ok, i need a beginers course in tuning
 

Hey guys, dont know if anyone can really help, i got a LT8 microtech in my S4 TII with an S5 Turbo motor, i had KD Rotary install it an it was tuned good. My turbo went bad so i had to go back to stock, anyway the tuning was way off, it bogged and was way to rich, i copied a few different maps from the post at the top of the microtech forum on here. then it ran worse and worse, it was fouling out plugs left an right, so i messed with it til i got it to where it would run but its still bad, it still boggs and stalls, and wont run well, i just needed it to i can move it in the garage, which is all i can do with it, since it hardly runs, any i need a crash course on tuning this thing, i gotta learn to do it and no local people are any help with out $150 an hr for dyno time, so anything anyone could help me with would be great, even better if someones local and could meet up an show me, anyway if anyone could help it would be appreciated, thanks in advance

i think some posts are missing, doesn't make much sense to me or he is a real DB..

you don't need a wideband to tune a car out of boost, it can easily be done by feel but if your settings are so far off now no matter what you do it will hardly get any better. what you need to do is find a table with the stock settings and go from there. re-read the manual for the basics on how to set things up from scratch. all you need to do is focus on the idle and load maps for now, start with the idle: if it stumbles and you have to hold your foot on the throttle to keep it running and burns your eyes then it is pig rich, the ">" next to the setting in the idle vacuum will tell you which 'block' the EMS is using to get a basis for idling, find which vacuum area it is idling at with the ">" next to it and lower that number if it is running rich or increase it if it is running lean. running lean means the motor will start to hunt or bounce before it wants to stall out, it will run smooth, much smoother than when the idle is pig rich but it will want to stall out much easier.

after you have the idle smooth and stable then you can move to the load maps, fine the ">" next to the block it is idling at and start with that number and work up from there using the same basics from running lean vs rich that i gave above. rev the engine lightly to 2500RPMs and let it drop to idle again, if it stumbles and spits smoke then it is rich, lean the blocks all the way up to the 0"Hg blocks out until they are linear(each step up should be similar to each other step, if you have done dots to dots you know that if you have one point that is much higher than the next it will look staggered, which is not linear, this is much easier accomplished with a laptop since with the laptop software it gives graphs that are easier to see and adjust linearly) with each other and it revs smooth, same for leaning out if it hiccups when you try to rev it.

once you have it idling smooth and revving smooth to 2500RPMs then you can start readjusting the load maps on the road. this is kind of tricky but i prefer to do it all myself. take the car out to a wide open clear of traffic road and start by driving the car up to 10"Hg with a light load, meaning drive it in about 4th gear and hold the throttle til you get 10"Hg showing ">" and adjust that point until it runs smoothly. slow the car down to a low but operable speed of the engine and once again put your foot lightly on the accelerator until you get to the 5"Hg block and it has a ">" next to it and holding it steady to keep it in that load block, adjust the fuel until it runs smoothly. repeat until you are finished and done with the 0"Hg block and stop there, you could probably do it up to 3-4PSI without the use of a wideband safely but there is always a risk since your timing maps could be off and engine damage could result and is more easily pushed with boost.

after that is done, next step is invest in a wideband O2 sensor for boost level corrections.

good luck

-Ben

Hmmm, did you turn "OFF" your timing? on the LT8.

you mean "locked" the timing? that would definitely cause some running issues but not idle issues.

it is much easier having someone with experience looking over your shoulder though when dealing with standalones. personally i started from scratch and learned it all on my own through the forums, sites and with the manual. it isn't that difficult to get the hang of but it does take time if there is no one around to show you the ropes.

im hopeing to get to to mess with it tomorrow, im gonna go slow and start off like Kkrack said, starting with the idle, i dont have a problem adjusting it, just knowing where i need to be and start from is the hard part, i just take my laptop out an stay online so i can read through everything while im adjusting it, and first thing i will do is check to see if the timing is locked, thanks for the repleys, im sure i will be back soon with new info, thanks again

double check and make sure the TPS is set properly and adjusted in the EMS properly also, if it is off even a hair the timing will be way off and idle will suffer if it will even idle at all.

i check out what i could an no luck, cant get it any better, atleast its running, im gonna have to take it somewhere and pay to get it dyno tuned i guess, thanks for the help

could you give some advice on boost level corrections?

it is basically the same but you really need a wideband to do any adjustments in boost or engine damage can result. a good target AFR is in the 11-11.5:1 range. a wideband with datalogging capability is the best way to go about it with an RPM input so you can see what the AFR is at at each RPM stage and adjust your load maps accordingly. once you have your load maps roughly tuned then you can begin adjusting it in matrix mode but that is a bit more tricky to explain how to do it, some people just live with a decent standard map tune since matrix mode takes a little more time to setup. the way i do the load maps is with a steady foot on a long straight away until you get to lowest boost setting your wastegate can manage(ie turn your boost controller all the way down) by starting at 0"Hg and working to 2PSI then 4PSI, etc etc etc until when at WOT you are at your low boost level and tune to that stage then begin turning up your boost controller a little at a time so you can adjust each 2 PSI segment, once at about 8PSI your map on your laptop should start taking a linear form and you can ramp it accordingly keeping it slightly on the rich end. say for example if i tune to 16PSI if i look at the map i can tune the fuel to 20+ PSI since it follows a linear pattern and i have verified this while road testing and on the dyno though actually tuning to that PSI level is the best and most accurate way to keep your AFRs on target but you can overtune with this method and it is a good idea anyways.

keep in mind the standard maps shipped with the microtech for FC is an aggressive timing map, you can actually get detonation in the 8-10PSI range if it is not refined. i personally begin with a 13 degree total advance at 10-15PSI of boost and may up the timing a few degrees from there, iirc the maps i originally had were in the 18-20 degrees of advance range, not a good thing..