6.4L Y Pipe Swap

[spark plug]

$$$$$$$$

Just curious. How is the Y pipe change working? Any difference in power or fuel mileage?

 

[HEMIMANN]

Interesting show on Engine Masters Friday evening, on Motor Trend TV.

They tested a Hemi for the 1st time (they're big Chevy small block fans). One of the tests they did was the effect of a crimped y pipe and an open, fabricated y pipe. The speed sweep test results showed miniscule difference in torque and power.

Obviously, there has to be some difference due to the flow restriction differences, but it wasn't enough to feel the difference, or warrant the expense. The same can't be said due to long tube headers, which have consistently shown measured torque increase ~ +10% on any V8 (google for results).

My read on this are cat-backs are worthless for increased performance, unless you like a noisy truck. Many do, but not me. I was going to put LT headers on until I saw the difficulties in a heavy duty frame, plus the expense.

I'll just live with my canned tuner package. It helped a lot towing heavy (for me) loads, like wet, black, dirt in my utility trailer.

 

[spark plug]

Interesting show on Engine Masters Friday evening, on Motor Trend TV.

They tested a Hemi for the 1st time (they're big Chevy small block fans). One of the tests they did was the effect of a crimped y pipe and an open, fabricated y pipe. The speed sweep test results showed miniscule difference in torque and power.

Obviously, there has to be some difference due to the flow restriction differences, but it wasn't enough to feel the difference, or warrant the expense. The same can't be said due to long tube headers, which have consistently shown measured torque increase ~ +10% on any V8 (google for results).

My read on this are cat-backs are worthless for increased performance, unless you like a noisy truck. Many do, but not me. I was going to put LT headers on until I saw the difficulties in a heavy duty frame, plus the expense.

I'll just live with my canned tuner package. It helped a lot towing heavy (for me) loads, like wet, black, dirt in my utility trailer.

I see you added a TB. Im debating on doing the 87mm. How did you like that. I do plan to do a tune, once they can unlock the 22 PCM

 

[HEMIMANN]

I see you added a TB. Im debating on doing the 87mm. How did you like that. I do plan to do a tune, once they can unlock the 22 PCM

It helps reduce the acceleration response lag to an extent. I can't speak to whether it's more or less than an electronic throttle controller, since I don't have one.

Doesn't Hemifever (a site sponsor) have a custom tune ECM for the Gen V truck? I'd sure think so by now.
You just send them your factory ECM back as a core so they can wipe it and create another custom tune ECM.

 

[Hawkeye Jim]

Just curious. How is the Y pipe change working? Any difference in power or fuel mileage?

All I did was swap the factory muffler with a Mufflex. Maybe .5 mpg highway gain. That could be the engine breaking in too. No difference in feel of acceleration. Just a bit louder. Still planning on swapping the Y Pipe soon. I know both made a big difference in my 1500. Seems like not so much in the 6.4L.

 

[Hawkeye Jim]

Interesting show on Engine Masters Friday evening, on Motor Trend TV.

They tested a Hemi for the 1st time (they're big Chevy small block fans). One of the tests they did was the effect of a crimped y pipe and an open, fabricated y pipe. The speed sweep test results showed miniscule difference in torque and power.

Obviously, there has to be some difference due to the flow restriction differences, but it wasn't enough to feel the difference, or warrant the expense. The same can't be said due to long tube headers, which have consistently shown measured torque increase ~ +10% on any V8 (google for results).

My read on this are cat-backs are worthless for increased performance, unless you like a noisy truck. Many do, but not me. I was going to put LT headers on until I saw the difficulties in a heavy duty frame, plus the expense.

I'll just live with my canned tuner package. It helped a lot towing heavy (for me) loads, like wet, black, dirt in my utility trailer.

Did they change both the Y Pipe and the muffler? Both are restrictive so if you change 1, you still have the other restriction. Curious. and was it a 5.7 or 6.4?

 

[HEMIMANN]

Did they change both the Y Pipe and the muffler? Both are restrictive so if you change 1, you still have the other restriction. Curious. and was it a 5.7 or 6.4?

They like to test one item change at a time, unlike what we were taught per Taguchi Design of Experiments.

So yes, they left the muffler the same. It was a 5.7L. You can google on Motor Trend TV and watch it yourself, I believe. I'm just the middle man here.

 

[Hawkeye Jim]

They like to test one item change at a time, unlike what we were taught per Taguchi Design of Experiments.

So yes, they left the muffler the same. It was a 5.7L. You can google on Motor Trend TV and watch it yourself, I believe. I'm just the middle man here.

I will do that Boss. Thanks.

 

[BigLazer4u]

So you got a sound clip? Looks like a set up I’d consider replicating.

I do. https://youtube.com/shorts/VEjsPpZNNTY?feature=share