Relation: Race Power / FTP for long events

Since 2001, over 90,000 cyclist's have joined Cycling Forums to discuss topics from general cycling to equipment, training, racing and travel or vacation destinations (especially in europe during the tour de france). We also feature an great deals in our online store, 100's of articles, classifieds and product reviews.

I usually race in event 110/130km long on hilly road with some serious uphill (total ascent 1500/2000 m).

My avg power is around 250/260 watt and my NP about 270/280.

Is there a relation between NP/time and FTP? I know there is for shorter distance (I use it for interval workout), but can I apply it also for longer races?