AFC & Injectors, High high can I go on a AFC.

[Powers_Vang]

I thought I read some where on here that an AFC can only control injectors up to a certain CC. Please clearify. I have a 50trim on w/255 Walbro & need injectors w/AFC. Any insite on to which injectors to use would be greatly appreciated. Thanks.

 

[dsm-onster]

Any insite on to which injectors to use would be greatly appreciated. Thanks.

I used a MAFt to tune my 650s. I was getting 12-15 counts of knock up top with 5* base timing. It mods the same way: fools the ecu into a lower airflow map. Which consequently has a higher timing curve... You have a 2g: less aggressive timing curve than me. BUT, you also have higher compression... I don't know... I would never go past 650cc though! 15 counts of knock was too much... since then i've gone DSMLink No knock way past 18 psi

 

[Powers_Vang]

Would 550cc be ok for a 50trim? I don't have to be king of the hill. hahaha... Just wondering if this setup with the 550cc will work or if I do need 660cc. & yea, its weird that the AFC can only handle up to certain injectors.

 

[oldman]

its weird that the AFC can only handle up to certain injectors.

This came straight from dsmchips, should make things more clear for you.

the big problem is that all those air/fuel controllers work on the same principal: they lie to the ECU about the airflow, to get the ECU to reduce the injector pulsewidth. And, yes, it does work. However, the ECU also uses the amount of airflow to decide many other things, like what timing advance or A/F ratio to use. So, the larger the injectors you have, the more your piggyback computer LIES to the ECU, and the further off the factory maps you are running.

 

[GPTourer]

I think 660's are as big as you can go. At 16psi I see about 14-16 degrees of timing at redline. An AFPR is a must.

 

[RedTurboEclipse]

I use to run AFC2 with my Denso 660s/Walboro 190 no AFPR @ base FP.. they have said to flow more than that.. and had no problem controlling them as far as idle and what not.. also another ex-DSM owner from here use to run Greddy(Denso) 720s with AFC and also had no problem.. with that Walboro 255.. it is recommended to get an AFPR.. I couldnt tell you how my timing was because I am now running DSMLink and it runs sooooo much better..