afm porting

[ABUSEDDOG]

When porting the afm on a 84 do you remove the edge on the floor of unit that faces the motor, it's on the long side of the passage and looks a little restrictive, the corner is almost a 90 degrees. My first inclination is to grind it.

opinions/ ideas.

cheers!

[Supracress]

Hey I am polishing up my AFM and had the same idea to get rid of that hard 90 deg corner while it's off the car and all. I don't think it will make much a difference but every little bit helps, plus it's free. (damn that square passage and super restrictive flapper door!).

[Chrisfrom1986]

So did you guys follow through with this?

[Road Ripper]

I did mine a couple of years ago, but never put it on a car yet. I removed those hard "blocked" corners and just made everything smooth, like in a head porting job. Just take off any edge that might cause turbulance. Probably won't make any extra horsepower, but it was good porting practice.

If you think our AFM is restrictive, check out the ones on the Celicas or the 3VZE V6 trucks! Ours is a train tunnel compared to those!

[ABUSEDDOG]

Yes. I did finish porting the unit. I don't really have any experience with vane type air flow meters, it was a learning experience in progress. I have cracked open the black cover to try the mod. I have not installed it yet. I wanted to purchase an a/f gauge to check for any changes.

I will not get to install it until spring, winter here is long and ugly. I wanted to return the motor to stock condition exhaust/ intake/fans and run the vacum/af gauges to monitor changes with the different modifications. It's not a verry high tec/exotic setup, as a matter of fact all of the parts being used are from the local pick a part. Hopefully the educational value will out wiegh the hp gains which will be probably be minimal, but it should be interesting and fun!!

:)

[Supracress]

Yes. I did finish porting the unit. I don't really have any experience with vane type air flow meters, it was a learning experience in progress. I have cracked open the black cover to try the mod. I have not installed it yet. I wanted to purchase an a/f gauge to check for any changes.

I will not get to install it until spring, winter here is long and ugly. I wanted to return the motor to stock condition exhaust/ intake/fans and run the vacum/af gauges to monitor changes with the different modifications. It's not a verry high tec/exotic setup, as a matter of fact all of the parts being used are from the local pick a part. Hopefully the educational value will out wiegh the hp gains which will be probably be minimal, but it should be interesting and fun!!

:)


hope you share those results when you get them, I'd be inteseted to see what you get.


and yes, those celica AFM's are FTL! My brother tells me the celica guys swap in supra afms as an upgrade in performance, he has an 85 gt-s.

[Road Ripper]

As long as you'll be playing around with little performance mods, have you read about the one where you install a potentiometer inline in the coolant temp. sensor to fool the computer into thinking the engine is cold when it's hot? In this way you're able to richen the fuel mixture by manipulating the coolant sensor input, and you can turn it off when you want to. Since you'll be installing an A/F guage, you could easily monitor the mixture and "butt-dyno" the results.

[Dean]

I ported the AFM on my 82 race car. I can't give any real results on what it did for performance though. When I put it on, I also rigged up a cold air intake at the same time. It dropped my quarter mile times by 0.25 seconds so I gained about 10+ HP at the rear wheels. I attributed most of the gains to the cold air intake.

About adding a potentiometer inline to the coolant temp sensor... This mod has been done to my 82 race car and it is very effective at richening up the mixture. I can make the car blow black smoke by adding about 2000 ohms resistance. 200 to 500 ohms seems about right, depending on other mods and conditions. If you do this mod on an 83+ car, be sure to check one thing for me. I've been told that if you do this, it will affect the ignition timing as well as the A/F ratio. On the 82, the ECU doesn't control ignition timing so I don't have to worry about it on my car. I'd be interested to hear your results.

[StanS]

a few peeps have reported that porting hteir afm gave some small improvement. The engine side of the AFM is the important side to port. This makes sense theoretically since it should reduce turbulence after the AFM a little and allow slightly higher flow.

[rabidchimp.com]

You could just be wasting fuel. Use a good wideband air/fuel ratio monitor to see what effect it has..and whether its necessary or not.
-Aaron

As long as you'll be playing around with little performance mods, have you read about the one where you install a potentiometer inline in the coolant temp. sensor to fool the computer into thinking the engine is cold when it's hot? In this way you're able to richen the fuel mixture by manipulating the coolant sensor input, and you can turn it off when you want to. Since you'll be installing an A/F guage, you could easily monitor the mixture and "butt-dyno" the results.

[WadeT]

No gains porting the AFM. And you're more likely to more harm than good. I have seen LS1 guys spend all day porting their MAF only to gain 5HP.

[williamb82]

5hp from porting a maf for 1 day doesnt seem like a bad gain really. lol.

[suprablazed]

some guys spend 500 bucks for 5 hp , ill spend a day porting if it saves me 500 bucks. mines almost done anyway.

[Dean]

You could just be wasting fuel. Use a good wideband air/fuel ratio monitor to see what effect it has..and whether its necessary or not.
-Aaron

I agree with the Chimp here. You should only need this mod to richen things up if you know your car is running lean. As I said before, be sure to check the effect on ignition timing if you do this.
However, I have seen good results with this mod on a very strong running 6M being run with the 1982 5M ECU. Mark gained several HP at the wheels by doing this.
My 1982 race car's 5M benefits from this due to having more mods done than most cars.

[Chrisfrom1986]

However, I have seen good results with this mod on a very strong running 6M being run with the 1982 5M ECU. Mark gained several HP at the wheels by doing this.
My 1982 race car's 5M benefits from this due to having more mods done than most cars.

Are you trying to tell me that I shouldnt have replaced my 82 wiring with 85 to run the 85 ecu on my 6m? DAMN!

[Crocket]

some guys spend 500 bucks for 5 hp , ill spend a day porting if it saves me 500 bucks. mines almost done anyway.

Ya, but that's 5hp on an engine with between 400-500hp. Our 2.8litre 160hp engines, you may get 1-2hp, with possible driveability problems if not done right?

Sonny

[suprablazed]

WHile you make a good point, i fail to see what the driveability problems would be of porting the afm, or well i guess how could you do it wrong? you simply smooth out the backside of it, not tampering with anything of importance. as i look at it now it is mainly just the bottom lip and a few corners. as far ar the "fins" on the top right and bottom, i am using a filler to make it smooth and not cause turbulance rather than grinding them out. the left side air duct wall is smooth enough not to fiddle with. I fyou belive i am making a mistake in my judgements please let me know i would hate to have to buy a new one.

[Crocket]

I just meant if somebody had no idea what they were doing, and ported both ends of the AFM, or ported WAY too much material, then they'd be doing more harm than good.

Sonny

[ABUSEDDOG]

I removed the step down, in the front of the vane, all of the raised portions on front and rear pipe peices except for the short side on the back. All of the raised pieces are solid material and can be ground almost flush.

I spent the most time removing material on the long side radius in the back on the air bypass/idle chamber, if it helps I measured from where the chamber ends to the oppisite side and it was 1.945 in. across. The wall is thin enough to just about nick your finger.

The meaurement in the front of afm, right in front of the air intake temp sensor.... floor to roof is2.61 in.

I don't really know how you could negativley affect performance, unless you put a hole in it somewhere that would let in unaccounted air....it's just a tube with a door in it.


Soon as I get a new camera, I' post some pics.


cheers. :)

[StanS]

Suprablazed: No filler should be used after the air filter. If the filler breaks down it will be sucked into your engine almost guaranteeing mechanical damage.

The correct mod to get additional hp is to install an EWP and engine temp controller. Running your engine (84+) at say 180 deg will allow more intake air to flow and the computer will add the extra gas. But you should always run the engine 10-15 minutes at 195 F before shutting the engine off so you boil off the acids in the oil if you want to maintain engine life. You also get a few hp since the mechanical pump is unloaded at hi (2700) rpm. (I believe that the fan clutch is set for 2700 rpm).

[Road Ripper]

Electric water pumps aren't reliable enough for a daily driver. It's easier to switch to an electric cooling fan setup.

If epoxy was used as a filler, with good surface prep (scratching the surface) it shouldn't come loose. Maybe a piece of metal window screen stretched over the end of the plastic crosstube or throttle body before the rubber hose is slid on could act as a safety strainer.