And I'm really getting tired of people automatically posting the same into every requests thread, saying how wrong they (creaters) are with opening a new thread, giving a link without even checking if the content matches what he's asking for in the OP.
He's asking for a topspeed tune, the search function gives 0 results, neither does your link help, because there's no topspeed tune for this car.
@OP
I have a 3000m tune with a trapspeed of 253mph.
What you definitely should do is to set ride height max/min. Try a wing, because my 3000m tune reaches higher speeds with wing than without.
The rest.....I can't really help you, because I've never tuned it for topspeed.