Supercharger Installed, AFR Questions (noob tuner) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ihatesmog · 03-30-2010, 02:15 PM

I haven't done a build thread yet but will in a week or so. I just got my Eaton M62 installed and fired er' up Saturday night. Ran great, (of course just at idle) haven't got to actually put load on it yet. I've been doing some searching and think i understand safe AFR's but wanted to ask for suggestions/recommendations as i have never done this before. As i understand it, not many people run the MSD BTM so hopefully you guys out there have some advice for me.

I just got my wideband yesterday and will be installing it along with a new non-abs MC tomorrow - then driving/tuning it. Here's my set up:
KA24DE (OBD II if that matters)
8.8:1 Arias Forged Pistons
Crower Forged Rods
Fully O-Ringed Block
Port & Polish
Fully balanced/blueprinted
ARP head studs & main studs
custom turbo cams (don't have the specs)
Ceramic coated pistons, valves, & bearings
Stock exhaust & headers - using EGR bung to mount wideband

I live in CA and have access to 91 octane. I know of one place in the area i can get 100 octane from the pump but will be running 91 99% of the time. This is a 1-2 day a week driver.

All that being said, what should i be aiming for for a safe AFR assuming I get around 9-10 PSI? Looking for idle, cruising, and full throttle. From what i read it seems 11.5:1 is good and safe for boost/full throttle, 14.7 for idle and cruising. I'll be tuning with an LC-1 wideband and BTM. Thanks for any input.
_________________

R33E8 · 03-30-2010, 02:29 PM

Yeah those are decent AFRs but more importantly you need to retard the timing under the boost..

Nevermind, I see that the MSD BTM already does that.. I would probably retard 2 degrees per lb of boost to keep it safe until you get something to monitor your knock like a knocklight..

importdude · 03-30-2010, 02:41 PM

what are you using to tune

ditch the btm and go chipped ecu+nistune/ any other rom editor

fckillerbee · 03-30-2010, 02:51 PM

Quote:

Originally Posted by importdude

what are you using to tune

ditch the btm and go chipped ecu+nistune/ any other rom editor

a little new on the chipped ecu....how... and then nistune is a piggy back?

YucA · 03-30-2010, 02:59 PM

Quote:

Originally Posted by fckillerbee

a little new on the chipped ecu....how... and then nistune is a piggy back?

NIStune - Nissan Realtime ECU tuning

+1

NINJASPY · 03-30-2010, 03:13 PM

do you have injectors?
fuel pump?
you have the msd btm to control timing, what do you have to control fueling?
superchargers tend to heat soak really bad, you might get 2-3 runs before it heats up and it will fall flat on its face(and/or a/f ratio may change because its heat soaked). I had that problem on my previous car(97 grand prix gtp m90 eaton i think)

ihatesmog · 03-30-2010, 04:49 PM

sorry, yes forgot to mention the fuel. I have 370cc injectors and a walbro 255. Not going to chip it, not running nistune. Maybe eventually, but was tuning basically off the BTM and wideband. I have a q45 MAF but was going to try and use the stock MAF for now. Just trying to get running safely and then can fine tune later. I don't see why the BTM wouldn't work if the fuel supply is there, and boost never gets over 10 PSI. I also have lower compression 8.8:1.

Not too sure on the heatsoak factor, not really even sure what that means but i'd guess the SC heats up and looses boost? elaborate for me.

***S14DB*** · 03-30-2010, 05:04 PM

How are you tuning off a wideband?

ihatesmog · 03-30-2010, 05:18 PM

Quote:

Originally Posted by S14DB

How are you tuning off a wideband?

ok so i'm not "tuning" per say off the wideband, but will be using it to moniter AFR while i "tune" with the BTM.

importdude · 03-30-2010, 05:22 PM

then how are you going to tune fuel
rofl

you are on the path of failure

***S14DB*** · 03-30-2010, 05:22 PM

Quote:

Originally Posted by ihatesmog

ok so i'm not "tuning" per say off the wideband, but will be using it to moniter AFR while i "tune" with the BTM.

OK, that retards the timing. How do you trim fuel?

ihatesmog · 03-30-2010, 05:30 PM

I won't be trimming fuel. It basically is what it is. If i'm running too lean then i have a greddy emanage blue that i could wire in, but was hoping to stay away from that. I have OBDII so it's kind of a PITA. I don't mind running rich, it's running lean i'm worried about.

importdude · 03-30-2010, 05:57 PM

you don't mind washing down your walls with gas and gas in oil

okay

ihatesmog · 04-01-2010, 01:42 PM

it works fine. thanks for the encouraging words. I swear the only thing this site does is fuel me to prove everyone wrong. But hey, motivation is motivation no matter where if comes from.

Seriously though, i hooked up the wideband and am idleing at 14.7. It actually bouces around a bit from like 14-15 but i think it's cause i didn't ground the gauge properly. It did stick most of the time between 14.5-14.8.The OBDII ECU is still learning, I think a few more starts and it'll be fine. I do get your theories on why it wouldn't work, and yes, i understand that you can all tune your cars better than i can. But who's to say i would "fail"? When revving, under no load, it dropped to about 11:1 AFR - between 11-12 i guess (again, bouncing a bit). The SC spooled up to about 5 PSI at 6500 RPM, which seems about right under no load. Yes, i'm sure the next comment will be "but you haven't put load on it yet so you have no room to talk" - well, so far so good, and so far i've proven most wrong.

If anyone knows any other fellow factory OBDII ECU users please let me know, i'd like to continue my tuning talk with them. Now i'm starting to contemplate getting the EGR system back in and trying to pass smog LOL! (j/k!)

03-30-2010, 02:15 PM	#1
ihatesmog Join Date: Jul 2008 Location: NorCal Age: 43 Posts: 39 Trader Rating: (0) Feedback Score: 0 reviews	Supercharger Installed, AFR Questions (noob tuner) I haven't done a build thread yet but will in a week or so. I just got my Eaton M62 installed and fired er' up Saturday night. Ran great, (of course just at idle) haven't got to actually put load on it yet. I've been doing some searching and think i understand safe AFR's but wanted to ask for suggestions/recommendations as i have never done this before. As i understand it, not many people run the MSD BTM so hopefully you guys out there have some advice for me. I just got my wideband yesterday and will be installing it along with a new non-abs MC tomorrow - then driving/tuning it. Here's my set up: KA24DE (OBD II if that matters) 8.8:1 Arias Forged Pistons Crower Forged Rods Fully O-Ringed Block Port & Polish Fully balanced/blueprinted ARP head studs & main studs custom turbo cams (don't have the specs) Ceramic coated pistons, valves, & bearings Stock exhaust & headers - using EGR bung to mount wideband I live in CA and have access to 91 octane. I know of one place in the area i can get 100 octane from the pump but will be running 91 99% of the time. This is a 1-2 day a week driver. All that being said, what should i be aiming for for a safe AFR assuming I get around 9-10 PSI? Looking for idle, cruising, and full throttle. From what i read it seems 11.5:1 is good and safe for boost/full throttle, 14.7 for idle and cruising. I'll be tuning with an LC-1 wideband and BTM. Thanks for any input. _________________

03-30-2010, 02:41 PM	#3
importdude Zilvia FREAK! Join Date: Nov 2006 Location: san j0 Posts: 1,391 Trader Rating: (19) Feedback Score: 19 reviews	what are you using to tune ditch the btm and go chipped ecu+nistune/ any other rom editor __________________ built ka-t

03-30-2010, 05:04 PM	#8
*S14DB* AFC #1 Join Date: Oct 2003 Location: 昨晩あなたのお母さんの家 Posts: 20,181 Trader Rating: (3) Feedback Score: 3 reviews	How are you tuning off a wideband? __________________ Comments should be taken as Opinions not as Statements of Fact

03-30-2010, 05:22 PM	#10
importdude Zilvia FREAK! Join Date: Nov 2006 Location: san j0 Posts: 1,391 Trader Rating: (19) Feedback Score: 19 reviews	then how are you going to tune fuel rofl you are on the path of failure __________________ built ka-t

03-30-2010, 05:57 PM	#13
importdude Zilvia FREAK! Join Date: Nov 2006 Location: san j0 Posts: 1,391 Trader Rating: (19) Feedback Score: 19 reviews	you don't mind washing down your walls with gas and gas in oil okay __________________ built ka-t

03-30-2010, 02:29 PM	#2
R33E8 Zilvia Addict Join Date: Jul 2006 Location: NJ Age: 35 Posts: 798 Trader Rating: (14) Feedback Score: 14 reviews	Yeah those are decent AFRs but more importantly you need to retard the timing under the boost.. Nevermind, I see that the MSD BTM already does that.. I would probably retard 2 degrees per lb of boost to keep it safe until you get something to monitor your knock like a knocklight..

03-30-2010, 03:13 PM	#6
NINJASPY Zilvia FREAK! Join Date: Oct 2007 Location: So-cal Los Angeles 626 Age: 44 Posts: 1,009 Trader Rating: (13) Feedback Score: 13 reviews	do you have injectors? fuel pump? you have the msd btm to control timing, what do you have to control fueling? superchargers tend to heat soak really bad, you might get 2-3 runs before it heats up and it will fall flat on its face(and/or a/f ratio may change because its heat soaked). I had that problem on my previous car(97 grand prix gtp m90 eaton i think)

03-30-2010, 04:49 PM	#7
ihatesmog Join Date: Jul 2008 Location: NorCal Age: 43 Posts: 39 Trader Rating: (0) Feedback Score: 0 reviews	sorry, yes forgot to mention the fuel. I have 370cc injectors and a walbro 255. Not going to chip it, not running nistune. Maybe eventually, but was tuning basically off the BTM and wideband. I have a q45 MAF but was going to try and use the stock MAF for now. Just trying to get running safely and then can fine tune later. I don't see why the BTM wouldn't work if the fuel supply is there, and boost never gets over 10 PSI. I also have lower compression 8.8:1. Not too sure on the heatsoak factor, not really even sure what that means but i'd guess the SC heats up and looses boost? elaborate for me.

03-30-2010, 05:30 PM	#12
ihatesmog Join Date: Jul 2008 Location: NorCal Age: 43 Posts: 39 Trader Rating: (0) Feedback Score: 0 reviews	I won't be trimming fuel. It basically is what it is. If i'm running too lean then i have a greddy emanage blue that i could wire in, but was hoping to stay away from that. I have OBDII so it's kind of a PITA. I don't mind running rich, it's running lean i'm worried about.

04-01-2010, 01:42 PM	#14
ihatesmog Join Date: Jul 2008 Location: NorCal Age: 43 Posts: 39 Trader Rating: (0) Feedback Score: 0 reviews	it works fine. thanks for the encouraging words. I swear the only thing this site does is fuel me to prove everyone wrong. But hey, motivation is motivation no matter where if comes from. Seriously though, i hooked up the wideband and am idleing at 14.7. It actually bouces around a bit from like 14-15 but i think it's cause i didn't ground the gauge properly. It did stick most of the time between 14.5-14.8.The OBDII ECU is still learning, I think a few more starts and it'll be fine. I do get your theories on why it wouldn't work, and yes, i understand that you can all tune your cars better than i can. But who's to say i would "fail"? When revving, under no load, it dropped to about 11:1 AFR - between 11-12 i guess (again, bouncing a bit). The SC spooled up to about 5 PSI at 6500 RPM, which seems about right under no load. Yes, i'm sure the next comment will be "but you haven't put load on it yet so you have no room to talk" - well, so far so good, and so far i've proven most wrong. If anyone knows any other fellow factory OBDII ECU users please let me know, i'd like to continue my tuning talk with them. Now i'm starting to contemplate getting the EGR system back in and trying to pass smog LOL! (j/k!)