Thanks, I have spent more hours in a post secondary classroom than anyone should in a lifetime.
My head is filled with so many cool ideas every time I get a new idea an old one is forced out. Mostly I think about manufacturing techniques these days. My focus is almost exclusively on a design project I've been working on for about 15 months now.
http://www.mx-3.com/phpBB3/viewtopic.php?f=7&t=78902
I have just started doing FEA on the rear subframe.
VAF to MAF Conversion??
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- Senior Member
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Re: VAF to MAF Conversion??
94' RS/GS/MS/CF Monster Turbo...coming soon.
93' GS SE, the Black Beast, the former love of my life...soon to be gutted and crushed.
94' GS, black on black, now in several small pieces...and one large crushed piece.
2007 Mazda3 GT Sport --- super fun
2004 Honda RC51 --- Lost forever to some theavin' bastard
My Worklog
My feedback thread
Never attribute to malice that which can be adequately explained by stupidity.
93' GS SE, the Black Beast, the former love of my life...soon to be gutted and crushed.
94' GS, black on black, now in several small pieces...and one large crushed piece.
2007 Mazda3 GT Sport --- super fun
2004 Honda RC51 --- Lost forever to some theavin' bastard
My Worklog
My feedback thread
Never attribute to malice that which can be adequately explained by stupidity.
- Josh
- Supporting Member
- Posts: 3432
- Joined: April 18th, 2002, 2:01 am
- Location: Washington state
- Contact:
Re: VAF to MAF Conversion??
Since it is related.. I thought I would put this right here
http://max.pilotpowersupply.com/2011/06 ... v_version/
http://max.pilotpowersupply.com/2011/06 ... v_version/
Josh
95' AWD MX-3 RST - (work log - http://www.mx-3.com/phpBB3/viewtopic.php?f=46&t=73765 )
94' GS - KLZE DD (work log - viewtopic.php?uid=2713&f=46&t=79063&start=0 )
05' MS RX-8 - Parted out and Sold :'(
Feedback - http://www.mx-3.com/phpBB3/viewtopic.php?f=37&t=49519
Cardomain Page - http://www.cardomain.com/ride/408020
Face Book page http://www.facebook.com/pages/Mazda-MX- ... 3472959216
95' AWD MX-3 RST - (work log - http://www.mx-3.com/phpBB3/viewtopic.php?f=46&t=73765 )
94' GS - KLZE DD (work log - viewtopic.php?uid=2713&f=46&t=79063&start=0 )
05' MS RX-8 - Parted out and Sold :'(
Feedback - http://www.mx-3.com/phpBB3/viewtopic.php?f=37&t=49519
Cardomain Page - http://www.cardomain.com/ride/408020
Face Book page http://www.facebook.com/pages/Mazda-MX- ... 3472959216
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- Senior Member
- Posts: 5554
- Joined: August 25th, 2004, 2:01 am
- Location: Edmonton, Alberta, Canada
Re: VAF to MAF Conversion??
That is a very good idea. This is one of the things that always made me want to run the Megasquirt. I just want to use the Barro sensor and do away with the VAF altogether.
In thinking about this over the long years since it occured to me that the whole "Mass of air hitting the cone...blah blah blah" is obviously not true. In a rudimentary way the VAF is actually measuring the volume of air passing the cone. X opening = X CFM = X volts to the ECU. The ECU must be estimating intake air mass using the IAT input and some sort of assumption about pressure. As far as I know though, there is no pressure sensing device in the control system...so I'm not sure how it knows the difference between an engine running at sea level and one at 4000ft.
Someone smarter than me should put their two cents in.
In thinking about this over the long years since it occured to me that the whole "Mass of air hitting the cone...blah blah blah" is obviously not true. In a rudimentary way the VAF is actually measuring the volume of air passing the cone. X opening = X CFM = X volts to the ECU. The ECU must be estimating intake air mass using the IAT input and some sort of assumption about pressure. As far as I know though, there is no pressure sensing device in the control system...so I'm not sure how it knows the difference between an engine running at sea level and one at 4000ft.
Someone smarter than me should put their two cents in.
94' RS/GS/MS/CF Monster Turbo...coming soon.
93' GS SE, the Black Beast, the former love of my life...soon to be gutted and crushed.
94' GS, black on black, now in several small pieces...and one large crushed piece.
2007 Mazda3 GT Sport --- super fun
2004 Honda RC51 --- Lost forever to some theavin' bastard
My Worklog
My feedback thread
Never attribute to malice that which can be adequately explained by stupidity.
93' GS SE, the Black Beast, the former love of my life...soon to be gutted and crushed.
94' GS, black on black, now in several small pieces...and one large crushed piece.
2007 Mazda3 GT Sport --- super fun
2004 Honda RC51 --- Lost forever to some theavin' bastard
My Worklog
My feedback thread
Never attribute to malice that which can be adequately explained by stupidity.
- Josh
- Supporting Member
- Posts: 3432
- Joined: April 18th, 2002, 2:01 am
- Location: Washington state
- Contact:
Re: VAF to MAF Conversion??
I am not an Electrical Engineer by any means. But this system it pretty sweet. Looking around the web several BMW guys are running this with great success. There are several systems out there like this, I will be picking mine up soon, I just haven't gotten around to doing it yet. When I do I will report my findings.
On the OP (even though its from 08') the VAF to MAF conversions takes place on the OBII cars. It can be done on ours but it is an elegant dance between resistors and other electrical type things I have very little knowledge of to make the swap work. There was something I read on PT or MX-6 club on it I will try and find it again.
On the OP (even though its from 08') the VAF to MAF conversions takes place on the OBII cars. It can be done on ours but it is an elegant dance between resistors and other electrical type things I have very little knowledge of to make the swap work. There was something I read on PT or MX-6 club on it I will try and find it again.
Josh
95' AWD MX-3 RST - (work log - http://www.mx-3.com/phpBB3/viewtopic.php?f=46&t=73765 )
94' GS - KLZE DD (work log - viewtopic.php?uid=2713&f=46&t=79063&start=0 )
05' MS RX-8 - Parted out and Sold :'(
Feedback - http://www.mx-3.com/phpBB3/viewtopic.php?f=37&t=49519
Cardomain Page - http://www.cardomain.com/ride/408020
Face Book page http://www.facebook.com/pages/Mazda-MX- ... 3472959216
95' AWD MX-3 RST - (work log - http://www.mx-3.com/phpBB3/viewtopic.php?f=46&t=73765 )
94' GS - KLZE DD (work log - viewtopic.php?uid=2713&f=46&t=79063&start=0 )
05' MS RX-8 - Parted out and Sold :'(
Feedback - http://www.mx-3.com/phpBB3/viewtopic.php?f=37&t=49519
Cardomain Page - http://www.cardomain.com/ride/408020
Face Book page http://www.facebook.com/pages/Mazda-MX- ... 3472959216
- _-Night-Shade-_
- Senior Member
- Posts: 2664
- Joined: January 15th, 2009, 8:00 pm
- Location: Toronto, Ontario, Canada
Re: VAF to MAF Conversion??
Just to add to this, since I saw earlier in the thread that it was mentioned - there actually is a barometric pressure sensor. It's built into our ECUs.
wytbishop wrote:Actually Mike that's not correct. The air entering the engine must be measure by mass or else a barometric pressure sensor must be used to compensate for altitude and temperature (Ideal Gas Law). Our cars do not have any sort of pressure sensing device. The cone in the VAF is acted on my a calibrated spring to hold it closed. The mass of the air entering the engine opens the VAF. Two cars running at the same RPM but at different altitudes would have different air/fuel ratios because the denser air at lower altitude has greater mass for the same volume and imparts a greater force on the cone of the VAF.Nd4SpdSe wrote:Besides, the ECU is designed to calculate based on volume, not mass (this being the difference between VAF and MAF).
Unless I'm wrong and the MX-3 has a baro sensor that I don't know about. That would make me sound pretty stupid.
- MrMazda92
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- Joined: October 8th, 2009, 5:35 pm
- antispam: No
- Location: Midwest
Re: VAF to MAF Conversion??
MegaSquirt, VAF delete is full of win.
Still waiting on an external IAT sensor for mine. ;(
Still waiting on an external IAT sensor for mine. ;(
Daily:
'12 Challenger R/T + STP - 3.92 w/ LSD, JG Cam, headers, SkipShift delete, Clutch Delay Valve delete, Hurst STS, RAM Clutch Adjuster, StopTech 6 Piston Brakes, Sticky Nittos, 435 WHP
Kid Hauler:
'08 Suburban LT 4WD - TVS 1900 Blower, LF SC Cam, headers, AFM delete, true 5" lift, 33x12s, 523 WHP
First Love:
'92 GS 5 spd - Straightneck KL/67mm TB, MegaSquirt/Coilpacks, 5 lugs/Speed6 brakes/FD wheels, wiretuck, coilovers, headers, AEM WB, Borla
Deleted: VAF/Power Steering/Air Conditioning/EGR/ABS/Auto Seatbelts/etc
'12 Challenger R/T + STP - 3.92 w/ LSD, JG Cam, headers, SkipShift delete, Clutch Delay Valve delete, Hurst STS, RAM Clutch Adjuster, StopTech 6 Piston Brakes, Sticky Nittos, 435 WHP
Kid Hauler:
'08 Suburban LT 4WD - TVS 1900 Blower, LF SC Cam, headers, AFM delete, true 5" lift, 33x12s, 523 WHP
First Love:
'92 GS 5 spd - Straightneck KL/67mm TB, MegaSquirt/Coilpacks, 5 lugs/Speed6 brakes/FD wheels, wiretuck, coilovers, headers, AEM WB, Borla
Deleted: VAF/Power Steering/Air Conditioning/EGR/ABS/Auto Seatbelts/etc
- _-Night-Shade-_
- Senior Member
- Posts: 2664
- Joined: January 15th, 2009, 8:00 pm
- Location: Toronto, Ontario, Canada
Re: VAF to MAF Conversion??
Yeah that's nice; we're all waiting for lots of things. I'm waiting for some people on this board to stop spamming. This is a technical discussion thread, not your diary. If you feel the need to update whomever you think is interested in what you're waiting on, please do so in your worklog.MrMazda92 wrote:MegaSquirt, VAF delete is full of win.
Still waiting on an external IAT sensor for mine. ;(
- MrMazda92
- Supporting Member
- Posts: 5201
- Joined: October 8th, 2009, 5:35 pm
- antispam: No
- Location: Midwest
Re: VAF to MAF Conversion??
While I understand the point you are trying to make, I do post plenty of technical information in this section, as well as others._-Night-Shade-_ wrote:Yeah that's nice; we're all waiting for lots of things. I'm waiting for some people on this board to stop spamming. This is a technical discussion thread, not your diary. If you feel the need to update whomever you think is interested in what you're waiting on, please do so in your worklog.
Daily:
'12 Challenger R/T + STP - 3.92 w/ LSD, JG Cam, headers, SkipShift delete, Clutch Delay Valve delete, Hurst STS, RAM Clutch Adjuster, StopTech 6 Piston Brakes, Sticky Nittos, 435 WHP
Kid Hauler:
'08 Suburban LT 4WD - TVS 1900 Blower, LF SC Cam, headers, AFM delete, true 5" lift, 33x12s, 523 WHP
First Love:
'92 GS 5 spd - Straightneck KL/67mm TB, MegaSquirt/Coilpacks, 5 lugs/Speed6 brakes/FD wheels, wiretuck, coilovers, headers, AEM WB, Borla
Deleted: VAF/Power Steering/Air Conditioning/EGR/ABS/Auto Seatbelts/etc
'12 Challenger R/T + STP - 3.92 w/ LSD, JG Cam, headers, SkipShift delete, Clutch Delay Valve delete, Hurst STS, RAM Clutch Adjuster, StopTech 6 Piston Brakes, Sticky Nittos, 435 WHP
Kid Hauler:
'08 Suburban LT 4WD - TVS 1900 Blower, LF SC Cam, headers, AFM delete, true 5" lift, 33x12s, 523 WHP
First Love:
'92 GS 5 spd - Straightneck KL/67mm TB, MegaSquirt/Coilpacks, 5 lugs/Speed6 brakes/FD wheels, wiretuck, coilovers, headers, AEM WB, Borla
Deleted: VAF/Power Steering/Air Conditioning/EGR/ABS/Auto Seatbelts/etc