No constant answer - parasitic losses will include alternator, air cond, power steering, fan, and any other accessories. And it will make a difference if there is a lot vs minimal electrical draw on alternator and whether fan clutch is in good shape etc. Then figure efficiency loses in transmission and rear end. 15% may be ballpark loses, but I suspect it may be a bit high at the HP range you are at or a bit low on a 100 HP engine. Back in the 70's when they went to Net HP instead of previous Gross HP, we did a 240Z which was140 or there abouts Gross rated HP but in the 80-90 HP range Net on a chassis dyno. You could pick up about 10% by opening up exhaust and another 4 to 5% by losing Air Cleaner element, but it was difficult to get over 100 HP with alternator and fan plus transmission losses. I would kind of guess the losses are more nearly a constant 40-50 HP rather than a %. but best to run engine alone on dyno before installing in car if you really want to know. Dave Schwandt wrote: > > > Figure losing 15% in the drivetrain, at least that's what they figure > on a > big truck. > > That makes it approximatley 490 HP > > Dave Schwandt > ----- Original Message ----- > From: "bluesport62" <LUCKYL46@xxxxxxx <mailto:LUCKYL46%40aol.com>> > To: <Chrysler300@xxxxxxxxxxxxxxx <mailto:Chrysler300%40yahoogroups.com>> > Sent: Wednesday, September 30, 2009 8:02 PM > Subject: [Chrysler300] dyno > > > HI GANG. MAYBE SOMEONE CAN ANSWER THIS QUESTION. IF A DYNO READS > 417HP AT > > THE REAR WHEELS WHAT IS THE HORSE POWER AT THE FLYWHEEL? THANKS JOE > > QUEENS NY > > > > > > > > ------------------------------------ > > > > To send a message to this group, send an email to: > > Chrysler300@xxxxxxxxxxxxxxx <mailto:Chrysler300%40yahoogroups.com> > > > > For list server instructions, go to > > http://www.chrysler300club.com/yahoolist/inst.htm > <http://www.chrysler300club.com/yahoolist/inst.htm> > > > > For archives go to http://www.forwardlook.net/300-archive/Yahoo > <http://www.forwardlook.net/300-archive/Yahoo>! Groups > > Links > > > > > > > > > > ------------------------------------ To send a message to this group, send an email to: Chrysler300@xxxxxxxxxxxxxxx For list server instructions, go to http://www.chrysler300club.com/yahoolist/inst.htm For archives go to http://www.forwardlook.net/300-archive/Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Chrysler300/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Chrysler300/join (Yahoo! ID required) <*> To change settings via email: mailto:Chrysler300-digest@xxxxxxxxxxxxxxx mailto:Chrysler300-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: Chrysler300-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/