Curiousty on going with a lexus AFM

Turbo Habanero

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Apr 28, 2009
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Im curious about installling the lexus afm but i have not really seen anything about what you need to do to support this.

I mean you cant just bolt up and go right? wouldnt it lean out the Car?

So my question is what all needs to be done to run it properly?
 

airhead04

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Aug 21, 2009
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If you really arent sure what needs to be done in order to run a Lex, then Im not to sure if you want to actually go through with it. As your more then Likely going to break something.

BUT:

If your really wanting to go through with it, youll need to upgrade the injectors to 550cc or higher. An Ajustable fuel pressure regulator will be helpful. And something to tune your car with so it does run EXTREMELY rich. Thats a start. More ppl will chime in and tell you more things Im sure.
 

Poodles

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Jul 22, 2006
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Yes it will lean the car out if not correctly paired with 550cc injectors. It's a royal bitch to get it onto the accordian pipe too (this is when the pipe is new, if it's old, it's not going on without splitting or cracking).
 

radiod

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Dec 13, 2007
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Do a quick search and you'll find TONS on the lexus afm mod ;)

What it comes down to though is the electronics are the same, just the housing is 25% larger. Pair the 25% larger meter with 25% larger injectors (440cc -> 550cc), and you get to a very close match in terms of the air/fuel calculations. You can usually run without doing anything more in terms of tuning, but it's still a good idea to have some sort of fuel computer such as the SAFC to do a little tweaking.

Because you are putting in larger injectors, you need to do a bit to your fuel system as well. A higher output fuel pump (such as the 255lph walbro), combined with an adjustable fuel pressure regulator, and some sort of solution to alleviate the return line restriction such as the j-tube mod or a soft fuel line kit. So your check list will look something similar to this...

Lexus AFM body (if you have good electronics, you can just drop that in)
550cc injectors + clips
Fuel pump
Adjustable Fuel Pressure regulator
J-tube mod or soft fuel line kit
SAFC or equivelant

Here's a website with some part numbers of compatible lexus afm's...
http://www.jblmk3.com/cars/lexus.php

Remember, whenever you're doing any sort of tuning it's always a good idea to have a wideband.

EDIT: Found this...pretty much everything you'd need to know for install etc.
http://mkiiisupra.net/bbs/showthread.php?t=13885&highlight=guide+controller
 
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Turbo Habanero

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thankyou very much everyone i do have a wide band and i have a Lexus AFM and 550 injectors so far have not installed any of it yet except the wideband. Ill have to do research on the J-tube mod i have heard of it but dont actually know what it is.

Anyway just like the reasurence behind my research just for the extra piece of mind.

Thanks again
 

radiod

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Dec 13, 2007
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The second thread I linked in there actually goes through a j-tube bypass (Post 14, Step 28). It's essentially a restriction pipe bolted to the side of the block to created fuel pressure in case the fuel pressure regulator were to fail. Unfortunately it's tends to create more pressure than you want if you don't eliminate it somehow when beefing up the pump/injectors.

speedy said:
radiod...... good info sir....
This is really only from years of contemplating doing it myself and researching, I honestly haven't done any of it myself. Just a lot of researching and reading everyone else's information. Soon though hopefully....assuming nothing else goes catastrohpically wrong with my car ;)
 

Turbo Habanero

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So ive read that 2nd link a few times now and i have a few things i was curious about or more then less want to just be 100% sure about.

In the photo below there are 3 braided lines i have the same AFPR (uninstalled)but i do not have the 3rd line that is not attached to the AFPR in photo. I believe it connects to the back of the fuel rail and gets rid of the Pulsation Damper.

My question is this 100% must do ? or can i skip this line and leave the stock one in?
Im sure i cant cut corners so if not Can someone point me to a place to get a replacement line ?
Im sure any braided fuel line work?

Another question is about the J-Tube Mod/Just eliminating it.. So basically installing the AFPR it self is eliminating the J-tube as the fuel lines no longer go to it at all after the AFPR is installed? Or am i missing something here. (Just wondering if it is really that simple)

Sorry if the questions seem stupid or like i overlooked the answer.. i Just would rather be sure then sorry later.

p1682138_1.jpg
 

gottadiesel

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Feb 16, 2009
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Turbo Habanero;1682138 said:
In the photo below there are 3 braided lines i have the same AFPR (uninstalled)but i do not have the 3rd line that is not attached to the AFPR in photo. I believe it connects to the back of the fuel rail and gets rid of the Pulsation Damper.

My question is this 100% must do ? or can i skip this line and leave the stock one in?

To the best of my knowledge, the 3rd one is not needed for what would appear to be your overall HP plans (the lexus AFM/550 upgrade) I have done the same fuel system mod, looks like the same setup I bought from DM, but like you said, only the AFPR and the two lines, not the 3rd. I have also coupled that with two other upgrades, one is the fuel pump, I personally went to the Denso Mark IV pump and also did a fuel pump relay/ resistor mod, not exactly the same as commonly noted on this site, but works well for my setup. I have left my fuel pump dampener in place, I think it serves a good purpose as long as it does not get in the way (perhaps higher HP applications).

Turbo Habanero;1682138 said:
Another question is about the J-Tube Mod/Just eliminating it.. So basically installing the AFPR it self is eliminating the J-tube as the fuel lines no longer go to it at all after the AFPR is installed? Or am i missing something here. (Just wondering if it is really that simple)

Sorry if the questions seem stupid or like i overlooked the answer.. i Just would rather be sure then sorry later.

Yes it is that simple, you also get rid of the banjo bolt stock setup on the rail...
 

hvyman

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It dampens the osilations from the fuel pump. Kinda like a shock and spring(pump is the spring).

If your going to do this mod you and run higher boost you need a bigger pump. Which also with that the jtueb should be drilled/by passed anyways.

If your going to be a higher hp level getting rid of the dampner isnt that bad of a idea and all high hp cars do not have 1.

Just get lex, 550, afpr, wide band, pump. Install all. Set fuel pressure to about 35 psi. Up the boost and watch your afr's. A safc/ maft would be really usefull at this stage as well.
 

Turbo Habanero

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gottadiesel;1682199 said:
To the best of my knowledge, the 3rd one is not needed for what would appear to be your overall HP plans

Yeah im not really sure what my goal is yet.

so far i've seemed to accumulate a bit of parts no idea what i can make with this stuff.

INSTALLED

I've redone my head with arp's and felpro since i didn't machine the block.
Ive put new vavles and seal in it.
3inch turbo back stock elbow untill i buy a new downpipe (bic performance is more then likely the one i will get)
HKS cone filter

UNISTALLED

AFPR (aeromotive)
wideband sensor/gauge (AEM)
Lexus AFM
550cc injectors
walbro 255
Intercooler kit (godspeed)

LOOKING AROUND FOR AND STILL GATHERING INFO ON THESE PARTS..

Suspension Options (looking to drop TEMS)
SAFC
Boost Controller (thinking about the AEM True Boost)

NEAR FUTURE.

FFIM (It's so much more pratical makes the bay look alot cleaner too)
CT-26 upgrade 50trim

I've been buying these parts for the past tear and a half i hope soon enough i can get it all together
 

hvyman

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You dont really have the turbo yet you really use the lex and 550's.

Skip the 50 trim and get a 57.
 

Turbo Habanero

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hvyman;1682670 said:
You dont really have the turbo yet you really use the lex and 550's..
I have them but they are not installed. I have just come across some things that i would use in the future.

So by your comment im assuming it wouldnt be good to use this stuff with a stock turbo? even if i kept the boost around 12lbs

hvyman;1682670 said:
Skip the 50 trim and get a 57.
Why is that? any specific reason other then size?
 

Poodles

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Jul 22, 2006
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hvyman;1682663 said:
It dampens the oscillations from the injectors opening and closing. Kinda like a shock and spring(pump is the spring).

FTFY If you're familiar with the way the ACIS system works, it's the exact same concept, but it's dampening it instead of enhancing it. Stops rich and lean conditions based on the oscillations.

hvyman;1682663 said:
If your going to be a higher hp level getting rid of the dampner isnt that bad of a idea and all high hp cars do not have 1.

Not true.
 

hvyman

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Most people get rid of it once they start leaking or when they go to dual feed.

If they didnt there wouldnt be the bypass hose.