(re)Tuning my LINK for drivability, help! (new turbo)

[zep]

Bring a note pad, baby.

[mjrstar]

sounds like you have a plan, i didn't see much in the way of knock detection mentioned. if i was you I'd bump fuel up by 5-10% from about 5psi onwards and make sure it's not running mega timing above 5000rpm/12psi and the engine should survive nicely. I like around 11.6-11.7 : 1 a/f at full load, i suspect things would not last too long if thrashed in the 13:1 zone. I also aim for a cruise tune in the high 15's (off boost).

By not mashing the loud pedal you should be able to stay out of the "danger" boost level.

[kpr]

may have been mentioned already as haven't read through everything. but if you want to be safe, take 10 degrees advance out of everything in the boost part of the ignition map. bit lean wont blow you engine up if there is bugger all timing in it. long as your not hard up it for long periods. i usually chop heaps of timing out past the boost level ive tuned a car to, just incase it over boosts or someone plays with the boost.

[eke_zetec_RWD]

yea, take the timing out to tune the afr. dnt have to worry bwt it pinking firm that.

later on with knock senser or phones ect add timing back in. dyno assisted. excess timing is pointless if its not resulting in more power.

a wideband is the go. link g3 might have a quick tune function which will actially do the fueling for you on your drive down

if wired and set up correctly!

[kpr]

yeh depends on firmware version. from memory only the latest g3 firmware has quick tune, older versions didn't.

i wouldn't suggest upgrading firmware, unless you had more time on your hands. as sometimes it does weird stuff.

[zep]

Thanks for the replies guys.

And a MASSIVE thanks to John (CGXPWR) who tonight not only welded a mount for the wideband to my dump pipe, but also had a quick look at and fiddle with the tune to make sure it was safe enough to drive to Palmy. He seemed to think that it was a relatively safe tune regardless, so I'm interested to hear other's opinions on Friday

[fishtailfred]

if i was you I'd bump fuel up by 5-10% from about 5psi onwards

+1, good call.

and make sure it's not running mega timing above 5000rpm/12psi

In general more RPM = more timing is OK. I realise that you probably meant full spool RPM, though. I'd expand upon this, make sure it's not running aggressive timing anywhere above 100kPa.

I like around 11.6-11.7 : 1 a/f at full load, i suspect things would not last too long if thrashed in the 13:1 zone.

There are two reasons that we run richer than stoich:

1) Incomplete atomisation/evaporation/burn, by adding more fuel, we use more of the available air, maximising the amount of mixture actually burned, and thereby maximising power too. This varies depending on injector type, size, placement, fuel pressure, pulse width, etc etc etc. The aim is to burn all of the oxygen. If the setup is nice (few are), this number will be close to stoich. Closer to stoich = more power, believe it or not.

2) To artificially cool the charge and prevent detonation. Sometimes it's most effective to do that, other times it's better to tune it relatively lean and retard the timing to match.

If the tuner made sure it didn't detonate when hot, when tuning it, then his timing figures were probably pretty retarded, but there's nothing wrong with an NA AFR assuming that other parameters match. Basically running very rich is a hack (yes, my setup was included) and you want the exact AFR that yields you no left over O2, as per item one. If your compression is too high, boost too high, octane too low, etc, then it might be a permanent part of the tune, but it's not optimum and there are other ways of achieving safety without running rich. Rich is just a convenient, easy, safe way to get started.

I also aim for a cruise tune in the high 15's (off boost).

You can go a lot leaner, but you should watch EGTs if you're taking that to the extreme. You may also lose mileage from excessive lean-ness in cruise.

may have been mentioned already as haven't read through everything. but if you want to be safe, take 10 degrees advance out of everything in the boost part of the ignition map.

Do this with caution. If the timing is already pretty low, removing 10degrees could place it in a VERY retarded spot. If timing is too retarded, turbos, valves, chambers, engines and manifolds get HOT, which is not ideal and is dangerous.

Adding some retard isn't a bad idea. just check what it is first. You probably don't want less than 15 or 10 or so, in boost.

bit lean wont blow you engine up if there is bugger all timing in it.

True, even if you are hard on it for long periods, perhaps.

i usually chop heaps of timing out past the boost level ive tuned a car to, just incase it over boosts or someone plays with the boost.

An excellent move!

Fred.

4am, time for bed, 1600cc injector 2.3 volvo to tune on FreeEMS tomorrow. Out with the ms3, yay.

[zep]

P.S. I appears that if I drive calmly I can stay off boost all together. This might change when I have Thriller + luggage in the car, but not by too much.

[kpr]

may have been mentioned already as haven't read through everything. but if you want to be safe, take 10 degrees advance out of everything in the boost part of the ignition map.

Do this with caution. If the timing is already pretty low, removing 10degrees could place it in a VERY retarded spot. If timing is too retarded, turbos, valves, chambers, engines and manifolds get HOT, which is not ideal and is dangerous.

Adding some retard isn't a bad idea. just check what it is first. You probably don't want less than 15 or 10 or so, in boost.

was going to add depends on the engine and advance to start with, but got lazy. also was more aiming at just in case he comes on boost for a short period. as you say, shit is going to heat up if you go too far. but still better than detonation, that will kill your engine in seconds.

[fishtailfred]

Yep, all true. If your manifold isn't designed for expansion, though, you'll quickly find out about it's weak spots if you get it hot

[zep]

Back from nats. Everything seems to be okay.

While John turned the MAP cut up, it was still hitting it so we took the wastegate apart to find that one of the banjo fittings had been improperly manufactured and had no hold in it. Fixed that, wacked in a 10psi spring, and went for a burn with Cam at the laptop. I didn't get to see the numbers as I was driving, but he said that it was running a bit rich on idle, bit lean off boost, and fine on boost.

We noticed that the extractors were getting pretty hot, like glowing red, after long cruising. I assume this is due to the lean off-boost driving.

Gonna have a proper go to re-tune it in the next few weeks.

[kpr]

might not have enough timing in it off boost. will cause it to heat up. too lean wont make it hot. around stoich (14.7 afr) is the hottest burn. leaner or richer and temps drop off. up in the 15's is sweet for cruise afr. generally runs bit cooler and uses less fuel. not as good for the trees tho

[fishtailfred]

might not have enough timing in it off boost. will cause it to heat up. too lean wont make it hot. around stoich (14.7 afr) is the hottest burn. leaner or richer and temps drop off. up in the 15's is sweet for cruise afr. generally runs bit cooler and uses less fuel. not as good for the trees tho

BIG +1, sounds like it's retarded to shit. I know people that cruise in the 17 - 19 range with as much as 55 btdc advance. you're looking at some serious egts with that, though, despite the above being true.

It's important to note that "cruise" could mean different things to different people, cruise in my books is well under 100kpa, maybe 40 - 70 or so? If you were german, you might be cruising with 3psi, at which point the conversation changes.

Define cruise?

Fred.

[kpr]

yeh same deal here. well under 100, i would usually call "cruise". but some setups would kill that theory

and unless zep looks like this chap

im guessing hes cruising at 100kph, not double that.

[zep]

Yeah, cruise as in driving long distance and not getting pulled over.

Still need to get back in there and do the retune soon. Will have to set about some time to retrieve the exact settings that things are running at.

[fishtailfred]

Yeah, cruise as in driving long distance and not getting pulled over.

This is a thread about tuning, right? Talk kPa

I guess I wasn't clear. I've driven cars that took full throttle to do 110 (which is a safe place to be at pulling over wise), they were "cruising" at 100kPa. I've driven others that were cruising at 140 (OK with radar detector ) with a slight touch of the throttle, they were "cruising" at probably 40kPa. The latter would be happy with 50* advance and 16:1 AFR, the former would need 13:1 AFR and ~30* timing. Hence the question.

Ratios make a difference too.

Also, what you should be doing is this:

1. 
   [*:ffer4j8s]Save settings with some information about what they contain, date, comments, state of mods, fuel, etc.
   [*:ffer4j8s]Take datalogs with laptop or other device each and every time that you drive it, save with reference to tune ID.
   [*:ffer4j8s]When you get a chance, review all datalogs since last tuning session and make some positive changes
   [*:ffer4j8s]Repeat 1 - 3!

Normal driving patterns, with a bit of thrash here and there, will give you a LOT of good info about what to change in the tune.

Fred.

[fishtailfred]

Also, post a screen shot of your timing map so some people in here can give you some hints about what to fix. And VE/fuel map while you're at it.

And another thought, did you verify that the timing on the laptop matches the timing on the engine? If you had shit apart, maybe something changed? I had a pulley damper slip while setting the cam timing on my engine once, I cut that fucker in half with an angle grinder to ensure it never happened again.