Reading another thread about open/closed loops and people are saying sc's go into open loop only at WOT. I was messing around with my safc and saw that when I floor it, it only reads 88-89% throttle. The TB is all the way open however. Is my car even going into open loop? Is there a way to adjust the tps?

Also read that if you set the safc's Hi and lo settings when its in closed loop the ecu will just be fighting the safc and that you should only tune the open loop, so set it at like 97lo 98%hi throttle. My hi and lo are set at like 40 80, and I can tell the ecu is fighting those changes.

setup is safc2/vpc and 550cc
Runs good but doesnt quite boost as hard as it use to and smokes black

Not to sure what to do?

 

anyone have input?

 

All the afc's I have seen do not read the TPS percent correctly. Tps generally is a 0-5v signal. Most TPS sensors will not reach the 5v range and more like 4.2v-4.6v. The afc will think you are, in your case 80% tps. Dont worry about the tps value. Just set your high throttle range below your max percentage. So I would set your high throttle range for 70% or so.

Do you have a wideband? If so what is your AFR during this smoking?

Lawrence

 

You can make your safc2 learn what the highest voltage is for your tps.

 

Thanks for the info man
and I dont recall my afrs as I havent driven her in 6 months (damn ND winters lol)

How would I go about this?

 

Look for the owner's manual on the apexi website. Read the section for "auto learn" the voltage range.

For my sc400, I think the max was around 3.6 Volts for the TPS

 

it will always fight the ecu, the stock ecu doesnt have an exact tps switchover point into open loop that anyone has actually figured out, it seems to not want to switch at all even at 100% tps if the rpms arent high enough which means small turbos confuse the crap out of the stock ecu, especially when you are just at 50% throttle or going uphill and the car makes partial boost. this completely confuses the ecu and it will adjust wildly, and when you return back to normal condition (after the road flattens) the car will not run right until it swings and relearns again. if you happen to full boost while the ecu is confused you may get detonation or some really nasty backfires (been there, done that, moved on) so basically it works best for turbos which are huge and take longer to spool, as in boost comes on only in higher rpms and when mashing the pedal.

the only thing you can do to counteract this learning process is to disconnect all the o2 sensors. you wont be passing any emissions test like that but it wont confuse itself nearly as badly. and then you can dial in corrections on the safc. it wont work perfect but may work better for you.

 

hmmm... I think its standalone time

 

You could try converting to MAP based and get a JDM ecu with a MAP sensor.