Volvo K24 turbo in audi application.

[A80Avant]

when i look at my older megatune and early vemstune setups i notice that on the 3071R turbo i did have to reduce the VE table after 6500rpm slightly as the mixture was becoming too rich. From idle to full boost (2bar) i can see about almost 40 values difference with my 630cc injectors on the 3076 but only about 28 values difference on my 3071.

So when eyeballing that VE table it may not seem entirely wrong.

However when one sees the log, i can say that actual lamda to target is always leaner. Even if the values were set initially somehow there was no provision of seeing IF those values are still working under many or all circomstances. I cannot believe that a VE value of 108 can be used similarly from 1.9bar to 2.6bar of boost. There was no provision in this map to get the map a bit richer on onset of boost, time where the knock is more prominent to happen!.

I run much more timing and boost from ruf. Why mine doesnt it knock?

This leaves me to believe that i cannot personally exclude a mechanical fault, bad fuel batch, in conjuction with a map that has NO safety features whatsoever.

Let ruf. take the head off and look for possible injector/ spark plug failure etc as well.

[Billman]

most cars will actually have the VE go down with increasing rpm, due to cams losing oomph up top. especially stock AAN cams.

So you think that it was something else and not a lean condition that led to it? He said it happened between 5000-6000RPM.

This value represents not the "actual" VE value so maybe the cams loose omph but the engine still needs the cooling effect.

Unfortunately the log he posted doesn't show boost above 1.3 bar.

[Mcstiff]

[a4kquattro]

Yes however this map seems very wrong to me and far from everything I saw till now.
See that at 2 bar i.e. he has 108 from 700 RPM till 8500 RPM.


In comparison my to my old full ADU spec map.

most cars will actually have the VE go down with increasing rpm, due to cams losing oomph up top. especially stock AAN cams.

[Billman]

Yes however this map seems very wrong to me and far from everything I saw till now.
See that at 2 bar i.e. he has 108 from 700 RPM till 8500 RPM.


In comparison my to my old full ADU spec map.

[a4kquattro]

billman, you are forgetting that 'map multiplication' is in effect on the VE table. the fuel injected with a VE of 100 at 100kpa is not the same as the fuel injected at 200kpa at the same rpm (unless you've done something like setup alpha-n mode).

[Billman]

In vems you adjust the main fuelling table through "VE". This comes in a calculation with the "req fuel" value and the ECU translates that in InjDC.

He requests 104 VE (fuel) and this amount gives at 1.1 bar a lambda value of 0.94. At 2 bars of boost the value is set at 108.
This is a very small VE value change and that why I say that most probably the lambda during 2 bar would be close to 1.

Idle lambda value was set at 80. So you can see that from idle to 1.1bar he has almost 20 value difference and from 1.1 to 2 bar only 4. And this is the point where it must become even richer.

As this goes way off topic I would suggest going further with it at the aftermarket topics where one can see other "vems maps".

[prj]

it means near to 14.7AFR with 2bar of boost?

If what Billman is said is correct, then yes.

Have got also one bad experience with 034 lately. A guy bought a heavy duty check valve for the breather, that got stuck on first use and the turbo boosted the crank case.
Result... messed up crank and brand new bearings are garbage now...

So technically the part that was bad from the get go caused engine failure :/

[andy10v]

I thought somebody on here had the 034 rs2 chipset at one point and it was rather low powered compared to what was on offer over here.

Anyway bad luck, hope you get her up and running again soon. Is it just going to be a stock engine with rods or any other plans.

Just curious, what kind of boost profile were you using, ie peak at what rpm and what at redline?

[Rocco]

and who mapped it if is it possible to know?

it means near to 14.7AFR with 2bar of boost?

[prj]

Anyway, if the K24-7400 car was really running close to lambda=1 at full boost, then that explains everything and I think there is nothing further to discuss.

I just hope the engine will be fully mapped to run correctly in the future, as it does not really matter what hardware you throw at it, it will still blow up every time with lambda=1 at that boost level.

[prj]

Umm...Jamo those are *wheel* not crank numbers.

Even then, not that good...

I also strongly disagree with this:


But hey, garbage in, garbage out, right?

[Jamo]

Umm...Jamo those are *wheel* not crank numbers.

I'm aware of that they are STILL low, to me any US dyno figure I see are equivelant of european crank figures, I've yet to see evidence otherwise

[UrS4boy]

That is a seriously cr@p setup, on the Rolling Road days I did stock RS2's with 3" exhaust blew that out the water unchippped!

Umm...Jamo those are *wheel* not crank numbers.

[djh]

out of interest if thats 034 do they do anything any good?