Performance Chips - Before & After Dyno's
 

Whoa! The acrimonious thread I started on performance chips can be settled if anybody has got dynamometer readings of BHP and torque through the rev range taken before and after fitting a performance chip, with no other modifications having been made. That is same air in, exhaust configuration, fuel used etc before and after chip installation. Lets see the figures!

My personal view is that in the UK the after market chips enable the 964 to take advantage of the 98/99 octane fuel we have available by running the car with more ignition advance than the standard Motronic chip which is optimised for UK 95 octane fuel. If the only fuel available in the US is 91 octane I would guess no benefit can be obtained by fitting a performance chip.

When I had my chip fitted I tried this but without success at G-Force in Aylesbury. We managed to get a dyno reading with the stock chip but they failed to get a reading with the performance chip - the wheels spun each time (and no, I don't think it was due to huge amounts of power from the chip). We gave up, and I settled for the fact that at least with the stock chip my power output seemed OK.

US octane ratings are RON + MON / 2. And each state has different gas. Near NYC we can get 93 or 94 R+M/2, which roughly the same as 98-99 in the UK.

Geoffrey and I have data (some 35-40 pulls) of various chips, exhaust, airbox mods ect. none with a fully stock exhaust but all of our data is with stock headers ( they are really very good ). There is know doubt that the rs chip yields Rwhp ( 11 rwhp) alone. A few more can be had with fuel and timing changes. even more with cat by pass, primary and secondary by passes, and air box mod . Should you bother for the street,?? I can't say as my car is a track only car, But it is fun to try.