I can imagine they have far more grip with wider tyres on but....... The whole point of them is not to have a huge amount of grip so you don't have to being going overly fast to unsettle the car.
I had these made a while back when I had my 133. Just been doing a clear out and found them so thought I'd see if anyone's interested.
Each sticker dimension is: 60mm x 17mm
£4 posted
Yeah, there's more pull at the top end of the rev range mate. Sounds decent as well.
When I switched back to stock to sell the car it felt a bit strangled in comparison.