Largest injectors for lexus afm.

[suprafredde]

Hi all.

Lexus afm is equal to 550cc injectors.
Can I run larger injectors with less FP?

Have a lexus afm sitting on a shelf and dont have the money for a standalone right now.

Driftmotion has Siemens 680cc at a great price. And my question is will I be able to run them with the lex, or are they too large?

( and yes with an aeromotive FP and a walbro intank pump and some piggy fuelcontroller)

regards
suprafredde

 

[MKIIINA]

do you have a wb02? that will really be the determining factor because to run the larger injectors you need to bump fp down to compensate for the different size injectors. i haven't looked at the DM website recently but unless they are under 350 or so you'd be better getting some 550s and not having to worry about messing with FP.

What kind of fuel computer do you have btw?

 

[Boost Lee]

It's certainly doable, and it's been done on several occaisions.

But to be honest, it's not something that's really recommended unless you do have all of the necessities in being able to compensate for all that fuel. (As MKIIINA said, a WBo2).

I don't know at what line I'd have to draw and say if it's worthwhile to get 680's over 550's, but with a Lexus AFM, 550's are such a perfect matchup that unless you're POSITIVE you're going to be making enough power to outflow the 550's...

My opinion is that you stick with getting 550's...and if need be, sell them down the road when you can afford the *right* setup (680+ and a standalone).

Jeff

 

[zurud]

If you're cheap enough. You can lex afm with stock 440 injectors up to 18 psi fuel cut. I run lex afm/550. It runs rich up top 10.0 afr. Now I need piggyback to take the fuel out. Now I am thinking of going back to stock 440 so I dont have to take fuel out using piggyback. Running 10.0 afr is nice and safe but it will make you lose horsepower.

 

[suprafredde]

Running the 18 year old stockers is not gonna happen.

Yes my friend has a WB I can borrow so no worries.

Sounds like the 550s is what I want then.

Thank you all for your time.

suprafredde

 

[suprahabsfan]

Running the 18 year old stockers is not gonna happen.

Yes my friend has a WB I can borrow so no worries.

Sounds like the 550s is what I want then.

Thank you all for your time.

suprafredde

Just out of curiosity, how are you gonna borrow a wideband?

 

[MKIIINA]

If you're cheap enough. You can lex afm with stock 440 injectors up to 18 psi fuel cut. I run lex afm/550. It runs rich up top 10.0 afr. Now I need piggyback to take the fuel out. Now I am thinking of going back to stock 440 so I dont have to take fuel out using piggyback. Running 10.0 afr is nice and safe but it will make you lose horsepower.

very bad idea. this has been proven time and again to not be a good path for motor longevity. I should know, I am one of the guys who has strapped a car to a dyno with 440s and a lex afm, verrrrrry lean.

You could pull some fuel out of a STOCK fuel setup as our cars run very rich and make more power. I highly doubt you would need to pull out very much to get to 11.0 from 10.0

 

[bountykilla0118]

very bad idea. this has been proven time and again to not be a good path for motor longevity. I should know, I am one of the guys who has strapped a car to a dyno with 440s and a lex afm, verrrrrry lean.

You could pull some fuel out of a STOCK fuel setup as our cars run very rich and make more power. I highly doubt you would need to pull out very much to get to 11.0 from 10.0

Well did you tune it at all????? Thats funny i am running a lex afm and stock 440's ...... however I do have a SAFC II and an AEM Wideband I have to add 13% fuel at WOT across the board and my A/F ratio is roughly 11.8 and peaks at 12.3. If I had an AFPR i am sure I would not even need an SAFC. At cruise it bounces around 14-15 and at idle it is pretty lean at 16 but thats not going to harm anything.

 

[MKIIINA]

tuning is a different story. this was a relatively stock car that literally all we did was swap afm's out. While I will admit that you could use 440s and lex afm AND tune (you have an SAFC) its not what many people will see or do. They want the fast and easy which is just swapping in the lex afm and no tuning or wb02.

when i tested the car bottomed out at under 12.5 iirc (i'll dig out the dyno sheet, i know i posted it on here a while ago) What are your other mods btw?

 

[gofastgeorge]

........I do have a SAFC II and an AEM Wideband I have to add 13% fuel at WOT across the board and my A/F ratio is roughly 11.8 and peaks at 12.3..

That is what smart people do..........
Like you, they use some sort of fuel management,
and the gauges to see what's happening.

Then there is the people who know nothing of how things work.
They usually end up burning down an engine,
or just running real slow.........

 

[bountykilla0118]

tuning is a different story. this was a relatively stock car that literally all we did was swap afm's out. While I will admit that you could use 440s and lex afm AND tune (you have an SAFC) its not what many people will see or do. They want the fast and easy which is just swapping in the lex afm and no tuning or wb02.

when i tested the car bottomed out at under 12.5 iirc (i'll dig out the dyno sheet, i know i posted it on here a while ago) What are your other mods btw?

My mods are the basics.... 3in exhaust from the turbo back, K&N, boost controller, and 2.5in hard pipes w/HKS BOV. I made 283rwhp and 293tq at 11-12psi on the stock afm without a decent tune and now I am running 14-15psi and tuned but no dyno...... I have beaten up on a few newer sport cars since spring an older 911 Porsche and Porsche Cayman at the same time. They both pulled out of the dealership looking for someone to stomp on but they picked the wrong guy ….. Also I have eaten R/T Chargers, Audi TT, Z4 and my friend with a 57 is not much faster than I he just put down barely over 400rwhp. However someone just offered me a nice bit of change for my car soooo its gone and i miss it already ..... but i have a hard top lined up already!

That is what smart people do..........
Like you, they use some sort of fuel management,
and the gauges to see what's happening.

Then there is the people who know nothing of how things work.
They usually end up burning down an engine,
or just running real slow.........

I feel ya on that!

 

[gofastgeorge]

Quote:
Originally Posted by gofastgeorge
That is what smart people do..........
Like you, they use some sort of fuel management,
and the gauges to see what's happening.

Then there is the people who know nothing of how things work.
They usually end up burning down an engine,
or just running real slow.........

I feel ya on that!

There are a couple of people on a simular thread
(about running lean with Lex & 550s - No management)
that think I am all wet.....
Don't dare argue with them,
people get kicked off this forum that way......

 

[jdub]

There are a couple of people on a simular thread
(about running lean with Lex & 550s - No management)
that think I am all wet.....
Don't dare argue with them,
people get kicked off this forum that way......

You're talking about this thread:
http://www.supramania.com/forums/showthread.php?t=75293

George - What you posted in that thread had nothing to do with if a S-AFC was good idea or not...it is a good idea, but not necessary for the Lex/550 combo. There are a lot of guys here (including myself) that run it without any piggyback fuel control at all. What you posted was this:

A Lexus AFM with 550 injectors is NOT a direct swap......
I see no mention of any fuel managment up-grade such as a Apex-I Super-AFC.

Most likely the 550s & Lexus AFM is the cause of your lean condition.
Everything I have seen is that 680cc injectors come closer to being correct for the Lexus AFM,
but even they need a little tweaking.

680 injectors is also not necessary with the Lex/550 combo and will cause you to run filthy rich.

You also posted this about the purpose of the fancy adjustment screw you can get for the Lex:

No, sorry.........

It causes more air to go by the sensing element,
and causes a higher frequency signal to the ECU,
thus richening the mixture..........

Completely wrong since the lower chamber bypasses the Karman Vortex sensor. The screw allows a crude adjustment of air to help lean/rich as appropriate. I don't even use one.

You seem to have NFI of how this set-up works...that is why you are catching flack about it. So get off your "poor me" horse and take the time to learn how it works...then you might get someone to listen to you. Posting the kind of crap from post #12 above (leaving certain "details" out) is even worse....it's down right juvenile.

You won't get kicked off here for debating a subject...this is NOT SF.
You will get slapped in public for posting BS (like you have)...if you have an argument that supports what you are saying about the above, we're all ears.

 

[bountykilla0118]

ouch

 

[1-2clutch-u]

dammn yo. your right sf woulda baned you. but a slap that could be worse.