Whats with these things?
usually the ones that claim the 25hp and such are nothing more than a resistor... they trick the IAT sensor into making the car think it's really cold out (30s) ... in so doing they want you to believe it's adding timing yada yada
Truth is there are several tables in the PCM that are IAT referenced (timing being one of them) but in a stock PCM very little timing is taken out during normal operating conditions ... and fact is if the incoming air temp is 130* ... do you really want to tell the PCM it's only 30*? Just to get a degree or two of timing (stock PCM will pull a couple degrees timing if the IAT is really high ... it's a safety thing... hot IAT means hotter than normal incoming air charge means higher chance of pre-ignition/detonation)
The only way I can see doing the "resistor chip mod" as being viable... is if you program your IAT referenced timing tables in the PCM so that you can use a potentionmeter of known resistances to manually add/remove a certain degree of timing (this is popular in the Grand Prix world... mostly because until recent years no company had do it yourself tuning packages)
http://cgi.ebay.com/ebaymotors/RACIN...QQcmdZViewItem
Regardless... it's a waste of money


