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Discussion Starter #1
SO whos running 15lbs of boost on stock 440s with a LEX afm and still getting a steady ass 11.4 afr all the way to redline?! Anyone else running this set up(assuming most you cool cats got 550s) but im curious as to how much my 440s got and how long they will last at 55psi of fuel pressure lol.
 

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It might run right......?
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Everytime i tried to run a lex on stock injectors it was also stupid lean. Its just too much unmetered air for the injectors. Your either going to need to get 550's or put the stock AFM back on it.
 

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Everytime i tried to run a lex on stock injectors it was also stupid lean. Its just too much unmetered air for the injectors. Your either going to need to get 550's or put the stock AFM back on it.
Im in the process of modifying the screw for the unmetered air to make it block off more if not all the unmetered air. Working on it now acutally so ill let you know how that works out.
 

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Discussion Starter #5
Its getting super steady AFRs at 15psi tho... I just got my in car camera going but unfortunetly its to wet out to get any traction, so once the weather permits ill upload a vid.
 

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the whole reason behind the lex and the 550's is the fact that the extra 110cc is about perfect for the amount of air unseen coming into the engine. So the ECU makes fuel trim adjustments like it has 440's in it and it all responds correctly to the adjustments. The afc just kinda gives some ability to clean this up.

i tried a few times on the dyno to do what you are doing to get around fuel cut. And it always went lean for me. Your only real chance is as u stated crank the Fuel pressure up which creats issues in itself. And a note i had a stock turbo and stock engine cept the exhaust system doing this. You are moving MORE AIR than i was with your mods listed in your sig.
 

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Discussion Starter #7
Oh ok. I was under the impression that the Lex housing helped in response due to the increased size of it. The max boost i run is 15psi. Im gonna put my stock housing back on tomorrow and try and run 15psi and see what the tune is like then. I have my wideband mounted on my steering colum aswell as my boost gauge, so my eyes are always on them AFRs and never let me get outta hand thanks to my SAFC2. So in reality i should be able to tune it easier with my stock housing instead of the lex one?
 

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Oh ok. I was under the impression that the Lex housing helped in response due to the increased size of it. The max boost i run is 15psi. Im gonna put my stock housing back on tomorrow and try and run 15psi and see what the tune is like then. I have my wideband mounted on my steering colum aswell as my boost gauge, so my eyes are always on them AFRs and never let me get outta hand thanks to my SAFC2. So in reality i should be able to tune it easier with my stock housing instead of the lex one?
It'll be really rich, since you've cranked up your fuel pressure. The Lexus AFM will make it run lean with no other mods, the 550's will make it run rich with no other mods. The Lexus AFM and 550's together are close to balancing out. In your case, you raised the fuel pressure to match the Lex AFM. So removing the Lex AFM will make it rich as balls.

I think you're fine if your A/F's are like that. Just make sure your timing advance is set correctly for 10* BTDC and things should be just fine at 15psi.

Just remember that fuel pumps will run out of flow at higher pressures a lot sooner than they would at lower pressures. Some pumps perform better at high pressures than others of comparable static flow.
The Bosch 044 pump is great at higher pressures. Assuming you're running a 1:1 boost-referenced AFPR, running a 55psi base pressure will mean 70psi of fuel pressure at full boost of 15psi.

If you're on that 57trim listed in your sig, you should be fine. Once you upgrade to a larger turbo, you might run out of fuel flow depending on the walblow pump you're running.

Has the car been to a dyno in this configuration?
 

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That set up IMO is just a pain in the ass. I would just go with a MAFT PRO much better set up and it gets rid of the MAF and it's really easy to tune.
 

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^^^plus one for Maft pro


but the easiest fix for you is to pick up some RC 550s or some other top brand injectors. Running stock injectors on the LEX maf sometimes works but usually doesnt. after you get them i bet you could maybe even increase your boost a touch :)

check it http://www.supraforums.com/forum/showthread.php?t=77708
 

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Discussion Starter #11
I havent been on a dyno... But im not running my boost reference on the regulator cause i found to to flucuate alittle to much for a steady enough tune(what with boost creeping up alittle or bleeding off alittle) so its a static 55psi. Im wondering if i can lower fuel pressure and go back to a reg AFM and still run that much boost and get that good of AFR. I got a 255lph i also have a boss 044 chillen in a box in my room was thinking of throwing it inline further down the road when i wanna do E85.

I know all about 550s, but i was having problems with the stock housing in lets say 3rd gear at 3000 rpms(15psi) if i just went WOT it would hit fuel cut, then smooth out.(if i went wot at say 2k rpms in 4th gear and pull across it into boost it wouldnt hit fuel cut) as soon as i went to a LEX housing and messed with some Fuel pressure and tune, it allowed me to go WOT in 3rd gear at 3000rpms without hitting fuel cut! so thats why im using it without 550s.


I agree on the MAFT pro but i am a sorry supra owner whos cash flow is trickling down to more important bills at the moment then buying injectors that will surly decrease gas milege and fuck my wallet even more lol.... as this is my daily driver.
 

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With all those mods to your engine you really need to switch to 550's. It'll give you more to tune off of and more fuel is better then not enough. Especially 15+ psi. The safc neo should be fine with what you're trying to achieve/
 

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Discussion Starter #13
I know i would be better off with 550s... This i know.... But i dont have em sooooo im working with what i got... i have a wideband so i know im getting fuel were i need it. Im using a safc2 not neo also but same deal. Anyone wanna buy me some dyno time so i can see what kinda numbers im putting down on 440s. cause im thinking its atleast 350bhp. kthnx lol
 

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I know i would be better off with 550s... This i know.... But i dont have em sooooo im working with what i got... i have a wideband so i know im getting fuel were i need it. Im using a safc2 not neo also but same deal. Anyone wanna buy me some dyno time so i can see what kinda numbers im putting down on 440s. cause im thinking its atleast 350bhp. kthnx lol
then it looks like your just gonna have to spend a lot more time tunning yourself.

550s and a maft pro wouldnt kill your mpg, hell it'd prolly help mpg cuz you could get a better tune.

Id just keep trying to tune and tune which is gonna be hard i'll assume cuz you dont have a dyno or a ton of open road? or just keep saving for some 550s man. Your car will run much better with some 550s. also a AFPR would help too. do you have a walbro??

ahh yes now i see your sig, you do have a walbro :) good
 

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Discussion Starter #15
ahh yes now i see your sig, you do have a walbro :) good[/QUOTE]

I do have an adjustable fuel pressure regulator. I plan on getting it dyno'd soon enough. I have an in car camera set up now so when it stops raining ill go drive it and show off my tune on 15psi aswell as the rest of my car.... Keep in mind i only have $2,800 into the car including what i paid for it.
 

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One of my customers MK3 Supra with a 57trim 550ccs and the MAFT PRO running leaded race gas 110 I got 24MPG just driving around the city with blasts every now and then.
 

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One of my customers MK3 Supra with a 57trim 550ccs and the MAFT PRO running leaded race gas 110 I got 24MPG just driving around the city with blasts every now and then.

damn thats good. gives me hope as ill have a 67mm TO4Z with maft pro lol


ahh yes now i see your sig, you do have a walbro :) good
I do have an adjustable fuel pressure regulator. I plan on getting it dyno'd soon enough. I have an in car camera set up now so when it stops raining ill go drive it and show off my tune on 15psi aswell as the rest of my car.... Keep in mind i only have $2,800 into the car including what i paid for it.[/QUOTE]

wow dude..thats so cheap lol lucky

i still stand by gettin 550s ASAP tho
 

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I'm a part of this conversation too!

But seriously... Lex/550s/walbro on STOCK Fuel pressure and the j-tube drilled out/bypassed made my 91 run pig rich. It was WAY more fuel than it could have ever needed. My bumper was sooted along with everthig else under the car. It would blow flames every time I shifted (during races/beating).

If anyone has actually dynod a STOCK fuel/tune 7mgte, raise your hand. Cuz I know I've done it and it ran 10:1 after 4500rpm. It was idealsupras car and it was just bpu. The stock ecu runs it so rich under boost that I pulled 11% out on his safc2 just to get it to 11.5-12.0 at 14psi after 3500rpm.

So, the simply swapping the parts does not yield a perfect tune and cancellation of fuel vs air.

I ran a Lexus meter on my STOCK 440s and had to add "only" 12% to get my afrs in check. However, I then changed my stock ct26 actuator for a modified ct12a actuator to have 15psi of boost, no boost controller. Of course, with added fuel correction via safc and 15psi, I hit fuel cut instantly. The next step I had to do was raise my base fuel pressure to 52psi, no vacuum. This allowed me to run 17psi daily, on a Lexus meter, with 440cc injectors. And my afrs were 11.2-11.8. I WOULD hit fuel cut on a cold night in 3-4-5 gears however.

Now, I'm on map ecu, and log my boost vs afr vs rpm. So I know I'm peaking 17psi on the stock ct. No other fuel system
Changes yet.
 

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Only one problem I see with running over 11.4 11.7 on a piggy back.....Cold air. There is no adjustment for running in cold weather, or any kind of cool air. Cool air will cause a lean condition, and Poof....detonation with the probability of major motor failure. Smoke and mirror piggy backs will yield more power, but true engine management is needed for reliable rwhp.


Sure it can be done with a cheap SAFC, or any piggy back, but is it a good way of blowing your motor at some point...... surely it may.
 

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I'm a part of this conversation too!

But seriously... Lex/550s/walbro on STOCK Fuel pressure and the j-tube drilled out/bypassed made my 91 run pig rich. It was WAY more fuel than it could have ever needed. My bumper was sooted along with everthig else under the car. It would blow flames every time I shifted (during races/beating).

If anyone has actually dynod a STOCK fuel/tune 7mgte, raise your hand. Cuz I know I've done it and it ran 10:1 after 4500rpm. It was idealsupras car and it was just bpu. The stock ecu runs it so rich under boost that I pulled 11% out on his safc2 just to get it to 11.5-12.0 at 14psi after 3500rpm.

So, the simply swapping the parts does not yield a perfect tune and cancellation of fuel vs air.

I ran a Lexus meter on my STOCK 440s and had to add "only" 12% to get my afrs in check. However, I then changed my stock ct26 actuator for a modified ct12a actuator to have 15psi of boost, no boost controller. Of course, with added fuel correction via safc and 15psi, I hit fuel cut instantly. The next step I had to do was raise my base fuel pressure to 52psi, no vacuum. This allowed me to run 17psi daily, on a Lexus meter, with 440cc injectors. And my afrs were 11.2-11.8. I WOULD hit fuel cut on a cold night in 3-4-5 gears however.

Now, I'm on map ecu, and log my boost vs afr vs rpm. So I know I'm peaking 17psi on the stock ct. No other fuel system
Changes yet.
I have dynoed several stock supras. They do run extremly rich like your saying on stock setup. But as u know put a lex on that and it goes lean. Gotta do something to get more fuel into it.

You also have to remember this guy has a bigger turbo and some other mods to allow more flow. Comparing that to what u dynoed and tuned he is going to need even MORE fuel.
 
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