Lexas AFM - NA??

stomis

stomis

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Mar 22, 2010
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So I've done the reading a 400 series AFM and 550 injectors needed. Surprisingly I couldnt find any NA information on this. I'm not sure if its because an NA doesnt need it or what but from what I figure more air in, more fuel, more power whether its compressed or not no?

The reason I'm asking is because while yes its an NA motor its still going to move air. And that tiny inlet in the stock 7m AFM seems like its restricting, even for a NA motor.

So whats the thought on this?

Has anyone done the lexus AFM on an NA motor?

Would 550s dump way to much fuel on a motor with no boost?

What about running the Lexus AFM with no injector upgrade? I would think since its not a higher density of air in more space being sucked in like the turbo counter part and is simply more air intake space that the stock injectors could adjust for the additional air no?
 
Dirgle

Dirgle

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The NA AFM operates differently, and is not compatible with the Lexus AFM or 7M-GTE. The NA uses a flapper door to meter the air and the Lexus uses a Karmen vortex generator.
 
stomis

stomis

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Mar 22, 2010
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Bah found exactly what I was looking for on second search. Scratch this.

---------- Post added at 09:15 PM ---------- Previous post was at 09:13 PM ----------
Dirgle;1547854 said:
The NA AFM operates differently, and is not compatible with the Lexus AFM or 7M-GTE. The NA uses a flapper door to meter the air and the Lexus uses a Karmen vortex generator.
Click to expand...

Are there any flapper style AFMs off any applications with a bigger inlet or is a fuel system and a LS1 MAF with a piggy back the only option?
 
Dirgle

Dirgle

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Not that i'm aware of. However, the purpose of the LEX AFM isn't to simply allow more air into the engine by way of a larger opening. It's purpose is to cause less of the air that is being taken in to be metered, by a specific percentage and increase the amount of fuel that is added by that percentage through a specific size fuel injector. The purpose of the LEX AFM isn't to make more power. It's to safely raise the fuel cut on the 7M-GTE. An increase in power is a byproduct of having the fuel cut raised, But the LEX AFM itself does not create extra power.

As it is, an NA motor does not fully utilize the fuel injectors it has, so there is no point in going with larger fuel injectors and by association a larger AFM. The only thing a larger AFM will do is throw your fuel ratios off and make less power.

Now if you go with a MAF style piggy back you do remove the restriction of the AFM but you'll only gain a few HP. The money would be more effectively spent on going turbo.
 
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Nick M

Nick M

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Sep 9, 2005
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Dirgle;1547881 said:
Not that i'm aware of. However, the purpose of the LEX AFM isn't to simply allow more air into the engine by way of a larger opening. It's purpose is to cause less of the air that is being taken in to be metered, by a specific percentage and increase the amount of fuel that is added by that percentage through a specific size fuel injector. The purpose of the LEX AFM isn't to make more power. It's to safely raise the fuel cut on the 7M-GTE. An increase in power is a byproduct of having the fuel cut raised, But the LEX AFM itself does not create extra power.

As it is, an NA motor does not fully utilize the fuel injectors it has, so there is no point in going with larger fuel injectors and by association a larger AFM. The only thing a larger AFM will do is throw your fuel ratios off and make less power.

Now if you go with a MAF style piggy back you do remove the restriction of the AFM but you'll only gain a few HP. The money would be more effectively spent on going turbo.
Click to expand...

I have a slight correction. The fuel cut is raised by the metered air moving slower through the larger opening. Opening the bypass screw will slow it even further by reducing the air moving through it, but I don't think that is a real good choice. MAFT-Pro as you pointed out is a better tuning choice.

If you are staying naturlay aspirated and want to get rid of the vane airflow meter, you could also get the MR2 Turbo VPC from HKS. It uses the same vane airflow meter.
 
stomis

stomis

NA Die Hard
Mar 22, 2010
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Nick M;1548003 said:
I have a slight correction. The fuel cut is raised by the metered air moving slower through the larger opening. Opening the bypass screw will slow it even further by reducing the air moving through it, but I don't think that is a real good choice. MAFT-Pro as you pointed out is a better tuning choice.

If you are staying naturlay aspirated and want to get rid of the vane airflow meter, you could also get the MR2 Turbo VPC from HKS. It uses the same vane airflow meter.
Click to expand...

I'm intrigued but not having much luck finding the VPC for an MR2.

Ah ok I see its basically a simplistic piggy back that only handles air in. Looks like I'm going to have to find one used. Any idea what year MR2 I'd be looking for?
 
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