My understanding has been that trap speeds are an indicator of power, (or what the car is capable of).
There are a few quarter mile calculators on the internet that will calculate estimated whp based on vehicle weight and trap speed, and also estimate ETs based on weight and power. HERE IS A LINK TO ONE
Using the 90mph trap and estimating a weight of 3050, the calc estimates about 173whp (seems a bit high but whatever), then using that weight and estimated HP, the calc estimated a quarter mile time of 15.1 @ 90mph.
I'm not sure what the assumptions are with this calculator (like 60' times)... MAYBE on an absolutely perfect run with a great launch you could hit that time, but I highly doubt that it's likely... It's difficult to get a good launch in a FWD, especially without slicks or drag radials. Seems like if you could get your 60's down in the 2.2 range, you could hit a 15.5. With an exhaust and header, I think high 14's are possible
, but the limiting factor would be traction; a low 15 seems much more likely. For comparisons sake, 02-03 'bug eye' WRXs could run high 14's at 92-93 mph stock, but they could also pull 60' times under 2 seconds.