I recently changed my allignment to the Prodrive setting i.e. 1 mm toe-in front and back and 1 degree negative camber.

Cornering has greatly improved but I feel that the car is now struggling to get beyond 220 km/h whereas before it easily went to 240 km/h (it's a '96 WRX with 260 hp).

Had only 1 run sofar so maybe wind played a role but was wondering whether the toe-in increases the rolling resistance and therefore reduces top speed.

If correct this doesn't bode well for the tire wear...

Hope to hear

Tnks

Frank

 

You will have to allow a few miles for the tyres to "settle in" to their new alignment settings. The adjustment will not fully take effect untill this has occurred and the tyre edges have bedded in.
You may well find the speed may be affected as the settings are for "handling" and not simply for highest road speed. At the end of the day, do you want top end speed or something that feels very sure footed round corners?
It is a very fine line to attempt to get both all the time