[Drew778]

Originally Posted by EDFHOBBIES

3 weeks or sooner. I think he will have me something this week for my 2650 103mm TB that needs a tune vs the standard non tune one.

Any updates?

I had a roto fab CAI with dry filter, but sold it because I was trying to sell my car....I have the stock airbox with a green filter and a TM ported tb now.

I’m trying to go the stealthy route also 😬

[EDFHOBBIES]

Initially we did data testing and well the results were on par on my 2650 we went from 666 to 699 rwhp just from the swap no tunning on the non tune version 4 inch. I'm putting him in touch with 2 friends that are stock to see what the power would on them.

[Drew778]

Originally Posted by EDFHOBBIES

Initially we did data testing and well the results were on par on my 2650 we went from 666 to 699 rwhp just from the swap no tunning on the non tune version 4 inch. I'm putting him in touch with 2 friends that are stock to see what the power would on them.

Thanks!

[ZLRob]

This is a crazy old thread but there is still relevancy to it.


I should preface any of this by saying that I did not do this mod for any perceived audible increase of the blower, I already have enough as it is, but I did it just to see if it did anything to my set up because at my power levels there was a high chance that I am/ was being restricted with the factory unit as has been discussed ad nauseum in other threads involving the RF intake and similar.


As it turns out, Callaway was onto something and EDFHobbies opened up the floodgates on it entirely.


All things being equal outside of this mod, doing this and this alone gave me a 5% increase in fueling (ie there has been a change in airflow to where things are getting more air than before) up top in the RPM band and the power gain was so considerable that it actually knocked out my high side fuel control to point where the HPFP needed some tweaks done to it in order to try and reign it back into proper control.


Previous HPFP running degrees up top was about 102* max during my run. This run took me and capped my HPFP to 130* duration and sporadically dropped out fueling after that due to the fact that it topped out.


MAF frequency also increased by 106 Hz up top.
Peak boost pressure increased by 1.41 PSI and stayed fairly consistent up top as well.
Oh yeah, I forgot to mention that where I used to be within 3% fuel control at idle which is incredibly clean on the fuel trims, doing this mod changed that to where the trims are now sitting between 10-11% LTFT's, which is by all accounts dirty.


The mod works, but it works considerably better on an engine that requires the extra airflow to see any sort of benefits from it.


GM did a great job on the factory set up, the issue is once you start going past factory power levels, it becomes a bottleneck, but you can still revise it similar to what Callaway, Hawk, and EDF did to allow your engine more breathing room if that's what it requires, otherwise the factory unit is good to say about 650 RWHP (at most, more than likely it's probably only good to about 600 RWHP) before you have to do something about it if you want to keep it for whatever reason.


Just figured I'd update this for anyone currently on the forum using the factory set up or for anyone who likes looking/ knowing about data changes based on hardware changes/ revisions.

[ZLRob]

Update:


Addressed the high side issues in tune and reflashed. Finally was able to get out for a run to see where things would land not expecting too much out of it all... Here's the data as follows:


Before intake mod
723.5 RWHP
765 Ft. Lbs RWTQ


After intake mod
752.2 RWHP
794 Ft. Lbs RWTQ


With saying that, as it turns out, the 5% gain in fueling was worth 28.7 RWHP and 29 RWTQ. Which by all accounts are impressive results based on a very straight forward change to the stock intake alone. The gains obtained from this mod are the equivalent to RotoFab numbers with the hood down. Power drop off doesn't seem to be as prevalent after 6100 RPM before for the set up like it used to be, which tells me that indeed the intake was choking things out up top. The car seems to respond better all around and even under low effort driving conditions (stop and go traffic etc.) it seems to feel a lot happier now with less hesitations and weird little quirks that it had before. Things are just smoother overall.


All other data points remained close or similar to the previous post, the only considerable change being the high side dropped down to 113* at its peak, so fuel control is well accounted for and well under control now.


I'm going to call this mod a success and I'm going to call the new power delivery this thing has perfect for the streets, which is where the car predominantly lives with many and plenty Italian tune ups to keep things clean and cleared out. As far as any road racing or general track duties are concerned, she's ready to throw down and hold her own, reliably and for many years to come.

[hawk02]

If you compare the OEM airbox on the Cadillac CT5-V Blackwing to the one on the ZL1, the Blackwing has an additional inlet near the passenger-side front fender. I’ve always suspected that extra airflow contributes to its ~18 hp advantage with the LT4—along with the wideband O2 sensor helping keep fueling in the optimal range.

You’ve confirmed what I suspected—and clearly, the Cadillac engineers felt the engine needed to breath better.

The other change is the intake tube is hard plastic instead of the rubbery tube used on the ZL1. No worries about collapsing under WOT.

[SpeZ]

Originally Posted by ZLRob

Update:...

Hmm, my 2019 ZL1 SC750 from Callaway just has the stock airbox with a green filter.

Actually at WOT the barometric pressure drops up to 1.5 PSI which means the supercharger creates a vacuum in the intake.
This leads to high wear of my LT5 TB which usually only lasts 1-2 seasons each time before it starts dropping off throttle body codes at WOT.

The main restriction is caused by the air filter. The surface is just not large enough.
A cone intake like rotofab offers a lot more filter surface.

For sure doing cuts in the stock airbox allows to suck in more air through the restriction. I see it as 1 main restriction from the filter and another smaller restriction by the small opening.

106 Hz to be fair does not sound like alot to be honest.

I might gonna try this anyway, if I fixed my fender liner. Which basically is barely there anymore.

Can you share what exactly you did on your stock intake?
I did already cut out all the grids from the lower half. Worried about the upper half in terms of MAF reading with changed airflow.
I am considering cutting the lower half like in the first post of this thread.

[hawk02]

Originally Posted by SpeZ

Hmm, my 2019 ZL1 SC750 from Callaway just has the stock airbox with a green filter.

Actually at WOT the barometric pressure drops up to 1.5 PSI which means the supercharger creates a vacuum in the intake.
This leads to high wear of my LT5 TB which usually only lasts 1-2 seasons each time before it starts dropping off throttle body codes at WOT.

The main restriction is caused by the air filter. The surface is just not large enough.
A cone intake like rotofab offers a lot more filter surface.

For sure doing cuts in the stock airbox allows to suck in more air through the restriction. I see it as 1 main restriction from the filter and another smaller restriction by the small opening.

106 Hz to be fair does not sound like alot to be honest.

I might gonna try this anyway, if I fixed my fender liner. Which basically is barely there anymore.

Can you share what exactly you did on your stock intake?
I did already cut out all the grids from the lower half. Worried about the upper half in terms of MAF reading with changed airflow.
I am considering cutting the lower half like in the first post of this thread.

No doubt the OEM paper filter is more restrictive than an oiled panel or cone, but my hesitation is how much a different filter alters the MAF signal due to changes in airflow quality. GM calibrated the MAF around the stock paper element, so changing that can shift the transfer function.

Turbulence clearly matters—otherwise GM wouldn’t have designed the airbox with a diverter/straightener ahead of the MAF. In my experience, a higher-flow filter might pick up a bit on the top end, but it can cost some mid-range torque if the MAF readings get skewed.

Of course, once you’re tuning, that concern largely goes away.

[ZLRob]

Originally Posted by hawk02

If you compare the OEM airbox on the Cadillac CT5-V Blackwing to the one on the ZL1, the Blackwing has an additional inlet near the passenger-side front fender. I’ve always suspected that extra airflow contributes to its ~18 hp advantage with the LT4—along with the wideband O2 sensor helping keep fueling in the optimal range.

You’ve confirmed what I suspected—and clearly, the Cadillac engineers felt the engine needed to breath better.

The other change is the intake tube is hard plastic instead of the rubbery tube used on the ZL1. No worries about collapsing under WOT.

It's crazy just how many refinements Cadillac made after the fact the Camaro rolled out. They were worth merit too because the results definitely speak for themselves.

Originally Posted by SpeZ

Hmm, my 2019 ZL1 SC750 from Callaway just has the stock airbox with a green filter.

Actually at WOT the barometric pressure drops up to 1.5 PSI which means the supercharger creates a vacuum in the intake.
This leads to high wear of my LT5 TB which usually only lasts 1-2 seasons each time before it starts dropping off throttle body codes at WOT.

The main restriction is caused by the air filter. The surface is just not large enough.
A cone intake like rotofab offers a lot more filter surface.

For sure doing cuts in the stock airbox allows to suck in more air through the restriction. I see it as 1 main restriction from the filter and another smaller restriction by the small opening.

106 Hz to be fair does not sound like alot to be honest.

I might gonna try this anyway, if I fixed my fender liner. Which basically is barely there anymore.

Can you share what exactly you did on your stock intake?
I did already cut out all the grids from the lower half. Worried about the upper half in terms of MAF reading with changed airflow.
I am considering cutting the lower half like in the first post of this thread.

106 Hz doesn't sound like a lot I agree, but when you are talking about frequency changes up top even a little goes a long way. The mod I did followed Hawk's and the only thing I did was go further than his cuts but not as far as EDF went on this box to preserve some of the boxes structural integrity. I didn't take a photo of the box but I took a photo of just how much I took off. It looks ugly, but I cleaned up the box once I finished my cuts, mostly at the ribs. Used a Dremel 3000 with the cut off wheel and a straight drill type cutting tool to dig into the plastic ribs. Then a small grinding stone to trim and smooth the remaining portion of the ribs which were exposed.

Originally Posted by hawk02

No doubt the OEM paper filter is more restrictive than an oiled panel or cone, but my hesitation is how much a different filter alters the MAF signal due to changes in airflow quality. GM calibrated the MAF around the stock paper element, so changing that can shift the transfer function.

Turbulence clearly matters—otherwise GM wouldn’t have designed the airbox with a diverter/straightener ahead of the MAF. In my experience, a higher-flow filter might pick up a bit on the top end, but it can cost some mid-range torque if the MAF readings get skewed.

Of course, once you’re tuning, that concern largely goes away.

Yeah and so for the filter itself, I am not too sure who makes the green filter or what it's airflow properties are, but I am and have been using an AEM DryFlow filter. It has proven to make the most airflow over the years between them, K&N, AFe, and definitely the paper stock one. I even proved it myself on another application years ago measuring between factory and the AEM, so using it on the Camaro when I first got it was no contest between it and the stock paper filter.