on both volutes also.

That gated housing may help on a rig thats a DD and tow mule that spends a lot of time below 2500rpm. Will be interesting to see what KC finds out on testing one on the 6L.

ja_cain · Jun 8, 2017

KCTurbos said:
I am about to be testing a some of these... I can post up some pictures if you like.

I am building a custom turbo for my 6.0 race truck.

s369sxe with a billet aluminum dual ball bearing center section. I am going to try a .83 t4 divided housing that actually gates BOTH volutes. It is a really tight fit. I am going to test it against a .91 and 1.0 non-gated housing back to back and see what it does to EBP, Boost, HP, and tq. I am hoping to have a monster street truck that makes 700-800hp on fuel only and can spray up to 900hp... but I am pretty picky with how my truck spools.

That thing sounds like it might be bad azz! It's cool that you have the capability, intellectual curiosity and motivation to mod these turbos that way. A 364.5 modded that way would be cool to try in a zf-6 dd that occasionally tows heavy. A super clean 350 rwhp 7.3 truck that doesn't smoke even if you lug it would be the holy grail for me. Just nice linear power. I don't want to have to go to compounds to achieve this, which is just retarded for a 350 rwhp truck. Thanks again for your contributions to the thread!

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lincolnlocker · Jun 8, 2017

KCTurbos said:
If you went up to 4200rpms you might also see similar EBP to what I was running, but I know most 7.3 guys don't run the rpms out that far.

because most cant without the Pistons playing wack-a-mole with the valves.. most start floating around 3600rpm and normally the power curve starts to fall off quick... now mine on the other hand, has seen over 4k... i have a boost gauge plumbed into the ebpv line and its creeping close to 1:2 boost/bp by then on the street even with the gate set at 36-38 psi. on the track hooked to the sled, i dont think it has ever gone past 1:1.5 boost/bp but im not usually watching that gauge then...

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mikeeg02 · Jun 8, 2017

KCTurbos said:
very cool. Thanks. I imagine with a 1.0 housing I would see better, The 6.0 is a dog with that big of a housing. We prefer the .83 and .91 housings.

If you went up to 4200rpms you might also see similar EBP to what I was running, but I know most 7.3 guys don't run the rpms out that far.

I know we are "theorizing" a little about wastegates. What I would want to do is run that similar setup with a 1:1 ratio all the way up to 40psi and then bleed off the excess pressure through the wastegate. I have notice on my truck (once again a 6.0) that as EBP climbs up faster than boost, the byproduct is that boost really starts to fall off.

For example I ran am s362sxe with .83t4 and 68 turbine. It would build a solid 1:1 ratio at 2800rpms at 45psi of boost. But by 4000rpms it would be at 25psi of boost and 75psi of EBP. Every turbo I have tried has the boost "fall off" even though when studying the compressor maps it should be able to maintain about 35-40psi of boost. I wonder if it is just from the turbine housing choking out so bad?

I posted videos earlier, and I can repost them again if you'd like. But with my setup, (and loaded heavy) I can make a smoke free ~15psi at 1,500 rpms. ( not that I'm advising anyone to do that) but this turbo spools up really fast on my truck.

I completely agree about your theory on gating off the back pressure, and I see the same thing, the turbo basically parks at ~42 psi, and as soon as it hits ~40 psi the back pressure goes up, and on my setup its to ~65psi. Which is 1:1.6, (which isnt awful) and only seen (for me) in short bursts. If I was competing with it, it would definitely be gated, because like you, I think its from a restriction on the turbine side. But since its such a rare occasion for me to be in that situation, it doesnt bother me.

Also, I have seen both boost and back pressure climb faster than one another. For me, it seems to depend on the situation, but they are generally only a needles width apart from one another up util 40psi.

mikeeg02 · Jun 8, 2017

KCTurbos said:
I am about to be testing a some of these... I can post up some pictures if you like.

I am building a custom turbo for my 6.0 race truck.

s369sxe with a billet aluminum dual ball bearing center section. I am going to try a .83 t4 divided housing that actually gates BOTH volutes. It is a really tight fit. I am going to test it against a .91 and 1.0 non-gated housing back to back and see what it does to EBP, Boost, HP, and tq. I am hoping to have a monster street truck that makes 700-800hp on fuel only and can spray up to 900hp... but I am pretty picky with how my truck spools.

Swaan said:
Never did test it. It looked like it would fit .
They made the housing for both 68 and 74 wheel. Just got to tell them what wheel you have. It was gated on both volutes also.

What company makes them again? When I was looking around the only ones I could come across were the t3s, and then I think finally gave up. Ultimately though, If I went to a gated housing, I wouldnt want to go any smaller than a .9, (I think the gated ones found were .83s?) because I know how well mine works with a 1.0

I am looking forward to your results of your test with both housings.

gnxtc2 · Jun 8, 2017

Get a boost controller that could pulse the wastegate will help with backpressure.

Billy T.
[email protected]

Swaan · Jun 8, 2017

mikeeg02 said:
What company makes them again? When I was looking around the only ones I could come across were the t3s, and then I think finally gave up. Ultimately though, If I went to a gated housing, I wouldnt want to go any smaller than a .9, (I think the gated ones found were .83s?) because I know how well mine works with a 1.0

I am looking forward to your results of your test with both housings.

Southeast power systems turbocharger division.

Scroll thru there Facebook page and you will see those housings.

mikeeg02 · Jun 8, 2017

That's right. I think when I inquired they weren't available for the 80/74. They are now. ~$400. Trying to find out the gate opening size per volute. Worried on the big end it may still choke it out some.

KCTurbos · Jun 8, 2017

For anyone wondering about fitment... here are a few pics. I am going to change out the wastegate actuator for something different, but this gives you the general idea

The Brad · Jun 8, 2017

mikeeg02 said:
That's right. I think when I inquired they weren't available for the 80/74. They are now. ~$400. Trying to find out the gate opening size per volute. Worried on the big end it may still choke it out some.

It's still only available on the .83 housing.

mikeeg02 · Jun 8, 2017

How big are the gate openings per volute?

The brad : originally they were only available for the smaller turbine size. Same .83, it wasn't available for our turbines until last December it looks.

KCTurbos · Jun 8, 2017

mikeeg02 said:
How big are the gate openings per volute?

The brad : originally they were only available for the smaller turbine size. Same .83, it wasn't available for our turbines until last December it looks.

Are you asking me???

On the housing I have it is really hard to get in there and measure exact. But I am getting about 13mm. So 2 13mm gate openings. I might try to open them up to about 18mm openings.

If there was enough interest I could get some .91 housings made.

mikeeg02 · Jun 8, 2017

Yessir. 13mm seems kinda small, especially downsizing the housing so much. How hard would it be to get a .91 housing done up like that ?

KCTurbos · Jun 8, 2017

mikeeg02 said:
Yessir. 13mm seems kinda small, especially downsizing the housing so much. How hard would it be to get a .91 housing done up like that ?

I would have to get my own mold made, MOQ of 100, probably cost round $300-$400 each. So it is a pretty big investment and I am not sure if there is really any market for it.