AFC air Deceleration setting help

[240sxvaj]

I'm back from second dyno tune w/different dyno shop and this guy was way better with great results 247whp and smooth acceleration. one problem that he wasnt able to fix was the air decel, said that the car will have hard morning start up based on some of his customers, so he didnt want to mess with it. I was wondering if anyone knows how to fix that problem, i have an AFCneo and 91ka24de-t25(redtop), HKS ssqv bov(atmospheric). Car runs great after boost but sometimes it stalls after releasing off the gas pedal after boost.

does everyone know if i can fix this stalling after boost problem and not have morning start up problem. Thanks in Advance.

[Tx-Sx-FS]

how much boost are u running..mind me getting ur settings cuz i have same setup with no top end tune...

my decel is 4.5 0.4 3.5

runs smooth in shift and stopping...whats ur timing set to? thanks

[240sxvaj]

how much boost are u running..mind me getting ur settings cuz i have same setup with no top end tune...

my decel is 4.5 0.4 3.5

runs smooth in shift and stopping...whats ur timing set to? thanks

I dont remember but i think it was around 15 for timing not too sure i'll double check, i'm making 247whp 241.5lb ft torque to wheel with stock wastegate which reads around 7psi on my boost gauge.

i havent check my AFCsetting but if you want, i'll give it to you, just have to wait until i get back home.

this is my setup T25redtop, jgs oil line kit/vac blockdwerk 450cc injectors, walbro 255lph pump, Z32fuel filter, Hardwire kitnismo fprgreddy type-m FMICHKS hotpipe/ssqv bov comboMegan Elbow, blitz3' downpipe, buddyclub spec2 exhaust, (delete-cat)AFCneo, koyorad

[Tx-Sx-FS]

this is KAT setup right? just with the T25, ya post them, ill have to do math to convert to 370cc injectors...anyone know the percentage larger 450 than 370s??

oh change on decel

3.51.53.5

[240sxvaj]

this is KAT setup right? just with the T25, ya post them, ill have to do math to convert to 370cc injectors...anyone know the percentage larger 450 than 370s??

oh change on decel

3.51.53.5

Yes Ka24de-t25Here it is, just like on the AFCneo

500 1000 1500 2000 2500 3000 3500 4000 4200 4600 5000 5400 5800 0 0 0 0 0 -3 -3 +4 +1 +4 +2 -4 -4-1 -1 -1 -2 -1 -1 -1 -1 -1 -1 0 0 0

6200 6400 6900 -4 -4 -4 0 0 0

Beware this is based on my setup and everycar is different so you should have a wideband to make sure you dont F*ck up your motor. plus i havent check the timing for where it is exactly at. i need to get it checked but i know the timing is good and gauranteed no detantion for mysetup. Probably going ECU tuned enthalpy when i get a t-28 w/more $$ safest way to go.

[240sxvaj]

almost forgot, i tried messin with the air decel, but nothing happened. i found a write up on how to set it (http://forums2.nicoclub.com/showthread. ... fc+setting )and went by it, but nothing happens and then i tried your setup and nothing happened. i Think something is wrong here. sensor set at 6in6out if thats a problem.

[Tx-Sx-FS]

6in6out sounds different..mine is 3in1out but ive seen 2in2out / 2in 5out so there are different answers..if urs runs smooth dont change it. whats ur throttle %'s?? ill be getting on wideband tomorrow hopefully.

now ur decel should effect idle and between shifts

[240sxvaj]

6in6out sounds different..mine is 3in1out but ive seen 2in2out / 2in 5out so there are different answers..if urs runs smooth dont change it. whats ur throttle %'s?? ill be getting on wideband tomorrow hopefully.

now ur decel should effect idle and between shifts

Yes, it runs smooth with 6in6out. first time i got it, apex tech guy told me to set it at 5in5out and it idle like crap. also it wouldnt respond to fuel correction so what we did was changed it to 6in6out and everything worked fine but doesnt seem like the air decel is working at all. Plus i am running stock Maf

low throttle is 20% and high is 50%

[boznuttz]

If you really don't feel like messing with your Dec Air settings, you can just try to recirculate the BOV air back into the intake after the MAF.

The reason a car would stall with an open atmospheric BOV is because metered air escapes after it is measured by the MAF, and the engine will run rich and stall.

[240sxvaj]

If you really don't feel like messing with your Dec Air settings, you can just try to recirculate the BOV air back into the intake after the MAF.

The reason a car would stall with an open atmospheric BOV is because metered air escapes after it is measured by the MAF, and the engine will run rich and stall.

yes, i understand how bov works and yes it gets a wrong signal asking for the lost air and sends more fuel to engine causing the car to stall. Thank though

The reason why i want to fix it with AFC is because i dont want to recirculate the bov. i was wondering if i get tuned ECU like enthalpy, would they be able to fix that problem? As of right now i just leave it in gear after boost to slow down and doesnt have a problem.

[Tx-Sx-FS]

your settings seem off, if u have significantly larger injectors ur numbers would be in the negative 10-20's high throttle... (the 370's are -27 so u would be -47 for low) just mathematically since ur only running 7psi. thats great numbers for 7psi on KA-T25

[esahuque]

your in/out settings are wrong hot wire 6 is for a nissan sentra SE-R maf.if you have your stock maf in your in /out settings should be 5 in/ 5 out.if your running a Z32 maf it should be 2 in/ 5 out.try that, then try setting your dec settings.

[Tx-Sx-FS]

ive tried 5in5out 2in5out and only combo to make my car run is 3in1out...not sure why

[240sxvaj]

your settings seem off, if u have significantly larger injectors ur numbers would be in the negative 10-20's high throttle... (the 370's are -27 so u would be -47 for low) just mathematically since ur only running 7psi. thats great numbers for 7psi on KA-T25

Hummmm... i noticed that it eat-up a grip of gas compared to dyno first dyno from JERdevelopment, but when accelerating everything seems smooth. weird. I'm starting to get tired of these dyno shops and go buy a wideband and learn everything myself.

it used to be -17's at low throttle and second dyno is now at -1 doesnt seems right and when it used to be at -17 the car wouldnt stall after boost and now it stalls after boost.

[Tx-Sx-FS]

whats ur vacuum at idle?? mine is at -10 but thats low, needs -18ish so im looking for boost leak next weekend. but if it ran better before change it...if u have a leak too it will run lean and not be fixed on safc.

[240sxvaj]

whats ur vacuum at idle?? mine is at -10 but thats low, needs -18ish so im looking for boost leak next weekend. but if it ran better before change it...if u have a leak too it will run lean and not be fixed on safc.

I'm actually at 20 and car holds boost pretty good. idles fine and runs good but stupid decel wont work. i just double check the afc wires and everything is good and going to solder it in a bit. maybe i should upgrade to z32 maf if that helps?

[Tx-Sx-FS]

it wont do any good right now since u only have t25, the turbo will run out before the mafs...the stock maf run out at 250rwhp.

[Popscribble]

Usually resirculating the BOV is an easy way to do it my turbo miata did the same thing (couldnt get the afc to fix it) GL

[jmac636]

Ka-t likes the bov recirculated between maf and turbo. My ka-t runs great after recirculating the bov. Before it would try to stall and backfire intermittently. You could also smell fuel. Good thing is after recirculating not only does the car run better I can still hear the noisey bov swwoooshhh!!!Bringing back a thread to help others is always a good thing. So whoever reads this pass it on beaatch!

[kouki_hmongster]

Ka-t likes the bov recirculated between maf and turbo. My ka-t runs great after recirculating the bov. Before it would try to stall and backfire intermittently. You could also smell fuel. Good thing is after recirculating not only does the car run better I can still hear the noisey bov swwoooshhh!!!Bringing back a thread to help others is always a good thing. So whoever reads this pass it on beaatch!

if you are lucky you can get away w/out recirculating, i dont understand why though. when i first did my turbo setup i got a dyno tune using only afcneo w/ 450cc injectors and no problem for me. ran good but after i got my second tune i started stalling. also i heard there are some people w/out bov stalling problem, i wonder how they do it and not talking about the people who convert to map.

[jmac636]

My car actually never stalled. The rpms would drop and I would get an anoying backfire because of excess gas not being burned off during decel. Your spark plugs also will not as long venting atmosphere. There is a reason why oem turboed cars use bpv.