Venusian Days and the Runaway Greenhouse Effect: I think the problem with the question is that there are many factors that can create extreme weather. I'm going off my memory of astronomy class so forgive me if this isn't 100% accurate. Venus's day contributes to its bad weather because the long day causes the sun to cook one side for way too long, then all the water vapor goes to the other side, and since water vapor is a greenhouse gas, the other side gets cooked. Then the whole planet gets so roasted that the interior outgases more water in addition to all the nasty chemicals it has today, forming a feedback loop. I don't think you want to build a planet with a runaway greenhouse effect.
Day Lengths, Wind Cells, and Oceanic Currents: The thing about day lengths longer than 24 hours is that in the absence of being roasted, you can actually get lower wind speeds, and since you want an eccentric but still earth-like planet, that's what you would likely get with a longer day. Instead, I would speed the day up. I just read that without the moon, we might have an eight hour day, and as a result 100 mph winds. Speed that up to 6 hours, and you go from Earth's 3 wind cells to 7 wind cells, which in turn affect how many oceanic currents you have. Oceanic currents and wind cells are where you get hot and cold chasing each other, and as a result very bad weather! So, if you want Earth with really bad weather, that's the direction I would suggest you go.
Tidal Locking: You could also make your day the same length as your year, but this will create a very particular type of planet. Assuming other factors don't cause a runaway greenhouse effect, you will have a frozen night side, a tiny habitable strip along a band of permanent dawn/dusk, and a neverending mega-hypercane on the side facing the sun. My personal spin on this would be to make the orbit just a little eccentric to make the sun move up and down in the sky and give it a little bit of a day-night cycle, but that is just my crazy idea, maybe it would break the tidal locking if you did the math. Additionally, if you tilted the axis of a non-tidally locked planet ninety degrees, I would think you'd get the same effect, except the spin would affect air currents, which would no longer be straight, but would spiral. This option might be more plausible for an earth-like planet around a sun-like star, because the distance and/or presence of a large moon might prevent tidal-locking. EDIT: I was reflecting on this and realized tilting a planet ninety degrees wouldn't be anywhere close to tidal locking, because it would still result in a day-night cycle, just one that is as long as the year, whereas tidal locking has no day-night cycle, and rotates once every year.
Other Factors that Affect Weather: As I said before, other factors affect extreme weather. Tall mountains and large bodies of water have a major effect on weather, and can be placed strategically for maximal weather mayhem. Check out Artifexian's channel. He has a great deal of information on several of the things I just covered. In this video, he explains rotation periods and wind cells. At the end, he also explains that Middle Earth is already full of mountains, so if you just make the body of water in the center bigger and connect it to an ocean, you get never-ending thunderstorms.
Conclusion: I wouldn't just use the length of the day to make a bad weather version of Earth. I would look at other properties of planetary motion and/or unfortunate geographic coincidences as a better vehicle to accomplish this.