How to tune a car, from scratch!

[to4garret]

Hi Guys,

In the next few weeks i will be undertaking my own tuning session with a freshly installed LinkPlus ecu.

it comes with a very rough startup map standard.

now i have all the gear, headphones for knock, wideband, laptop etc.

i do know the basic's on tuning an engine and i would feel far more confident on adjusting a already setup tune rather than starting completly from scratch.

now i dont what to hear "take it to a proper tuner, dyno etc" i want too, and will tune it myself im prepared to accept any consequences that may arrise, this is partly because i want to learn new things.

what im wondering is the general procedure on starting to tune a fresh motor.

i.e. do you hold it on load point low in the revs first, adjust your AFR's first and then timing adjustment later?

basically im just after some feed back from people.

Thanks alot!
Craig.

 

[mannynz]

Is your fresh motor already run-in ?
Theres a few ideas out there on how this should be done.

As for tuning. You will need a data logger or some other means of measuring the necessary sensors.

I would start with the basic(start-up) map/tune.
Gather all necessary data from the above tune.

from the data above, you can adjust what you think need adjusting.
Alway make sure your on the rich side of air fuel ratio.

I would susgest 1 adjustment then 1 test drive and log.
This way you'll get better understanding.

 

[doommachine]

Sort out your off boost performance first... too many people just sort out WOT, then your car cruises like crap.

 

[to4garret]

i think i have half a plan now,

i will get her started, then spend a few minutes (hours) stabilizing the idle and familiarizing myself with the ECU's tuning software.

once i am happy, i will slowly get some one else to drive up and down my street while i monitor the logs, keeping the car below 2krpm

while at that point i will start tuning AFR's, i know the timing is very conservative on the base map, so AFR's will be first.

starting at light load upto 2krpm, then 3 krpm, then by using the brake at 2krpm we can apply some load and move up/down in the map, tuning those AFR's.

i will complete the idle -> 3krpm AFR tune around my local streets then i will move to a free way to tune higher.

first off will be 4krpm in 2nd light/no load, by this stage in the tuning i should have a rough idea on how it will scale, though i still wouldnt have hit boost yet.

then 5krpm in 2nd, light to no load.

now will be on boost load points, i plan to fatten it up as boost comes on, my main on boost AFR target will be 12:1, as boost comes on, i will look for around 11.5:1, remember i will not be tuning timing at all, just AFR's.

so as i progress through each rpm the brake will be applied to log and put load on the engine shifting me into different load cells which i can monitor and change in real time.

once that has done and the AFR's seem good i will put the head phones on and tune the knock sensor. there is seperate scaling for the sensor, so once you have set you mins and max's the ecu will do the rest.

then i will repeat the same steps as i have done for the AFR's but for timing, putting as much in until i start hitting knock, once that happens i think i will pull about 3 deg out because i will be tuning at night and even though the Link has temp compenstation i dont really want to be on the raggered edge.

these are my thoughts right now, can any one add anything?

Cheers,
Craig

 

[to4garret]

oh yea,

the engine is 160,000kms old so its pretty run in

the brakes and clutch will be brand new how ever

 

[doommachine]

I reckon you should wire your wastegate open to begin with, trust me, if the car runs badly off boost, it will shit you. Also, you can tune it for no load in the driveway no worries, so go all the way up to 5-6k before going for a drive. I found through messing about that theres very little difference in injector pulse width as the engine speed increases (I do not have a wideband though, and this is off boost - on boost I haven't touched), so if you can work out what you need at 20 in of vacuum at idle, it will probably be close at 4k rpm.

 

[to4garret]

i have an external gate

i will free rev first and adjust accordingly cheers, but its the first bout of tuning on road that freaks me hahahaha.

oh well guess i will get it soon enough.

 

[doommachine]

Hmm.. so you can't disable it in some way? Ah, you'll probably be fine just doing free revs to start, unlikely you'll build any boost.