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Been toying with an idea to put vents on the #2&6 cell of an XL Cloud. Has anyone done this?
Purely would be a span canopy .

Looking for thoughts/ experience

why do you need vents for a span?

I don't
But also jump it out of Cessna and want to play with accuracy flying. I want to be able to sink it in without stalling.

Edited:
For BASE jumps I was thinking only spans

why do you need vents to jump out of planes?

I need the vents for accuracy flying - classic accuracy style.

So reword original question.
Has anyone ever used an XL Cloud on a BASE jump? Perrine height?
Has anyone here modified an XL Cloud with vents?

Why does it need to be classic to be accuracy style?

Yes they have been used for things lower then that. Not an awesome canopy but they work. And I'm not a canopy snob. As to vents, I'm surprised it doesn't already have them. They've been putting vents in that canopy for like 35 years. It's called a soft cell. It's an accuracy mod to lower toggle pressure. It's one or two huge cut outs in the #2 and #6 cell farther back on the canopy, like between the C and D lines. They were big, about 3 sq feet per cell.

Lee

So the ones you have seen, were the vents an open window patch supported with binding? or were they one way valve vents?
My plan was open window. thoughts?

Fill volume on the cells is really large and will take a long time to open. You are really a test pilot on gear that the BASE community abandoned a long time ago with good reason, no matter how much you modify it. I recall in the early 1980s and maybe late 1970s hearing about people doing this. It was quickly realized to be a horrible idea. Some of the canopies from that era, like the Stratocloud, worked great for slider down but they were not full on accuracy canopies. I see no reason for accuracy canopies given the current art of BASE canopy design. Interestingly, the old designs, like the Unit, etc., often had multiple attachment points and some bottom skin vents - which proceeded their introduction in the base community by almost 20 years.

They were just big fucking holes. No valves, no mesh. Some times they were just hot cut in the fabric but the "nice ones had tape sewn around the edges. like on a 7TU. That was classy work back then.

Lee

My strato cloud has vents like the one is the photo. I though they were factory. Now not sure.

I believe those were to create "soft cells" which serves a totally different purpose to the venting I assume the OP was asking about.

Would you please explain their purpose?

Classic Accuracy guys love fine tuning different aspects of their canopies. This is 1 of the ways they old school the shit out of their gear. It basically reduces the internal pressure in the "ported" cell.
Straight from PD in regards to the Zero Accuracy canopy:
"2. Venting: PD has pre­installed tapes for soft cell “ports” on the bottom surface and wingtip 
vents on the rear stabilizers to make it easy to further enhance the performance of your Zero."
"Soft cells serve two functions: they reduce toggle pressure (approx. 10%), and 
they improve stability in turbulence—particularly if a gust strikes the canopy from the side. The 
soft cell absorbs the impact and keeps it from transmitting spanwise."

P.S. I have no experience with these canopies other than what I have been told.

Thank you sir.