Jump to content
HybridZ

afm and intercooler question


Guest dan4011

Recommended Posts

Guest dan4011

when we were piecing together my intercooler set up on my 280z turbo, we decided to place the air flow meter in from of the throttle body instead of on the turbo like original zxt's, it seems to work good if not more efficiantly but ive never really driven a 280zxt other than stock. any views about what you think is better? pros cons

Link to comment
Share on other sites

Several things wrong with this idea:

 

The afm isn't designed to be pressurized.

 

It is now not measuring air at the temperature of outside air, so there is no way that you will have proper A/F ratios.

 

It would probably work ok off boost, but will have problems on boost.

Link to comment
Share on other sites

Guest dan4011

yea i thought the same thing, i have yet to really get higher into boost because im still breaking the motor in but at about 5-7 lbs it seems to do just fine. no problems. im only running a low amount of boost as it stil has a n/a block (10-12 lbs) so i think this set up will work, ill let you guys know how it does under full boost tho.

Link to comment
Share on other sites

Several things wrong with this idea:

It is now not measuring air at the temperature of outside air' date=' so there is no way that you will have proper A/F ratios.

[/quote']

I'm not trying to argue with you, I'm just curious.

Air temp going into the engine needs to be registered for the engine to know which "fuel map"(I know, not exactly with this ecu) to use for what air temp. If the turbo is raising the air temp going into the engine after the AFM then shouldn't that be registered aswell for proper A/F's?

IE: Outside air is 45* and AFM calculates for this, but the turbo has raised temps 20* after the registry to making it 65* inlet air temp. A/F is now not what the ecu is calculated for at 65*

I know, this is where the O2 sensor comes in, but that still adjusts what the ecu has already determined to be according to the inlet air.

Link to comment
Share on other sites

Guest dan4011
I'm not trying to argue with you' date=' I'm just curious.

Air temp going into the engine needs to be registered for the engine to know which "fuel map"(I know, not exactly with this ecu) to use for what air temp. If the turbo is raising the air temp going into the engine after the AFM then shouldn't that be registered aswell for proper A/F's?

IE: Outside air is 45* and AFM calculates for this, but the turbo has raised temps 20* after the registry to making it 65* inlet air temp. A/F is now not what the ecu is calculated for at 65*

I know, this is where the O2 sensor comes in, but that still adjusts what the ecu has already determined to be according to the inlet air.[/quote']

yea i was thinking about that, if you have the afm after the boost and intercooler its measuring the actual air thats going into the intake manifold, where as when on the turbo its not meauring whats actually going into the motor, just what the turbo is pulling in. correct me if im wrong as i am no expert but thats just what im thinking.

Link to comment
Share on other sites

Why not just relocate the air temp sensor ? Ive looked at my turbo AFM's i have lying around. And it easy looks like you can remove it, rewire it and put it in the boot infront of the turbo. Easly getting the required Air temps.

 

you could also use the Air temp blacking plate of a N/a AFM

Link to comment
Share on other sites

its measuring the actual air thats going into the intake manifold, where as when on the turbo its not meauring whats actually going into the motor, just what the turbo is pulling in. correct me if im wrong as i am no expert but thats just what im thinking.

 

it still is measuring the amount af air that is going into your engine. the turbo does not add air, just changes the pressure, temp, etc.

Link to comment
Share on other sites

Guest dan4011
it still is measuring the amount af air that is going into your engine. the turbo does not add air, just changes the pressure, temp, etc.

well yea i know its still going to have the same amount of air flowing through no matter what side of the turbo its on, but it seems like it would get a more accurate reading in front of the throttle body

Link to comment
Share on other sites

Well i have a a/f guage. Will show me if i lean out.

 

Wideand or cheesy rich/lean narrow band gauge. If narrow band you are better off measuring it's actual voltage.

 

 

 

Another problem blowing through an afm is the ecu is assuming the airflow through it is at atmosphere. In your case the density varries greatly. The ecu does not know that. Most are fully open at peak torque and you may have enough lag that it won't matter as boost will come about then or a little latter depending on the turbo.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...