T/Ajammer

I'm sure this is a stupid question but here goes......
Is it possible to tune for unleaded regular gas and if so would the engine run better on the unleaded regular gas than it would on unleaded primium?

samz28

yeah copy the low octane tables to the high octane.

then do like -5 degrees across the low octane tables.

probably lose alot of power but if yo po' why did ya get a gas hog?

sorry had to say that. Thats the answer. It will work. Then just reflash when you get better gas to before.

horist

well... you don't need to drop that much timing out ... I've seen cars run fine w/regular 87 octane w/out any adjustments ... but since you're in NM i wouldn't try it... hot day plus load = ping city ...

You could have it tuned to lower timing some ... not sure how many degrees though ... the low octane tables would definetly be fine... but you'll lose a ton of performance ... realistically it's not worth it...unless you have access to ls1 edit or hp tuners for free ... (20 cents per gallon x # of gallons you go through) ...

samz28

welll yeah i have hptuners so its 20 seconds to reflash. no big dealio.

i spose if i were to go on a long distance trip, never mind this car is too loud and gas hungry...

jimmyblue

iTrader: (11)

I would like to see someone do a fine-tune for premium,
get dynoed, then go retune for best on regular and see
how much was lost/gained. Since regular unleaded is
supposed to have more energy content than premium,
it might end up at a wash (especially if running lower
ECTs, etc. can suppress ping "enough").

Here, guinea guinea pig...

T/Ajammer

I think you missunderstood. I'm not looking to tune for regular unleaded. I ask because I bought my T/A used and was wondering if it might have been tuned for the low octane fuel prior to my owning it. On the rare occasions that I've used regular it seems like it may acctually run better. It's hard to say. I just know that with either octane it dosn't seem to have the power it had when I bought it a year and a half ago. I changed plugs first and not much improvement. Recently I cleaned the MASS and noticed a drastic improvement for the first day or so. Now, although it still has much more power, it isn't as much as right after the cleaning. Seems like maybe the timing is getting pulled. I don't no.......pulling out what hair I have left!!

samz28

atap/efilive/hptuner scan it under wot and log the timing and KR and octane scaler (hi/low) pid.

Or have a buddy read in your ecu and look at the tables compared to stock.

T/Ajammer

I don't have any scanning tools as yet. Do you suppose Autozone could get the tables?

samz28

Find a local (regional forum) drive to him, and datalog.

if the high/low scaler is at less than 100% you got a problem (crap gas?) if you are getting KR at wot you got a problem too. might be oil from pcv, who knows.

there's gotta be someone with a real scan tool. hell any gm tech has tech II they could go make some runs with you and log.

Gotta buddy up bro or pony up for a scanner.. why i got hptuners, scanner, logger, edit in one $500 package. Worth every cent. Keeps gettin better with each new version.

T/Ajammer

I have no problems at wot. It kicks *** on the afterburners. The real noticible performance loss is taking off from a rolling start in low 2 (I've got an A4). Like applying throttle after making a right turn that I havn't slowed enough to make it downshift to low 1. From no throttle all the way to about 3/4 throttle (just before the afterburner) there is no change, It accelerates at it's own speed (slow) untill about 45-50 mph when it will kick in and respond to changes in amount of throttle. Without Gearhead friends or hundreds of dollars in scan/edit tools I guess I'll never get this figured out! I've been wanting a good scan tool. Guess I'll have to bite the bullet and just get one. Guess I could sell one of my guitars..........Nooooooooo!!!

samz28

yah well maybe the TB bump stop mod, a torque converter, and a scantool/editor would solve that. My car was a dog with the stock tc. there were many dead spots, but if your TPS isn't moving for some odd reason (ie the asr/cruise cable adjuster),etc.

good luck. regional forums and clubs rule for what you need a hand

T/Ajammer

Thanks for the advice. I'll look into regional forum for help. Is a tc install a bitch? Which one would you suggest?

jimmyblue

iTrader: (11)

Regular unleaded burns faster. So in operating regions
where you could've stood more spark, regular may well
perform better. Same effect in positioning the burn
pressure pulse vs crank angle.

But it will also be much more prone to ping at the higher
cylinder pressures (WOT) and if it can't be made to play
nice, cost you peak HP/TQ. Or not, if you have the engine
set up right for it. That would have to be put to the test.

T/Ajammer

Now that makes sense. Although it did seem to perform better sometimes, not always, when I ran a tank of regular, It would also throw SES light and codes for right and left rear 02 sensors as soon as I went WOT. That's the only time I get those codes. Dosen't happen at WOT when running premium
91 octane, which is as high as I've seen around Albuquerque.