Lex Afm+57 trim+440's=bad????
- Thread starter Ozz89supra
- Start date
91blackeye;1378199 said:
Not 100% sure but I believe its a section of the fuel-return system. Apparently you can by-pass this when you are running more than stock fuel.....
GC89;1378126 said:
I agree 100%!
And yes, I'm corrected on my fuel pressure mis-information. It is 40 psi. Sorry...
Here's the link:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=73
91blackeye;1378199 said:
It's part of the fuel system. The hole has to be drilled out when a Walbro 255 is installed.
It is located on the driver's side of the block about mid-way down. It is in the shape of a 'J' (hence the name 'J' Tube) and can be seen fairly easily. It's a goldish color.
And yes, with the Aeromotive AFPR Kit, it is bypassed totally.
CajunKenny;1378259 said:I agree 100%!
And yes, I'm corrected on my fuel pressure mis-information. It is 40 psi. Sorry...
Here's the link:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=73
It's part of the fuel system. The hole has to be drilled out when a Walbro 255 is installed.
It is located on the driver's side of the block about mid-way down. It is in the shape of a 'J' (hence the name 'J' Tube) and can be seen fairly easily. It's a goldish color.
And yes, with the Aeromotive AFPR Kit, it is bypassed totally.
Wait it HAS to be drilled with a walbro???? I thought that was optional...... Let me know :1zhelp:
GC89;1378126 said:
CajunKenny;1378259 said:I agree 100%!
And yes, I'm corrected on my fuel pressure mis-information. It is 40 psi. Sorry...
Here's the link:
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=FI&P=73
You guys already need reading glasses at your age
Read that TSRM page a little closer...stock fuel pressure is 23-30 psi with the vac line connected to the FPR (normal configuration). Vacuum is what produces the 1:1 rising rate under boost.
That's a significant change to the fuel calculator results for an 80% duty cycle. That's why it is a very good idea to use 550 injectors with a Lex AFM...on 440's, you have to increase the FP and duty cycle to get the desired HP results.
Sure it can be done, but Kenny is right...it's not a good idea because it takes your margin of error to zero.
FYI - Everybody seems to want to run the Lex/550 combo at 35-40 psi FP...that is way too much. You want to keep it at the TSRM mid-range.
Ozz89supra;1378423 said:
Yes...the restriction in the J tube will produce high FP with the increased flow of the Walbro. The J tube is actually a back-up in case the stock FPR fails. Increasing the flow overwhelms the stock return with the J Tube restriction in place...you drill it out and let the AFPR handle it.
jdub;1378468 said:You guys already need reading glasses at your age
Read that TSRM page a little closer...stock fuel pressure is 23-30 psi with the vac line connected to the FPR (normal configuration). Vacuum is what produces the 1:1 rising rate under boost.
That's a significant change to the fuel calculator results for an 80% duty cycle. That's why it is a very good idea to use 550 injectors with a Lex AFM...on 440's, you have to increase the FP and duty cycle to get the desired HP results.
Sure it can be done, but Kenny is right...it's not a good idea because it takes your margin of error to zero.
FYI - Everybody seems to want to run the Lex/550 combo at 35-40 psi FP...that is way too much. You want to keep it at the TSRM mid-range.
Yes...the restriction in the J tube will produce high FP with the increased flow of the Walbro. The J tube is actually a back-up in case the stock FPR fails. Increasing the flow overwhelms the stock return with the J Tube restriction in place...you drill it out and let the AFPR handle it.
Alright
jdub;1378468 said:You guys already need reading glasses at your age
Man...apparently so!! Thanks for jumping in here and clearing things up!
So whats the worse thing that can happen if I dont drill out my J tube??? and is there are write-up for it. I tried searching it but no luck on how to drill into it. Thanks!
i have put on a t04e on my 7m put on a apexi neo with th afpr from drift motion with a full 3" exhaust with the walboro 255 and i run a safe 15 psi and plenty of power for the streets if i were u get the apexi neo ist a good investment
You shouldn't be hitting fuel cut at only 9psi on a ct26-57 unless you're boosting in death valley in sub zero temperatures -- check, recheck, and triple check for boost leaks because you have one. On my old 60-1 CT26, I would hit fc at 11-13psi depending on weather. A 57 should be very similar...
Once the boost leak is fixed, you'll need to retune your SAFC as it will be way too lean once your engine is actually getting all of the air the AFM was seeing...
As for MK3 fuel pressure, its 33-40psi at atmospheric pressure. As jdub said, it will be 23-30psi at idle (10psi vacuum). With 10psi boost, it will be 43-50psi. That means the stock 440's are good for 265-305rwhp depending on your engine's efficiency and your individual fuel pressure.
There is no need for a Lex AFM at 305rwhp. conversely, there is no good reason to having a Lex AFM paired with stock 440s. Upgrade both at the same time if you choose to go the lex/550 route
Once the boost leak is fixed, you'll need to retune your SAFC as it will be way too lean once your engine is actually getting all of the air the AFM was seeing...
As for MK3 fuel pressure, its 33-40psi at atmospheric pressure. As jdub said, it will be 23-30psi at idle (10psi vacuum). With 10psi boost, it will be 43-50psi. That means the stock 440's are good for 265-305rwhp depending on your engine's efficiency and your individual fuel pressure.
There is no need for a Lex AFM at 305rwhp. conversely, there is no good reason to having a Lex AFM paired with stock 440s. Upgrade both at the same time if you choose to go the lex/550 route
Ozz89supra;1380156 said:
Here's your answer.
jdub;1378468 said:
Just remove it, drill it out, clean it, and re-install it. Not too difficult.
CajunKenny;1380206 said:Here's your answer.
Just remove it, drill it out, clean it, and re-install it. Not too difficult.
Ok I might do it early tomorrow. I just finished putting in my walbro, now I just gotta put the tank back inn so im getting there
If your vac lines are original or just old in general, old lines get brittle and get minute cracks. Small enough that they're hard to see or just a hairline crack, and when you hit boost they start leaking and if you've got enough little cracks it can make a pretty big difference. Might just want to get new vac lines, they aren't too expensive
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Ozz89supra;1380295 said:
Cool beans man! Hopefully, you didn't do this with a full tank of gas! :sarcasm:
Double check your wiring, connections, and hoses before you put her back up.
Keep us posted...
CajunKenny;1380355 said:Cool beans man! Hopefully, you didn't do this with a full tank of gas! :sarcasm:
Double check your wiring, connections, and hoses before you put her back up.
Keep us posted...
Soo I started her up this morning and my AFRS are now 11-12 idling lol. I gotta take her out and adjust fuel with the safc later tonight. Yeah I had to drop the tank twice because I forgot to plug in a connector :cry: but at least I did it right..... I also got a little distracted because my friend just bought a 93 240sx so we were messing with that for a little also :biglaugh:
Did you drill out the 'J' tube yet?
The only thing that should be doing to a 240 is watching it fade in your rear view mirror! :biglaugh:
The only thing that should be doing to a 240 is watching it fade in your rear view mirror! :biglaugh:
CajunKenny;1380738 said:
About tht J tube....... :: no :: havent done it .....yeah he bought a 93 coupe, 5 speed, Ka24de so its slow, but he just wants it to drift since he already has a WRX
Ozz89supra;1380697 said:
Hmm I didn't read through the whole thread so maybe this is not applying to you but here goes:
You cannot ajust the closed loop afr's with the s-afc.
First get it idling around 14.7 by setting the fuel pressure before you ajust the s-afc. Check whether the ecu has trouble ajusting the AFR's by checking your Vf signal.
Drilling out the j tube should help a lot!