Getting the most out of your Apexi S-AFC= Stock MAF honeycomb removal

[Innovator]

You need to set the low idle setting (1000 rpm) at +15 to get the car to idle perfectly in closed loop. Only at idle do you want to actually go to possitive correction.

Otherwise, set the low settings at -15 to -20 above 1K rpm.

I love it this way folks. It's like a bigger set of turbos!!

[Bluv69k]

so let me get this right.
You removed the sides and top and bottom of the mas honeycomb. You then had to richen you high and low, lets say roughly 10%. What is you low/high % set at? What is you base timing set at? any thing special? And thats all I have to do? just adjust the s-afc to compensate for the "missing air flow"? How easy are they to reinstall if this dosn't work well?

Can someone explain in some detail what open and closed loop is?

[Jeremy R]

Originally posted by Innovator


With what supporting mods?

Show me a DR 500 car with the stock internals that had that much HP.

you are aware that nightmare's old car that boo00st has now did dynoe 405awhp with STOCK 9b turbos with supporting mods. he ran an 11.8 with the stockers. But he had the cfds, vpc, injectors, and everything. Search it and you'l see.

[HellBringer]

475AWHP at only 17psi through the stock MAS? Where are my wading boots......

[Bluv69k]

any instructions on the right way to remove the honeycomb?

[BAdAzZV8]

When you remove a restriction in the MAS(combs) you are letting more air in, but not all of it is being metered. That is why it leans out your car, b/c more air is getting in and not being metered. That is why he can richen his AFC and get timing retard.

The vette guys gut their MAFs to run a little leaner b/c factory settings are a bit rich.

So multiades, he is correct when he says that you can richen the AFC when gutting the MAS. You see, not all the air is being metered, so there is no correction at the MAS as you stated, there is only the AFC correction.

[Mad Scientist]

I'm sorry I'm being lazy and not reading all of this....

but the reason the honeycomb is in there is to spread the flow of air out equaly throughout the MAF....which helps maintain the correct ratio of air passing over the wire as through the rest of the MAF....

by removing these air guides you can get an air signal that doesn't reflect the actual amont of air traveling trhough the MAF...and it can change from moment to moment...

while it may seem like a "restriction" it is actualy there to help your car run correctly.....and unless you have a wideband controlling a fuel controler full time....thise will hurt gas milage and only give you more power under the best of circumstances....based on your tuning ability

Innovator I know you say you are a mechanic (not distputing that) but this is one of the things you should know.....it is there for a reason...not just as a restriction

[BAdAzZV8]

The honeycomb is only used to straighten the air when it needs it, ie when the intake has bends in it. Most of us probably have some form of intake which feeds directly to the MAF, so there are no bends in it. The combs really aren't anything but a restriction, they don't need to straighten the air b/c it's already straight.

[Innovator]

Originally posted by Mad Scientist
I'm sorry I'm being lazy and not reading all of this....

but the reason the honeycomb is in there is to spread the flow of air out equaly throughout the MAF....which helps maintain the correct ratio of air passing over the wire as through the rest of the MAF....

by removing these air guides you can get an air signal that doesn't reflect the actual amont of air traveling trhough the MAF...and it can change from moment to moment...

while it may seem like a "restriction" it is actualy there to help your car run correctly.....and unless you have a wideband controlling a fuel controler full time....thise will hurt gas milage and only give you more power under the best of circumstances....based on your tuning ability

Innovator I know you say you are a mechanic (not distputing that) but this is one of the things you should know.....it is there for a reason...not just as a restriction

Yes I am a mechanic. ASE master tech. (I know, big deal) I also do an assload of tuning at my shop. I know exactly how the Karman sensor works, thank you...

I specialize in Audi and VW, but since I bought the VR4, I've been sucked in by it's potential. I really do love my car.

I've tried just about everything on my car. I had an ARC2, and I didn't like it. It made great power, but the drivabilty suffered greatly during partial throttle to WOT transitions.

Bigger injectors, smaller injectors, IHI turbos, 17G's, bla bla....

Right now, I am more happy with my engines performance than ever before. The stock MAF with this modification and a 12:1 A/F has given me smooth throttle response, safer timing, and 50 more HP that with the unmodified MAF.

My car is still in closed loop when it should be, and as I said, it has absolutely no runability issues this way. I have full adjustabilty using the AFC, and there is no downside. And FWIW, my fuel economy has improved, because I can now run a leaner A/F, without the risk of detonation...

Before the car ran pretty strong at 11:1. It had less power when you leaned it out. 11:1 is very rich as you may know. Now, it runs best at 12:1 with the modified MAF. Leaner makes more power, and that cannot be disputed. Lots of you guys have to run rich, because you had too much timing, and your injectors are too big, compounding the problem that the AFC can cause.


The fact is, my car is significanty faster now!

Splain that one Lucy...

[Innovator]

Originally posted by HellBringer
475AWHP at only 17psi through the stock MAS? Where are my wading boots......

Actually, it's more like 18.5 psi midrange, tapering to 17 psi to redline.


Look, I really don't care if you believe me or not. I'm not selling anything, and I have no reason to make false claims.

MY car made the power I claimed. It will likely make even more in the winter.