what does the knock 0 1 2 windows mean on VEMS?

[popdemonic]

Billman,do you have any ideas on tuning MAT/TPS enrichment?let'say orginally,i never do anything on this table.i found that the RPM usually drops once
the MAT is getting higher.What's the ideas to tune this table.i assume the most effective regions on the table would be at 0% TPS and paricular MAT.
for example,if i drive the car on stop n go traffic.the MAT always stick stick around 71-80 C Deg.should give it more or less fuel?
Thanks Mate.

[Billman]

Best option is to set VE table at 20 degrees.

Then adjast MAT/TPS enrichment according to temperatures in order to have the least EGO correction. I have the biggest deviation at IDLE because apparently the injector characteristics change when the temperatures go up.

I have i.e. 100 at 20 degrees, 102 at 40 degrees and 104 at 60 degrees (TPS 0%).

[prj]

Stop and go traffic you should just run Lambda=1 or 1.03 for best economy, regardless of IAT.

The way this is done in stock ECU is there is a fuel enrichment map based on RPM and IAT, and a timing correction map based on IAT.

Both of those maps have a cylinder charge (LOAD) based lockout, so they are only activated when the ECU is running open loop/at higher loads.

I tune this to progressively enrich with higher IAT.
I also add timing pull with IAT. At 80C I pull 2.25 deg or more.

To make cars WOT-proof I usually start progressively flooding the engine and pulling timing, until the driver wants to let off the gas by himself, which from my tests happens at around 80-85C, at which lambda is close to 0.71 and timing severely retarded. At over 60C IAT the engine starts getting very knock prone.

This together with knock control prevents damage to the engine on sustained high RPM, high load situations. I have tested WOT 6th gear for over 4 minutes on a tuned AAN producing about 500hp and no damage resulted. I saw IAT a bit over 90C during this.
The cooling effect of additional fuel helps prevent detonation and cylinder temperature spikes, as well as offsets the rise in EGT's due to retarding overall ignition timing.

Good luck.

[popdemonic]

What's your ambient temp in your country?When i first start up the engine,i normally see it 35C Deg and quick rising up to 50C Deg.
The ambient temp in Thailand is 30-35C Deg.Should i start to get the VE setting at my based temperature.For example,get the VE Table
at idle somewhere like 30C Deg and add more MAT/TPS enrichment linearly as the MAT goes up.

Today i tried to playing around bit on MAT/TPS enrichment table after that i need to lower the number on VE table at idle cells since it's going too rich
due to the enrichment.Is this the correct tuning between VE Table & MAT/TPS enrichment? Added the enrichment and lower the VE Table on idle cells.

My MAT/TPS enrichment just like 20-50C Deg @100 , 60C Deg @104 , 70-90C Deg @107.

[prj]

It is OK if you see up to 70-75C IAT.
But over that you don't really want to push. If they are going higher than 75, you need to think of better charge cooling or reduce charge pressure.

If it's so hot all the time where you live then install meth injection.
Or your car will be just slow all the time

[Billman]

It is OK if you see up to 70-75C IAT.
But over that you don't really want to push. If they are going higher than 75, you need to think of better charge cooling or reduce charge pressure.

If it's so hot all the time where you live then install meth injection.
Or your car will be just slow all the time

Over here I can't tune as I wish right now now because we have even at night above 25 degrees.

[popdemonic]

lol,on cruising it's fine.i always see 45-50C Deg.only sits standstill IAT will jump up 75-80C Deg.In Thailand,we never had snow.there're 3 seasons
over here.Hot season,Hotter Season and F!@K hottest season.Summer on April,i saw 45C Deg Ambient temp on Instrument Cluster.
A/C cut out due to the high pressure was exceeded.UrS cars has the A/C problem when been using under very hot climate.the Viscous coupling
fan could not be able to cooling the A/C system.you couldn't imagine you need to sit inside the car without A/C during the unmoving
traffic for 2.5hrs with 45C Deg outside temp.it's best way to loss your weight.i ended up removing my visco fan and installed 16" electric fan
pull type so far i still never had any a/c cut out after that.Before going for the electric fan,i have done so many things ie,new a/c compressor,
condenser,drier,recharged r134a.i'd say any suspects.i just changed them all.

[prj]

On cruising IAT will always be fairly high when it's hot outside.
This is quite normal.

However, when you start pushing it a bit more, IAT will actually drop a bit towards ambient and then start to rise again.

It is this IAT delta you should look at. If you have more than 20C IAT delta (difference between lowest and highest in 3rd gear pull from 2000 RPM) then you are over stressing the compressor of the turbo or you have inadequate charge cooling.

It's not about absolute numbers, it's always about the delta.
As I said, for your climate you need better charge cooling, or buy a V8.

[AudiS2Turbo]

If your VEMS was assembled for original MAT sensor then in order to fit 1.8t sensor you need to remove an SMD resistor from inside VEMS.

this is what Billman means : http://www.vems.hu/wiki/index.php?pa...onicAirTempMod

The Piggyback Resistor must remove when you use the 1,8T NTC.

[ChrisAudi80]

Pop, I think in our climate going with AWIC might be a good idea. A little more complicated system, but the charge temps might be more stable.
I have been reading a lot about this lately.

http://www.frozenboost.com/product_info.php?cPath=216&products_id=1034&osCsid=9e1a9b38d1dca3a4fd626b97a9b28d05

[ChrisAudi80]

Cannot edit previous post.

If you go with this type of AWIC:

http://www.frozenboost.com/product_info.php?cPath=218&products_id=209&osCsid=9e1a9b38d1dca3a4fd626b97a9b28d05

it will fit in the location of where the stock SMIC sits now.

and something like this heat exchanger:

http://www.frozenboost.com/product_info.php?cPath=217&products_id=1002&osCsid=9e1a9b38d1dca3a4fd626b97a9b28d05

which should fit in front of the AC rad. Since you are running all electric fans, an extra fan for the heat exchanger might not be necessary.

The Bosch Cobra water pump recommended should be available in Thailand as it is used on MB kompressor cars.
A water reservoir tank (approx 3L) in the truck would be good.

OR: Go with an FMIC and water/meth injection as PRJ says, but that requires more tuning

BTW, strange you had the AC cut out at high ambient temps. I've never had that happen.

[prj]

Don't waste money on those water to air coolers, they will never cool anything below ambient, will weigh more, etc.

There is a thread about this already, but the fact is that they are only useful for drag racing where you can put the reservoir full of ice.
Completely useless for a street driven car.

Also, if you are fitting meth injection there is no need to fit a FMIC.
In fact you could run no intercooler at all with meth injection.

[ChrisAudi80]

Don't waste money on those water to air coolers, they will never cool anything below ambient, will weigh more, etc.

There is a thread about this already, but the fact is that they are only useful for drag racing where you can put the reservoir full of ice.
Completely useless for a street driven car.

Also, if you are fitting meth injection there is no need to fit a FMIC.
In fact you could run no intercooler at all with meth injection.

I know they cannot cool below ambient, I did not say that either. A big FMIC weighs quite a bit, too. Besides, we're talking about an S6 here. What does 2 kilos matter?
The point is, they do not heat soak near so much and in Pop's (and my) case there is a lot of high IATs. You mentioned delta T. With a proper AWIC system, the IATs would be more stable, because of the water. AWIC cores have less pressure drop, too.

Went searching for the thread you mentioned, but could not find it.

I don't agree they are useless on a street car. AWIC systems cost is similar to a FMIC.
Running water/meth is good and would invalidate the need for FMIC, however, a good water/meth system (ie. HFS-3) costs more than an AWIC system.

Strange that some people really don't like AWIC systems.

[prj]

The point is, they do not heat soak near so much and in Pop's (and my) case there is a lot of high IATs. You mentioned delta T. With a proper AWIC system, the IATs would be more stable, because of the water. AWIC cores have less pressure drop, too.

Uhm, won't heat soak as much? FMIC's don't really heat soak.

So please tell me exactly why you think drawing heat out of the air into water and then cooling that water is somehow more efficient?

It's actually not. It's a lot less efficient. And your water-to-air setup (wherever you fit it) will be heat soaked ten times more than a FMIC ever will.

People "don't like" these systems is because they are a pure marketing buzz. Anyone with even a slight idea about physics/thermodynamics understands that air->water->air efficiency is much lower than air->air.

Once your water is going to be 50C+ degrees celsius it's going to be pretty useless at cooling anything. That's why I said they are only useful in drag racing when you can fill the reservoir with ice.

[pasbogdan]

Stop and go traffic you should just run Lambda=1 or 1.03 for best economy, regardless of IAT.

The way this is done in stock ECU is there is a fuel enrichment map based on RPM and IAT, and a timing correction map based on IAT.

Both of those maps have a cylinder charge (LOAD) based lockout, so they are only activated when the ECU is running open loop/at higher loads.

I tune this to progressively enrich with higher IAT.
I also add timing pull with IAT. At 80C I pull 2.25 deg or more.

To make cars WOT-proof I usually start progressively flooding the engine and pulling timing, until the driver wants to let off the gas by himself, which from my tests happens at around 80-85C, at which lambda is close to 0.71 and timing severely retarded. At over 60C IAT the engine starts getting very knock prone.

This together with knock control prevents damage to the engine on sustained high RPM, high load situations. I have tested WOT 6th gear for over 4 minutes on a tuned AAN producing about 500hp and no damage resulted. I saw IAT a bit over 90C during this.
The cooling effect of additional fuel helps prevent detonation and cylinder temperature spikes, as well as offsets the rise in EGT's due to retarding overall ignition timing.

Good luck.

That is why i can enjoy the car only in the evening when it is not so hot outside?