What is clearly visible? Come again.
You posted two timing maps. Do you realize that the load axes are different between the timing maps?
The lower compression engine runs more timing everywhere in the power band.

Do you disagree with this?

We have gone way off topic here...

Hi

Im building a GTX3071r 1.8T with 82mm pistons (9.25:1 CR), supertech valves, top mount manifold, 4" maf housing with tial 38mm wastegate.

Im looking at injectors and need some advice.  Ill be running a ME7.5 BAM ecu.

What size injectors do people recommend?  Ive heard 680cc's will do the job, but I want plenty headroom so they not running a high DC.  Also what make is the better ones?  Ive read a bit able misfires on idle, spray patterns etc so just wondering what people have had experience of on here and what they would recommend.

Chris



I would go with the ID720cc injectors thats what I am running on my Golf with 9.5:1 at 430bhp on a T304E .64 hybrid @2bar.

Huh? Why are you ignoring the numbers when load equals to cylinder filling?
Let's put it this way. The lower compression ratio engine can run more timing and extract more power at the same cylinder filling as the lower compression ratio engine.
There is no "0-full". Load is already a percentage, you are trying to calculate a percentage of a percentage.

How you can compare timing at DIFFERENT load sites is beyond me.
What do you think would happen if you dropped the CR to 9.0:1 on the Leon engine? You could run the same timing as the TT runs at the same load spots.
Except maybe up top, where the smaller turbo would equate to more backpressure, but you would still run more timing across the range.

And you do not think this would make more power?

I agree, it is exactly the same here. Don't worry about the filter though, it's not 5$ and it did not pose a restriction (I tried a different one).
However, that car had an AJQ engine in it, with a stock small port head and stock cams, and I did not see anything wrong with the timing.
That setup ran 2.4 taper 2.1 bar. I have boosted a S4 2.7TT before to 2 bar, and the timing looked exactly the same on stock cams. Different cams - different timing, some headwork, and again massively different timing.
If I could run 20 degrees of timing at 30 psi at 6800 rpm on 9.5:1 CR on a stock head and only see the car make 430 hp, I would try to see and understand what is wrong. Probably first thing on the list would be a leak down test and look for excessive blow-by as my experience would suggest that something is very off with the dynamic compression of the engine.

I've come across this many times where an engine would not knock but also would not make any power without huge timing advance. Most of the time the leak down test would be pretty bad and it would start smoking quite soon after, because all the air was going past the rings. Other cases the valves were not sealing as well as they should.

I have not said lower CR will always make more power.
The timing maps you posted clearly show that lower CR makes more power in this application (1.8T k03 vs 1.8T k04 factory).
If you look at what LOAD means in ME7, you will see that your comment about 0-full was not adequate and that in fact to compare timing between these two engines you should compare timing at the same load sites.
This is how Motronic has worked since the early 80's. This how it works until today, where from factory load = cylinder filling.

On the GT3582 you are for sure not running stock cams nor stock head. You are running big cams with big overlap.
With big overlap comes the fact, that not all the air that goes into the cylinder gets compressed. This results in low dynamic compression, even at a high compression ratio.
An extreme case can be seen in NASCAR where they run very high compression ratio, because the airflow is choked through a restrictor.

You need to understand that compression ratio heavily depends on the head and cam configuration. I am mostly talking standard head here, your race car is an exact opposite.
Making conclusions from what you see on that, at high RPM and then applying that to a car on stock head is not a correct approach.

Of course it would not explode, I just think it will make more power

The question is all about extracting power for me, not about "making it work". You can make things "work" with just about anything you put on the car, but that's not the point, is it ?
I don't see any reason for your 30 psi comments besides personal offense. It is just a number used as an example, because it is nice and round, nothing more, nothing less.
As to making power, you can either run lots of boost, or you can rev very high or have a very good VE.

Personally, I think I would rather see less power, but have a car that is going to respond well to different throttle applications, and have a nice graph plotted on a dyno with the car having plenty of drivability, and also power held nicely across the revs (needless to say probably more suited to the smaller k03/k04 turbos, but lets use that as an example).  I have seen plots of power and boost of these turbos using less boost but making more power....however, what you say to make power is lots of boost or good flow of a engine.....How does that work if here in the UK we are seeing better figures and dyno plots if we use less boost 

How would you recommend to tune a k03/k04 turbo'd engine to produce a strong stage 2 map?  What boost? What lambda? What timing does it run? What are the EGTs like?

here??



From that it would appear that you say that to make power you need lots of boost and also rev the engine very high?  Tuning is certainly not my forte however, from what I have seen, the need to rev high, especially on a smaller k03/k04 turbo car is un-necessary, as ive seen many hundreds of cars tuned with those turbos on making their peak power at 4500-5000rpm.


Answer my question?  How would you tune a k03/k04 car?

Do you hear voices in your head?
where do you dream up this stuff?? lmao.. sorry but you really do seem quite insecure and sad, responding like you do in forum posts.

I'll leave you to throw out the insults.. you are far more adept at it..  Practice makes perfect... and damn, you do get to practice a lot - lmao

"have a nice day"