afm from lexus

mercuryfreak200

?Which parents?
ok i found an afm from a sc400 with a v8 should i install it now with my motor stock or wait until i get the injectors and wideband o2 sensor. i mean if i put it on my car is it going to run to rich lean or the same. i also found a 3000gt at the junk yard just happens to be a twin turbo but the turbos were gone i wanted to pull the intercooler gone too but will the injectors for that work they are after market how do i tell what the flow is????
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
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Fullerton,CA
stock vr4 injectors are 360cc and would be a down grade. get 550's to go with the lex or you will run lean.
 

Supracentral

Active Member
Mar 30, 2005
10,542
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mercuryfreak200;1502516 said:
ok i found an afm from a sc400 with a v8 should i install it now with my motor stock or wait until i get the injectors and wideband o2 sensor. i mean if i put it on my car is it going to run to rich lean or the same.

The entire point of the Lexus SC400 mod is that it increases airflow by 25%. If you add 550 cc injectors, you will notice that they are 25% larger than the stock 440's. By using the two together, you get "close" to stock AF ratios. Then you use the wideband and the tuning tool of your choice (i.e. ApexI S-AFC or the like) to correct to "normal".

If you run the Lexus without the 550's, you will run lean, fuel cut will not function until it is FAR too late, and you risk detonation and damage to your engine. Do no do this.

mercuryfreak200;1502516 said:
= i also found a 3000gt at the junk yard just happens to be a twin turbo but the turbos were gone i wanted to pull the intercooler gone too

Neither is really worth a damn on a Supra if that's what you were intending to do...

mercuryfreak200;1502516 said:
but will the injectors for that work they are after market how do i tell what the flow is????

3000 GT's use Low Impedance, Ball & Seat injectors, with the average upgrade being in the 500 to 850cc range, however if the flow rates are not stenciled onto the injectors, it's nearly impossible to tell which they are.

More importantly, even if they are stenciled, any fuel injector (especially used ones) should be sent out to be flowtested and cleaned before they are used.

If you send them to someone like RC, they can do it for you:

http://www.rceng.com/Fuel-Injector-Cleaning-P43C0.aspx

However, based upon the questions you are asking, I would strongly suggest that you read a lot more on this site, and understand what you are doing before you start doing it. Far too many of these cars are winding up in the junk yard due to poorly thought out mods being done by inexperienced people.

My $.02, your mileage may vary.
 

mercuryfreak200

?Which parents?
i'm not doing the mods my mechanic is he has built countless supras one of them he built has 1400 horses at the wheels they took it to a supra meet in texas somewhere and blew them out of the water (it ran 8 sec. all day). i on the other hand have been talking with him and he told me to ask around to what kinds of mods are out there and he would do them for if he thought i would gain anything from them. this is my first supra and i don't want it in the junkyard, like you i want it on the road its my dream car i only want the best and if i can learn somthing and pass it on then great which is why i ask questions even if it means i get "flamed" but i do appreciate the concern it took me a long time to find one and i don't want it screwed up.
 

Randy954

New Member
Jan 3, 2010
3
0
0
vallejo, ca
hmmm im running a lexus afm with stock injectors... Is that bad? My mods are 57trim, 255 wally, aero fpr set at 42psi (i think), intake, dp, and exhaust.. i know im running rich atm but im going to check my afr's tomarrow..
 

whitemike

Banned
Aug 30, 2009
1,164
0
0
Winter Park, Florida, United States
Supracentral;1502596 said:
The entire point of the Lexus SC400 mod is that it increases airflow by 25%. If you add 550 cc injectors, you will notice that they are 25% larger than the stock 440's. By using the two together, you get "close" to stock AF ratios. Then you use the wideband and the tuning tool of your choice (i.e. ApexI S-AFC or the like) to correct to "normal".

If you run the Lexus without the 550's, you will run lean, fuel cut will not function until it is FAR too late, and you risk detonation and damage to your engine. Do no do this.



Neither is really worth a damn on a Supra if that's what you were intending to do...



3000 GT's use Low Impedance, Ball & Seat injectors, with the average upgrade being in the 500 to 850cc range, however if the flow rates are not stenciled onto the injectors, it's nearly impossible to tell which they are.

More importantly, even if they are stenciled, any fuel injector (especially used ones) should be sent out to be flowtested and cleaned before they are used.

If you send them to someone like RC, they can do it for you:

http://www.rceng.com/Fuel-Injector-Cleaning-P43C0.aspx

However, based upon the questions you are asking, I would strongly suggest that you read a lot more on this site, and understand what you are doing before you start doing it. Far too many of these cars are winding up in the junk yard due to poorly thought out mods being done by inexperienced people.

My $.02, your mileage may vary.

Ding ding ding! This is a re-usable post right here. Mike you nailed it sir, please sticky this lol

When I saw this thread I was like, "why the HELL isn't there a writeup explaining what the lex/550 mod does!?!?"
 

suprarx7nut

YotaMD.com author
Nov 10, 2006
3,811
1
38
Arizona
www.supramania.com
To the OP: Just because your "mechanic" has "built" countless fast Supra's doesn't mean you should be in the dark when it comes to your mods. It's your car so you need to take full responsibility for everything that happens to it. You did have the clarity to ask before doing something to your "dream car" so I sincerely tip my hat to you. :)

I agree with the above about the lex/afm mod being a sticky if it isn't already. I never really understood it until lately, but it's SOOO simple that it's a shame to see so many misunderstand it.

That being said, I swear if I hear somebody back anything up by saying [my mechanic said it would be good. He's built xx number of 3000rwhp Supras and has done more than any of you losers] my head is going to explode.

The op didn't quite do this, but it just reminded me of the occurrence. /rant
 

Drake69

Enjoyin' mah ride...
Aug 24, 2009
648
0
16
55
Richmond, Virginia, United States
In all honesty, there needs to be a sticky thread explaining not only the Lexus injectors/AFM mod, but a detailed explanation of how fuel cut works, what is AFM, and why engines WORK THE WAY THEY WORK. It almost has to be that remedial to get the point across. Without understanding what an engine does, people (not just kids, mind you) will put on all these mods without thinking about WHAT THEY DO, HOW THEY WORK, IF THEY WORK IN CONJUNCTION WITH ONE ANOTHER, etc... They just do this because others do it, and don't even stop to consider the consequences.

Not to be condescending, but it's almost like grade school.

Sorry, off the damn high horse now...
 

Supracentral

Active Member
Mar 30, 2005
10,542
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mercuryfreak200;1502625 said:
he has built countless supras one of them he built has 1400 horses at the wheels they took it to a supra meet in texas somewhere and blew them out of the water (it ran 8 sec. all day).

My team was the TX2K5 champion in the unlimited street class. The red arrow points at me:

tx2k5-unlimited-champs-crewchief.jpg

Left to right: Yamil Widy, Mike Donohue, Chris Anderson, Jarret Humphries, Jim Nixon & William

The 8 second Supra club is pretty exclusive, there are only a handful of us who ever built them that fast and ran them at the Texas meet.

And we all know each other. Who's the mechanic?
 

mercuryfreak200

?Which parents?
the mechanics name is greg idk who the driver was i know that it is black but it was built in like 04 i belive i remember it being up at the shop alot they were running it a kcir to help with tuning it think it had 2jz but not sure i know it had quote me if i'm wrong but corella rods ehh??? i can get some pics from him and post them u'd probably know it if you saw it i don't know alot about supras but thats why i joined this forum so i can search and learn. but i do know he lives here in kansas city cause i see it at the shop every once and a while