Need help tuning.

[CBgst]

My mods are big28, walbro255, filter w/adapter, uicp, 1st gen bov, afpr, 550s, s-afc, logger.

I just installed my injectors and the afc. I FINALLY got the car to run right. Now I need to tune it. Right now the afc is set at -20 for the high and low settings. I'm new to tuning so any help would great. Where do I start? Should I tune for exhaust gas temps or should I tune for timing. I'm at 15psi for now. What sort of exhaust gas temps should I tune for at wot( I think it's 1600 but I'm not sure). What timing should I see at wot. Thanks in advance.

 

[candela]

Try and tune for as high of timing as you can get. Normally on my 01 octane crap i get between 12deg and 18deg timing. Once you get more than a few counts of knock, is when the ecu starts to pull timing I think its around 6 or 7 in my car. Usually it runs great at around 16-18deg timing. Watch the egt and make sure it doesnt go over 1650, but you should really tune for timing. o2's shouldnt go much under .84 in any car I think, even with the differences. Im sure someone will correect me but this is usually how I go about this.

 

[CBgst]

My timing is around 8 degrees at wot. It doesn't get higher than that no matter what I set the afc at. At -20 my exhaust gas temps were really high. I had to set it at -7 all the way across so the exhaust gas temps wouldn't go past 1650. Any ideas on what the problem could be.

 

[candela]

I would keep it at 15psi and try and tune for low throttle first. Follow rre directions. Just try and hold steady your rpm in whatever increments you have your afc at. Ex: hold rpm at 2000 and watch your logger's o2 voltage. Lean out the afc very slowly until you see your o2 stop ocsilating (fluctuating), and see what your afc is set at. Try to go about 2% increase (richer) from there and that should be a very good basis for part throttle with those 550's and t 28. After you have your low settings tune for high (usually easier). Log in 3rd gear and gradually get on the throttle. If I wee you I would zero out the afc for high throttle and go from there. Try and use throttle setting for low-35% and high ~75% that way you should run pretty good before wot as long as the low th settings are ok. Post back some of your logs with; o2, timing knock, air temp, octane fuel, boost setting, egt, Throttle pos., and you injector duty cycle...

 

[Taboo]

Originally posted by candela
Try and tune for as high of timing as you can get.

That is incorrect. If you go way over 20' of timing advance, the cylinder pressure goes through the roof and the main and rod bearings are taking beating while chances of detonation are greatly increased - all for the price of minimal HP gains. A great way to blow the head gasket...

Originally posted by candela
tune for low throttle first. Just try and hold steady your rpm in whatever increments you have your afc at. Try and use throttle setting for low-35% and high ~75% that way you should run pretty good before wot as long as the low th settings are ok.

Low Throttle settings of the S-AFC have absolutely no effect on the final A/F ratio at part-open throttle since it's the O2 sensor that has the last word.

Originally posted by candela
I would keep it at 15psi. After you have your low settings tune for high (usually easier). Log in 3rd gear and gradually get on the throttle. If I wee you I would zero out the afc for high throttle and go from there.

Gradually getting on the throttle won't do anything for Hi Throttle tuning. You need to go WOT. Also, don't start at 15psi of boost. Start at low boost level (10-12psi) to keep the intake air temperature low to avoid unnecessary knock, set the A/F ratio and timing advance and start raising the boost 'til the ECU starts pulling the timing. There are just three things one should tune for: 1620' max EGT, 18-20' timing advance and maximum boost level without timing retard. Everything else (such as tuning for 0 knock or 0.90V O2 sensor output) is useless.

 

[CBgst]

I made a few logs today. For some reason my timing is being pulled at 3k and then I gradually start getting it back all the way until about 18-19 degrees at around 6k then it stays there until 7k. I made all the pulls in 3rd gear starting at about 2k. I get about 18-19 degrees at 2k up until about 3k then it drops to 7-8 degrees. No matter how I set the afc at 3k it did the exact same thing everytime. I tried to richen it up but the same thing happened. Is this right or something wrong.

 

[william cordero]

my mods: 2g mas, k&n filter, 3'' turbo back exhaust, mbc, dejontool intake pipe, apexi s-afc,
mach1 bov. need help tuning afc. low throttle up or down?how much?hi throttle, up or down?
i have no idea how to use. installed 3 days ago.

 

[CBgst]

I don't know if this really matters but o2 voltage is ranging between 0.90v - 0.98v. Is this right? It changed because I changed the settings but is this close to where I'm supposed to be.

 

[CBgst]

Originally posted by william cordero
my mods: 2g mas, k&n filter, 3'' turbo back exhaust, mbc, dejontool intake pipe, apexi s-afc,
mach1 bov. need help tuning afc. low throttle up or down?how much?hi throttle, up or down?
i have no idea how to use. installed 3 days ago.

Hey get your own thread man.J/K Anyway I'm not sure about 1st gen but I think you'll probably need to richen things up because of your 2nd gen mass. I'm not 100% sure though but anyway when you change the settings to positive it richens it up negative leans it out. You really need some sort of logger to tune it though.

 

[CBgst]

Can someone tell me what there timing looks like. I'm just trying to figure out if I'm going in the right direction with my tuning. The car feels good but it's really hard to tell. I'll be on the dyno with in a month so hopefully I'll be able to tune it pretty good then.

 

[44pirate]

Originally posted by CBgst
I made a few logs today. For some reason my timing is being pulled at 3k and then I gradually start getting it back all the way until about 18-19 degrees at around 6k then it stays there until 7k. I made all the pulls in 3rd gear starting at about 2k. I get about 18-19 degrees at 2k up until about 3k then it drops to 7-8 degrees. No matter how I set the afc at 3k it did the exact same thing everytime. I tried to richen it up but the same thing happened. Is this right or something wrong.

Starting at 2K in 3rd, when does boost kick in, prolly that's when timing gets pulled. As long as it's a gradual climb to 17-18 degrees its good.

 

[CBgst]

Well I never thought about that. Thanks for the help.