Has anyone installed one of the 3+ psi boost pulleys available from Auto Specialties Performace (ASP) on a supercharged Xterra? They claim all that is necessary after install is to allow the computer to re-calibrate by clearing the memory (i.e. disconnect the battery for a few minutes). I'm curious whether anyone who has installed one has felt the 26hp rear wheel increase they claim and whether you had any problems with knocking on 91 or 92 octane premium gas. They also claim that no change is required in octane rating.

Thanks!

2001 supercharged? is that aftermarket?????

Ooops, sorry. Poor typing skills. It's 2002 factory.

Their data doesn't seem to agree. Consistently higher horsepower from higher boost, yet no increase in fuel octane requirements to retard pre-detonation. Lots of factors will affect pre-detonation besides octane ratings. Altitude (amount of oxygen in the air), Temperature, Humidity. They're all related. It'd be interesting to see under what conditions they tested for pre-detonation to qualify their statements.

Regardless, here's some links to other people's posts on running the SC with higher RPM's.

http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=70;t=00002 2#000000
http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=70;t=00003 7#000000
http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=70;t=00006 3#000000
http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=70;t=00012 5#000000
http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=70;t=00011 7#000000

Hope they help.

Thanks for the other links. I called ASP again and relayed some of the info to them regarding ping. I asked to speak the their head technician, and from what I could tell, he was fairly knowledgable. He stated that their pulley is actually 2.35 inch and said in testing (with Texas 92 octane gas), anything smaller would ping. He said the Pulley Boy pulleys are a copy of theirs, but wasn't sure if it as 2.30 inch or 2.35 inch. He reiterated that they have never had anyone return their pulley for pinging problems, nor have they recieved any complaints of pinging, no matter what state the customer lived in. Then again, when I asked whether they would refund my investment if it did ping, their responce was no, because "you'll never get the pulley off again without damaging it". I guess if I do this I'll just have to anticipate the potential that it might just be $250 right off if it does ping on the crap 91 octane stuff we get in San Diego.