Lexus AFM
- Thread starter Obsessionw/Boost
- Start date
Based on what I've heard from you so far with your experiences with the lex AFM, I'd hazard a guess and say the resetting ecu is the main contributing factor to a properly running setup with the stock injectors. The ecu would have to relearn everything so it would think the lex AFM was the stocker and compensate for any air it is missing through the AFM sensor that the o2 sensor is telling that it's getting due to a lean/rich condition...
How much of a power gain do you think you've gotten just from switching housings?
How much of a power gain do you think you've gotten just from switching housings?
I cant image the gain being so big if he is using the stock ct. I was think of running the lex afm with the stock 440's but if you are only running 14psi or so why bother. I run 14psi with the stock AFM but i have a rather big hole in my accordian hose 
. My idle is not even rough enough for someone to tell but me. If you are going to upgraded the turbo you should upgrade the fuel...... To me it does make any sense if you are shooting at 14-15psi to do it when you can do a "free mod" and get the same result. So for now my lex AFM is just sitting waiting until i want to make some decent power that will require some decent fuel management
. My idle is not even rough enough for someone to tell but me. If you are going to upgraded the turbo you should upgrade the fuel...... To me it does make any sense if you are shooting at 14-15psi to do it when you can do a "free mod" and get the same result. So for now my lex AFM is just sitting waiting until i want to make some decent power that will require some decent fuel management
In that case...
Although I didn't hit fuel cut on the pull I did, thinking about how the ECU responded to it; the gains would be pretty much nil. I think that probably it just lowers the frequency it needs to see before cutting out, knowing that its running the injectors as much as it can just to keep up with the 02 sensor.
Although I didn't hit fuel cut on the pull I did, thinking about how the ECU responded to it; the gains would be pretty much nil. I think that probably it just lowers the frequency it needs to see before cutting out, knowing that its running the injectors as much as it can just to keep up with the 02 sensor.
In other words, to get the best gain out the Lexus AFM mod you must also buy 550 cc injectors, possibly an AFPR, and a fuel tuning device to get good gains?
You need to bring Vf back to a more normal state to see the gains. Whether that be with electronics and spoofing the 02 signal like me or, like you said, injectors/afpr/fuel pump.
^See... we had something good going here, and then you go and do that.
SS5k: I think as long as you get a pump with more pressure capability you could easily bump the FP on a good condition set of stock injectors and be fine. I believe on the mailing list way back when this was referred to as the Lex/Hall mod.
SS5k: I think as long as you get a pump with more pressure capability you could easily bump the FP on a good condition set of stock injectors and be fine. I believe on the mailing list way back when this was referred to as the Lex/Hall mod.
I'd also like to note that if anyone goes to and tries it, THEY DO SO AT THEIR OWN RISK! You have been warned. Some have blown their engines and it's been blamed on this, whether that is the case or not is hard to prove from setup to setup.
I would also suggest for them to send out their stock injectors to be cleaned and flow matched. There is a link in this tech section somewhere to a very cheap/reliable person that does this.
I would also suggest for them to send out their stock injectors to be cleaned and flow matched. There is a link in this tech section somewhere to a very cheap/reliable person that does this.
I agree on both, this is not really stuff for general consumption. I just wanted to dispel the myths that it CAN'T be done.starscream5000 said:
anything can be done, is it a good idea is a better question. the bottom line is you cant expect to slap on a lex afm on a mainly stock car (read fuel system) and expect it to be as safe. your trying to add in 25% more air and keeping your fingers crossed that your injectors, fuel pump, regulator, and 02 sensor are all doing their best to compensate. add in higher than stock boost on there throw in a larger turbo for good measure and you are asking to lean your car out. check the dyno sheet i posted, the car didnt like it and we had to keep a very close eye on detonation. we were on a dyno with a wb and still that a/f worried me. {shrug} your car just my 2 psi
I intend to run 550s and the lex AFM in my car, however some have had
good results without doing so. I refer to J. B. Lunsford website:
"I do not run the 550s on my car. I don't think they are necessary on a car with anything less than a full t04 turbo or bigger with more than 15 psi boost. This section is for information only.
You will need the following parts for the upgrade (this does not include the appropriate gauges and monitoring"
http://www.jblmk3.com/lexus.php
good results without doing so. I refer to J. B. Lunsford website:
"I do not run the 550s on my car. I don't think they are necessary on a car with anything less than a full t04 turbo or bigger with more than 15 psi boost. This section is for information only.
You will need the following parts for the upgrade (this does not include the appropriate gauges and monitoring"
http://www.jblmk3.com/lexus.php
mkIIIman089 said:
Dude its a joke lighten up a bit ..... But on a serious tip I have spoken with many people about this. I believe in the "rule of thumb" with injectors by that i mean 440's should support 400rwhp and 550's should support over 500rwhp.
But if someone's goal is to get past fuel cut on the stock system with a stock setup the lex afm is overkill. It allows air to pass "un-metered" about 25% more air with the stock signals/readings. A nice size hole in the accordian hose give you the same effect for free. For me I have really good results with my free/ghetto mod, granted my car is tuned 291rwhp and 336lbs of tq.
But if someone starts upgraded their turbo why not upgrade their fuel. I am personally stuck between running an upgraded ct26 57trim on the stock 440's vs 550's because i believe that the 440's will support my power goals for now.....
Last edited:
I have read that webstie time and time ago but why the extra riskWayne G. said:
Necessity sometimes does not leave enough room for errors though. If I only work enough to pay my bills and something happens that cost more than what I have I have an issue…. Now don’t I? But in car sense lets say I get an upgraded ct26 and I set my boost controller to 14psi or lets say 12psi and the winter rolls around or better yet I suffer a waste-gate malfunction and I boost lets say 24psi on the 440’s for a few second by mistake. I have an issue don’t I?
Remember a really good guy from the community had a similar mishap with his BOSS turbo and what less than 2 months later his motor ….. Ummm gave out on him. So shit happens that why I don’t know if I want to play with the fire and not have the right stuff to maintain it safely…. Or at least the safest I can possibly do.
Are you sure the issue with Malloy's overboost was due to a mechanical malfunction of the BOSS turbo he had? I thought it was due to a FUBAR'd MBC. Something about the little check valve inside melting... :dunno:
I never said it was b/c of anything specific I just said similar b/c he ended up boosting like 30something psi for whatever reasonstarscream5000 said:
But my point is ..... Stuff happens like failing parts so you should try to eliminate as much as you can. With the injectors maybe have more is better. I know the 440's can support a decent amount of power but adding the 550's leaves you more head room. Like I said I am stuck between the two for now.bountykilla0118 said: