Definitely with, and my personal preference is pin stripes in a different color to accent your racing stripes. Just sayin', but you do you since it's your car, not mine
Without. There is too much going on with the pin stripes being the same color, it reminds me of those 90s Waldoch vans. Now if you go another color, then with. Also, if you go with a different color, make the pinstripes touch the black. Not sure what color your calipers are, but yellow would look good, so would red. But whatever color it is, it would need to match that accent color you have on the calipers, or roll bar, or whatever.
That said, with white and black, it's hard to make an accent color tie in well. If your stripes were colored, then it gets easier and you have more wiggle room on selecting a color.
But it's your car, not mine. Run with whatever you like best!
I like accent colors so l would go bronze pinstripes to match some bronze wheels to wake up all the white and black. Goes great with red calipers in my opinion as well.
I vote with, but also second one of the others who replied about maybe considering a secondary colour
I have the factory stripe that is the thick stripe and a narrower stripe, I have highlighted mine with a single orange pinstripe. The orange detailing also extends to the brembo brake stickers, 5.0 badge and the "powered by ford" engine cover
And if you look carefully, an orange Jelly belly air freshener. All thr "my colour" lighting and dials are all orange too. My local Football Team (Soccer for you guys the other side of the pond) play in Tangerine so I always add a bit of Tangerinne (orange) to every car I have owned.
I'm kind of partial to pinstripes since 1968 when we had a 10th grade teacher with a '68 Mustang with 1/4 inch pinstripes the same color as the wide stripes (with a 1/4 inch gap in between).
And then my neighbor purchased a '70 Torino Cobra which had 1/4 inch black stripes surrounding the black-painted hood (also with a 1/4 inch body color gap in between). So that has been my preference since, as you can see from my car.
But, there's no right or wrong on choice. It is whatever YOU like. Go for it!
As presented, I would say no pinstripe. Agree with others, the pinstripe should be a different color and sit right next to the black stripe. My previous Triple Yellow S550 had black stripes with red pins. I really liked that color combo.