Formula for calc'ing HP based on MAF flow?
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From: Live Oak, FL - in the woods where the creatures lurk.
Re: Formula for calc'ing HP based on MAF flow? I've found that that value works out pretty good, at least for a stock MAF on a NA, mostly stock car. I have no idea what the resolution on the MAF flow is w/ heavily modified cars, but would like some feedback. I don't think it's the be-all / end-all formula, however.
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From: Bellevue, Wa
Re: Formula for calc'ing HP based on MAF flow? definetly not.
but was just curious to see what it comes up with prior to hitting the dyno.
I was told this formula assumes 100% efficiency which we of course don't get.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">That ignores AF, timing, compression, et cetera. That value is "what's the most power this amount of air can produce with 100% effeciency."</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I wonder what a good guestimate of percentage loss would be?
I pulled 20% out of my butt as a guess and the resulting number does fall in line with what I think the car is making.
<small>[ September 06, 2002, 06:13 PM: Message edited by: Blackbird ]</small>
but was just curious to see what it comes up with prior to hitting the dyno.
I was told this formula assumes 100% efficiency which we of course don't get.
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">That ignores AF, timing, compression, et cetera. That value is "what's the most power this amount of air can produce with 100% effeciency."</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I wonder what a good guestimate of percentage loss would be?
I pulled 20% out of my butt as a guess and the resulting number does fall in line with what I think the car is making.
<small>[ September 06, 2002, 06:13 PM: Message edited by: Blackbird ]</small>
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From: Bellevue, Wa
Re: Formula for calc'ing HP based on MAF flow? are you sure?
I hit 59.1 lb/min but the car certainly doesn't feel like it has 590 fwhp.
anybody know if I have modified my maf curve to compensate for bigger injectors if it throws that value off?
thanks.
I hit 59.1 lb/min but the car certainly doesn't feel like it has 590 fwhp.
anybody know if I have modified my maf curve to compensate for bigger injectors if it throws that value off?
thanks.
Re: Formula for calc'ing HP based on MAF flow? Hi Heath,
Does the powerdyne use a draw through ot blow through MAF setup? I found with the blow through on the ATI my MAF flow was about 10-15% higher then the 'magic formula,' may explain why yours is higher. Supposedly if its a draw through it should be more accurate, cant say because I never tried it.
I believe if you changed you MAF numbers either with edit ot a MAFT it will change the number as well. When I went to bigger injectors and just used a MAFT at -20 base it changed the MAF flow quite a bit.
<small>[ September 07, 2002, 04:56 PM: Message edited by: kp ]</small>
Does the powerdyne use a draw through ot blow through MAF setup? I found with the blow through on the ATI my MAF flow was about 10-15% higher then the 'magic formula,' may explain why yours is higher. Supposedly if its a draw through it should be more accurate, cant say because I never tried it.
I believe if you changed you MAF numbers either with edit ot a MAFT it will change the number as well. When I went to bigger injectors and just used a MAFT at -20 base it changed the MAF flow quite a bit.
<small>[ September 07, 2002, 04:56 PM: Message edited by: kp ]</small>
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From: Bellevue, Wa
Re: Formula for calc'ing HP based on MAF flow? draw thru and yes I have modified the MAF table to adjust for my injectors.
getting close on tuning finally so pretty soon I will just hit the ol dyno and see what it can do <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
getting close on tuning finally so pretty soon I will just hit the ol dyno and see what it can do <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
