0 registered members (),
177
guests, and 4
spiders. |
Key:
Admin,
Global Mod,
Mod
|
|
Forums69
Topics113,638
Posts1,341,421
Members1,814
|
Most Online731 Jan 14th, 2020
|
|
|
Placing MAF after the turbo???
#1554986
12/11/2015 22:31
12/11/2015 22:31
|
Joined: Oct 2010
Posts: 549 Bulgaria
Ferrarist
OP
Enjoying the ride
|
OP
Enjoying the ride
Joined: Oct 2010
Posts: 549
Bulgaria
|
I know that sound bit heretic, but it's not that uncommon on other turbo application and projects..... Just started my new trackday car and because have no space related problems, i'm considering the option to fit the MAF just before the throttle body. It's called "blow through" setup. Pull through is MAF before turbo. Pros and cons..... I'll be able to use less pipe length from IC to TB.... With blow through there's much less leak potential after the MAF. With suck/pull through, there's tons of leakage points... It also allows not to use some intake pipes and less restriction in front of the turbo Intake tepm sensor is separate from the MAF and ECU will still read correct. BOV and dump to atmosphere with no issues..... Maybe slight increase in throttle response..... Our MAF's are Hot Film type(not Hot wire) and less prone to failure. However MAF will get more dirt in this place.....oil leak from the turbo and chances of damaging the sensor are greater..... Is there someone tried this setup?
Last edited by Ferrarist; 12/11/2015 22:35.
20VT - Alfa 156 2.0 - Alfa 156 Mid-Engined RWD - Locost 20VT
|
|
|
Re: Placing MAF after the turbo???
[Re: avtokrator]
#1555032
13/11/2015 13:39
13/11/2015 13:39
|
Joined: Oct 2010
Posts: 549 Bulgaria
Ferrarist
OP
Enjoying the ride
|
OP
Enjoying the ride
Joined: Oct 2010
Posts: 549
Bulgaria
|
but won't it measure less air than actual, since the air is already compressed, measuring same flow there will be more air actually flowing through, and if then that reading gets correlated to pressure, the ecu would "think" it's even less, well, I suppose it works so, mean the ecu calculations... MAF measure air MASS - 1 kg air is 1kg no matter if it's 10bar compressed or 1....Mass is different from volume..... No problem with that....
20VT - Alfa 156 2.0 - Alfa 156 Mid-Engined RWD - Locost 20VT
|
|
|
Re: Placing MAF after the turbo???
[Re: Ferrarist]
#1555038
13/11/2015 15:03
13/11/2015 15:03
|
GrahamL
Unregistered
|
GrahamL
Unregistered
|
In theory this should work, but you'll have much more chance of oil contamination if the oil breather system is still connected + more chance of heat damage to the AFM due to proximity to the engine block.
The ECU data tables for the AFM will have been calibrated with the AFM in the standard position, so with the AFM being after the turbo the air passing the AFM will potentially be hotter than ever expected which may throw things out of range. In theory this won't be a problem if it was calibrated over such a wide range, but in reality... who knows what might happen, it may cause a slight error in the readings.
|
|
|
Re: Placing MAF after the turbo???
[Re: Ferrarist]
#1555049
13/11/2015 17:09
13/11/2015 17:09
|
Joined: Oct 2010
Posts: 549 Bulgaria
Ferrarist
OP
Enjoying the ride
|
OP
Enjoying the ride
Joined: Oct 2010
Posts: 549
Bulgaria
|
I will try it anyway, can revert it to original position if needed.....
20VT - Alfa 156 2.0 - Alfa 156 Mid-Engined RWD - Locost 20VT
|
|
|
Re: Placing MAF after the turbo???
[Re: Ferrarist]
#1555051
13/11/2015 17:38
13/11/2015 17:38
|
GrahamL
Unregistered
|
GrahamL
Unregistered
|
It's worth a try, yes, will be interesting to hear the results.
I once tried cutting out the plastic grid in front of the AFM to remove the restriction but it didn't like it at all and the engine would misfire horribly and almost cut out at anything over 3K rpm as it came on boost.
So obviously the AFM is calibrated to expect the air flowing over the sensor in a certain way, which removing the grid changed significantly. It may be that having the air much hotter and under more pressure has a similar effect, or maybe it'll still all be within the expected limits of variation.
|
|
|
Re: Placing MAF after the turbo???
[Re: ]
#1555053
13/11/2015 17:58
13/11/2015 17:58
|
Joined: Oct 2010
Posts: 549 Bulgaria
Ferrarist
OP
Enjoying the ride
|
OP
Enjoying the ride
Joined: Oct 2010
Posts: 549
Bulgaria
|
I once tried cutting out the plastic grid in front of the AFM to remove the restriction but it didn't like it at all and the engine would misfire horribly and almost cut out at anything over 3K rpm as it came on boost.
Tried same on my 156 Twin Spark - almost same result. Ecu read air temp from different sensor, and with no temp sensor into the MAF i guess there will be no problem...... Many 350Z Nissans run same blow through MAF setup.....
20VT - Alfa 156 2.0 - Alfa 156 Mid-Engined RWD - Locost 20VT
|
|
|
Re: Placing MAF after the turbo???
[Re: Ferrarist]
#1555329
16/11/2015 17:00
16/11/2015 17:00
|
Nobby
Unregistered
|
Nobby
Unregistered
|
What does FC performance do with the big MAFs? Pretty sure they don't have mesh on them.
Chris
|
|
|
Re: Placing MAF after the turbo???
[Re: ]
#1555332
16/11/2015 18:17
16/11/2015 18:17
|
Joined: Apr 2011
Posts: 360 England, Devon
lost55
Club member 2057
|
Club member 2057
Making a profit
Joined: Apr 2011
Posts: 360
England, Devon
|
What does FC performance do with the big MAFs? Pretty sure they don't have mesh on them.
Chris Good point. Dont know if Leighton has his own calibration curve to use in his map. Hopefully he'll update us.
|
|
|
Re: Placing MAF after the turbo???
[Re: Ferrarist]
#1555353
16/11/2015 22:15
16/11/2015 22:15
|
Joined: Oct 2010
Posts: 549 Bulgaria
Ferrarist
OP
Enjoying the ride
|
OP
Enjoying the ride
Joined: Oct 2010
Posts: 549
Bulgaria
|
Also curious to know.....
20VT - Alfa 156 2.0 - Alfa 156 Mid-Engined RWD - Locost 20VT
|
|
|
|