Wrong Cylinder Size

I have pumped a few times with a custom made pump. It has a pistol grip pump with a vacuum gauge that is pretty good quality. My real question pertains to the cylinder. It is a clear, thick walled, hard plastic cylinder that is 2.5 inches ID and 7.5 inches long. I use a commercial donut to form a good seal. I currently measure 6.75 BPEL and 5.5 inches in girth mid shaft with 5.25 inches girth at the base. I pump to around 5 in Hg for three 10-15 minute intervals. I really want to maximize my pumping results, especially length which I know is difficult. Do you think that my cylinder is too large, particularly in diameter, to achieve efficient results? Would a 2 inch ID cylinder be more effective? Should I even try a 1.75 ID cylinder even though I will probably pack it? Any comments and suggestions about how to better my pumping would be greatly appreciated!

Thanks

No offense to you personally, but here is the link to the “pumpers” forum Pumper’s Forum

They should be able to help you.

As long as your donut seal is comfortable and works well, there is no need to buy a larger cylinder. Your cock doesn’t know what size vacuum chamber it is in. The main reason for choosing the correct size is to find a size that allows for significant expansion while not being too big to allow your balls from being drawn in be the vacuum. But your donut seal seems to solve this issue.

If the donut seal is getting to be too much of a hassle, the correct size cylinder for you would be a 9.0X2.0.

nv,

If you have the funds, I’d buy a 9” x 2” cylinder. Psychologically, I found it more visibly encouraging as a newbie to monitor my pumping growth progress by first starting with a 9” x 1.75” cylinder, packing it, and then moving on to a 9” x 2” cylinder, packing it, moving on to a 9” x 2.25”, etc.