Gt3071r - which A/R to go ?

[prj]

Here is an extreme case of meth vs no meth (same car, overlaid the graphs).
Here boost is different also, but boost was kept flat and in both cases the boost was not raised after the car stopped making power.

Without meth the boost is about 1.4 bar. I think it would be possible to gain around 30hp more without meth compared to what is shown, but this was chosen as a point on a "conservative" map.
With meth the boost is about 1.9 bar.



Difference is a little over 100whp, which is around 125hp at the crank.

It really depends on your setup how much you gain, but around 10% gain is totally normal, if your ECU has some timing reserve that is pulled back on normal running.
If you full on tune for it, and run a lot of it the difference can be up to 20%.
Just like it is if you run race fuel vs 98 RON.

If you have a conservative map and you do not add any timing, nor add boost, then the gains are around the 5% level, because water actually retards the burn, so to get the same power as before you would need to advance the timing in the first place. The main power booster is the fact that the air is cooled much more, so the cylinder is filled much more at the same boost level.

[Rocco]

Yes your engine had a hugely worked head and very good profile cams. So the gains on w/m just by increasing timing need to be adjusted on the rest of the head work then. So saying to someone on the forum you will gain 50 hp on w/m without taking into account the rest of the engine I take it as a mean hp of gain. So then w/m can give you anything between nothing and 100 hp? :confused:

Vas, I was talking about my last car...from Bulgaria.

The Pk engine never been on any dyno and without any meth system Dmitri calculated 575hp roughly with 98 octane and a 3076 0.82ar

[A80Avant]

Vas, I was talking about my last car...from Bulgaria.

The Pk engine never been on any dyno and without any meth system Dmitri calculated 575hp roughly with 98 octane and a 3076 0.82ar

Ah. Sorry. You have had so many different cars it's hard to keep up

[Rocco]

Ah. Sorry. You have had so many different cars it's hard to keep up

Like with the girls

[Thuppu]

Like with the girls

Hope your wife doesn't read this

[A80Avant]

Here is an extreme case of meth vs no meth (same car, overlaid the graphs).
Here boost is different also, but boost was kept flat and in both cases the boost was not raised after the car stopped making power.

Without meth the boost is about 1.4 bar. I think it would be possible to gain around 30hp more without meth compared to what is shown, but this was chosen as a point on a "conservative" map.
With meth the boost is about 1.9 bar.



Difference is a little over 100whp, which is around 125hp at the crank.

It really depends on your setup how much you gain, but around 10% gain is totally normal, if your ECU has some timing reserve that is pulled back on normal running.
If you full on tune for it, and run a lot of it the difference can be up to 20%.
Just like it is if you run race fuel vs 98 RON.

If you have a conservative map and you do not add any timing, nor add boost, then the gains are around the 5% level, because water actually retards the burn, so to get the same power as before you would need to advance the timing in the first place. The main power booster is the fact that the air is cooled much more, so the cylinder is filled much more at the same boost level.

That are some nice results but not comparable evidence. Could you dial the boost down on that car and redo the measurement with and without w/m?
Assumptions are the root of all problems!

[prj]

That are some nice results but not comparable evidence. Could you dial the boost down on that car and redo the measurement with and without w/m?
Assumptions are the root of all problems!

Why would I dial the boost down on that car?
This is just the other extreme, real results are in the middle. I wrote a fairly good explanation with %ages that should be pretty close to on target.

The same car at 1.4 bar went from 230kw to 274kw by just enabling w/m injection and adjusting the ignition angle a little bit (same as Motronic would adjust by itself).

This is a 20% increase. Boost PID left untouched.
So, a 400hp car would easily go to 480hp with water/meth on Motronic...

[A80Avant]

So you had those results then. That's what you need to show in order to understand true w/m improvements. Good stuff.

[prj]

So you had those results then. That's what you need to show in order to understand true w/m improvements. Good stuff.

Not "true" in any way - you can almost always run more boost with w/m, so you can make huge gains if you map appropriately.
But even without mapping you can see that 20% gains are possible.

That is why I said that 50hp was pessimistic, not optimistic for a 430hp car.
Optimistic would be 90 hp.
The higher boost you run, the bigger difference there is from each degree of timing, and the more benefit you get from w/m cooling down the intake.

[A80Avant]

Interesting..

[prj]

It's just the interesting bits that are always left out.
Like making 410 hp on RS2 injectors, which later when I hold in my hand I can see that have been modified (bigger holes) and actually flowed 420cc on the car.
Or someone claiming they made 480hp on an I5 with a 3071R, and then conveniently leaving the water/meth out.

That's how incorrect expectations are born, and why everyone and their mother tries to over-inflate hp figures.
Bit of a , sorry.

[DJones]

It's just the interesting bits that are always left out.
Like making 410 hp on RS2 injectors, which later when I hold in my hand I can see that have been modified (bigger holes) and actually flowed 420cc on the car.
Or someone claiming they made 480hp on an I5 with a 3071R, and then conveniently leaving the water/meth out.

That's how incorrect expectations are born, and why everyone and their mother tries to over-inflate hp figures.
Bit of a , sorry.

Conveniently, lol, I forgot. I have to say when I drive it on the road without water it doesn't feel like I have lost the sort of power you allude to.. Mine isn't mapped for it.

Oh and I'm not claiming it you saw the graph but yes granted with water.

[prj]

Conveniently, lol, I forgot. I have to say when I drive it on the road without water it doesn't feel like I have lost the sort of power you allude to.. Mine isn't mapped for it.

Doesn't matter, it's Motronic and it will advance the timing.
That dyno graph, the car also "isn't mapped for it". Yet made 20% more power . Following same logic, your car would indicate 400hp.

The fact is, dynos measure IAT at the intake, not inside the manifold, so cars on water/meth always show much higher numbers. On the road with better cooling the difference is not always as pronounced.

Age old trick - take the IAT probe and stick it somewhere hot - instant increase of numbers. Stick it somewhere cold, instant decrease.

[DJones]

Doesn't matter, it's Motronic and it will advance the timing.
That dyno graph, the car also "isn't mapped for it". Yet made 20% more power . Following same logic, your car would indicate 400hp.

The fact is, dynos measure IAT at the intake, not inside the manifold, so cars on water/meth always show much higher numbers. On the road with better cooling the difference is not always as pronounced.

What matters is you referring to me trying to misguide people, how did you reach the decision? I don't actually care what hp it makes and never have which is why it hadn't seen a RR in 6 years since mapping. The Feel that's what I wanted so what interest do I have in conveniently misguiding folk or at least being advised by you that that's what I'm doing?

[prj]

What matters is you referring to me trying to misguide people, how did you reach the decision? I don't actually care what hp it makes and never have which is why it hadn't seen a RR in 6 years since mapping. The Feel that's what I wanted so what interest do I have in conveniently misguiding folk or at least being advised by you that that's what I'm doing?

I think you take this way too personally. As I said, it was just a rant.
Everyone and their mother does it - give a figure for some specification, and leave out some important details.

Pretty much the same as if I say that I make 520hp on my RS4 with stock turbos.
And then forget to mention that I have w/m injection, bigger injectors and 044 pump.

Don't take everything as a personal attack, it was not my intention at all.