Headers + Evolve-R Header Tune Dyno = Power Loss :(

[mfanatic325]

Yeah, and even after I got an Active Autowerk tune, my dynos were also consistent.

Conditions between baseline dyno day and post-NA tune dyno day were very similar, and the operator was the same. I actually was the one that ran my own car on the dyno every single time (because I am friends with the dyno owner and have ran other cars on his dyno before; thusly gaining his trust). The process was always the same: one or two minutes break in between runs, with a cooling fan running at all times. I really don't understand how there's such variance with the owners of the Z4M Evolve tunes however

[exdos]

The variability of dyno results may be due to the fact that, in "real world" conditions, the Z4MC's OEM intake harnesses the ram effect, which isn't replicated on a static dyno, and different dynos at different facilities will have different fans producing different airflows to the engine.

In order to assess the effectiveness, or otherwise, of the fans used at each dyno facility, it would be very simple to simultaneously hook up the car to a datalogger and observe 2 parameters: Airflow through the MAF and Intake Air Ttemperature. In real world conditions in a 3rd gear run, with the OEM intake, you would expect to see approximately 31lbs/min airflow at 8,000rpm and IAT of approximately 7 degsC above ambient. If you are seeing significantly different figures to these, then it will significantly affect the density of the charge and consequently, performance.

[TNZ4MC]

Here is my stock dyno run on a hot day. I now have evolve tune/euro headers and s-pipe/el diablo exhaust. I will hopefully get to the dyno again in the coming weeks and see what my gains are.

[H2O]

Agreed with Exdos on air starvation at high RPM

[z3speed4me]

Oh DD, the heartbreaker dyno... if you see good gains on there, you know you are doing ok!

[ajw45]

Out of curiosity, did you also get an a/f reading too? Any reason you didn't run the dyno to 8k rpm?

Originally Posted by TNZ4MC

Here is my stock dyno run on a hot day. I now have evolve tune/euro headers and s-pipe/el diablo exhaust. I will hopefully get to the dyno again in the coming weeks and see what my gains are.

[TNZ4MC]

The guys from Carma performance had their dyno setup at a big car meet and only did two quick runs for cheap. I'm sure they could dig up some a/f numbers. But I am not sure why they did not go to redline.

[TNZ4MC]

Originally Posted by z3speed4me

Oh DD, the heartbreaker dyno... if you see good gains on there, you know you are doing ok!

Yeah my Audi TT with a Garrett 50trim turbo only made 278whp at 17psi. It is an extremely conservative dyno.

[mfanatic325]

Originally Posted by TNZ4MC

Yeah my Audi TT with a Garrett 50trim turbo only made 278whp at 17psi. It is an extremely conservative dyno.

Yeah...your car should be making significantly more than that

[kosh2k]

Why do the AFR's drop off considerably like that? Something looks very wrong with the tune as it runs lean and then all of a sudden drops. It looks like the ecu is detecting knock and adjusting for that.

[exdos]

Unless a static dyno is placed in a wind tunnel, then a static dyno is operating in a totally artificial environment which doesn't replicate "real world" driving conditions. Since there is no standardized dyno cell environment, different dyno shops will use different protocols, which will produce variable result and make comparisons between vehicles and results from other dyno shops unreliable at best.

Torque output from an engine is very closely tied to the Volumetric Efficiency (VE) of the engine, and VE is an expression of the mass of the air/fuel mix in the cylinder charge in comparison to the theoretical mass of air/fuel at ambient atmospheric pressure. A VE of 100% occurs when the actual A/F mass in the cylinder charge equals the theoretical A/F mass. In the case of the Z4M, the OEM air intake is designed as a "ram air" intake, where the forward velocity of the car running into air (with mass) increases the dynamic pressure of the air in front of the car due to the "ram effect" (i.e. the reason why strong winds can demolish buildings etc.). When this air, with increased dynamic pressure enters the air intake system, if it cannot immediately flow through the engine, then the air slows down and this increases the static pressure inside the air-intake system, consequently, the air entering the cylinders in such circumstances will mean that the mass of A/F in the cylinder charge will exceed the theoretical A/F mass and thus the VE will be greater than 100%. It is published that the Z4M (and other S54 engined vehicles with similar ram air intakes) can achieve a VE of 106%.

Now, in the case of a Z4M on a static dyno with a fan placed in front of the car which creates an airflow equivalent to an air speed of a moving car at, say, 70mph, only, when the engine rpms are below that which equates to a road speed of less than 70mph, the pressure of air inside the air-intake system will exceed that which occurs in "real world" conditions, and so the performance of the car on the rollers will be artificially enhanced and the dyno plot will record this. Once the engine rpms exceed a speed equivalent of 70mph, there will be relative air-starvation in comparison to the situation that occurs in "real world" conditions, consequently, the A/F mass will be less than normally ocurrs, and so the VE diminishes as the engine rpms increase, with a consequential loss in performance as shown by fall in torque/HP.

Likewise, air density is related to air temperature, where colder air is denser; therefore, VE and performance are affected by both temperature and pressure. The positioning of the fan will also be critical to individual dyno runs, in the same way that the positioning of a lamp is critical to the lighting effects that it can create. So, unless the conditions in the dyno cell are properly controlled, and known, then the results are relatively meaningless.

Looking at those plots (below), they all show a sudden change to the engine running rich which occurs at 6400rpms and above. In view of the above, once the airflow begins to seriously diminish, and consequently the VE is seriously diminishing, despite the attempts of the Vanos to maintain cylinder fill rates, but the calculated load remains at 100%, is the DME transferring to richer fuelling in an attempt to maintain power? Alternatively, is the relative air starvation and lack of cooling air flow through the engine bay causing engine temperatures to rise and thus the fuelling is richer to keep cylinder temperatures down?

In any event, I bet the car in question performs totally differently in real world driving conditions.

[dre99gsx]

I disagree with above statement (theoretical aside...), since you can dyno an E46 M with no fans and get the same curve with helper fans on (at least the first pull). I highly doubt the Z4M ecu is expecting some sort of "ram air" effect at X RPM.

[David70]

Originally Posted by exdos

Unless a static dyno is placed in a wind tunnel, then a static dyno is operating in a totally artificial environment which doesn't replicate "real world" driving conditions. Since there is no standardized dyno cell environment, different dyno shops will use different protocols, which will produce variable result and make comparisons between vehicles and results from other dyno shops unreliable at best.

Torque output from an engine is very closely tied to the Volumetric Efficiency (VE) of the engine, and VE is an expression of the mass of the air/fuel mix in the cylinder charge in comparison to the theoretical mass of air/fuel at ambient atmospheric pressure. A VE of 100% occurs when the actual A/F mass in the cylinder charge equals the theoretical A/F mass. In the case of the Z4M, the OEM air intake is designed as a "ram air" intake, where the forward velocity of the car running into air (with mass) increases the dynamic pressure of the air in front of the car due to the "ram effect" (i.e. the reason why strong winds can demolish buildings etc.). When this air, with increased dynamic pressure enters the air intake system, if it cannot immediately flow through the engine, then the air slows down and this increases the static pressure inside the air-intake system, consequently, the air entering the cylinders in such circumstances will mean that the mass of A/F in the cylinder charge will exceed the theoretical A/F mass and thus the VE will be greater than 100%. It is published that the Z4M (and other S54 engined vehicles with similar ram air intakes) can achieve a VE of 106%.

Now, in the case of a Z4M on a static dyno with a fan placed in front of the car which creates an airflow equivalent to an air speed of a moving car at, say, 70mph, only, when the engine rpms are below that which equates to a road speed of less than 70mph, the pressure of air inside the air-intake system will exceed that which occurs in "real world" conditions, and so the performance of the car on the rollers will be artificially enhanced and the dyno plot will record this. Once the engine rpms exceed a speed equivalent of 70mph, there will be relative air-starvation in comparison to the situation that occurs in "real world" conditions, consequently, the A/F mass will be less than normally ocurrs, and so the VE diminishes as the engine rpms increase, with a consequential loss in performance as shown by fall in torque/HP.

Likewise, air density is related to air temperature, where colder air is denser; therefore, VE and performance are affected by both temperature and pressure. The positioning of the fan will also be critical to individual dyno runs, in the same way that the positioning of a lamp is critical to the lighting effects that it can create. So, unless the conditions in the dyno cell are properly controlled, and known, then the results are relatively meaningless.

Looking at those plots (below), they all show a sudden change to the engine running rich which occurs at 6400rpms and above. In view of the above, once the airflow begins to seriously diminish, and consequently the VE is seriously diminishing, despite the attempts of the Vanos to maintain cylinder fill rates, but the calculated load remains at 100%, is the DME transferring to richer fuelling in an attempt to maintain power? Alternatively, is the relative air starvation and lack of cooling air flow through the engine bay causing engine temperatures to rise and thus the fuelling is richer to keep cylinder temperatures down?

In any event, I bet the car in question performs totally differently in real world driving conditions.

So you're saying the power output is drastically affected by the "ram air" affect of the car moving. Seems like we should then expect the high rpm power of the car to be drastically affected when in first or second gear or when behind another vehicle. With the engine being essentially an air pump it seems like the affect of a 70 mph wind (actual car moving) vs a 30 mph wind (or some number output by a fan) is being overstated. Besides your claims I don't think I have ever seen claims of "ram air" intakes making a drastic power difference. If so, mfg. companies could just add plastic shrouds and larger air intake piping for virtually nothing compared to the lengths they go to to get another 10 hp out of the engine and then having to deal with mpg decreases. Basically how have you found this huge increase in power when no one has (or please post examples). Is there something special about the S54? Not saying you are wrong but it seems like you are comparing wind to forced air (turbo or supercharger).

I have read some of your other posts and again, since I haven't proven you wrong I can't say you are, I am just skeptical. I also possibly don't understand.

[exdos]

Originally Posted by dre99gsx

I disagree with above statement (theoretical aside...), since you can dyno an E46 M with no fans and get the same curve with helper fans on (at least the first pull). I highly doubt the Z4M ecu is expecting some sort of "ram air" effect at X RPM.

You are comparing apples with oranges when comparing the OEM air intakes of the Z4M with that of the E46 M3.

The E46 M3 has multiple intake sources, as below. This is analogous to being able to be able to breathe through the mouth as well as the nose.




The Z4M intake only has one inlet, as below.




It is therefore much easier for the Z4M's air intake to be "strangled" since all the air enters the system just one way, only, and if that gets restricted, there is no alternative airway to compensate.

[David70]

Originally Posted by exdos

You are comparing apples with oranges when comparing the OEM air intakes of the Z4M with that of the E46 M3.

The E46 M3 has multiple intake sources, as below. This is analogous to being able to be able to breathe through the mouth as well as the nose.

The Z4M intake only has one inlet, as below.

It is therefore much easier for the Z4M's air intake to be "strangled" since all the air enters the system just one way, only, and if that gets restricted, there is no alternative airway to compensate.

The analogy only matters if breathing through my mouth only isn't sufficient or the one opening doesn't supply me with enough air. Or to say it another way, if I open my mouth as wide as possible it doesn't mean I can run any faster.

[exdos]

Originally Posted by David70

So you're saying the power output is drastically affected by the "ram air" affect of the car moving. Seems like we should then expect the high rpm power of the car to be drastically affected when in first or second gear or when behind another vehicle. With the engine being essentially an air pump it seems like the affect of a 70 mph wind (actual car moving) vs a 30 mph wind (or some number output by a fan) is being overstated. Besides your claims I don't think I have ever seen claims of "ram air" intakes making a drastic power difference. If so, mfg. companies could just add plastic shrouds and larger air intake piping for virtually nothing compared to the lengths they go to to get another 10 hp out of the engine and then having to deal with mpg decreases. Basically how have you found this huge increase in power when no one has (or please post examples). Is there something special about the S54? Not saying you are wrong but it seems like you are comparing wind to forced air (turbo or supercharger).

I have read some of your other posts and again, since I haven't proven you wrong I can't say you are, I am just skeptical. I also possibly don't understand.

With a ram-air intake like that of the Z4M, the engine Volumetric Efficiency is constantly varying and is not specifically fixed at any rpm for each and every gear ratio or at any specific speed. Since the ram pressure varies with the speed of the vehicle and since the static pressure within the enclosed air-intake system varies with both the speed of the vehicle and the consumption of air through the engine this means that the VE is different in different circumstances, such as throttle position, load, speed, rpm and gear ratio. You are correct in stating that VE is different in first and second gears: the VE in 1st gear can only manage about 70% max under WOT acceleration, about 90% in 2nd gear and over 100% in 3rd gear and above.

Take a look at these two graphs below that I've done which demonstrates the VE of my Z4M in different scenarios.





You've asked: "Basically how have you found this huge increase in power when no one has (or please post examples)." The simple answer is: I'm fascinated by the ram-air intake principle therefore I've been prepared to keep on studying and experimenting when others would have long before given up, or simply dismissed ram intakes as being useless (as many seem to do). I've owned a S54 Z3MC since 2003 and when I was fitting some AC Schnitzer aftermarket front flippers, I became aware of the air-intake of that car being related to the flipper position and I wondered if the new flippers would also have any impact on the air-intake (which they do) and so I started datalogging and experimenting and discovered some very measurable changes that could be made with some ingenuity on my part. I systematically analyse all the data and attempt to work out precisely what is happening. I am completely open-minded on this subject and only pursue measurable changes and ditch anything that doesn't work. I've read a huge amount about all manner of technical stuff to help me with my goal of increasing torque and achieving peak torque at the highest rpms. The gains that I can achieve are from a combination of modification to the OEM silencers and not just from the air intake. In the case of the Z4M intake, I've had a "Eureka" moment when I've seen a common link with totally unrelated but analogous applications of the similar scientific principles.


The formula for horsepower is: HP =Torque x RPM/5252
and the figure of 5252 in the formula has great impact on the HP figures. If peak torque is 100ft/lbs and if it occurs at exactly 5252rpms, then peak HP will be 100hp (i.e. 100ft/lbs x 5252rpm / 5252 = 100HP). If the peak torque of 100ft/lbs occurs below 5252rpm at, say, 4900rpm then the HP will be less than 100hp (i.e. 100ft/lbs x 4900rpm / 5252 = 93.3HP) and likewise if the peak torque of 100ft/lbs occurs above 5252rpms, at say, 5500rpm, then the HP will be greater than 100hp (i.e. 100ft/lbs x 5500rpm / 5252 = 104.7 HP).

Now if the peak torque can be increased by say, 6% so that the peak torque is now 106ft/lbs and due to using an improved air intake that harnesses the full potential of the ram effect, the torque curve now becomes a long plateau where peak torque now occurs at, say, 6700rpm, the HP can be calculated as 106ft/lbs x 6700rpm / 5252 = 135.22hp. Therefore, if the OEM figures produced peak HP of 100hp at 5252rpms, then in this illustration, it shown that a 6% increase in peak torque which occurs at higher rpms can produce a 34.53% gain in HP. I'm not obtaining large increases in HP through hocus-pocus: I'm just using sound scientific principles to maintain/increase VE/torque at higher rpm and as you've now seen any large HP increase is entirely down to basic mathematics!
All I do is value every last drop of increase in static pressure that I can produce in the intake system.

[exdos]

Originally Posted by David70

Or to say it another way, if I open my mouth as wide as possible it doesn't mean I can run any faster.

I think you will find that it will not improve your peak velocity but will enable you to maintain it for a greater distance by allowing your muscles to have maximum aerobic utilization.

[O-cha]

Please dont feed the troll known as exodus.

[exdos]

Originally Posted by O-cha

Please dont feed the troll known as exodus.

Insulting me seems to be your speciality

[johanness]

Originally Posted by exdos

Insulting me seems to be your speciality

No, we just don't enjoy listening to you try to sell us on your DashDyno. Anyone who BELIEVES he can attain 370RWHP by modifying the stock Z4M intake alone (using your theories droned on about in this thread & others)... Is crackers.

Thus troll

[David70]

Originally Posted by exdos

I think you will find that it will not improve your peak velocity but will enable you to maintain it for a greater distance by allowing your muscles to have maximum aerobic utilization.

Ever notice world class runners running with their mouths wide open? They don't because this isn't the limiting factor in their "engine".

You never answered the question of why car manufacturers or anyone that does or could build a "ram air" intake haven't come to the same conclusions you have. Hard to believe that in the history of vehicles (especially with resources car manufacturers have had over the years) they don't realize the huge affects of simply funneling more air to the engine with shrouds and larger piping. Somehow you are the only one?

[exdos]

Originally Posted by David70

Ever notice world class runners running with their mouths wide open? They don't because this isn't the limiting factor in their "engine".

Pro-cyclists keep their mouths wide open when performing at VO2max: just watch videos of Lance Armstrong (and all the others) on the mountain stages of the T-D-F.

Originally Posted by David70

You never answered the question of why car manufacturers or anyone that does or could build a "ram air" intake haven't come to the same conclusions you have. Hard to believe that in the history of vehicles (especially with resources car manufacturers have had over the years) they don't realize the huge affects of simply funneling more air to the engine with shrouds and larger piping. Somehow you are the only one?

A lot of work was done with ram-air in the days before Electronic Fuel Ignition became predominant when engine fueling was with carburetors, but it was found difficult to get carburetors to work reliably with ram effect producing different air pressures, and the limitations of carburetor technology at the time was superseded by EFI.

The manufacturers may well have come to the same conclusion as me and know a hell of a lot more about ram air, and I'd be shocked if they don't. BMW certainly understand it. There's absolutely LOADS of technology that's been developed and works which never sees the light of day. Manufacturers have to produce vehicles that pass different governments' regulations for both emissions and noise control which means that manufacturers have to place restrictions on what they produce. Take your US spec Z4M for example, it has a different exhaust manifold to my OEM Eurospec Z4M: if you guys think that fitting Eurospec headers will improve your car's performance, surely you can see that removing further restrictions in the exhaust system (i.e. gutting the silencers) will also help? In the same way, surely improving the OEM ram-intake must also work? The only way that you can discover what works and what doesn't is by measuring, recording and analysing the results, and how many people can be bothered to do that, especially those who claim that the dyno is the only way of assessing performance?