alright guys... heres the story iam 19 and i am out for knowledge and iam all ears when it comes to learning.. i want to learn how to tune a turboed car on a piggyback system... can anyone help a newbie learn how to tune a car? i go to wyotech some might know some may not its an automotive school. i just passed the full auto program and my next program is street rod and custom fab.. i could of taken high performance but it would only benefit myself, the only thing i really am curious on is the whole tunning and how to do it..

 

dude it all depend son which piggy back they all tune differently but same genral priciples....


tune fore 11.5-12.0 afr for saftey and performance

retard 1 degree of timming per each psi above 5psi...this is a general rule of thumb for newbs

dont kill our children tryna tune it

do only 4th gear pulls for tuning

 

how do you get a good base tune in order to start fine tuning after that? so timing, air/fuel, and of course boost are the main things to look at? are there anything else? sorry for the newbie questions.. i have a greddy blue piggyback.. if that helps any.. how do you get the software?

 

I was always told to do 5th gear pulls for tuning because that's where the engine is up the most load?

 

Wyotech huh? lucky! Ill be there probably 2012...military paying for it all too

 

for tuning a piggyback knowing the fuel trims is key to keeping the cel monster away. you can get the fuel trims by using an obd scanner such as a scangauge 2. Most piggybacks are fairly easy to use but does take some time getting used to it and how they opperate. Knowing what sensors it taps into helps to understand how the managment opperates.

going back to fuel trims. some piggy backs alter the o2 signal, in this case you need to make your o2 map jive with your fuel map. you will see just how close your getting by viewing the fuel trims. The closer you get to the sweet spot the lower the trims will be, this means having a fuel trim of -20 or +20 is bad so your goal is to get the value of the fuel trim as close to 0 as possible.

Ill try to explain more later, right now im tired.

 

Here's a good read on tuning.

http://www.gadgetonline.com/U-Tune.pdf

 

3rd, 4th, 5th gear...doesnt really matter....i personally tune 3rd and check with 4th....although fine tuning in 5th is stupid imo as the high speeds needed to check all rpm bands.....target afr's are 11.0-11.5 11.5 being the most commonly tuned afr. reason i disagree with 12 is because sounds like youll be on stock motor.

best thing for a noobie to do is go to www.efi101.com and read. read. oh yea and read some more.

 

its nice to have the military pay for schooling.. iam one of them also.. where could i get the software for it?

 

GI Bill FTW!

Good luck tuning your car. I personally am going to take mine to a tuner when I got everything ready to go

 

ptuning will do my tune just because i dont know anything about it yet lol. i just want to know how to do it..

 

a note learned this weekend, scangauge only works during closed loop for tuning.at w.o.t. it's no good. buy a tuner learning disk, it's much cheaper than a motor.

 

under wot, or open loop, the ECU isn't monitoring the fuel trims anyway. It just goes to a certain value of a/f ratio depending upon maf/load/temp/rpm/etc. So the scanguage is fine for looking at LTFT's.

 

in my personal experience the AFR's are always higher in 3rd than 4th gear by about .2 - .3 AFR and about .1 - .2 between 4th and 5th. Only problem I see with 3rd gear on the street is u might get wheelspin depending on power levels, at least I used to pre-LSD. 4th used to give me a bit cleaner curve on my logs pre-LSD, but it puts a higher load on the engine and transmission and the speeds can get a bit high for a full pull and tunning urself. For whoever that said to use 5th, don't do it. Too much stress on the drivetrain and u need a lot more road to get that high on the rpm's.

I've been tuning for 11.9 and it feels great, anything over makes me uneasy and it doesn't make much of a difference in power. Under it feels like it looses some power on the butt dyno. BTW, I'm running E65.

 

holy cow...they make e65 now.....with e85 you can tune to 12-12.5 from what ive heard.

 

^^ I think its still E85 but on winter and depending on places then turn the mixture to a higher gasoline content to improve cold start up.

Lower gears appears richer to me but it elicits a slightly more linear boost curve.. 4th is my favorite, no wheel spins, less attention on the streets, quicker boost build and more flat than the lower gears..

Fuel trims, you would want your ems/ecu to be pulling a bit fuel at all times.. you dont want +numbers on your trims.. I say -4/-5 is a good spot. But fuel trims is a closed loop style tuning for partial load/throttle. For full load/throttle you got to get it on spot, you will not get any help adding or pulling fuel to correct your afrs

 

interesting. What wyotech campus are you at ? Sacramento I take it ? or Pennsylvania ? I am attending the Wyoming campus, been here for six months already taking collision and refinishing bout to go to refinishing. I did ASM, and now I have street rod, chassis fab and upholstery after refinishing.