Yet another Vafc Hacker needing help
Does anyone run the hack setup with a JRSC using RC 310's? If so, I need some tips for setting this thing up. I'm boosting 10psi on a 99si. I have a JRBTC. The Autometer shows 12PSI which is likly close to 10. I have a B&M and have also drilled out the fpr to .035 diameter but still cant get my idle down below 1200 - 1300 rpm. What runs best? I plan to put it on the dyno but the local tuner shop is booked for a week. I'm new to this as you can tell. Any helpfull setup info would greatly be appreciated.
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310s seem a little small to be running 10 psi, sell those. Buy some DSM 450cc injectors off http://www.thepartstrader.com for $50. Then you can run the VAFC hack and boost 10 psi. But with 310s maybe 4 psi. As for the idle if you really must use those 310cc injectors, try taking out maybe 20 percent fuel at idle. Leave the rest of the RPM range alone.
u can't run the hack with 310's alone. only way around it is if you increase your fuel pressure and use the afc to tune the fuel down. I'm using 370s and my fuel pressure at idle is 60 psi without vacume. with vacume its around 50 psi.
Heres what might work for you:
Set idle fuel pressure to 84 psi without vacume. This will bring your 310's up to 450's.
Then start at -45 % on the afc and work from there. Now I don't know what kinda fuel pump u have and wether it will be able to handle those fuel pressures. Also, i don't know what the jrbtc does.
Anyone else?
Heres what might work for you:
Set idle fuel pressure to 84 psi without vacume. This will bring your 310's up to 450's.
Then start at -45 % on the afc and work from there. Now I don't know what kinda fuel pump u have and wether it will be able to handle those fuel pressures. Also, i don't know what the jrbtc does.
Anyone else?
Believe it or not. I had 10psi with stock injectors. No problems. Had timing set to stock and the BTC dialed in at 5 clicks. Fuel pressure at Idle was 42. Thought stepping up to bigger injectors would open up some more hp. Anyway If I can't do it, the mech. who set it up first says he can. I don't know. Thanks though.
Thanks. I'll give your advice a try. Hope it will help. I have a JR fuel pump. Also the btc is Jackson Racing's version of a manual boost timing controller. A must if you have nothing else. . I hear people talk about relocating the map sensor and/or removing the JR regulator if you have a B&M. Does this solve anything? Thanks again.
He's saying with the Hack 310's are too small. Yes they can work with an FMU, but the hack settings have to be at least -35%. That will be way too lean. You realize you don't run the FMU with the hack right? Anyway like file said, get some 450's or 440's.
Oh yeah. I meant to metion that I tinkered with it some earlier yesterday and increased fuel pressure to 50 @ vacume. I set it to -22% and I seemed to be going in the right direction but when I decreased the afc more I threw a CEL. I guess you need to raise the pressure more as you decrease the afc.
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Hey. Like I said before I'm new at this. So whatever is needed to do to make it right is what I'm looking for. If I need 450's then I'll get them. Can you find them saturated so I don't have to wire in a resistor. About the FMU. See thats another thing. Since I already have the 310's in does it need to go now or when I step up to 450s. Thanks
You could get a set of RC 440cc injectors that are saturated. It will cost you more, but you won't have to run the resistor box. And yes the FMU has to go. The AFC hack doesn't use it. Same goes for your check valves or missing link.
Ya, I'd like to see someone try that actually. I think the pump will handle about 80psi, they usually crap out at over 100psi. Also with the AFC shortening injector pulsewidlth it will make it easier on the pump. One question though. Do you know of a regulator that will hold about 80psi pressure?
actually, i'm doing that right now, but i have 370's and running 60 psi for fuel pressure without vacume. I have a walbro high flow pump too tho. Plus, i'm using the b&m fpr, seems to work good.
Coo, I knew it worked with the 370's O just haven't seen anyone do it with the 310's. Do you think you could hit 80+psi with the B&M or a different regulator?
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