Lexus AFM

[Obsessionw/Boost]

I want to upgrade to a Lexus AFM and RC550's but right now I only have money to spend on the Lex. Would I gain anything upgrading my AFM and running my stock 440CC injectors? Would it cause me to run lean?
I'm running a stock CT26@10psi. I don't want to get a Lex now, and it isn't beneficial at all. Even if it will help me a little bit, I'll get it. What do you guys think?

-Ryan

 

[starscream5000]

You would gain a possible blown motor without strict tunning. Lean, hell yes.

 

[mkIIIman089]

Gain anything? No, not really...

Harm anything? No, not really...

 

[kabanimk3supra]

you should just buy it and wait till you get the injectors, then put it all together and tune your car.:thumbup:

 

[marlonvip]

Dont use the lex without having the 440 cc injectors flowtestet first................big chance of running lean with the lex and NO rc 550:-(

 

[huntin5L]

Even if he did put on just the afm, which i know is a no no, wouldn't the fuel cut stop the motor from becoming to lean to cause harm to his motor?

 

[starscream5000]

No, the lex AFM alows roughly 25% extra fuel to pass through without the ecu "seeing" it, that is the reason for the bigger injectors.

 

[Obsessionw/Boost]

Okay so if I were to get the Lex without the 550's, it would lean me out. That's the last thing I want to do. I'd rather run rich than run lean. I've honestly never seen a Supra that doesn't run a little rich anyways. Thanks for the input fellas!

-Ryan

 

[huntin5L]

Yes that is what star is saying. I wasn't exactly sure about how fuel cut would play into it with just doing the afm upgrade. What he is saying is your ecu thinks it will be getting less air than really is, which will cause you very lean mixtures. A big no no. Horsepowerfreaks has the injectors for very decent prices, just wait and get them to do this right.

Okay so if I were to get the Lex without the 550's, it would lean me out. That's the last thing I want to do. I'd rather run rich than run lean. I've honestly never seen a Supra that doesn't run a little rich anyways. Thanks for the input fellas!

-Ryan

 

[Obsessionw/Boost]

That is what I will do. My CT2657 won't be here for another few weeks anyway. Might as well wait and do the turbo along with the fuel.

 

[starscream5000]

People run with the stock injectors and Lex AFM, but they're dumb if they don't have the devices to see how the motor is reacting to the setup and some way to tuning it if it goes too lean. I don't recommend it, but I'm sure there'll be a few comming on here shortly saying "I'm running teh lex AFM with stock injectors, no problems here."

 

[Nick M]

By right, you should use the 550's with that airflow meter. But the stock settings are very rich to begin with. Less air observed also equals more timing.

I would not run the Lex meter with out the bigger injectors.

 

[mkIIIman089]

People run with the stock injectors and Lex AFM, but they're dumb if they don't have the devices to see how the motor is reacting to the setup and some way to tuning it if it goes too lean. I don't recommend it, but I'm sure there'll be a few comming on here shortly saying "I'm running teh lex AFM with stock injectors, no problems here."

I'll oblige.

Starting with a clean slate the stock ECU will be able to correct out 90% of what the Lex AFM does with 02 sensor feedback, in an otherwise stock setup.

While its not all I'm running, I do use the stockers with a Lex AFM.

Also, you're in for a serious shock if you think I'm dumb.

 

[starscream5000]

How's your motor fairing with your setup? There's been others on here have engine failures with this combo before. Do you think it's becuase they don't reset the ecu and/or have no way to increase fuel pressure or upgrade the fuel pump, etc?

What exactly do you have on the motor as is right now? Still a secret? That's what your profile says

 

[shaeff]

a quick search would have yeilded the other 8 billion times i've posted this link...

http://rob.carlile.home.mchsi.com/lexus/lexus1.htm

read it. when you're done, read it again. after you understand it, read it one more time!

-shaeff

 

[mkIIIman089]

How's your motor fairing with your setup? There's been others on here have engine failures with this combo before. Do you think it's becuase they don't reset the ecu and/or have no way to increase fuel pressure or upgrade the fuel pump, etc?

What exactly do you have on the motor as is right now? Still a secret? That's what your profile says

Fine so far, it has been ~8k miles with it like this, no problems.

I think that when most people do just pop it in there and call it a day, then go out and see if fuel cut is gone; they frag their engines.

When I was 1st experimenting with it by itself, I reset the ECU, then drove it for a little while very lightly so that Vf would stabilize. It still ran 14.7:1 under cruise, only leaned out at idle; Vf was locked on full add to keep it like this mind you. So I did a 3rd gear WOT pull and A/Fs were still in the 10s from 5000-up. (Which was hardly a change at all from where they were with the stocker)

If you're really interested I can probably find the Zt-2 log file still.

I'm now using the ZT-2 narrowband adjustable switching point and an SAFC. Everything else in the fuel system is stock.

 

[starscream5000]

I am assuming you are running your engine in tip top shape too. Think of what condition the sensors are in, in a lot of these +20 year old supras. A lot of people don't understand that a faulty sensor coupled with the lex afm could be disaster. Such as an o2 sensor on it's way out.

I find it amazing that the A/F's are that rich, plenty of room for improvement .

 

[bountykilla0118]

Fine so far, it has been ~8k miles with it like this, no problems.

I think that when most people do just pop it in there and call it a day, then go out and see if fuel cut is gone; they frag their engines.

When I was 1st experimenting with it by itself, I reset the ECU, then drove it for a little while very lightly so that Vf would stabilize. It still ran 14.7:1 under cruise, only leaned out at idle; Vf was locked on full add to keep it like this mind you. So I did a 3rd gear WOT pull and A/Fs were still in the 10s from 5000-up. (Which was hardly a change at all from where they were with the stocker)

If you're really interested I can probably find the Zt-2 log file still.

I'm now using the ZT-2 narrowband adjustable switching point and an SAFC. Everything else in the fuel system is stock.

Hey man post it

 

[starscream5000]

I agree. This would be great information to sticky, with a big note that this is what it's supposed to do with a careful eye on the A/F's, a reset ECU, and properly running electronics throughout.

 

[mkIIIman089]

Hmm, looks like the original log file I had was deleted. I only have the tuned log files now... I think if people saw them they would shit themselves to think a car can run like that, LOL.

As far as my engine, when I did that all of the sensors were originals, no codes, no perceptible issues with it what-so-ever. Now the only difference is a new CPS, plus I'm obviously using the ZT-2 to simulate the narrowband signal. I will also add that was before I had the SAFC as well, so there was zero input from any kind of scaling device.

Yea, A/F's were still that rich. That was the point in time when I pretty much stopped believing nearly all of these "experts" on the internet.

My own sticky, eh?