Subject	How does the ECU calculate the A/F ratio?
Posted by	chenc544 on February 27, 2006 at 10:41 AM
	This message has been viewed 173 times.
In Reply To	The ratio should be the same. (n/m) posted by Kenny on February 27, 2006 at 09:53 AM
Message	I assume it's done through the MAF and O2 sensor combination. It measures the airflow volume coming in and calculates how much fuel to inject and use the O2 to determine how complete is the burning process. It then adjusts the fuel volume accordingly. Is this correct? So at altitude wouldn't you need more air volume to maintain the proper oxygen to fuel mixture for the burn? I guess the engineer in me just wants to know.
Follow Ups	Results from Sat's Dyno Day at Denver - chenc544 08:59:32 02/27/06 Is the A/F accurate? - Only1Z 09:12:52 02/27/06 At altitude don’t I need a leaner A/F ratio? (n/m) - chenc544 09:40:45 02/27/06 The ratio should be the same. (n/m) - Kenny 09:53:29 02/27/06 How does the ECU calculate the A/F ratio? - chenc544 10:41:47 02/27/06 At WOT it uses the fuel maps in the ECU. (n/m) - SactoTodd 10:55:55 02/27/06 Todd covered the first part. - Kenny 11:12:43 02/27/06 It seemed as if almost every car, mine included - colocomp (Denver) 09:55:16 02/27/06 Okay...cool - Only1Z 20:04:39 02/27/06 Is that on pump gas? - Kenny 09:33:34 02/27/06 It's on pump gas but my A/F is actually richer than others - chenc544 09:43:05 02/27/06 I have done some research and Woody has gone as - colocomp (Denver) 09:40:54 02/27/06 I agree that SAE correction on FI cars is totally bunk - maglito 11:43:41 02/27/06 I seem to recall Z1 had higher numbers with the 1420's - colocomp (Denver) 12:43:16 02/27/06 But as long as FI cars are compared to FI cars, - Woody75 (Denver) 12:55:00 02/27/06 Keep in mind, the air is thinner up there. The ECU's - Ash's Z 11:33:07 02/27/06 Thanks Ash, good read (n/m) - chenc544 11:55:44 02/27/06 Also remember the highest octane they can get there is 91 - maglito 11:55:48 02/27/06 The actual pressure is - colocomp (Denver) 11:58:22 02/27/06 I dont think I said that it was any different than you did. - Ash's Z 16:09:23 02/27/06 There are to many variables to accurately predict - colocomp (Denver) 16:30:16 02/27/06 Actually, it isn't as complicated as you think. Since this - Ash's Z 16:48:11 02/27/06 They are not JWT boost jets. - Woody75 (Denver) 16:55:49 02/27/06 I'm sorry that it is coming off as an insult to you Woody. - Ash's Z 16:59:10 02/27/06 It's your time, I could give two shits either way - colocomp (Denver) 17:25:48 02/27/06 The personal attacks are quite pre-pubescent my friend. - Ash's Z 17:37:45 02/27/06 I would like to see the dyno for each possible combination - colocomp (Denver) 17:41:45 02/27/06 I'd be happy to provide the information to show you - Ash's Z 17:52:21 02/27/06 lol - colocomp (Denver) 18:16:52 02/27/06 Is that a bottle of turbo dog on your desk? (n/m) - ShakaShaun 18:44:37 02/27/06 Good eye - colocomp (Denver) 18:49:06 02/27/06 I tell ya its more like NA dog..... - Zluster(Sir Sam) 23:25:37 02/27/06 Asshat? All I see is you getting out of hand with the - Ash's Z 21:14:11 02/27/06 I have dyno'ed at 14psi with boost jets a few years back - colocomp (Denver) 21:29:28 02/27/06 Here's some information for you that may bring what I am - Ash's Z 23:20:02 02/27/06 I am sure the Denver guys with your program - colocomp (Denver) 06:41:55 02/28/06 You know, it is quite shameful that you guys abuse this - Ash's Z 11:46:29 02/28/06 I believe the term you're looking for is "tunnel vision" - 300zx90 (CO) 12:12:52 02/28/06 I am glad you noticed that - - colocomp (Denver) 19:24:10 02/28/06 Lol- No need to get emotional - colocomp (Denver) 12:21:50 02/28/06 Sorry about the name calling, I don't want you to get - colocomp (Denver) 21:30:51 02/27/06 Ugh, here we go again. - Woody75 (Denver) 12:17:49 02/27/06 If it weren't for math and engineering, you wouldn't drive - CaliguyPurdue 13:30:08 02/27/06 I have been concise every time......buy JWT :) - Woody75 (Denver) 14:04:12 02/27/06 Fair enough :) (n/m) - CaliguyPurdue 14:59:09 02/27/06 2nd (n/m) - Zfreak(Denver) 15:32:52 02/27/06 4th (n/m) - ShakaShaun 17:07:50 02/27/06 Well, if it was pinging, it was likely because of the fuel - Ash's Z 16:23:08 02/27/06 BTW, my C-class programs are actually MORE conservative - Ash's Z 16:27:58 02/27/06 Where's the beef? You just said it. - Woody75 (Denver) 16:43:24 02/27/06 Heh, let me put it all together and show you what I mean. - Ash's Z 16:57:48 02/27/06 I don't need your info post. I'm fine thanks. (n/m) - Woody75 (Denver) 17:03:10 02/27/06 ash is a sheep herder. :-) - Spongerider :) 17:35:09 02/27/06 I am fully aware of what the SAE has put together for - Ash's Z 17:39:31 02/27/06 It depending on the type of SAE Correction used - Spongerider :) 18:37:03 02/27/06 Not really. The only thing that has changed in their - Ash's Z 01:05:11 02/28/06 Hmm, you didn't answer my question... (n/m) - Spongerider :) 13:17:33 02/28/06 I am suprised you got your head out of Greg's ass - Riddick 20:30:41 02/27/06 Hey ash, you forgot one? Greg who? (n/m) - Spongerider :) 20:57:08 02/27/06 ? I'm not Riddick if that's what you are implying. - Ash's Z 23:22:36 02/27/06 Correct. (n/m) - Riddick 11:08:33 02/28/06 No, you being the sheep herder you forgot to - Spongerider :) 13:14:54 02/28/06 Sigh. You win bro, I flat give up. (n/m) - Ash's Z 16:21:12 02/28/06 No I don't have you confused with someone else. - Riddick 16:33:01 02/28/06 Baaa, baaa. You are so original (yes you are! :-) ) - Spongerider :) 16:47:51 02/28/06 Your credability just flew out the window. (n/m) - Riddick 20:28:38 02/27/06 No it didn't, it's quite well & intact. (n/m) - YugoBernie (NoVA) 00:43:19 02/28/06 Reread the posts Bernie. Out the window........ (n/m) - Riddick 11:09:47 02/28/06 Lol. Oh no. (n/m) - Woody75 (Denver) 12:36:30 02/28/06 enter, the martyr. (n/m) - Spee 22:48:51 02/27/06 Ash, can you add to my 1mm OVERSIZED VALVES POST - Shawn300zTT GT28R MD 00:01:18 02/28/06
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