: this may sound weird, but can you run a standalone that would run both MAF and MAP?
06-18-2011, 02:09 AM
my reasons are more for curiousity, but also have logic. when i finish the rally car build, i plan to run pikes peak, and the elevation difference will play a little havoc w/ power. so to maximize efficiency, can you run both? has anyone every done it? unless my logic is wrong. but MAF can't fully compensate for high altitude, can it? i mean, it runs it safe, but you lose a substantial amount of power and if you can gain even a little back, it helps.
i got the idea from my buddy who is working on a company that builds turbo kits for 2 stroke sleds. he is running a dual MAF and MAP setup on his standalone tuning, that way, he can run at jackson hole, and here in MI where we are low elevation. so i'm curious if it can work on our cars
06-18-2011, 11:09 AM
Its been done for years to a point the Focus started doing it in 2005 , I have always been curious at what point the MAP helps but it is there and doesnt seem to change anything in the power turning it off
06-18-2011, 07:30 PM
so the 05 ecu is capable of handling this? and the duratecs run both?
i believe the pike's peak hill climb is 8k feet in about 15 minutes, so if the idea of 1 psi lost (atmospheric) to 2000 feet, 4 psi lost brings down 4/14.7 is about a 1/4 loss in power. (i know there is alot more than just that in power, but its definitely a good loss)
06-18-2011, 07:31 PM
I'm not sure why you'd want to sue both. MAF already compensates for elevation in the sense that it matters, air density.
... The hot wire will heat less dense air faster and that is how the MAF can guess the elevation. Higher elevation in itself lowers air density.
In Advantage there are settings for Barometric Pressure (elevation), "Default BP Value"; MAF -> Scalar -> Default BP Value
Also there are Min's and Max's you can set; Misc ->Scalar -> Baro Pressure Max (30.50 stock) / Baro Pressure Min (18 stock)
These are used to help calculate load and in the air flow calculation.
You can use that to figure elevation. 18" is roughly 12,500 feet above sea level.
06-18-2011, 09:07 PM
interesting, i didn't know that maf could compensate that way. i was just under the impression, all maf based vehicles are tuned at sea level, so you'll never run too lean. the reason i'm curious too is cause snowmobile turbo kits are very different than auto turbo kits. in general, the tuning in the kits (as they are bolt on) are piggybacks that are tuned based on throttle angle only. some of the 2010 kits are now going to MAP based, and my buddy is experimenting w/ the 2 together, do i know why? not for sure, but this is what he's getting his PhD in is the tuning aspect.
06-18-2011, 10:38 PM
I'd assume he's adding a MAF to an existing MAP system, not a MAP to an existing MAF system.
My best guess is he'd be doing this to get more exact tuning ... and possibly to better the emissions of the sled, being that's fast becoming an issue (FYI, newer motorcycles have a cat and run O2 feedback; changed once FI became common place).
IYRC, the early days of OBDII (93-95), was also the transition from EEC-IV to EEC-V, some Ford's used both MAF and MAP (I know for sure my 1994 SHO did). The MAP was a backup plan, basically making sure the MAF was working properly. Basically same thing your buddies doing now.
If that makes any sense to you I'm not sure, bet some of it does though.
The easy explanation is that a MAF is the combination of a MAP sensor and an AIT sensor. Both end up with the same result, Air Density.
06-19-2011, 12:11 AM
We do something similar. We actually run 2 MAP's and no MAF. The first MAP is used in place of the MAF and the other is used for altitude compensation.
I'm told that the newer Focus uses a map for altitude compenstaion. It is MAP/intake temp sensor all in one.
06-19-2011, 12:33 PM
ya, that makes more sense, i'm sure he's adding a MAF on a new map system. sorry jon, not familiar w/ pre- obd2 stuff, oldest car i've owned (and still own being my jeep cherokee ) is a 1999