S-AFC or JWT ecu

[stil bil]

which one would be the best to have with a low boost turbo setup??

stock fuel pump and stock injectors??

jwt- $600
S-AFC- $400

[whateverjames]

i would have JWT tune the ECU for use with a turbo. i hear the afc needs to be tuned on a dyno to get your money's worth. you can either lean out the a/f mixture or make it too rich if you don't. and i think an upgraded fuel pump is required even with low boost. anyone know more about this?

[stil bil]

thats what i thought...

i dont think the fuel pump needs to be added just make the injectors supply enough fuel....

[240racer]

if you are running the stock injectors and MAFS then you don't need anything.  Until you change one of them, your stock ecu is fine.  The only thing the retuning does is account for different sized sensors and injectors.
you are looking at a real low boost setup for the stock fuel injectors at stock fuel pressure.  you could get a adjustable fuel pressure regulator, but then you need a new fuel pump.  I have 370cc/min inj. with the afc leaning it out a little since they are 37% more rich then stock.
neither the JWT ecu or the AFC piggy back are dyno tuned out of the box, but you can adjust the AFC

[stil bil]

i see where you are coming from, but i thought that the jwt ecu when using it for stock fuel setup did something that allows the injectors to supply more fuel...

[boosteds14]

get the jwt if you are running bigger injectors and a different MAF. if not get the s-afc.

in reality, for tuning purposes, u will need to get both. the jwt runs rich. the s-afc can adjust the MAF signal to run a little leaner for better tuning. i have the JWT ecu and i bought the HKS SAFC for tuning. when i dynoed the car, my a/f was as low as 10.9:1 at one point. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hmmm.gif" border="0" valign="absmiddle" alt=':hmmm:'>

[Jeff240sx]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (240racer @ Oct. 24 2002,12:32)</td></tr><tr><td id="QUOTE">if you are running the stock injectors and MAFS then you don't need anything. Until you change one of them, your stock ecu is fine. The only thing the retuning does is account for different sized sensors and injectors.
you are looking at a real low boost setup for the stock fuel injectors at stock fuel pressure. you could get a adjustable fuel pressure regulator, but then you need a new fuel pump. I have 370cc/min inj. with the afc leaning it out a little since they are 37% more rich then stock.
neither the JWT ecu or the AFC piggy back are dyno tuned out of the box, but you can adjust the AFC</td></tr></table><span id='postcolor'>
I really agree with this statement. &nbsp;Unless you plan on running a good (9+) psi of boost, I think that an afc would work. &nbsp;There are 8 programmable points to adjust the fuel curve +\- 50% in 500rpm increments. &nbsp;
What I don't agree with are people without a turbo telling others to do this and that, like spend the $600 on a JWT ecu, wait 2 months, because it is better. &nbsp;Not really... adjusted timing and a new fuel map. &nbsp;If you wanna go for power, you almost need a jwt ecu, becuase they program it for cobra MAFs, and higher fuel pressure, and its a custom job. &nbsp;For low boost, they'll send you a cookie-cutter program. &nbsp;And a lot of people with a jwt ecu want an afc anyway... cuz jwt runs really rich.
About the $400 afc, talk to boosteds14. &nbsp;PM him. &nbsp;He has great prices on the afc. &nbsp;
-Jeff

[boosteds14]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (stil bil @ Oct. 24 2002,03:05)</td></tr><tr><td id="QUOTE">i see where you are coming from, but i thought that the jwt ecu when using it for stock fuel setup did something that allows the injectors to supply more fuel...</td></tr></table><span id='postcolor'>
the JWT is great if you want to plug and play. no tunning if you dont want too. just plug in and go boosting. plus it is very reliable. the afc needs to be on the dyno with a sniffer to get it set up correctly.

[sykikchimp]

Don't try to run just the AFC on stock injectors if your gonna boost more that 4psi... &nbsp;You WILL need a rrfpr if you don't upgrade the injectors. &nbsp;Stock injectors go lean at about 4psi, add an rrfpr and you can get about 7-8psi... &nbsp; after that you really need to upgrade injectors. &nbsp;the S-AFC will NOT compensate for new injectors. &nbsp;The new injectors will require different pulse lengths than stock, and will run you way too rich. &nbsp;More so than any afc could compensate for. &nbsp;The ECU is always necesary when changing either Injectors and/or MAFs.

Look at it his way.. &nbsp;the S-AFC should be used to TUNE your fuel setup. &nbsp;It is NOT to be the center of your fuel setup.

To get different injectors, or mafs &nbsp;(anything that requires specific voltages to operate) you will need either a re-tuned ecu, or some sort of stand alone engine management.

[boosteds14]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (sykikchimp @ Oct. 24 2002,12:48)</td></tr><tr><td id="QUOTE">Don't try to run just the AFC on stock injectors if your gonna boost more that 4psi... You WILL need a rrfpr if you don't upgrade the injectors. Stock injectors go lean at about 4psi, add an rrfpr and you can get about 7-8psi... after that you really need to upgrade injectors. the S-AFC will NOT compensate for new injectors. The new injectors will require different pulse lengths than stock, and will run you way too rich. More so than any afc could compensate for. The ECU is always necesary when changing either Injectors and/or MAFs.

Look at it his way.. the S-AFC should be used to TUNE your fuel setup. It is NOT to be the center of your fuel setup.

To get different injectors, or mafs (anything that requires specific voltages to operate) you will need either a re-tuned ecu, or some sort of stand alone engine management.</td></tr></table><span id='postcolor'>
well said <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'> &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/thumbs-up.gif" border="0" valign="absmiddle" alt=':thumbsup:'>

[240racer]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE"> the S-AFC will NOT compensate for new injectors. &nbsp;

Look at it his way.. &nbsp;the S-AFC should be used to TUNE your fuel setup. &nbsp;It is NOT to be the center of your fuel setup.

To get different injectors, or mafs &nbsp;(anything that requires specific voltages to operate) you will need either a re-tuned ecu, or some sort of stand alone engine management.</td></tr></table><span id='postcolor'>
The AFC can compensate for new injectors just fine, it changes the MAF output voltage and adjusts it so the car runs with the correct a/f ratio. &nbsp;

I like the statement that the afc should not be the center of the fuel setup, I think for the most part that is always true. &nbsp;Some setups use a rrfpr as the center of the fuel setup, I think the afc is a better tool, I think it is more accurate, but either can be used. &nbsp;However, the precision of a ecu with more the 8 pts of adjustment cannot be beat.
I am using the afc as the central fuel adjustment tool, it works fine, however, the stock ecu (JWT or whatever) has more room for adjustment and precision. &nbsp;

Don't run stock injectors with any boost unless you have a higher then stock fuel pressure regulator. &nbsp;You can do it, I just don't think it's a good idea.

[Jeff240sx]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (240racer @ Oct. 24 2002,4:43)</td></tr><tr><td id="QUOTE">The AFC can compensate for new injectors just fine, it changes the MAF output voltage and adjusts it so the car runs with the correct a/f ratio. </td></tr></table><span id='postcolor'>
Yeah.. I was just gonna say, I know a couple people who are running KA and SR, both with z32 MAF and larger injectors off an afc. &nbsp;
-Jeff

[stil bil]

alright guys, thanks for the input!!

heres what i was thinking about doing in my "stage II"

Walbrow(sp) 255 fuel pump
370cc injectors
z32 maf
jwt ecu &nbsp;maybe an afc &nbsp;from what i hear either will work!!
then maybe 7-8 psi

[S14lover]

dammit man you guys drop knowledge we just need to pick the shiit up &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sneaky.gif" border="0" valign="absmiddle" alt=':pissed:'> &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sly.gif" border="0" valign="absmiddle" alt=':sly:'> &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

[sykikchimp]

Sorry about that.. I think I was thinking of some other tuning computer.. ?? &nbsp; you guys are correct.. &nbsp;the S-afc can compensate for larger injectors.