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Go All Electric
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Discussion Starter #1 (Edited)
I am going to start this thread with a bunch of copy/pasted information from the middle of a conversation that I have been having with a fellow member. BRB with the edits of the info.

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TRD91whtMK3 ver.2's list of performance mods:
-Blitz ESBC electronic boost controller at 10 and 15 psi

-MSD DIS4 ignition

-MSD 8.5mm super conductor wires

-HKS S-AFR

-NOS 100 shot wet nitrous kit

My response:

You run to 15 psi sometimes on the stock AFM? You mentioned something about taking the stock adjustable screw out and it raised your fuel cut to 18psi in the other thread. If this is true, I'm about to go look for the adjustable screw on my AFM.

What performance mods were you using when you ran your "14.7 @ 95"?

We, enthusiasts, always enjoy pics. It would be my pleasure to view any that you take of your car.

All sounds well. Best regards.

EDIT:

TRD91whtMK3 ver.2 said:
some mkiii's you can adjust the afm screw with, and some not... mine worked perfectly, i've hit 18psi before :eek:
Stock AFM on the right and Lexus on the left. I am almost positive that this is where the adjustable screw goes for both of the AFMs. Can you confirm this is the same location that you "adjusted the screw" at on the stock AFM?



EDIT: Actually, I know for sure this is it. The following picture has an internal view of the same comparison. The stock "adjustable screw" is clearly seen penetrating the stock AFM (ON THE LEFT) in this picture.



I think I just may be taking that stinker out.

Comments?

TRD91whtMK3 ver.2's reply: haha yep thats the screw, but DO NOT take it all the way out!! That will cause for a way too lean mixture, also, it may not work for you, some of my freinds tried it, with no luck, but it worked perfectly fine for me!

*current end of conversation because I thought that I should start another thread about it instead of continuing our converstion while hijacking another thread*
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also, it may not work for you, some of my freinds tried it, with no luck, but it worked perfectly fine for me!
This makes no sense at all. If it is a factory 7mgte with a factory AFM and his FC raised to 18psi by adjusting the stock screw and doing nothing else, this should be the same for everyone.

Question of mine:

How the heck would I adjust this screw or back it out? By the looks of the following picture, there is no way to grip it.



Lets talk about this. "Game on".;)
 

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Go All Electric
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Discussion Starter #2 (Edited)
EDIT DONE. I see you DocJ, you should reply sometime soon:D ;) .
 
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I have no clue about the some do and some don't thing, but a few of my freinds tried it, and still hit fuel cut at 13psi...

the way you get to the screw is drill out the aluminum where the screw head is, then you can back it out, just don't remove the screw all the way, i did this the first time and the car hesitated, it didn't run right at all....

not really much to it, just back it out a little bit, test it, if it hits FCO then back it out some more, etc...
 

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Go All Electric
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Discussion Starter #4
TRD91whtMK3 ver.2 said:
I have no clue about the some do and some don't thing, but a few of my freinds tried it, and still hit fuel cut at 13psi...

the way you get to the screw is drill out the aluminum where the screw head is, then you can back it out, just don't remove the screw all the way, i did this the first time and the car hesitated, it didn't run right at all....

not really much to it, just back it out a little bit, test it, if it hits FCO then back it out some more, etc...
Thanks. I figured I would just need a drill, but I wanted to make sure. It excites me to think that I could raise FC toward 18psi this way. I hope it works.
 

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Go All Electric
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Discussion Starter #6
chevyeater-on-sf said:
If I were going to do such a thing I would buy an adjustable fuel pressure regulator.
Seems reasonable, BUT, TRD91whtMK3 ver.2 isn't running one.

How is the car running Jayson? Is it a DD? What is your average boost set to? I wouldn't run anythng over 15psi on the stock ct26 because it seems out of efficiency and it has cause various problems for other who have attempted it.

I like to be safe. BUT, I also like to use the car to it's full potential and defy some thoughts on what "needs" to be done.

If I really do need an AFPR, I would get one. BUT, I am not convinced that I would need one yet.
 

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I hit fuel cut at 15-16 psi with the stock screw backed all the way out. Generally run 9-10 psi, but after getting my car back from the mechanic they hooked up the MBC wrong and up the boost went... pretty fast too. :)
 

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Go All Electric
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Discussion Starter #8 (Edited)
wrsupra said:
I hit fuel cut at 15-16 psi with the stock screw backed all the way out. Generally run 9-10 psi, but after getting my car back from the mechanic they hooked up the MBC wrong and up the boost went... pretty fast too. :)
Another good comment on this proceedure:D .

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Here is something ADJUSTER posted on 2-20-03:

The easy trick to get past the FC at 12/13 is to leak some air past the meter. You can either back out the air screw, or you can add a breather/filter to an unused air inlet fitting on the accordian intake hose. (By this time you might have removed your PCV dump as it coats the intake with oil vapor, and/or you just want to spit in the face of environmentalism... LOL) A simple backing out of the air screw in conjunction with a breather can net you 15 psi easy. Do the breather first, then adjust the screw out till you get a nice consistant FC at about 16 psi, then you don't have to worry about running lean, unless a injector fails, then you are in trouble, but that is true at 10psi too.
So long story short, with the right mods, you can run 15 psi on 440's, but you will need more fuel, more pressure, gauges to monitor the engine and air fuel ratio.

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Add a breather to the accordian hose eh? Might this leak some air? All you do is make a hole it the accordian hose and put one of those breather filters on and seal around the cracks, right? <---This sounds like it would leak to me. <---Comments?

Notice he mentioned that you need a little more fuel and some guages. Most people mention a pump and an AFPR. Think that the 12v mod and an AFPR would do well?

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EDIT: Just wanted to mention that I am not trying to be a cheap-skate. I am just looking to reach the peak poetntial of the stock ct26 in the cheapest manner for now because I am going to be buying a new truck and a bike and I wont have money for serious modifications to the supra for quite some time. Yet, I am seriously getting tired of running 11.5 peak psi and dropping to 8psi. The car needs a little cheapo work until the time comes for it to be reborn. I won't start any cheap mods until after I get my truck so that I won't be risking damage to my DD. I will be less concerned of the cheap mod chances of damage when I really don't need the supra because I have a truck for a DD.
 

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All i have to say is why risk running lean and destroying a motor when you should just do the proper procedure to bypassing fuel cut, instead of finding shortcuts, I mean with a 550 and lex and all supporting, its like having insurance for the motor... just my 2 cents, aight peace
 

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Go All Electric
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Discussion Starter #10
BoostAddctn said:
All i have to say is why risk running lean and destroying a motor when you should just do the proper procedure to bypassing fuel cut, instead of finding shortcuts, I mean with a 550 and lex and all supporting, its like having insurance for the motor... just my 2 cents, aight peace
Read my above edit.
 

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Go All Electric
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Discussion Starter #12
Howie said:
get a fuel cut defensor
Nope. 150$ and not nearly as safe = bad idea. I do appreciate your input though.
 
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BoostAddctn said:
All i have to say is why risk running lean and destroying a motor when you should just do the proper procedure to bypassing fuel cut, instead of finding shortcuts, I mean with a 550 and lex and all supporting, its like having insurance for the motor... just my 2 cents, aight peace
i've been driving my car for almost a year like this, and I drive my car VERY hard when I drive it, no problems what so ever,.... until the nitrous kit came... 100 shot on 91 pump with no timing retard detonates pretty badly :eek:
 

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Go All Electric
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Discussion Starter #14
Chevyeater wrote: "If I were going to do such a thing I would buy an adjustable fuel pressure regulator."
AWIDESUPIE said:
Seems reasonable, BUT, TRD91whtMK3 ver.2 isn't running one.

How is the car running Jayson? Is it a DD? What is your average boost set to?

I wouldn't run anythng over 15psi on the stock ct26 because it seems out of efficiency and it has cause various problems for other who have attempted it.

I like to be safe. BUT, I also like to use the car to it's full potential and defy some thoughts on what "needs" to be done.

If I really do need an AFPR, I would get one. BUT, I am not convinced that I would need one yet.
Jayson, you posted but missed my question to you. Care to reply?
 

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25psi = 14" brakes :)
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This is a pretty interesting post.
Here is what I've done.
Before I put the Walbro 255lph HP pump, and the Areomotive AFPR, I did the air screw mod on my 88T.
It ran fine. Did not appear to be lean at all under boost. I watched the EGT's, and never had any over 1300f, even up to 15psi. (FC was at 17psi the day I tested it.)
Now, this was on the stock IC as well, but with conduit IC pipe mods
I ran 14.5psi all the time, with the occasional 15psi spike on cool air. No problems, and on the stock CT. It was pretty dang awesome.
No breather hose/filter needed. Just backed out the air screw all the way, but did not remove it. (You could not see much of it anymore when looking down inside the AFM.) It is held in place by an O-ring.
Good luck, and if you don't have a EGT, or access to a wideband, I would not try this mod. If you fuel pump or filter is lacking, you could run lean and fry your motor. If you have the gauges and the guts, go for it then.
 

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Go All Electric
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Discussion Starter #16 (Edited)
adjuster said:
This is a pretty interesting post.
Thanks. That's what I thought too. Hence, I posted it.:D



Before I put the Walbro 255lph HP pump, and the Areomotive AFPR, I did the air screw mod on my 88T. It ran fine. Did not appear to be lean at all under boost. I watched the EGT's, and never had any over 1300f, even up to 15psi. (FC was at 17psi the day I tested it.) Now, this was on the stock IC as well, but with conduit IC pipe mods. I ran 14.5psi all the time, with the occasional 15psi spike on cool air. No problems, and on the stock CT. It was pretty dang awesome. No breather hose/filter needed. Just backed out the air screw all the way, but did not remove it. (You could not see much of it anymore when looking down inside the AFM.) Another good comment on this proceedure ..
Another good comment on this proceedure:D.

Just as I expected. Glad to hear things were ok w/o the pump and AFPR. BUT ... I understand how essential the EGT is for making sure that all is well.

When you say "conduit IC pipes" do you mean like Lunsford's PVC pipes? I plan on running the pvc pipes until I am done with the ct26 and I totally tear down the engine and throw a lot of money into it. I may also run the pvc pipe/dual IC mod but I have not yet decided.

When you say that the screw is held inplace by an O-Ring, do you mean that you put one on the tip of the screw that stays inside the AFM in order to secure it more?

Good luck, and if you don't have a EGT, or access to a wideband, I would not try this mod. If you fuel pump or filter is lacking, you could run lean and fry your motor. If you have the gauges and the guts, go for it then.
Thanks for the best wishes. I find the proper guages. I still need to decide which ones I would like to have.

I have no mechanical knowledge of a wideband sensor. All I currently know is that it is an "optimal" tuning tool. I don't know how I could use it if I had one, except for with a professional dyno tuner. Problem is that I don't know of any local dyno tuners, but, with my good networking skills I suppose I could find somebody who knows what they are doing to give me a hand.

I plan to transport the supra out of state when the time comes to give it new birth, unless an amazing tuner starts a local business.

Fuel pump and filter should be close to 100%. I could check this out to make sure.

I'll have all the guts I would ever need when I get my new truck. I won't have to rely on the supra for transportation any longer.


Thanks. More comments welcome. Best regards.

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EDIT: More things to think of.

Originally posted by ASL MKIII: "An EGT guage will not catch one cylinder leaning out. The only way it would help in that scenario is if you had a probe in every cylinder."
Originally posted by 1qwickmk3: "I am living proof that this is absolutly true.. an egt cannot respond quickly enough for you to realize there is a problem."
Originally posted by slowyoda89: "I have a chart here in front of me.440cc injectors under 100%duty cycle in a 6 cylinder will flow 458hp worth of fuel. so 440cc injectors with a fuel pump and regulater will flow saftly i would guess around 400 horsepower. I was also running a vpc at 15psi with no fuel system mods. That isnt the smartest think to do, I would atleast do a fuel pump. I dont think it is possible to run lean with a lexus,stock turbo,fuel pump,rising rate fpr.Vpc is the same thing with no ristriction what so ever,no lean nees here,and no fuel pump,and regulater before the new setup.15psi.
 

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boost freak
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get gauges, then try it. if you go lean, you'll need some sort of fuel control.

saying "it worked so-and-so's car" is just plain stupid. EVERY car is different, what worx for 1 won't work for another. find out what YOUR car likes.....
 

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Go All Electric
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Discussion Starter #18 (Edited)
drjonez said:
get gauges, then try it. if you go lean, you'll need some sort of fuel control.
Thanks for the encouragement.

saying "it worked so-and-so's car" is just plain stupid. EVERY car is different, what worx for 1 won't work for another. find out what YOUR car likes.....
I "kind of" understand how this statement could be true. I suppose the condition of various engines/engine components of the same type could be a large factor in various results, but other than that, I don't understand why results from one engine would not be the same on a replica engine with the same modification applied.

More comments?

Notice that I had some questions about using a wideband 02 and also some questions for Jayson (TRD91whtMK3 ver.2) and slowyoda89.
Responces please.
 

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Go All Electric
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Discussion Starter #19
Bump.
 
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drjonez said:
get gauges, then try it. if you go lean, you'll need some sort of fuel control.

saying "it worked so-and-so's car" is just plain stupid. EVERY car is different, what worx for 1 won't work for another. find out what YOUR car likes.....
that was my point, worked fine on mine, didn't work on my freinds, every car is different


supie... yes, my car is currently my DD, seeing as how i got rid of my other DD cuz it was a piece of shit that ate power steering fluid and oil, and i do have a walbro 255lph high pressure pump, i forgot to list that in my list of mods and yes, it runs perfectly fine.... only now i need to rewire my knock sensors dammit :mad:
 
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