680 cc injector supporting mods....

[Infinity03]

Is it possible to tune 680 cc injectors with just a MAFT?

i currently have a walbro 250, stock lines and injectors and i would like to throw in the 680cc's and be able to tune them with the maft and not have idle problems.

 

[project_tsi]

with a eprom ecu and chip already having compensation for the 680's then yes. If you dont have an eprom chip, then probly not at all. I run 650's w/ MafT and S-AFCII and am barely getting a decent tune out of it. I dont have an eprom right now, and its barely ideling.

 

[oldman]

Is it possible to tune 680 cc injectors with just a MAFT?

i currently have a walbro 250, stock lines and injectors and i would like to throw in the 680cc's and be able to tune them with the maft and not have idle problems.

It would be mighty hard to tune 680s with just a MAFT especially along with a Walbro 255 with out an afpr.

 

[vr4play]

I am running 680s, 255fp, no afpr w/ just the MAFT (MAF in intake pipe) and I am tuned well. I haven't hooked it up in RPM mode for the top end tune, and don't see a reason to do so.

 

[oldman]

I am running 680s, 255fp, no afpr w/ just the MAFT (MAF in intake pipe) and I am tuned well. I haven't hooked it up in RPM mode for the top end tune, and don't see a reason to do so.

Since most tuning is done during WOT and fpr overrun only occurs during idle and part throttle, one can easily have a good tune and still suffer from the effects of fpr overrun. What you save in gas over a period of time easily covers the cost of an afpr so the question becomes "why not?".

 

[Infinity03]

i didnt realize it but i have a full throttle speed and style fpr that was in in a box from my other talon i had last year so i am going to use that.

in addition with what i mentioned above i should be able to run the 680's with the maft setup?

i dont want to force myself into a dsmlink at the moment. i have like 3 projects going at once

 

[oldman]

i didnt realize it but i have a full throttle speed and style fpr that was in in a box from my other talon i had last year so i am going to use that.

in addition with what i mentioned above i should be able to run the 680's with the maft setup?

i dont want to force myself into a dsmlink at the moment. i have like 3 projects going at once

Like an afc, 650-680cc are about the limits of a MAFT so you might be good. With the addition of the afpr, you can always run at lower pressure to take a little out of the 680cc if need be. Make sure you have a logging device, I didn't see it in your profile.

 

[herostar]

We can give you a rough idea, but until you check it using a logger nobody will really know. Like posted before, put that afpr on there and then log it and see...

 

[sweet97]

I did OK with PTE 650-680's and the MAFT/AFPR with the only problem fighting extra timing a bit. I don't see how a Walbro 255 and no AFPR could run well without an AFPR, even at WOT as that is when mine ran poorly, in boost. ordered an AFPR quick! Great someone is getting away with it. By the way the RPM wire is for WOT, ALL WOT from off idle to redline not just the "high end". It is easier for the ECU to read rpm over airflow in that situation also. I would try the RPM mode as you will get a better WOT tune. Mark

 

[bullettdsm]

Since most tuning is done during WOT and fpr overrun only occurs during idle and part throttle, one can easily have a good tune and still suffer from the effects of fpr overrun. What you save in gas over a period of time easily covers the cost of an afpr so the question becomes "why not?".

Hey Oldman, aren't you getting tired of saying the same thing over and over again? !
It seems like in the last couple weeks you have answered that question at least 4-5 times. Maybe you should just put that on a sig so people would understand.

OK sorry for the hi-jack but I had to just interject that thought. Please continue.

MB

 

[vr4play]

I did OK with PTE 650-680's and the MAFT/AFPR with the only problem fighting extra timing a bit. I don't see how a Walbro 255 and no AFPR could run well without an AFPR, even at WOT as that is when mine ran poorly, in boost. ordered an AFPR quick! Great someone is getting away with it. By the way the RPM wire is for WOT, ALL WOT from off idle to redline not just the "high end". It is easier for the ECU to read rpm over airflow in that situation also. I would try the RPM mode as you will get a better WOT tune. Mark

Actually, according to the MAFT instructions, WOT is described as MAF ~ +800Hz. I don't know about you, but this has never occured in my car at just off idle. I usually don't see this amount of air flow until I am up in boost a good bit (usually ~10psi). My car pulls strong from idle to 22psi. I have no idle problems, just about no knock (1 knock rarely pops up on the MMCD), and no black smoke or stumble. My O2 reads .85~.87 at WOT, so I could probably lean it out a bit (if I hook up the RPM wire). But my reasoning for not doing so follows the old saying... if it ain't broke, don't fix it. FROM MY EXPERIENCE, the MAFT compensates for the 680s well.

 

[Infinity03]

The logger will be next, i know im totally going out of order but i wanted to get the money parts out of the way.For that matter i dont even have a boost gauge hooked up although its here and waiting. ive been buying parts over the past 2 years and i wasnt driving because of emission issues. now that i passed the echeck ( dont ask me how) im going through all of the stuff i got and am putting it on.

for the walbro pump - i have to find my reciept because i am not sure which 255 version i have. it was one of those things i just bought a while ago and i was able to throw it on so i did.

thanks for the replies and i will make sure to give reputation points. Sometime soon here i will be able to give pointers in tuning.

P.S.S - anyone know of any guides that teach you how to read logger information? i dont want revert to the forum to find out hi and low limit 02 readings and so on.

THANKS!!

 

[oldman]

Hey Oldman, aren't you getting tired of saying the same thing over and over again?

Not nearly as bad as boost leak threads.

The logger will be next, i know im totally going out of order

Please do not install the injectors until you have a logger, were you plan on guessing what the setting should be? It's a very dangerous game you're playing.

 

[Infinity03]

NOOOOO the injectors will be the last thing i install. although i am a$$ backwards with my mods i do understand the parts i purchased and what effects they will have if operated improperly. i got a beater laptop today and i just have to exchange the cable i ordered and i will be good to go as far as the logger is concerned.

Any recomendations for logger software?

MMCD, tunerstein, pocket logger (if it is worth the money) i would like to keep the cost down if it works the same.

 

[yukondoit]

not to hijack but this is on the same topic, will 550 run fine with maft setup, i plan on using tunerstein but havent ordered a cable yet.

 

[dsm-onster]

I think yu will be OK. I used just a maft to tune my 650s and i got an ok tune until i started ramping up the boost to where i wanted int to be on my compressor map.

i dont want to force myself into a dsmlink at the moment. i have like 3 projects going at once

... you've left yourself with only a few options: smaller injectors or deal with the best tune you can get out of your maft... the "lowering your fuel pressure" is a great option because you can still have the larger injectors for when the "boost bug" bites and in the mean time not suffer from the HELLATIOUS timing maps at injector compensation.

 

[1993eclipseGS]

I had 680cc injectors, A maft translator, And a 255lph walbro pump.

I was getting about 80 miles to a full to the max tank... I even tried leaning the car all the way out on the maft... not only was my bumper black, But my whole tail lights and the back part of my spoiler was black.

So no, I woulden't recommend trying it with just the a pump, translator, and those injectors.