Porsche's Anti-Lag System Doesn't Use Any Fuel
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- เผยแพร่เมื่อ 1 ก.ย. 2018
- How Porsche's Dynamic Boost Works - Eliminating Turbo Lag
Hyundai's Factory Anti-Lag System - • Anti-Lag - How Hyundai...
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Porsche's Dynamic Boost is a function designed to minimize turbo lag and improve throttle response for Porsche turbocharged engines. The system works by maintaining the throttle valve fully open when the driver lifts their foot off of the accelerator pedal. As a result, there's an increased amount of airflow through the engine, minimizing the amount of boost pressure that is lost.
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Answering the two most common questions!
1). Does this eliminate engine braking? Yes, while the throttle is left open engine braking is nearly eliminated. You use your brakes to slow you down when driving (or braking) fast, not the engine, so this is no problem. Engine braking will be like normal in most scenarios, just not when you're driving hard (in sport mode) and immediately lift.
2). Won't the engine run lean? No fuel is injected, none! Zero. So the air fuel ratio is infinitely lean, but this isn't a problem because nothing bad will happen without any fuel present.
How Aggressive Anti-Lag Systems Work (Bypass Valve) - th-cam.com/video/5g6cHs5vMRE/w-d-xo.html
How Ignition Timing Anti-Lag Systems Work - th-cam.com/video/wyJn40ExwZY/w-d-xo.html
How Hyundai's Anti-Lag System Works - th-cam.com/video/ccMg-KzMgU8/w-d-xo.html
Another phenomenon that can be demonstrated with the ignition off :p
My old Legacy could generate 2psi with the ignition off if I opened the throttle downhill with the engine doing more than 3000rpm
Wouldn't this increase engine breaking? When the throttle body closes, there is much less air going into the engine and thus it does much less work. With all this air chugging through it, it is being used much more as a compressor and thus doing more work.
This could also be useful during shifts, as the engine would want to drop the RPM differential between gears much quicker (granted the clutches are doing most of that work anyway since the shifts are so quick
Engineering Explained if the throttle is open. Would that tend to run a lean cycle or start lean cycling. I'm curious to see how to overcome this. I like the idea and thought of it as you described it and told myself. Dang it Porsche. Oh well. Great minds and all.
How would this affect rev hang? would this cause issues with shifting? TIA
If there's no fuel going I to the engine how is it going to stay running?
Easy method: full throttle around corners with no braking.
lasagna bloke That's how pedestrians do it because of their supreme handling.
DEJAVU
Easy method to wrap yourself around a tree
easy method: left foot braking ;)
@@bitkarek Nani ?!?! How can go that fast around that corner !?!?
Such a simple and obvious solution!
MRLIROCK id be scared of knock because there’s a lack of fuel, and if you boost your car and don’t have enough fuel, then There would be a knock
But because there is no fuel at all there can't be any knock
Knock knock! Who's there?
ytxstream but knock is when the air compresses in the cylinder and it heats up because the air is getting compressed. And what prevents the knock is the fuel because it cools off the combustion chamber and has something to go bang. So if there’s no fuel, wouldn’t the rods go bang down south?
@@lukasrosa9974 I would guess that the ignition is cut off before or right at fuel cut off so that when the cylinder charge starts to become super lean up to just air, the ignition will not fire the super lean mixtures. Since these aren't diesel engines, the compression of the changing mixture after throttle release will fail to accidentally ignite itself and just be pushed out of the exhaust. No real danger of detonation
Your Sunday episodes are equivilate too Saturday morning cartoons when I was a kid, I wake up early every Sunday to catch your latest video as soon as it releases
That is very kind, thank you!! :)
Saturdays for me ment going to my grandparents watching fox bobbies world and next eek the cat
@@EngineeringExplained of coarse man, And thank you for teaching me! My knowladge comes from people like you, so thank you for taking time outta your day to help better the world 1 mind at a time!
hey can we get a video with a summary of sorts showing all the different anti lag systems out there or at least the most popular and talk about their effectiveness kind of like the one you did about turbo and superchargers quite a while back.
Here are the two main types:
Bypass Valve - th-cam.com/video/5g6cHs5vMRE/w-d-xo.html
Ignition Delay - th-cam.com/video/wyJn40ExwZY/w-d-xo.html
oh wow 1st of all thanks 2nd of all wow couldn't actually believe you responded to me and 3rd does Porsches way cause any wear on the engine? And also icluding the other two systems which one according to you is most effetient/effective?
letting air pass throught the engine shouldn't harm it at all, and it cools it down! YEAH!
Jason's killer art skills
One of your best explanations ever. Sometimes, the explanation is so technical I get incredibly lost. But, this was one was easy to follow and understand. Thank you.
This concept makes sense, however in this case I would've appreciated if you went a little more in depth. Hopefully you could make a follow-up video if there's enough demand. There are so many questions, for example when does the throttle valve actually close? How does it differentiate between the different scenarios needing to close vs not. Does this eliminate the need for a blow off valve ? How does this effect engine braking? Thank you for making these videos, they are super interesting!
Does the fact that the throtle remain open means that there is less engine brake ? (because no negative pressure)
Basically yes.
When you're driving the car fast, engine braking is not as important from what I understand and know. You're relying a lot more on the actual brakes.
On a public road, where you would have the car in normal mode (or whatever), engine braking is much more useful - allows you to be smoother, and more frugal on fuel.
For a porsche its better because your reduce the snap oversteer which is a result of the rear engine design, for other cars it doesn't make much sense
Yes, basically instead of using the loss of the engine to slow down the car, they use it to spool up the turbos. It would still have some engine braking since it has to push the air through the turbos though.
Correct.
Makes almost no difference
The quality of your videos have gotten so good. I must say
I love your videos. You are so articulate that I can watch them at 2x speed and still understand everything clearly.
So there is an advantage to Drive By Wire Throttle... lol
Always have been.
I'm always the type to prefer a cable throttle myself. Simply for the fact I know how far the butterfly is open by where my foot is.
But this is seriously intriguing, that if I ever build my own car, I'd seriously look into Drive By Wire, and do a similar sort of thing, on a Sport button or something.
Race cars with sequential gearbox benefitted from drive by wire TB cuz they can tell the ECU to shut TB for a split second when shifting gears w/o letting off the throttle paddle
upgradedBACON if only it were that simple. Cable throttle can have a nautilus shaped cam that may give 50% throttle at 20% pedal application. I've had electric throttle that was completely linear but most people seem to like the fake kick in the pants so that's what the manufacturers program, and make even more comical with "sport" mode.
yup, makes the engine more tuneable easy, its all software :D
Thanks for the insightful explanation of how this clever Turbo tech works 👏
That's the longest video to explain the smallest change and how a simple change can make such an amazing impact. Thank you! :D
nice solution of Porsche to end the problem of the the turbo-lag in a very simple and reliable way, good video and cheers from Venezuela
A similar system was used in Formula One, but for a different reason. There was a period of time when F1 teams had the exhaust exit just in front of a diffuser to produce some additional down force. They kept the throttle open to keep the flow or air moving through the engine even when the driver lifted.
Very well presented and as always, excellent drawing for those of us who are visual learners - thank you for your well put together videos :)
This is really cool! Great vid as always
Great video. Well explained as always.
Genius idea and very good explanation!
Looks good. Another side effect of this will be that air still passing through the turbines too so the turbo's not only have an easier time of spinning but still something to help them do so. Infact they're only missing the gas expansion so they could hold quite a large percentage of their airflow for a reasonable time.
I can see this system making a noticable difference to throttle response when you're only off throttle for a short time.
I like intelligent solutions.
I bought a 718 cayman a year ago, and I'm blown away by how that tiny motor can generate boost so quick. Sure, there's a little bit of lag at low RPMs, but after 3k or so it's instant. Night and day from cars in the 90s
Good video.Its good to know these systems.
Man I love your channel..... Keep it up
Wow the way you explain this is top notch! So simple an 8th grader could understand.
Thanks for the clear explanation.
Very informative as always:D
porsche engineers are amazing , and so are your vids , always explaining things perfect, even my mom would understand haha
Thank you for sharing your knowledge :)
Wow great explanation and drawing. I could guess it by just glaring at the drawing before you even began explaining it. I'd have added inertia in the explanation somewhere.
Great explanation video! I guess the temperature inside the combustion chambers should increase rapidly and at the same time improve the thermodynamic efficiency while the fuel mixture become so lean at the moment you lift the gas.
Great video! enjoyed it very much. My 06 Saab 9-5 has a similar set up. I guess they were so much ahead of their time it hastened their demise 😅.
You once did a video on the type R's advanced suspension. Can you make another one comparing Ford's revoknuckles to GMs hiperstrut and Renault's thing. Because i understand that they all are some advanced steering-detached McPhersons, but what are the differences?
Jason, this sounds like a pretty simple solution which doesn't require any new components, do you think other manufacturers would be able to implement this in existing cars by just updating the software controlling the throttle?
Wow, great question! I'd love to hear a response from this question as well.
Even better.... could it be done by the owner? Throttle by wire is common now and even swappable to older models.
exactly, why is this a new 2018 technology?
For any vehicle that has electronic throttle control, yes this would be a simple software update to make it work. The implementation could be as simple as adding a statement that during DFSO the throttle is to remain open. However I could see some complications on fading back in the fueling. I'd think that you wouldn't want to just slowly fade back in fuel, since you'd be at WOT already, it would result in an extremely lean condition. So you'd likely need to add fuel very rapidly. I'm sure Porsche is doing something like this, but I'd be curious to see how it works during part-throttle, or if it's only active on a quick rate of change of requested throttle position.
It onlh makes sense on a porsche, this system reduces engine braking thus reducing the risk of snap oversteer, a commun problem with rear engine cars, they hit two birds with one stone, on a normal car this would mean more work for the brakes which will reduce your time on the track, the benefits don't overcome the drawback on other layouts, it doesn't make sense
Another very simple diagram and explanation to understand this technology! Porsche has always been on the forefront of technology as well as Audi. The VW group has a lot going for it with Lamborghini and Bugatti also.
Jason, can you do an updated video on torque converters, how they work, and what converter lockup is?
Thanks for all your videos.
you sir are a great teacher
Here is what you didn't mention (but should have had):
1) Not closing the throttle means you will have a stable airspeed inside the manifold. Low airspeeds mean bad air/fuel mixing, high airspeeds can lead to supersonic speeds and detonation. When you let of the throttle and push it back in you will have fluctuations and spikes, the airspeed will both spike up and spike down.
And another added benefit of a stable airspeed is that you know exactly how much air is entering the engine, whereas with fluctuations and pressure spikes you will not only have poorly mixed a/f, but you will also the composition of the a/f mixture will fluctuate (rich/lean).
2) One drawback of this technology: if you don't have direct injection or port injection you can get a lean mixture when you turn your injectors back on, so you just have to put the injectors as close to the engine intake as possible. And don't forget putting the fuel injectors further away from the intake has its benefits too. With this technology you can't do that, or you have to do what kawasaki did and use 2 injectors per cylinder (one being port injection, the other further away).
3) Another drawback: there can be uncertainly when for this technology for when to trigger: sometimes you let of the throttle completely, sometimes just partly and after that you still let of the throttle. In those cases you won't have a throttle that's staying open, but one that does funny things. This takes a lot of tinkering and setting up to make it work smoothly under any condition. And if you remap your ecu, you will have to redo some of that work.
The drawbacks are minor, and it doesn't cost that much to develop it, but that doesn't mean the drawbacks are not there. Overall it's a cool, but not new idea. People have had these sort of ideas before.
Really interesting that still in 2018 we can see such a simple and clever design being implemented.
On my side, I easily understand the “open throttle“ concept of Diesel engine but I could quite never understand the need for a throttle body valve on gasoline engine... Therefore this setup makes a lot of sense and helps me to understand.
WoW Awesome Technology ;] Thank You EE ;]
Interesting as always.
Hello. Thanks for being both informative as well as factual.
I would like to know how an air-cooled engine works and possibly why the air-cooled engine "died" off in Porsche's engine lineup.
Very nice methods. .. l like it
when you see things that are s simple like this always wonder why it had never been done before. Engineering at its best
That's brilliant! And a very will keep secret until now. More company secrets please!
Some programmable ECUs allow to cutoff spark and/or fuel to be used in flat-shifting, so... by just cutting the fuel, you can actually get some interesting effects in terms of keeping the boost higher on turbos (and even blowers), reduce losses in aspiration and reduce the drop in RPM in engines with lightweight flywheels (which can be beneficial when coupled with close ratio gearboxes).
It's actually very pleasant to daily drive a car with fuel cutoff when the clutch sensor is turned on and the revs are high.
Great video as always. Is there any chance you could do a video on the 'comprex' pressure wave supercharger? Seems to me like an interesting mix between a turbocharger and a belt driven supercharger.
Thanks, as always, Jason! Does this method have any effect on pumping losses?
Outstanding! I understand!
This reminds me at the trick that Renault's engineers found in 2013 for Red Bull in F1: in that circumstance, they used to keep the valve open (when lifting) to send the blown gases directly into the diffuser. There, the advantage was purely aerodinamic, but Porsche has maybe found another use to the same procedure... Very interesting!
Nice solution!
its called cold blowing..used in formula 1 to blow the diffuser, theyll leave the throttle wide open but cut fuel. clever for porsche to bring to production cars
Similare function to a HUGE blow-off, or bypass valve, I would assume this is more efficient ?.
For some reason, while thinking about the title and seeing the diagram without bypass valves at the beginning of the video, my brain went right to the old Renault F1 throttle strategy for the exhaust-blown diffuser. Looks like my hunch was correct 🤓. Same strategy, but using the "cold" exhaust to blow the turbine wheel instead of feed the diffuser.
good video! how's that not effect the braking ? is the clutch doing something special too?
make a video of the old subaru WRC rally cars antilag system!!! Why and whats that sound?
I think there is some old video on this channel about "classic" anti-lag
The old-school anti-lag system retards the timing of detonation and as a result unburnt fuel enters the turbine which detonates inside due to heat.
That detonation creates pressure and spools the turbine. That's the sound.
MISUFIRING SHYSTEM
@@ErebosGR And what a sound! Flames and pops!! Love it..
or a video of a skoda fabia R5 rally car turbo, and anti lag system
So with the throttle left open and the engine pumping air because it will still be revving while in gear, that's basically keeping the turbos slightly spooled as well wouldn't it? I would also think the air flow would also have a cooling effect on the combustion chamber and turbos which could help with performance and lower engine temp in the long run.
exactly
yes, thats wgat he said and no, that's not when the engine needs to be cooled, if you can keep combustion chamber temps down during full throttle that could help with preignition
Especially hot at a race pace
"slightly" might be the right word, yeah. The same way turbo'd cars barely make any reasonable boost when idling or off-charge, this solution should really be a mild-mild antilag, since the airflow must be really weak. Plus, I'm kind of curious on the long term reliability of this solution, since all the hot-cold-hot-cold cycle must put some thermal stress on the turbo.
Thanks for another nice video! My question is: If this is so simple and good, so why other manufacturers closes the throttle in the same conditions? What is the benefit of doing the other way?
Great informative video, thank you :) I guess all these dynamic engine managing technologies, dynamic boost, VTEC, VVTI, etc, would be abandoned when the Toyota hybrid patent expires, and its electric RPM+torque assistance feature becomes the standard.
Porsche is cool. The idea is so simple but it works.
This is a great idea. I always wondered why injected cars don't allow variable zero-throttle valve opening. For instance, what if you want to stay in a low gear for power but don't want hard engine braking when you back off throttle?
This makes a lot of sense and you didn't really need to verbally explain it with that diagram present. The throttle valve being shut is like turning the tap off. The compressor stalls because there is not enough air being pulled through it. The turbine stalls because there is not enough air being pushed through it. The entire intake airflow loses its momentum.
Hi I have a question. What do you think about putting a momentary switch in my turbo car that opens the throttle body completely? Like I could press it during cornering. Kinda like a manual version of this. Could it be bad for the engine you think?
There was an anti-lag system for the Diamond Star Motors cars having the 4G63 turbo engine. Man o man was that a bangy smoky noisy feature when activated. Quite the weird thing. DSMLINK was the part that enabled anti-lag. I drove one. Fun. And, did not need anti-lag because it was front wheel drive. But all wheel drive cars could benefit I'm sure. This ALS was for the drag strip. If you floored it with the clutch in, the ALS would activate. So you could use it on corners or on the start line. But, it's pretty scary to floor it when you have a pretty high power car already, typically with a big-ass turbo and intercooler and injectors and intake and exhaust and fuel pump and all the other supporting equipment. I think drive-by-wire was not a feature of the DSM cars. So you could not get the ECU to control the throttle butterfly, as the Porsche does.
hum so i have an old toyota datsun with a single turbo what part of the throllte area should i modify or replace to recreate an anti lag or is it just for twin turbo and sequential turbo set up?
Very interesting system
pumping only air around corners will probably keep the engine a little cooler. added benefit!
Question or comment followed by question. something I never thought about with turbo lag I always thought it was the difficulty of trying to spool up the turbos but what about compressing the incoming air? Does the blow off valve let out all the boost when throttle body is closed or is it still slightly pressured?
Porsche engineers are the best
Hi can u make a Vid on turbo surge if u fit the throttle in front of the turbo im building a turbo race car with the throttle in front of the turbo and will be running no dump valve. iv seen this on a 1980 f1 bmw turbo engine and i think it will help a lot in engine response and turbo surge im going to run a suck throw curb system hens no dump valve and with my reserge i found the f1 bmw clip and that makes me think that mt theory might work. please let me know. KEEP UP THE GOOD WORK!!
On koesnigen with electronic valve lifting they could even open the intake and exaust valves on every revolution so the engine could breathe and suck the turbo presure so they don t have resistance
Love the color coding. Cold to Hot.
Leave it to Porche to solve a problem in the reverse thinking. Good video.
I'm wondering, how the system work when you try rev-match while braking? Does it closes the throttle valve just to get right amout air and then opens it again, one you left of the throttle?
I built a turbocharged car back around 1980, and studied everything I could to figure it all out. The idea of leaving the throttle open is so bright. Yet another incremental increase in performance. By the way, I even drove to Los Angeles to meet with a guy named Ak Miller, who was advising the US car companies on turbocharging. He told me one thing I'll always remember- an engine is nothing more than an air pump.
Questions:
1. This seems like it would benefit NA cars as well, because the intake plenum draws a vacuum when TB is closed.
2. Which begs the question, why wouldn't this be standard operating procedure for engines anyways? Just stop injecting fuel. What's the point of closing the TB?
3. Which begs a 3rd question: are there any drawbacks?
I'm curious about the drawbacks too. Other wide wouldn't everyone do this?
The gains may be so minimal that other OEMs havent bothered. Also I'm not sure what kind of turbos the other OEMs use, but Porsche has variable geometry units which could adapt to this situation more easily than a fixed vein system. Also BMW doesnt even use throttle bodies, so they would have to implement a different program to keep air flowing.
there is far less engine braking when you let your throttle wide open because the pistons can move freely in atmospheric pressure while when you close the tb down it will create a negative pressure at the chamber resulting in strong engine braking. This means using this technique you only got the actualy brakes to decelerate and stop.
isn't bmw doing this all the time？
So basically the drawback is less Engine Braking which is useful in the cars that most people use. Its safer to have as much braking power as possible, so getting rid of the engine braking would stress the braking pads more which not only would be an added expense, it would also be more likely to be worn out in the case of an accident.
Jason, does it do this only in certain modes (ie only in Sport or Sport+) or does it function all the time?
Porsche engineering is the best
Thank you,Super great video again.....Do you think one day the Throttle body will be thing of the past and only regulate Fuel and spark very precisely that it can eliminate TB?..It would seem the me running that much air through the engine one could drop some excessive heat out of the head area,,,,TY 73s
@Engineering Explained is it possible to relate pressure ratio in the plenum to ignition advance in a boosted engine?
Brilliantly simple solution
I see this only being a matter of a few code lines in an ECU matched to a Drive-by-Wire throttle... Would this be possible with a car combined with a mechanical throttle body?
*Please make a video on Regera gearless Drive train and individually controllable valves of their new engines*
Thank You.
So does the ecu cut spark as well?... just thinking about all that air in the cylinders at say 5000+ rpm and spark and no fuel....
Can you make a video about the drag coefficient and the fact that it's not the only thing which should be counted to calculate the stopping force, but the frontal area as well. Seems like it's not spread widely enough
@Engineering Explained What about engine breaking using this method ? Will it reduce its effectiveness ? Meaning, will the Porsche slow down at a slower rate compared to a turbo car that completely shuts off it's throttle body?
I know this isn't related to this video, however, can you do a video addressing the S2000 low end torque issue? Would a VTEC controller fix that if you set it to say 4000rpm? Or would the profile of the cam be ineffective if engaged at lower rpm?
hai, in a boxer engine if the cylinder banks completely horizontal then when fuel is injected, due to gravity woudn't it get concentrated on side of the combustion chamber. i dont know but i guess you can explain. would the S.plug be placed from downwards so that all the mixture is ignited at once as in the spark being at the centre of the mixture, and also please explain if there any sort of swirl characteristics for the combustion flame how would it exist in such a engine design(being horizontal).
The spark plug is placed in the center of the head, between the four valves. The time between injection/ ignition is short enough to not allow fuel to collect on the cylinder walls.
I have a query...i m technician in Maruti Suzuki... In gasoline engines, engine is controlled by throttle body...in same case diesel engine , how they can we controlled...when we press gas pedal then what happened inside a diesel engine..i m asking this query to my trainer..he unbale toh explain me this...nd i m a big fan of ur channel and u do amazing job... through your knowledge...i m working on another level of perfection.
Sounds great
Pretty easy to to watch the TPS stay at 5-10% on off throttle and on corners. Does the ECU use the gyroscopic sensors at all to improve function?
Does that affect engine braking? What would be the long term affect of pumping dry pistons with no fuel and just air?
I have a question Jason. Is this like the off throttle blown diffuser that F1 used to use back around 2010-2012? & instead of using that airflow for blowing over the rear diffuser & producing more downforce, Porsche is using it to keep the turbo spooling for longer to have a sudo anti-lag system? Thank you for another great video.
Could this effect be replicated in a diesel turbocharged application if there is no exhaust braking restriction system fitted and jake brake turned off? Or is that rare to find/different to this?
What about combustion properties at the time of wide open throttle and less fuel will it burn that lean?
How does it affect engine braking Jason?
Super super super super nice video
"In order to make you happy on that corner exit".. hahahahaha XD
Would this system not have a drastically negative impact on matching the engine speed to gear speed due to sudden and powerful changes in torque? Also are the turbos standerd or veritable adjusting due to changes to air pressure with less dense air due to not being burnt?
Nice!
Would this cause additional heat cycling on the turbo? Would it also cause the catalytic converter to cool down to such an extent that it affects emissions?
This condition is only maintained very briefly so you can hop back on the throttle. If you lift for any amount of time, things go back to normal and you feel the engine brake.
No worries about emissions, Volkswagen owns Porsche, the VW group has that covered.......... :D