CAI data : open box vs close box. Data results

[Flyhalf]

So as many of you knows I track on roadcourse my 18 10speed.
I'm also data driven for a lot of my choices.
I made 2 years ago a video about JLT CAI testing
On dyno. Pre and post (tune no cai vs tune with CAI) showing a major gain on HP.
However after years there is still the debate on
"Hood up hood down " or "real results are hoods down
Ive already share what i think about it:
Hood must be up. Cause you try to simulate energy and heat to reach 160mph...without the air at that speed to cool down.
And you heat soak.
But i accept the critics and the challenges and I always try to find an answer.. once again with data.
I went a step further.
i have big hood vents just above my CAI.
With my tuner we wanted to see if a closed airbox will increase pressure in the airbox (ram effect) while now the air coming from the front evacuates from the vent .
So
I made a airbox cover (plexiglass) seal everything and
I data log pulls with and without the cover. Same street. Same time( 20mins apart)
Well results were these:
Roughly 2 lbs/min LESS AIR FLOW IN THE CLOSE BOX VS open CAI
REMEMBER that 1 lb/min is approximately 10 bhp

So for me from now ,at least with my vents, i stick with OPEN CAI. At least for roadcourse.

I'm not sure for drag if makes sense. But the temps rise slower on a close system but also cool down slower too.
Open cai temps raise and cool extremely fast.
And more air moved.
Just food for thoughts.
Hope this can help
Alessandro

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[Kennysum1]

Thanks for the data man. Lots of people come with claims and not even logs.

This is good to know for everyone. Working on my 22 road course build and I have a closed roush CAI (no tune yet) and I doubt to see any real gains over a OEM closed CAI. But it will say Roush on it and look cool

 

[WildHorse]

Roughly 2 lbs/min LESS AIR FLOW IN THE CLOSE BOX VS open CAI
REMEMBER that 1 lb/min is approximately 10 bhp

Tests are subjective. At the 1/4 mile track my 18+ airbox on my 17 GT is consistently faster than my 120mm PMAS.

 

[Flyhalf]

Tests are subjective. At the 1/4 mile track my 18+ airbox on my 17 GT is consistently faster than my 120mm PMAS.

With respect that is a subjective test.
Base on your specific application, on different days, different conditions ,.different weather etc.

This is a data driven test. Made back to back
With almost 2lbs/min less air in closed box.

Then ,as mentioned , we can say and investigate more if is better 2lbs of more air or a less dense air for the first 3 second of the sprint?

And to be clear. I'm not here to sell open CAI

 

[K4fxd]

How did your lap times compare?

This 2 lbs more air is this adjusted with fuel trims? IE are the trims the same.

 

[Flyhalf]

How did your lap times compare?

This 2 lbs more air is this adjusted with fuel trims? IE are the trims the same.

I will not test the car with the cover cause a dyno test and a "real life test " with 100mph air pushed in , proved less air in the engine.so less power.
I also doubt laptime will be a effective test Cause so many variables are there. The closest thing to a good test could be max straight speed. However u would need places like daytona or fontana to effective prove it (long enough) cause otherwise a more or less.speed could be because a better turn exit or later braking.

 

[Scootsmcgreggor]

Interesting Ale. Do you still have your stock intake to compare using this saMe testing methodology to your open CAI ? Would be really interesting.

 

[Flyhalf]

Interesting Ale. Do you still have your stock intake to compare using this saMe testing methodology to your open CAI ? Would be really interesting.

Somewhere it will be very hard.. to do soon.
I did test on dyno tho. And is way less power.
Trying to think what could be the different with this jlt covered... Maybe a better shape? Not sure tho.

 

[EFI]

close system but also cool down slower too.
Open cai temps raise and cool extremely fast.

That's interesting. I would've thought that a sealed box with the only source of air being through the front snorkel would cool down really fast especially if you have the grill fully open.

Is there that much air leaking through the bumper and around the headlights that an open element filter can use?

Also when you mean open CAI, do you mean literally just the cone filter at the end of the tube with no box? Or just the original JLT box but without the plexiglass cover?

 

[GregO]

@Flyhalf , how’s the GT350 manifold swap turning out ?

 

[Flyhalf]

@Flyhalf , how’s the GT350 manifold swap turning out ?

Not worth for peak power

That's interesting. I would've thought that a sealed box with the only source of air being through the front snorkel would cool down really fast especially if you have the grill fully open.

Is there that much air leaking through the bumper and around the headlights that an open element filter can use?

Also when you mean open CAI, do you mean literally just the cone filter at the end of the tube with no box? Or just the original JLT box but without the plexiglass cover?

The front tube is pretty sealed to the JLT box (i have the box)

With the open box i run 2f max 3 above ambient.
Sealed is the same. But in strong acceleration the temps are decreasing way faster on the open one. (maybe cause it takes cooler air from the hood vents ? While otherwise is from the inside the box which is warmer?)

@GregO the 350 seems to not be super worthy. The gain is not with peaks but a better usage between 6 and 7k rpm.
I kept the 2018 JLT CAI. is slighlty different (filter is slighlty smaller) but i dont think this is a huge difference. The graph shows the green line better around 6 7k

 

[GregO]

the 350 seems to not be super worthy. The gain is not with peaks but a better usage between 6 and 7k rpm.

I’m referring to the GT350 intake manifold not the filter to TB system.

 

[Flyhalf]

I’m referring to the GT350 intake manifold not the filter to TB system.

Yeah thats what i meant.
The ported 350 and TB does not give that much more.
The only thing i was saying is i kept the JLT CAI FROM THE 18manifold (which is slighty smaller)

 

[GregO]

Yeah thats what i meant.
The ported 350 and TB does not give that much more.
The only thing i was saying is i kept the JLT CAI FROM THE 18manifold (which is slighty smaller)

Are you still running the 2.25” exhaust connections at the header connect to mid-pipe ?

 

[Flyhalf]

Are you still running the 2.25” exhaust connections at the header connect to mid-pipe ?

I have headers. And borla atak 3.
However i had to put the borla resonator to pass sound at laguna.. maybe that is a little restriction? But it didn't change so resonator is a constant

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