Anti-lag question.

[mynameis66]

Not sure where to post this so here goes anyway.What does this actually do in the game?I know what its supposed to do but if i have it enabled strong,all i seem to get is burbles and pops from the exhaust on the over run.It doesnt seem to make the car quicker,ive done a few laps with and without it and theres no difference.I have the fully customisable computer added but the anti-lag doesnt seem to work as i thought it would.
Am i expecting too much or is it a bug in the game?I removed the anti-lag,exited the settings screen then re-entered the settings and enabled it but still not really doing much.

 

[Stakado]

Reduces the lag of the turbo in the gear switch. Makes gears switch more quick. Also burns a lot of fuel, so makes the car much worse in fuel economy

 

[Bullwinkle]

I’ve always wondered, and forget to ask: what is the difference between weak and strong anti-lag?

 

[TFSI400]

I’m not sure it actually reduces the time of the gear shifts themselves. Well, it shouldn’t.

Basically it should reduce transient lag. Which is the time it takes a turbo to get back on boost when the throttle body opens.

So for example a car with a huge turbo. At full throttle all the way through the revs from say 2000RPM it starts making boost at 4500RPM, hits full boost of 25PSI at 5000RPM, which falls off to 20PSI at the limiter which is at 7500RPM.

Say you’re gunning it full throttle in 3rd gear, change up a gear at 7300RPM: the throttle closes as you change up, much less exhaust gasses are flowing through the exhaust manifold with a closed throttle so the turbo loses boost, back onto the throttle at 5500RPM in 4th, the turbo then needs to build boost again as exhaust gases build flow again through the exhaust manifold.

This is transient lag. Different to the lag you experience at low-mid revs with an open throttle (where there’s simply not enough exhaust gas being blown out by the engine at low-mid revs to spool the turbo in the first place). The lag at low revs under an open throttle cannot be improved by an anti-lag system. But transient lag, the small delay in boost that occurs getting back on the throttle in a rev range where the turbo would ordinarily make healthy boost, can be improved by an anti lag system.

There are a few ways of doing anti lag, but generally it involves creating combustion in the exhaust manifold under a closed throttle (where there would usually be much less gas flow under a closed throttle). Provoking combustion in the manifold under a closed throttle creates gas flow which spools the turbo.

The advantage is a reduction in transient lag. The car won’t be quicker under open throttle and established boost. It doesn’t increase horsepower. It just makes the turbo react much faster, when in normal circumstances it would take more time to reach full boost again after a gear change, or a quick lift of the right foot before going full throttle again.

 

[mynameis66]

Cheers for the insight,the burbling and popping sounds great but after a while gets on my nerves.lol

 

[Bullwinkle]

I’m not sure it actually reduces the time of the gear shifts themselves. Well, it shouldn’t.

Basically it should reduce transient lag. Which is the time it takes a turbo to get back on boost when the throttle body opens.

So for example a car with a huge turbo. At full throttle all the way through the revs from say 2000RPM it starts making boost at 4500RPM, hits full boost of 25PSI at 5000RPM, which falls off to 20PSI at the limiter which is at 7500RPM.

Say you’re gunning it full throttle in 3rd gear, change up a gear at 7300RPM: the throttle closes as you change up, much less exhaust gasses are flowing through the exhaust manifold with a closed throttle so the turbo loses boost, back onto the throttle at 5500RPM in 4th, the turbo then needs to build boost again as exhaust gases build flow again through the exhaust manifold.

This is transient lag. Different to the lag you experience at low-mid revs with an open throttle (where there’s simply not enough exhaust gas being blown out by the engine at low-mid revs to spool the turbo in the first place). The lag at low revs under an open throttle cannot be improved by an anti-lag system. But transient lag, the small delay in boost that occurs getting back on the throttle in a rev range where the turbo would ordinarily make healthy boost, can be improved by an anti lag system.

There are a few ways of doing anti lag, but generally it involves creating combustion in the exhaust manifold under a closed throttle (where there would usually be much less gas flow under a closed throttle). Provoking combustion in the manifold under a closed throttle creates gas flow which spools the turbo.

The advantage is a reduction in transient lag. The car won’t be quicker under open throttle and established boost. It doesn’t increase horsepower. It just makes the turbo react much faster, when in normal circumstances it would take more time to reach full boost again after a gear change, or a quick lift of the right foot before going full throttle again.

Any idea what the difference is between strong and weak lag? Is there any reason why "weak" would be more desirable?

 

[TFSI400]

Any idea what the difference is between strong and weak lag? Is there any reason why "weak" would be more desirable?

I’d imagine Strong uses more fuel, and spins the turbo back up sooner than Weak, which spins the turbo up a fraction later but doesn’t use as much fuel.

If you consider that coasting (with closed throttle) is a solid fuel-saving tactic, if anti lag is in use you wouldn’t be saving anywhere near as much fuel when coasting. That crackling and burping is using fuel.

 

[HyperSpeeder]

I’ve always wondered, and forget to ask: what is the difference between weak and strong anti-lag?

Burns more fuel to create the effect, and creates a strong effect as a result.

Antilag is supposed to be used with big turbo. You usually have PP room, because big turbos peak late in the powerband and the lower torque down low makes the car lose PP points, which opens room for antilag.

In GT the turbos work as in real life, meaning a big turbo is not just a bigger boost, it actually increases power in the high rpm range and keeps boost high for much later than a smaller turbo. For racing, it can be advantageous to combine antilag and bigger turbo.

If running a regular manual transmission antilag is a must IMO.

 

[TFSI400]

Burns more fuel to create the effect, and creates a strong effect as a result.

Antilag is supposed to be used with big turbo. You usually have PP room, because big turbos peak late in the powerband and the lower torque down low makes the car lose PP points, which opens room for antilag.

In GT the turbos work as in real life, meaning a big turbo is not just a bigger boost, it actually increases power in the high rpm range and keeps boost high for much later than a smaller turbo. For racing, it can be advantageous to combine antilag and bigger turbo.

If running a regular manual transmission antilag is a must IMO.

It doesn’t increase horsepower. And it doesn’t reduce primary lag (lag under open throttle at RPM beneath boost threshold).

It reduces transient lag. Anti lag only works under a closed throttle 🙂

 

[HyperSpeeder]

It doesn’t increase horsepower. And it doesn’t reduce primary lag (lag under open throttle at RPM beneath boost threshold).

It reduces transient lag. Anti lag only works under a closed throttle 🙂

You're right, but without antilag the higher power is wasted when you shift. There's noticeable lag in several cars.

In theory, if a Medium turbo increases more PP, you could combine High turbo with antilag to keep the car with same PP but more power (as a result of the turbo), better transition (as a result of antilag) and the lag in corner exit could be partially compensated by driving style.

 

[TFSI400]

You're right, but without antilag the higher power is wasted when you shift. There's noticeable lag in several cars.

In theory, if a Medium turbo increases more PP, you could combine High turbo with antilag to keep the car with same PP but more power (as a result of the turbo), better transition (as a result of antilag) and the lag in corner exit could be partially compensated by driving style.

I know I’m right. And you’re changing what you’re saying. A bigger turbo might increase peak power, sure. But that’s not what you were saying.

Anti lag itself doesn’t create more power. All it does is allow that power to be accessed fractionally sooner after coming off and on the throttle.

For example.

Car A and car B are absolutely identical, same engine, same turbo, same ECU calibration. Except car B has anti lag.

Car A goes on the dyno. Dyno operator creeps up to 4th gear, floors the throttle at 1500RPM, all the way to the limiter at 7000RPM. Dyno graph is printed.

Car B goes on the dyno. Dyno operator creeps up to 4th gear, floors the throttle at 1500RPM, all the way to the limiter at 7000RPM. Dyno graph is printed.

Dyno graph A and dyno graph B are IDENTICAL.

I’ll reiterate the point. Anti lag does not increase power. It does not function under open throttle. It reduces transient lag.

 

[mynameis66]

I use manual shifting and to be honest it seems to make little or no difference to my lap times,like i said the burbling and popping grates after a while.👍

 

[TFSI400]

I use manual shifting and to be honest it seems to make little or no difference to my lap times,like i said the burbling and popping grates after a while.👍

You’ll probably get the most benefit from cars that don’t have gearbox/transmission upgrades. If you’ve got the full racing transmission upgrade, as well as the racing clutch and flywheel, your shifts will be faster in the first place. Faster shifts means less time between closed and open throttle, and therefore less time for the turbo to lose spool.

Also, a stock or low RPM turbo won’t suffer from transient lag as much as a high or ultra high RPM turbo. So bear that in mind.

But a car with a completely stock manual transmission combined with the biggest turbo available (remember, the larger the turbo the more transient lag you’re faced with) will probably be a car where you’ll feel the benefit of anti lag the most.

Thing is though, I doubt many of us upgrade the cars for high peak power using the biggest turbo, but leave the gearbox, clutch and flywheel stock. So it’s probably one of those features in the game that doesn’t really shine.

Or perhaps that S Part - the Ultra High RPM Turbo - is so huge that it really needs anti lag to wake it up 🤔 If I ever win one for a car I’m bothered about tuning I’ll have to do some experiments!

 

[nickg07]

Lag in GT is how quickly your turbo gauge in the HUD goes from anything to 100% of the maximum boost.

So say the boost drops to 0.5 bar on gearshift and takes 1 second to get to 1 bar, the anti lag should keep the turbo closer to.1 bar all the re between shifts meaning you have more power faster.

 

[Bullwinkle]

Lag in GT is how quickly your turbo gauge in the HUD goes from anything to 100% of the maximum boost.

So say the boost drops to 0.5 bar on gearshift and takes 1 second to get to 1 bar, the anti lag should keep the turbo closer to.1 bar all the re between shifts meaning you have more power faster.

So I was noticing a car the other day where the gauge not only drops to 0, but actually dove in the negative range quite a bit, nearly as much as it rises in the positive range when the throttle is all the way engaged. What is happening when that’s going on?

 

[TFSI400]

So I was noticing a car the other day where the gauge not only drops to 0, but actually dove in the negative range quite a bit, nearly as much as it rises in the positive range when the throttle is all the way engaged. What is happening when that’s going on?

That’s vacuum. All engines create vacuum. It’s normal. It’s basically the difference between the pressure in the intake manifold and atmospheric pressure. An NA car for example ‘sucks’ air in. This is called induction. This creates vacuum. A turbocharged car - ‘forced induction’ - forces/blows air into the intake manifold, much more air is pushed into the cylinders than an NA car can naturally suck in.

When you come off the throttle in a turbocharged car it stops blowing air into the inlet manifold, and pressure in the manifold reverts to vacuum (negative pressure). When you go back onto the throttle pressure in the manifold builds (positive boost).

My car IRL goes from around -21PSI on the boost gauge off-throttle (vacuum) to 29PSI on full beans (positive boost). That’s pretty healthy. And that’s why it’s handy to to have a boost gauge on a turbocharged vehicle. You’ll know if the car is making the boost your ECU is calibrated to request, but also whether the engine is sucking hard enough (sorry 😂) under closed throttle.

 

[Bullwinkle]

That’s vacuum. All engines create vacuum. It’s normal. It’s basically the difference between the pressure in the intake manifold and atmospheric pressure. An NA car for example ‘sucks’ air in. This is called induction. This creates vacuum. A turbocharged car - ‘forced induction’ - forces/blows air into the intake manifold, much more air is pushed into the cylinders than an NA car can naturally suck in.

When you come off the throttle in a turbocharged car it stops blowing air into the inlet manifold, and pressure in the manifold reverts to vacuum (negative pressure). When you go back onto the throttle pressure in the manifold builds (positive boost).

My car IRL goes from around -21PSI on the boost gauge off-throttle (vacuum) to 29PSI on full beans (positive boost). That’s pretty healthy. And that’s why it’s handy to to have a boost gauge on a turbocharged vehicle. You’ll know if the car is making the boost your ECU is calibrated to request, but also whether the engine is sucking hard enough (sorry 😂) under closed throttle.

Thank you. This all makes perfect sense to me. I used to work on old motorcycles for fun in a club, but we only dabbled. Back pressure and airflow were interesting problems to figure out, but when I found out just how complicated the fluid dynamics are for this I just quit trying. I gave up on my old Honda which I rebuilt several times for a BMW that I’ll never, EVER, work on. I don’t understand that voodoo mojo and I leave it up to the warlocks at the motorcycle shop.

Now the bug has bitten me again with this game, but for now I’ll settle with tinkering on my virtual cars instead. I can do less damage that way (mostly). I just wish they’d figure out the PP system so we could race with custom cars.

 

[TFSI400]

Thank you. This all makes perfect sense to me. I used to work on old motorcycles for fun in a club, but we only dabbled. Back pressure and airflow were interesting problems to figure out, but when I found out just how complicated the fluid dynamics are for this I just quit trying. I gave up on my old Honda which I rebuilt several times for a BMW that I’ll never, EVER, work on. I don’t understand that voodoo mojo and I leave it up to the warlocks at the motorcycle shop.

Now the bug has bitten me again with this game, but for now I’ll settle with tinkering on my virtual cars instead. I can do less damage that way (mostly). I just wish they’d figure out the PP system so we could race with custom cars.

Yeah I get you! It’s much less expensive doing things virtually isn’t it 😂

I did a piston ring in December so figured I’d do things right, full build with forged rods and pistons etc. I got the car back mid April to run in, and then unfortunately something went wrong with the rocker arms popping off the valves. So it’s back in being investigated, and 5 months later I’m still in the same position. It’s very frustrating, and very expensive.

I guess it’s cool having GT to scratch the itch in the meantime. It’s not the same, obviously, but it really appeals to me in terms of the upgrades and tuning 🙂

 

[Meythia]

Route X test with Huayra (and whatever parts I just had installed) on 20x fuel consumption on 5km checkpoint from rolling start with no car in lead to provide slipstream
no anti lag 9% fuel left, slowest time 49.82
weak anti lag 9% fuel, faster time 49.63
strong anti lag 8% fuel left, tiny bit faster time 49.61

As long as there is any non acceleration time, the anti lag system will spend extra fuel to make your next acceleration faster.
Difference between strong and weak would be more obvious on tracks that have turns you have to slow down for.

 

[Fuzzi0n]

This made me curious to see how much fuel it actually uses and it turns out if varies car to car and depends on the tuning parts too. I went to Route X and set the fuel usage to 15x, then ran up to a specific speed for each car and coasted down to 50 km/h while downshifting at the same points each time. Most of the race cars that have it hardly use any more fuel with anti-lag on weak or strong over it being off completely, whereas some of the tuned cars I tried it made a considerable difference. For example the Focus RS I have that's fully upgraded used about 19% more fuel while coasting from the same speed with the anti-lag set to strong compared to it turned off, however weak only used around 5% more than disabled. Not the most realistic test, but I wanted to do something that made a very obvious difference.

From other driving it seems to have minimal effect on lap times which would suggest you're better off using the PP it adds for something else if that's the type of race you've entered. For races with increased fuel consumption you're best off with the system disabled, not sure if weak would be worth it given the tiny amount of performance you get. If you do happen to need to save fuel with anti-lag enabled you can always keep a small amount of throttle on while braking or when you would be coasting, you'll use less than the anti-lag does at least.

 

[Bobby-Vegas]

Probably been said above.

Has a slight supercharged effect keeping boost up.

 

[Sunzi]

So, simplistically, in game terms - it keeps fuel burning while coasting to aid marginally (negligibly) quicker acceleration next time you gun it?

I notice it doesn't add any PP - the use of an ECU is recommended but is it both mods together or not at all? Or could you run it with lesser benefits on the stock ECU? I note that the addition of a Customisable ECU + the Anti Lag also doesn't affect the PP either (besides the ECU's contribution)

Some fantastic chat in here BTW. GTP knowledge base at its finest. Bravo.

 

[Meythia]

I notice it doesn't add any PP

Simply installing it doesnt, but you will see 3 new options
disabled
weak
strong

Enabling it will add a few PP.

 

[Sunzi]

Simply installing it doesnt, but you will see 3 new options
disabled
weak
strong

Enabling it will add a few PP.

Ah yes - it would help if I actually looked at all the options and then read the breakdown explanation (by pressing square) just did this and its immediately clear to me.

My fault ha! Thanks all the same though.

 

[XSquareStickIt]

I think I get the gist of what anti lag is supposed to do after reading the replies to this thread, but there's one thing I don't quite understand. If the anti lag is burning fuel in the exhaust manifold to keep the turbos spooling, why does the turbo boost gauge still dip between upshifts? Is this true to life? Or just the game misrepresenting something? The anti lag in this game seems to increase how quickly the boost builds back up to where it should be after coming off throttle instead of keeping it spinning all the time, but I may be wrong.

Super annoying how we can't anti lag engines that originally come with turbos. I won an ultra high rpm turbo for my BRZ Drift Car, which I slapped on a poor S13. It lags... a lot. But it's such a riot to drive.

 

[Meythia]

but there's one thing I don't quite understand.

Just the way the game has implemented it. Likely to make it easy to use.

 

[MGR]

I think I get the gist of what anti lag is supposed to do after reading the replies to this thread, but there's one thing I don't quite understand. If the anti lag is burning fuel in the exhaust manifold to keep the turbos spooling, why does the turbo boost gauge still dip between upshifts? Is this true to life? Or just the game misrepresenting something? The anti lag in this game seems to increase how quickly the boost builds back up to where it should be after coming off throttle instead of keeping it spinning all the time, but I may be wrong.

Super annoying how we can't anti lag engines that originally come with turbos. I won an ultra high rpm turbo for my BRZ Drift Car, which I slapped on a poor S13. It lags... a lot. But it's such a riot to drive.

I assume the antilag kit modelled within the game uses the secondary air injection (or rally style) version. When the throttle butterfly is closed a separate value opens to pipe fresh air into the exhaust manifold. The associated combustion happening in the exhaust manifold keeps the turbo spinning at high RPM - with the turbo boost generated now being vented via another valve to either to atmosphere or recirculated back into the intake plumbing prior to the turbo.

But because boost is measured from the intake manifold using a MAP sensor (Manifold Absolute Pressure) the pressure will still drop as the throttle butterfly is closed. It just means that boost within the manifold will climb much faster once the throttle butterfly is opened again.

 

[TFSI400]

I assume the antilag kit modelled within the game uses the secondary air injection (or rally style) version. When the throttle butterfly is closed a separate value opens to pipe fresh air into the exhaust manifold. The associated combustion happening in the exhaust manifold keeps the turbo spinning at high RPM - with the turbo boost generated now being vented via another valve to either to atmosphere or recirculated back into the intake plumbing prior to the turbo.

But because boost is measured from the intake manifold using a MAP sensor (Manifold Absolute Pressure) the pressure will still drop as the throttle butterfly is closed. It just means that boost within the manifold will climb much faster once the throttle butterfly is opened again.

This guy gets it 👌🏻

 

[O604]

It's car indigestion. When you feed you car turbo (pronounced Taco Bell), your stomach makes weird noises and you get extra build up and stuff explodes uncontrolablly out the tailpipe. In cases like this, when you run, it feels like you're running as fast as you've ever run.

 

[Bullwinkle]

It's car indigestion. When you feed you car turbo (pronounced Taco Bell), your stomach makes weird noises and you get extra build up and stuff explodes uncontrolablly out the tailpipe. In cases like this, when you run, it feels like you're running as fast as you've ever run.

I nearly spit my beer all over my computer when I read this!!!! I can tell from your profile photo that you're quite familiar with the "green apple quick step," am I right???