0.1bar at idle - 996 turbo

[ragpicker]

There could have been one more explanation. If, as Tom has said, you had a vacuum leak on idle, this would not have been picked up due to the maf delete. In certain circumstances the idle mixture could be slightly richer than ideal, the extra air being induced then causes the idle to raise which the ecu sees, then retards the ignition to try to maintain idle target value.

With retarded ignition the burn happens late, this causes some minor spool on idle. In other words, this is the basis of anti lag systems the world over, it's just that in this case the air may being supplied by a temporary vacuum leak rather than a jacked throttle or a bypass valve. The same thing can be attained by playing with the overlap via the variocam, but this would happen at all times.

I'm not saying this has happened, but it is possible, especially if after driving the car harder today has helped seal any potential leak due to a heat increase. ~But that is a long shot!

Oooof!

Pick that one out! :worship:

Will keep an eye on it then Mike and see what happens. It wouldn't surprise me, looking at the logs done in the past, if ES haven't fiddled with the timings along with the mixture to make all the pops and bangs in the exhaust...

Since I got the tune done I've had a CEL (P0171, P0174 (idle range banks 1&2 above limit)) which I believe is due to it running slightly lean at idle and partial throttles. This is probably due to the big injectors which it has and Emre trying to get them to only inject a tiny bit of fuel.

I haven't really bothered about the CEL because I wasn't doing many miles in it, but now its got a new engine and i'm doing more miles in it I want it sorting.. I've contacted ES who are happy to adjust the tune for me.

 

[deMort]

Yup codes are for too lean and outside compensate limits .. no maf and i guess this is to be expected :dont know:

long term too lean is not good though .. but as i always say .. i know jack about modified systems .. sigh .. i really need to try and learn more .

Got to admit .. i learn from the masters on threads like this :thumb:

 

[DynoMike]

It may be that what I've said is a blind alley, but the fact that it is mafless could mean that in certain circumstances ( barometric pressure, vapour pressure, temperature etc) that there is some excess fuel on idle. In this case any extra air from a potential vacuum leak will increase the idle speed, leading to the scenario in my previous post.

I remember you commenting about the induction noise before, so again, altered cam timing can give a similar result, albeit present at all times.

Your injectors are puppies - we managed to get some 2200cc versions to idle on a 1300cc engine A pity they were marketed as methanol proof when they were anything but. Now on 1500's but at 94% d.c so need to up the fuel pressure. Are you on 1100s?

 

[DynoMike]

Yup codes are for too lean and outside compensate limits .. no maf and i guess this is to be expected :dont know:

long term too lean is not good though .. but as i always say .. i know jack about modified systems .. sigh .. i really need to try and learn more .

Got to admit .. i learn from the masters on threads like this :thumb:

Demort, we all learn lots from your many posts too. :thumb:

 

[ragpicker]

Your injectors are puppies - we managed to get some 2200cc versions to idle on a 1300cc engine A pity they were marketed as methanol proof when they were anything but. Now on 1500's but at 94% d.c so need to up the fuel pressure. Are you on 1100s?

Is that on a Hyabusa? Bet it purrs like a kitten... :grin:

Yeah I'm on 1100's... There's still plenty of headroom left and I'm sure the boost could be turned up on the hybrids to wake them up properly, but I've had the engine (and gearbox) rebuilt with new rods and studs for reliability. I really don't want to be asking ES to turn it up again to the point where it needs more work, no matter how tempting it is. The car is a lot more than anyone needs on the road and still retains its drivability. Next mods will be suspension and possibly aerokit..

PS Mike, is your car at CG at the moment? A couple of my friends were there this weekend and commented on an adapted turbo?

 

[DynoMike]

PS Mike, is your car at CG at the moment? A couple of my friends were there this weekend and commented on an adapted turbo?

Yes it is up there again for a fettle. The only thing left to change on the suspension now is the rear diagonal arms and the front dampers! Everything else is new :lol:

 

[ragpicker]

Had a little look with the durametric today with the car at idle.

Ignition on but engine off - Ambient pressure 1015mbar. MAP reading 1017.
Engine running - Ambient 1015, MAP 1075-1090. Whilst it didn't do it, once the map reading goes to 1100 the boost gauge would show 0.1bar.

Injector angle +5 to +10 degrees.

Lambda set point 1.0
Lambda actuals 1.14 both banks.

Am I correct in thinking that the tune appears to have an anti-lag element to it?

 

[DynoMike]

Had a little look with the durametric today with the car at idle.

Ignition on but engine off - Ambient pressure 1015mbar. MAP reading 1017.
Engine running - Ambient 1015, MAP 1075-1090. Whilst it didn't do it, once the map reading goes to 1100 the boost gauge would show 0.1bar.

Injector angle +5 to +10 degrees.

Lambda set point 1.0
Lambda actuals 1.14 both banks.

Am I correct in thinking that the tune appears to have an anti-lag element to it?

Rags, the answer could be yes or no, dependant on what is causing the lean idle mixture. You really need to look at ignition timing and throttle angle too, along with actual cam angle values to establish if it has got an element of anti lag.

But.....the target lambda is 1.0, you have 1.14. It could just be something as simple as not enough fuel trim being added for the low ambient temps (as you are mafless). Or it could still be down to an air leak on the vacuum side.

Probably best to ask ES about it, as Emre wrote the tune. I do suspect he has tweaked the cam forward, or even more radically, he is using the high lift lobe at idle with the cam timing at the normal value. Either way, it is their I.P, so best to ask them.

Happy logging mate :thumbs:

 

[911tom]

That is a very lean idle. I have a gauge in my car and it has always been a fairly consistent lambda 1.0. Different car and tune so it does not say what is normal for your car.

 

[ragpicker]

Yeah, it is. A lean mix at idle isn't a concern though as there's no load on the engine. It is perfectly in-spec when on boost where it matters though.

I'm also confident there are no air/vacuum leaks. The car has only just been put back together and pressure tested for boost leaks at the turbo inlets. I will have a little look at the other parameters you mentioned Mike, but probably best if I don't post them on here as, like you say, its their IP.

I'm just waiting for ES to come back to me with a slight alteration to the tune now. I got an email from Amir the other day letting me know they are out of the country at the moment but haven't forgotten about me.

Will keep you posted.

 

[911tom]

Oh yes lean idle is not problem. As you say it is under load where it matters.