bhp

[Jeffrey Engel]

> From:          Andrew Rabbitt <AERabbitt at rce.ricardo.com>
> To:            "'diy_efi at coulomb.eng.ohio-state.edu'"
>                <diy_efi at coulomb.eng.ohio-state.edu>
> Subject:       RE: bhp
> Date:          Fri, 13 Jun 1997 09:50:45 +0100
> Reply-to:      diy_efi at coulomb.eng.ohio-state.edu

> 
> > Sometimes something a lot less awesome than a Merlin.  Several 
> > thousand miles ago I changed from Bosch Platinum plugs to Motorcraft. 
> > 
> > My 2.3l Turbo Coupe motor LOVED 'em!  I must have picked up 25 hp.  
> > My guess is that the Bosch plugs were misfiring enough to screw up my 
> > a/f ratios but not enough to detect in the seat-o-pants dyno.  
> > 
> I'm afraid that if you can't detect a misfire with your
> seat-of-the-pants dyno, I fail to believe you can measure 25hp with the
> same device!

Good point!  However, I've read that humans can't generally detect 
less than 7% misfire.  I suspect that with a couple percent misfire 
would add a bunch of HC to the exhaust and confuse the heck out of 
the EEC-IV.  Barrett Nicholas mentioned knock.  That is also 
possible.  My understanding is that platinum plugs run quite a bit 
hotter to keep the deposits burned off.

25hp?  You'd have to feel the difference.  It's quite noticeable.

je
jengel at fastlane.net

     "I can resist anything but temptation"
                                  Mark Twain