I installed a 'dynolicious' on my iphone yesterday - as far as I can work out a G-tech meter ripoff that uses the iphone's inbuilt accelerometers to test 1/4 mile times an HP;
best run;

the mph/and hp figures are actually kph+kw
0-100 8.18sec
1/4mile 15.85 sec@135.6 km/h
peak kw 114w - I don't think so!
there is some weird peak at the 3rd gear change which caused this hi kw reading. I did 2 other runs (but had start triggering issues which affected the 0-100kph times) in total and the average kw figure is 96kw, which seems more likely.
It would be interesting to see what other forum members with iphones get, especially those who have dyoned their car.
here is one of my bog standard 2000 corolla;
best run

3 runs
ave 0-100 time 10.39sec
1/4 mile 17.39@134.8km/h
peak kw 87
this seems about right.
Tis good fun and it has a cool realtime g-meter. - looks like a cheap tool($15) to Analise hilclimb runs/ laptmes.
ps, I'll look at the K&N part number the next time I take em off and post it here.