Turbo Swap S365 to S367

Dzchey21 · Nov 26, 2014

dseitler said:
It drives totally different than the 64.5/70. Lost the top boost numbers of 48 but still puts out 43lbs so far. I believe it will give me much more top end but the street has suffered a little running red light to red light. Still need more time to run it out. I got to say so far the 64.5/70 has the been the best street turbo I've tested. I miss the instant quick spool tire spinning street running that we do in South Florida. Not that the 67.7 won't do it but in short burst the 64.5 so far from what I see would take it.
Highest back pressure at max boost has been 55.7 psi and that is lower than the 70mm. But the strange numbers I see is that at cruising speed the 70mm would be at 3.9psi @ 5lbs of boost. The 74mm is at 4.3psi @ 5lbs of boost with a bigger Turbine. Should be the opposite I would think.
Where the 67.7/74 shines is the upper RPM band. From 40 MPH to 100 MPH is where this Turbo lives. Track times should tell the true story next Friday night when we go the the Florida West Coast. Should have more info ready tomorrow night to post with numbers. D

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My honest opinion on it is the larger turbine wheels have more leverage on the compressor wheels so it helps them spool, obviously there is a way to go too far with that as well.

Thanks for the feedback. Looking forward to the track times. I think your right even with less boost you are probably making more power since back pressure is down.

JDub · Nov 26, 2014

Dzchey21 said:
I think your right even with less boost you are probably making more power since back pressure is down.

The 67.7 should move more volume than the 64.5 did, even at less total boost.

CATDiezel · Nov 26, 2014

JDub said:
The 67.7 should move more volume than the 64.5 did, even at less total boost.

That would work if he made changes to the heads and stroked the engine. Other wise pressure in his case is a pure measurement of flow. But I get what your saying.

dseitler · Nov 26, 2014

Lower EGT's that I am getting with the 67.7/74 show that at WOT there is more air flow. Fuel setting has not changed so more flow would be the results of lower EGT's. As I stated before I believe the power band has shifted up the RPM band and peek power is now at a higher RPM. I should now be able to push more fuel where as before I found more fuel above 1649pw hurt my track times. I think now I should be able to run north of 1900 pw.

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Dzchey21 · Nov 26, 2014

Still on a stock motor?

Cat you will see more go even at lower boost. Air density will be higher

dseitler · Nov 26, 2014

Yes stock motor.

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CATDiezel · Nov 26, 2014

Dzchey21 said:
Still on a stock motor?

Cat you will see more go even at lower boost. Air density will be higher

You must have been hit by a turkey! The turbo didn't make the air thicker... lol. Engine consumption is still the same. I guess the engine is magically swallowing the air more efficient with a different turbo. I must be full of turkey!

CATDiezel · Nov 26, 2014

dseitler said:
Lower EGT's that I am getting with the 67.7/74 show that at WOT there is more air flow. Fuel setting has not changed so more flow would be the results of lower EGT's. As I stated before I believe the power band has shifted up the RPM band and peek power is now at a higher RPM. I should now be able to push more fuel where as before I found more fuel above 1649pw hurt my track times. I think now I should be able to run north of 1900 pw.

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Pressure is measured as a direct result of flow and what is referred to as "line pack" if nothing has changed but the turbo on your engine the exact same FLOW is entering the engine with 30psi of line pack.

30psi is 30psi. I don't care if the turbo is 3ft tall. Now whether or not you have back pressure resulting in engine braking...

Dzchey21 · Nov 26, 2014

how about heat...

CATDiezel · Nov 27, 2014

Your talking about less back pressure as a direct result if that's the case.

I don't want to muck up his thread.

Less air pressure on the same engine would be from investing MORE air into the cylinder bore.

Take the same engine and put a 100mm turbine wheel on it. 30 psi. Still line pack. And the cylinder is still investing the same amount of air... back pressure permitting. EGT'S cooler. Contribution to the more freer flowing turbine wheel. Even with less boost.

The only way to put MORE AIR or volume into the cylinder would be to raise the line pack (boost). Or cool the air below 32*. Or inject the remaining portion of the 80%~ air we breathe compressed.

Last comment. I should have just left my fingers off the android.

drunk on diesel · Nov 27, 2014

no, he's talking about adiabatic efficiency...

I can take a sealed container full of air and heat it up. This will increase the pressure inside the container, but it won't magically add air molecules.

A more efficient compressor will ingest and compress more air molecules at a given pressure.

compound that will less turbine restriction, and you get even more gain

CATDiezel · Nov 27, 2014

drunk on diesel said:
no, he's talking about adiabatic efficiency...

I can take a sealed container full of air and heat it up. This will increase the pressure inside the container, but it won't magically add air molecules.

A more efficient compressor will ingest and compress more air molecules at a given pressure.

compound that will less turbine restriction, and you get even more gain

I'll take it.

However. Line pack is still line pack. Hot or cold. You would need a hug intake air temperature swing to be that much more efficient a loss of 5 psi. This is a direct result in loss of back pressure on the exhaust manifold. He's no longer leaving 55 psi in the crown of the piston. He's only leaving (he didn't say, but less)

It's the same thermal equation we use on the pipeline to determine line pack at our current psi of 1200. Soil to pipe temp readings make a difference in it. Cooler gas more pack.

But hey... if he say it's more efficient and flows more I'll just go with it. He's the one doing the testing. Just throwing some food for thought out there.

At least he is testing the differences other than most companies that just throw a turbo on the market with no testing just youtube videos and a post or two that says it pulled my gooseneck good!!

6 L chevy eater · Nov 27, 2014

VOLUME

jcain · Nov 27, 2014

CATDiezel said:
Pressure is measured as a direct result of flow and what is referred to as "line pack" if nothing has changed but the turbo on your engine the exact same FLOW is entering the engine with 30psi of line pack.

30psi is 30psi. I don't care if the turbo is 3ft tall. Now whether or not you have back pressure resulting in engine braking...

If you think a 50mm turbo at 30psi and a 100mm turbo at 30psi are the same, you need to revisit your books.

Craig@MFI · Nov 27, 2014

jcain said:
If you think a 50mm turbo at 30psi and a 100mm turbo at 30psi are the same, you need to revisit your books.

Exactly

dseitler · Nov 27, 2014

Ooof

The 64.5/70 will give a peak boost at 2400 RPM of 48 psi @ WOT and the pressure will fade after 3000 RPM to 43psi @ 3650. Then depending on the Trans Tune I'm running it will fluctuate between 43 and 45.7 psi on a WOT pass. If I am running full lockup after second gear it will help maintain boost a little more even. This does not mean in any way the 64 is not doing is job. It is by far the best STREET Turbo I have tested.

If you live like we do down here in South Florida with lots of traffic and not a lot of roads to open these things up this is it. The quick spool, quick torque red light running short blast racing is what we do. We jockey for position try line up next to each other on every light. That's my point with the 70mm.

From what I have seen so far and it has been hard to get a full WOT pass without the track. The 67.7 will produce the boost and maintain all the way to the top of my shift points. A lot more testing on this Turbo is needed but I can definitely tell it pulls harder on the upper RPM. The 67.7/74 spools really quick. I was really reluctant to try this Turbo because of the way the box 366 I tested a long time ago reacted. This is not that Turbo for sure. Not even close. It spools quick and reacts fast to any throttle movement.

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MadDiesel73 · Nov 27, 2014

what were your back pressure numbers with the 64.5/70? im thinking 67.7/70 just dont know what kind of gains to expect.

dseitler · Nov 27, 2014

Most of the time under max conditions it was 57 to 58 psi. On time I recorded up hill a reading of 61 psi. I have a manual gauge and electronic that will record peak numbers and I had the alarm set at 63 psi. Never hit the alarm.

I could be totally wrong but I'm not sure if there has been a 67.7/70 on a 6.7 Powerstroke yet. We have plans for me to test that Turbo next after I am done with the 67.7/74. We were going to monitor back pressure and check on possible surging issues but the 6.7 heads flow so well I don't think that will be a problem. Like I said this might be done by now I passed and went for the 67.7 first and then was going back. My final goal is to have this done and then my final Turbo will be the 69/74. I'm convinced that's the right Turbo for me.

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