Fuel cut... Lex AFM? need a good writeup

[supraGhost]

Can anyone point me in the right direction?

i know fuel cut is at 1 bar. Is this limited by the ecu or something? i know i see a lot of people installing the lex afm (which btw doesnt search well lol) to get around this. does the sotck afm only read up to 14.7 psi and then just go "fuck to much air shuterdown"? or can it be modified? Sorry i just havent had a good writeup explaining why or how. How does tuning work with this then? sorry for noob questions. i just need a good read on this stuff.

thanks

 

[hvyman]

its not 14psi its actually between 9-12psi usually. and its not psi its how much air is flowed at a given temp. the lex afm is best used with 550 injectors because there both 25% upgrades both fuel and air.

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

read that and search about it.

 

[thevork]

http://rob.carlile.home.mchsi.com/index.htm

you might want to check out the "Lexus/Riemer air/fuel upgrade" link on that page

 

[Mario]

yea i had a thought like that a while ago what if we just hone the in side out a bit like maybe 2-5mm, but would this affect the honeycone sensor. i was told this wpuld be useless and dumb so i didn't try it. All though i wonder??? haha

 

[sneakypete]

not worth the risk of damaging the honeycomb. a lex afm can be found for less than $100 and ive seen 550s for sale here for around $300 from time to time

 

[supraGhost]

do you have to upgrade the injectors to run the lex afm?

 

[Jason Is Dizzy]

he doesnt need to HAVE the injectors with the LEXafm he can run without it if hes not trying to run past the fuel cut but if he is he can run a AFC or something to richen it up a bit

 

[frontierguy25]

No you don't have to as long as you have an adjustable fuel pressure regulator and a walbro pump and some descent injectors. I've seen it done many times with stock injectors as long as you can tune it you will be ok. You might want to pick up a fuel computer soon as well like a SAFR or SAFC or MAFT Pro......

 

[Jason Is Dizzy]

No you don't have to as long as you have an adjustable fuel pressure regulator and a walbro pump and some descent injectors. I've seen it done many times with stock injectors as long as you can tune it you will be ok. You might want to pick up a fuel computer soon as well like a SAFR or SAFC or MAFT Pro......

EXACTLY thanks for filling in the 2cents i forgot to add lolz

thats what im running a AFPR SAFC NEO and a lexi and i have noproblems

 

[sneakypete]

you should know that you wont see any gains with just the lex afm.... the whole point of getting one is so you can upgrade your injectors and turn up the boost

 

[Poodles]

lexus AFM is safest with 550 injectors.

Also, DO NOT try to bore the stock AFM out. The lexus AFM and the stock AFM are both the same size in that portion of the AFM. It's the port underneith that allow un-metere air past that is larger.

Also, it's based on flow, not PSI...

 

[grimreaper]

... using a fuel computer to tune 440's with the lex is going to be reverse engineering as well since you will "likely" be adding fuel

 

[supraGhost]

lexus AFM is safest with 550 injectors.

Also, DO NOT try to bore the stock AFM out. The lexus AFM and the stock AFM are both the same size in that portion of the AFM. It's the port underneith that allow un-metere air past that is larger.

Also, it's based on flow, not PSI...

so lets say i upgrade the turbo to a 57 trim or something which will flow more cfm at the same psi.... i will be able to run less psi than before without hitting fc?

 

[hvyman]

you will hit fc at a lower psi than with stock turbo. i have a 57trim stock boost like 5-8 depending on temp and i dont hit fc with the adj screw on the stock afm screwed in a lil.

 

[Jason Is Dizzy]

you should know that you wont see any gains with just the lex afm.... the whole point of getting one is so you can upgrade your injectors and turn up the boost

Well when your stock AFM goes out and you have a option to upgrade for cheap i went with it. more then probablly ill end up running some 550s but till then im totally happy with my performance

 

[thevork]

... using a fuel computer to tune 440's with the lex is going to be reverse engineering as well since you will "likely" be adding fuel

Just curious, When using the 440's with al lex-afm, how will normal driving be like? The s-afc can only ajust fuel consumption when the ecu is in open loop.

Most probably the Vf is maxed out completely. Won't normal driving and idling be lean as hell ?

 

[7MGTEsup]

Just curious, When using the 440's with al lex-afm, how will normal driving be like? The s-afc can only ajust fuel consumption when the ecu is in open loop.

Most probably the Vf is maxed out completely. Won't normal driving and idling be lean as hell ?

Just bump your fuel pressure up a few psi, I think stock is about 38 (vac dissconected) stick a multi meter on the diag box to get the Vf signal and bump the fuel pressure till the readings come back to 2.5v this should keep you closed loop fuling pretty close.

 

[Poodles]

Well when your stock AFM goes out and you have a option to upgrade for cheap i went with it. more then probablly ill end up running some 550s but till then im totally happy with my performance

Then you put the Lex AFM electronics in the stock housing.

inbeforetheiblewupmyenginethread

 

[Jason Is Dizzy]

Then you put the Lex AFM electronics in the stock housing.

inbeforetheiblewupmyenginethread

LOLZ

if everyone is so adamit about me taking off the lex i will lol

but with my afpr safc and my walbro i dont see a problem

but to make everyone happy ill go snag one from my friend lol

 

[supraGhost]

so do you use the electronics from the stock afm or from the lex afm?