Hi im a noob i guess but anyways i am a little curious on how to use the flex recording to convert my vhs to dvd because most of my vhs are around 2.5hrs to 3hrs long.

For sure Panasonics and Pioneer DVDRs have flex recording. To use it on a Panny you bring up the FR menu and enter in the time you want to fill up the disc. If your tape is 2hrs 32 minutes then simply enter that time(maybe add a minute extra) when you push enter the machine will fill up the disc with the time you've entered.
Note some machines do have a 2 1/2 hr. or even 3hr canned speed. I know the Philips HDD model does. Pannys canned speeds go from 2hrs all the way to 4hrs/disc. You need to use FR for speeds in between.

Panasonic's Flexible Recording feature fills or fits a recording of specific length to a blank or partially filled DVD for the best picture quality for the open space on a DVD. In addition to the FR menu, FR recording may be chosen in the SCHEDULE menu for a single recording that fills a blank DVD or fits the final recording onto a partially filled DVD. When scheduling the final recording on a partially filled DVD the "OK" indicates that there is enough room on the disc for the recording; "!" indicates that there is not enough room for the recording. On a Panasonic the amount of FR room on a blank DVD will range from one to eight hours, the range of best picture quality down to the poorest picture quality.

In my large dubbing project (around 5,200 titles) I made extensive use of FR as selected from the COPY menu in my older Panasonic combo recorders, the DMR-ES30V and DMR-ES35V models. The essential menu-initiated FR COPY feature is no longer found on Panasonic's 2007 and 2008 combo recorders.

Odd that this thread should come up now, right after I discovered--or rediscovered (I might have known about it early on)--the beauty of Panny's FR mode. When I first got my Panny DMR-E85, I used FR to squeeze an over-long program on the HDD to a single DVD-R. The problem was that the dub had to grind away in real time, tying up the machine and putting extra wear on the burner drive. Plus, I don't like dropping much below the SP data rate, except for talk shows and slow-moving documentaries, so I basically just lived with the 2-hours-per-disc limitation (actually about 2:09).....

Then last weekend, I wanted to dub a 2:20 program from VHS to HDD to DVD-R, and I thought, crud, I either have to blow 2 discs and waste space on one of them (or find a filler) or use the LP mode and lose a lot of PQ. I pulled out the E85's manual and discovered that I can use FR to record to the HDD. So I set it up for 2:25 (for a little cushion), dubbed the tape to the HDD, sliced-n-diced chapter breaks, and got a near SP-quality picture on one disc. Wish I'd realized/remembered this capability a long time ago!

Panny, and maybe only Panny, continues to use 720x480 in the LP Mode (up to 4 hours) only in a reduced bitrate than SP.

So any recording between 2 and 4 hours maintains excellent quality, especially when converting VHS tapes which are a reduced resolution than DVD.

I currently create NFL Sunday DVDs for my daughter's relative who is a Bears fan which consists of the weekly Bears football game (3 to 3-1/2 hours) in LP mode and then the following telecast of Bears Postgame Live on Comcast Sports Chicago (usually 1-1/2hr) in Flex mode off of my DirecTV HD receiver and the quality is especially good on his older standard definition TV, and even looks good on my HDTV.