Good video, but I hate to be a pain... Don't confuse lag with threshold. Lag is not the time it takes for the turbo to spool up. That's the threshold. Lag is the engines reactiveness to throttle changes while already ON boost. One might argue that putting your foot on the gas and waiting for the turbo to spool up is lag, since there is no big change in the rpm until the turbo sets in. But this is a common misconception. Since last describes your engines throttle response on boost, it can also describe letting off the gas while on boost. Some engines take longer to do this, because of large and long boost piping, impractical location of bov and therfore too much air in afr for a while after letting off the gas. But besides that thumbs up for the video!
Correct me if I'm wrong, but isn't the boost threshold the engine RPM at which the turbo begins producing significant boost when spooling? And I was under the impression that turbo lag was the time from going WOT with the RPM above the threshold to getting the boost from the turbo?
@@DJ_Level_3yeah Idk what mans is trying to do, the entire world thinks the time from wot to full boost is boost lag and thats never going to change and perfectly fine by me
I did a quick search and found the article where the OP got their information, and it's full of nonsense. It uses phrases like "exhaust pressure flowing through the turbo" which... no. Those are definitely some words placed in a specific order, but using a phrase like that indicates a fundamental misunderstanding of how this turbocharging shit works. So let's correct some misconceptions here: "Lag is the engine's reactiveness to throttle changes while already on boost". Nope, that's referred to as throttle response. You can have a "laggy" throttle response but that's not the same thing as "turbo lag", which is universally understood to mean "the delay between opening the throttle and the turbo spooling up to the point where it begins to produce a significant amount of boost". However, the two phenomena are often closely interrelated because they're both affected by many of the same design variables; engine size (i.e. exhaust gas flow rate), turbo size (i.e. rotational inertia), how well-matched those previous two factors are, compressor/turbine wheel design and how well optimised they are for a given engine configuration/application, manifold and induction system design (cast manifold vs. equal-length headers, overall length of the intake tract, filter and intercooler sizing vs. flow restriction, etc.). By managing/combining all these factors in various ways, one can achieve a forced induction setup with lots of turbo lag but very rapid throttle response once on boost, or vice-versa, or some desired middle ground between these states depending on what you're trying to achieve (racing engine, passenger car engine, load-hauling engine, etc.). "Threshold" typically refers to engine RPM at the point where the turbo's boost curve begins to rise sharply from the idle value, the "boost threshold". "Wastegate threshold" refers to engine RPM at the point where the wastegate is fully open, thus holding the turbo at the desired peak boost pressure. TL;DR - "Turbo lag" refers to the delay between the thottle being opened and the turbo reaching its boost threshold. The OP is confusing this with "throttle response", which refers to how readily the engine responds to changes in throttle input within any given RPM range. It's worth noting here that many modern sports cars with electronically controlled drive-by-wire throttle bodies are able to vary their throttle response at the push of a button (within the fixed physical limits defined by the engine/turbo/intake configuration).
Bov doesn't do anything for performance. That's what external waste gates and dump vales are for. Anti lag systems reroute exhaust gasses In the intake to what? Keep the turbo spooled up! So your explanation is factually wrong.
Can you also do an explanation of the old S1 E2 collage of wonderful sounds? Popping, squeaking, 2 step, air injection, wastegate, blow off and or whatever makes all those sounds.
the ignition/fuel gets cut off just to hold the RPM at the set two step RPM. So let's say its set at 3000rpm, when the ECU sees that the engine is going faster than 3000rpm, it cuts either the ignition or timing. This slows down the engine and when the ECU sees that it is below 3000rpm, it resumes ignition or timing. This happens very quickly (possible hundreds of times a second).
Honestly, the topic of damage is relatively subjective. Sure it will definitely damage some parts however I would assume that if you’re building the car for the specific purpose of using that feature I would recommend getting some durable parts for boosting.
ur so underrated wtf
haha thanks a lot man
Good video, but I hate to be a pain... Don't confuse lag with threshold. Lag is not the time it takes for the turbo to spool up. That's the threshold. Lag is the engines reactiveness to throttle changes while already ON boost. One might argue that putting your foot on the gas and waiting for the turbo to spool up is lag, since there is no big change in the rpm until the turbo sets in. But this is a common misconception. Since last describes your engines throttle response on boost, it can also describe letting off the gas while on boost. Some engines take longer to do this, because of large and long boost piping, impractical location of bov and therfore too much air in afr for a while after letting off the gas. But besides that thumbs up for the video!
Correct me if I'm wrong, but isn't the boost threshold the engine RPM at which the turbo begins producing significant boost when spooling? And I was under the impression that turbo lag was the time from going WOT with the RPM above the threshold to getting the boost from the turbo?
@@DJ_Level_3yeah Idk what mans is trying to do, the entire world thinks the time from wot to full boost is boost lag and thats never going to change and perfectly fine by me
Yeah I'm confused too. Isn't lag just the time required to reach the "threshold" on WOT? Doesn't seem like a misconception to me.
I did a quick search and found the article where the OP got their information, and it's full of nonsense. It uses phrases like "exhaust pressure flowing through the turbo" which... no. Those are definitely some words placed in a specific order, but using a phrase like that indicates a fundamental misunderstanding of how this turbocharging shit works. So let's correct some misconceptions here:
"Lag is the engine's reactiveness to throttle changes while already on boost".
Nope, that's referred to as throttle response. You can have a "laggy" throttle response but that's not the same thing as "turbo lag", which is universally understood to mean "the delay between opening the throttle and the turbo spooling up to the point where it begins to produce a significant amount of boost". However, the two phenomena are often closely interrelated because they're both affected by many of the same design variables; engine size (i.e. exhaust gas flow rate), turbo size (i.e. rotational inertia), how well-matched those previous two factors are, compressor/turbine wheel design and how well optimised they are for a given engine configuration/application, manifold and induction system design (cast manifold vs. equal-length headers, overall length of the intake tract, filter and intercooler sizing vs. flow restriction, etc.). By managing/combining all these factors in various ways, one can achieve a forced induction setup with lots of turbo lag but very rapid throttle response once on boost, or vice-versa, or some desired middle ground between these states depending on what you're trying to achieve (racing engine, passenger car engine, load-hauling engine, etc.).
"Threshold" typically refers to engine RPM at the point where the turbo's boost curve begins to rise sharply from the idle value, the "boost threshold".
"Wastegate threshold" refers to engine RPM at the point where the wastegate is fully open, thus holding the turbo at the desired peak boost pressure.
TL;DR -
"Turbo lag" refers to the delay between the thottle being opened and the turbo reaching its boost threshold.
The OP is confusing this with "throttle response", which refers to how readily the engine responds to changes in throttle input within any given RPM range. It's worth noting here that many modern sports cars with electronically controlled drive-by-wire throttle bodies are able to vary their throttle response at the push of a button (within the fixed physical limits defined by the engine/turbo/intake configuration).
Bov doesn't do anything for performance. That's what external waste gates and dump vales are for. Anti lag systems reroute exhaust gasses In the intake to what? Keep the turbo spooled up! So your explanation is factually wrong.
2 steps are mostly used for drag racing with turbocharged vehicles and anti-lag is used for roll racing etc
Can you also do an explanation of the old S1 E2 collage of wonderful sounds? Popping, squeaking, 2 step, air injection, wastegate, blow off and or whatever makes all those sounds.
All I know is car go bang
Agree with comments. had to really scroll down to see. Good video man.
greatly appreciated man!
Also isn't antilag activated when you lift off the gas/ accelerator pedal, while two step requires you to be on the pedal?
How does the engine run (pistons move) if the ignition or fuel is cut off?
the ignition/fuel gets cut off just to hold the RPM at the set two step RPM. So let's say its set at 3000rpm, when the ECU sees that the engine is going faster than 3000rpm, it cuts either the ignition or timing. This slows down the engine and when the ECU sees that it is below 3000rpm, it resumes ignition or timing. This happens very quickly (possible hundreds of times a second).
@@JCMediaYT Ohh. Now I get it. So it's basically an RPM limit. Thanks a lot mate. Was really confused with it. All clear now. 👍
@@akshayajaykumar12 yep, pretty much like your normal rev limiter but lower and usually adjustable. hope that helps!
This is how my brain works, it’s not digital 💯💯💯💯💯
Does it still damage/destroy my turbo when I run a ignition cut off 2 step on my turbo charged supra?
Honestly, the topic of damage is relatively subjective. Sure it will definitely damage some parts however I would assume that if you’re building the car for the specific purpose of using that feature I would recommend getting some durable parts for boosting.
@@malicebean3216 Alright, thank you.
Quality explanation
Thank you!
nice!
Subscribed
many thanks!
i would've preferred a 3d animation, but none the less very good explanation 👍