Turbo Lag: VG vs Wastegated

During our Killing a Duramax series, Gale Banks and the team upgraded the stock L5P variable geometry to a larger waste-gated system from Precision. While larger turbos do take longer to spin up, the test we devised really showed us exactly how much. The test also showed how much a VG turbo smoothes out the curve in turbo RPM.
See the rest of Killing a Duramax bnks.pw/3Pn0vCU
#amsoil ‪@AMSOILinc‬

[@rientsdijkstra4266]

Lesson: a bigger non VG turbo may give you more peak horsepower, but make your car slower in practice.

[@salninethousand2496]

Not necessarily slower but definitely less responsive.

[@rientsdijkstra4266]

​@@salninethousand2496 No and yes. Yes the big turbo is less responsive, but that lack of response is expressed through the fact that it takes more time for the engine to react and deliver full power. During which interval the engine will have little pulling power. Which means that during this interval the car is slower! And in real life situations - on the street, in traffic - it will be very hard to make up for the lost time later on. So in practice the big turbo is slower, for any situation other that the traffic light sprint where you can wind the engine and build the boost before you go.

[@M54B30_fan]

@@rientsdijkstra4266 you would build an entire car/drivetrain around a purpose. If this engine was used in pulling or drag racing, brake boosting, 2-step, or a better torque converter like Banks said should help. Most gas engines obviously peak towards redline and especially sport/race engines. You have to pick and choose your advantages and what you want. There’s always a trade off. Power down low probably means more up high. Power low might mean lower overall power, etc etc.

[@rientsdijkstra4266]

@@M54B30_fan Yep that is true. As said in an application where you have time to spool up the turbo before launching the lag is not such a problem. However in real life driving on the road, you normally can not first spool up the turbo, you just want power when you put your foot down. And the VG turbo is faster for the simple reason that you have the power (more) directly available. So indeed: it depends on the application!

[@dylan4972]

​@@rientsdijkstra4266 This test is for the same HP you don't run a larger turbo for the same hp. Never seen anyone being slower with a bigger turbo as the peak HP more than compensates.

[@Monfukin.tannan]

This guy is such a hero and a wealth of wisdom we are so lucky to be able to just listen to him explain these unbelievably complicated Concepts so simply for an individual like me

[@benjamindigregorio4403]

😊

[@yjkader]

He’s great at what he does, but calling him a hero is abit rich. Save the D riding for a bigger cause.

[@endurofan9854]

true brother, he's also one of the few people i learn from with the complicated stuffs on automobiles

[@Austin-cr1vc]

Gale. I’m 28 and I’ll always watch your videos. You’re the man and I hope I can shake your hand someday. You’re my hero and I’d give anything to learn motors from you sir. Any day of the week.

[@Gcanno]

The Shop is in Azusa California .

[@nigga_nigga]

fr

[@tomconner5067]

He’s on point, like a cam with a large overlap, you have to get on top of it before you want to be fully engaged with the drivetrain, I recommend a Fairbanks, best converter I’ve ever used.

[@RipeSnipe]

I like PTC, I think the dudes name is Dusty Bradford he hooks it up every time

[@jockeanus]

But you don',t want overlap on turbo?

[@jessepacheco6020]

At 82 years old Gale Banks is the epitome of "Do what you love and you'll never work a day in your life". I've been an engineer for twenty years and l pray that l have the same thirst for knowledge at his age.

[@KI4HOK]

I’ve always said that driving a turbocharged engine requires planning.

[@Dabitual]

Every engine requires planning if you’re doing it right.

[@randyschmidt19]

sizing the turbo properly should be in the plan

[@BruceMyersLBZ]

You put the reality of running a hopped up diesel, or turbocharged gas for that matter into perfect words my friend, good on you!!

[@yoitztanner2109]

Went bigger on my wrx but only vf48 for this exact reason I wanted less lag with just a tad more boost.

[@imitt12]

Especially a turbodiesel. I used to drive trucks that you could mat it halfway through a turn and it wouldn't be fully spooled by the time you straighten up.

[@P.I.E.]

This is why a compound setup is ideal. It eliminates the lag and acts more like a supercharger.

[@glidesense]

kinda expensive to set it up and programming it requires quite a bit knowledge

[@P.I.E.]

@glidesense how so? There is ready to install kits from a variety of aftermarket manufacturers. Most are plug and play with little to no tuning required, especially on diesels. Obviously, for gasoline engines, it would be more complicated.

[@glidesense]

@@P.I.E. it wouldn't be easier on diesels if you programming it to comply with egt and making it is as fuel efficient as possible but if you doing it for fun go ahead slap it in there, roll a coal and call it a day

[@P.I.E.]

@glidesense emmisons control systems hinder efficiency and performance. In most cases, if the mandated equipment is removed, most vehicles will run better, thus getting better fuel efficiency.

[@glidesense]

@@P.I.E. okay..... are we talking about emissions or turbo setup?

[@ScotDouglas]

Same test we did when designing turbo engines at GM. Time to 90% torque target was 1.5 seconds.

[@lifeisgood070]

How much faster is it in a manual? I know GM doesn't really make manuals anymore but.... i've always felt really big lag with automatic turbos compared to stick shift turbos even at the same RPM. It's probably because of the loss in the torque converter with all the fluid especially on CVT's

[@yeahididit9054]

Get a spool valve if you are having problems spooling it up. 💯 guarantee

[@bradhaines3142]

​@@lifeisgood070it's just the shift logic thats the issue, yours is different from an automatic and thats all the difference is

[@jefferykaighin7039]

I Love Love Love listning to Gale Banks. He explains the method to his madness, and I could listen to him ALL DAY! We're blessed to be able to listen and view his videos, Thanks to the internet!

[@endurofan9854]

i totaly agree with what you said bro, its purely a bliss having and hearing Mr. Banks teaching on internet

[@Alice.1219]

He is absolutely correct. I did this on my 2010 camaro 3.6 V6 twin turbo set-up. I went from a stock stall converter to a 4000 stall FTI converter and the turbo lag was reduced approximately 80-90%. When you launch from a dead stop, boost begins almost immediately. The car is a daily driver and the FTI converter hardly affects traffic driving. No flaring like in the old days with high stall converters.

[@endurofan9854]

i'm still wondering tho, the connection of turbo lag with the torque converter sett-up

[@mikeeiben3430]

The trick is to get the right stall speed so that you get instant boost when you stage the car. Too high of a stall will let the boost blow right through the engine and the pressure won't build up as high.

[@casey7616]

I could listen to him all day !

[@GMGUY1000]

Every time you talk i Learn new shit. thank you. You are the man🤙 Hello from canadastan.😉

[@pieterpostma2687]

This man knows what hé talking About. As an aircraft mechanic i can say listen and listen good at what this man has to say. Great job. Keep it going ❤❤

[@bryanaldrin4285]

Very much appreciate all of the information you guys put out! If you have anything for basic electrical diagnostics or gremlins. I would love some videos on that!

[@Elmo_Fuddleputt]

This man is an American treasure.

[@glennhampton1594]

His knowledge makes my brain hurt lol. Long live Gale Banks . A true legend in his craft 👏

[@dont.ripfuller6587]

I'm still absorbing the lessons on air density.

[@the305hauler]

Booyah 👊🏽 😁 👍🏽 🇺🇸

[@JoshuaBilger]

The absolute authority on all things deisel!

[@PiDsPagePrototypes]

These are big engines in big vehicles, in most driving, and especially towing, the driver's not going to just 'mat it', but will roll on to the power as needed, such as starting up an incline. There'd be more value in an Anti-Lag bypass system, that allows the turbo to remain at high RPM while dropping the boost through the gear changes to reduce driveline power loads and shocks.

[@msengineeringdavid3148]

No…

[@madmattthehatter]

Anti lag systems are great when you don't need to care about efficiency suck as a race situation. It works great in rally cars but it's horrible on fuel. You are better off with the vgt and work on improving on flow. - manifolds, down pipe, up pipe and to/from intercooler. You get more power and less lag.

[@danielfrazier840]

Diedels don't really work that way

[@francislutz8027]

You have no idea what you're talking about The simplest way to maintain impeller speed and keep the lag down in the charge pipes is to bleed off boost in the charge pipe or just bleed at the waste gate. These are diesels not some Honda on a video game

[@luislongoria6621]

No stu, stu, stu, stu

[@cbizkit36]

Do you have classes. Id love to learn through someone like you!! Always great information explained Well!

[@michaelwalker9118]

Mr Banks no one should ever doubt you!

[@kovacspis]

Gale and the team: you gotta continue this series guys! You have to. It's been too long.❤

[@07forty]

This man is a gem

[@blazbohinc4964]

Vgt turbos are awesome. I have one in my 1.5 tsi octavia. It makes peak torque at 1500rpm (gasoline engine mind you) and I can cruise on torque at 1200rpm no problem. Just because the turbo still makes boost. Insane.

[@kennethpowers8995]

This man’s advice is always spot on. I bet he would be mighty dangerous if he was into the grudge scene and built himself a car/truck.

[@milesstover3724]

guys from his era were just more serious and didnt use phrases like "grudge scene" in any possible context

[@kennethpowers8995]

@@milesstover3724 Heh someone worried about what grammar is being used to describe the class they run doest exactly scream grass roots racer either.

[@kennethpowers8995]

@@milesstover3724 Side Note: guys from that exact era are the ones who coined the term “grudge racing” in the first place. Just a little FYI

[@russellzigler2180]

Gail is a wealth of knowledge.

[@MAquiNAroJA12]

The fact anyone objects to this man is insane

[@TheRightsideofhalfWhite]

Makes sense 👍🏻

[@johnsullivan2329]

Listening to this man is an education.

[@Townsendcat2]

This man is a national treasure😊

[@patricwell8335]

Wtf bro is very smart..I'm hook now...his detail like me when it come to cars...in love

[@LandonClimbs]

Gale banks has hours of amazing content. Hes Einstein of the diesel world

[@jamesgarner307]

It's called stall converter, stock is around 15 to 18oo rpm where you can get a stall converter that is designed to stall up to about 2000 to 2500 rpm.

[@Dean0000]

@@jamesgarner307 to clarify you’re discussing the stall of a torque converter , they aren’t actually called stall converters (generally) just to clear up potential confusion

[@johnabbott3896]

Please pass your encyclopedic knowledge to the next generation of engine tuners....I'm not a mechanic, but I marvel at the way you explain things in a way even I can understand...

[@saywhat6632]

While this guy has incredible knowledge and comes up with insane calculations and good products, let's keep in mind some of what he's dealing with/trying to fix, is because good ole farm boys and country boys have enough brains to push these engines to insane limits by trial and error

[@josephgay6792]

Powerstroke lettts gooooo!!!

[@tomoday4450]

So smart 👍🏻

[@tylerwightman2315]

You are a wise man and a legend Mr. Banks! I take your word for gospel cause you really know your $#!+

[@ChasePalsson]

Could also look at gaining efficiency back elsewhere. Turbo blankets are a great way to reduce turbo lag by keeping the heat energy in the turbine instead of lost to heat radiation. A quality manifold rap and turbo blanket can close that gap up substantially.

[@amprohoe]

I read somewhere about an anti lag set up on a 2jz manifold, looked like it had an extra waste gate and fresh air tubes added to each manifold runner coming from turbo compressor side. Looked cool, I wonder.

[@JohnCoffins]

Hands down one of the smartest car guys out there. You put this man and a Japanese car wizard together and who knows what will happen.

[@ilyesatmania6510]

Legend

[@TomRad1]

I reduced turbo lag by not addressing the exhaust manifold leak. Spools great :)

[@ricksanchez3106]

Gale banks is the king!

[@Nza420]

Tight torque converter is the only thing for towing. Forget turbo lag.

[@Dr.Westside]

Im interested in the GM dual volute turbo . 90% of torque is available in 1.9 seconds without any VG because of hot side exhaust gas routing to the turbine . I have this turbo in my truck and it is ridiculously responsive . I'm wondering if this is going to be more of a common thing .

[@strykerentllc]

Loosen up the convertor and watch your mileage drop is a genius move as would be going to a taller gear ratio for around town driving. There's no free lunch folks, and each potential parts choice comes with the question--what's the objective? Racing...where, on the street? Yeah, that'll work out real well with your DL and insurance. Towing? You won't be looking to spool up while dragging 11,000 lbs. as torque will find the weakest link in your system and break it like a toothpick. Gale makes money on selling you performance parts you don't truly need. All of those semis on the road running down the highways and byways weighing 80,000 lbs. while ticking off a million miles without an overhaul aren't running Banks anything. Food for thought.

[@diesel-technology5507]

The next question should be, if the larger WG turbo has the exhaust side swapped out for a VGT system, would it hit surge before it could physically spool up

[@GIGABACHI]

VGT's are the shit for daily driving at 3500 different RPM. However, you can't beat the superior reliability, simplicity and lower price of admission of the Non-VGT turbos when shit hits the fan, pun intended. Choose wisely and you won't be disappointed with your choice(s).

[@jeremypilot1015]

"Turbo too big? Engine too logy? Mess with your torque converter, you'll thank me later." - Gale Banks

[@Baujahr90erAG]

Truly Mister Banks is an american national treasure!

[@Perceivedshift]

I had never heard of tuning a torque converter to reduce lag, holy cow!

[@seanerobertson32]

Never heard of a stall converter? Or changing the programming of the transmission?

[@dsprojects8580]

👍👍👍

[@JohnAlex-zx8jd]

Logicvs insanity❤❤

[@joeyoung4309]

Ive a turbo guy but the turbo rules ror diesel stuff changes and ive always been super skeptical about VG turbos especially when people are using them trying to mitigate lag. Instead of tsking known and understood measures of reducing lag (more compression, more motor, more timing, smaller turbine housing, smaller turbine wheel) they go buy these VG turbos and claim its capable of maong X power but will come on like a Y sized turbo.

[@kieren7763]

My neighbour has a modified stall on his dodge ram him backing the trailer in is just so painful when you got a high stall

[@matthewcanipe6581]

You’re good,,, I don’t say that often

[@thebad300]

and this is why my mazada 323gtx would out run skyline gtr in the 1/8 and hold them off in the 1/4 mile when i lived in japan in the 199x

[@noxious89123]

Surely this is indicative of a higher boost threshold, not more turbo lag? The two are commonly confused with everyone online only talking about "lag", when really what they're referring to is boost threshold. Turbo lag can only be tested when you're above the boost threshold.

[@christopherlamontnelson1729]

Well high stall converter will definitely get you moving easier with a non vgt. So will nitrous. Gale should show nitrous and how it effects air density and power

[@jasoncramer5091]

Ill take the manual transmission and sit there and hear the turbo spool up and enjoy the sound 😂

[@pigman4084]

OH MAN

[@fra_trk]

I'm a little confused because Banks is talking about horsepower vs time while the graph shows rpm vs time (got the idea tho)

[@Sdukes001]

When are we getting a compound turbo set up for street trucks for great towing and low egts?? 50 state legal

[@whirltech8031]

Goes to show how much *system* engineering OEMs put in. Need to mod the trans to access the bigger turbo's performance.

[@dylandesmond]

Electronic Boost tap. Run it at full. Have it electronically open at the desire boost level. Turbo lag fixed. No need to spend $1000 on a higher stall. 20hp of nitrous will spool it up quicker than a stock turbo too 😂

[@BloodAlwaysFindsItsLevel]

And the torque converter calibration will lead to other drivability issues.

[@MrLuvtheUSA]

Awesome test, but it would be more comparable if you used the same size turbo. I bigger turbo would have more lag then the smaller turbo even if both were non VGT

[@TheSnowsurfer7]

If love to work for this guy

[@johnsonferrufino5568]

I preffer a VG turbo than having more power but one day later, I have drove cars with turbo lag and a lot of power like some old models of N95 BMW and they are amazing powerful, but you want that with a diesel engine at all

[@SinisterNinjaOfficial]

When one is slow alone, put 2. No more lag.

[@makaylaburks3275]

So u would need like a 2000 stall converter or a 2500 to allow it to jump on the turbo faster 🤔

[@andymike6575]

Here’s an even better solution: compounds

[@Bloodcurling]

How'd that work for the 5L Cummins and 6.4L Navistar?

[@daviddroescher]

How is a 76/75 emissions compliant? The EPA would conciter ths a delete/defeat device. The mandate was sequential twin or VGT to get the BP higher than intake pressure( upside-down PR)to get a higher EGR flow into the motor. Cat went twin, then stoped making road use motors for the next gen emissions where DEF SHHOULD have replacedthe EGR instead of keepingthe motor killing EGR as a redundant NOx device._ .

[@bankspower]

This engine will never live outside the walls of our dyno cell. Emissions compliance is not relevant to this test. This video is from a much longer, more thorough video.

[@Dave5843-d9m]

Just got the correct turbo and be done either it.

[@W.Khairi]

Cool

[@Swarthysteak747]

4 seconds of lag is fucking hilarious 😂 so slow but so much turbo spool

[@nor-calcummins3947]

What’s the lag time when you factor in a downshift or two? Theoretically, it should come up on boost and power quicker, right? I know we’re talkin engine dyno specs here, which I understand. But what’s the change if we talked about on road performance?

[@sutherlacd27]

I have upgraded twin vgts in my 911 turbo and lag is essentially non-existent

[@nor-calcummins3947]

@@sutherlacd27 I’ve got a big single on my Cummins that’s wastegated. I know with a vgt the lag is minimal. When I downshift it comes on boost real quick. But when comparing diesel to gasoline turbo applications, it’s apples to oranges. The power comes on a bit different. Especially in what I assume is a boxer engine?

[@carbonfiber492]

My question to that is though how much can be gained back by altering the boost curve with modern electronics

[@7.3PSDA2]

Yep.

[@jaymoney4265]

If you do that wouldnt it lower RPM much quicker as well? Wouldnt that be equally as bad (similar to running a LW flywheel) where RPM would drop so fast it would take time to bring them back up?

[@sailingcitrinesunset4065]

Compound turbo's 1 big & 1 small

[@TheSgtsMess]

Really interesting. Absolutely no idea what you just said. Hahahah

[@barney.likes.peugeot1044]

What about a manual transmission, without a torque converter?

[@MsOMGwtfnoOb]

Is it a good idea to increases displacement in a 2jz gte vvti 3.0 to a 3.5 and use a twin-scroll turbo ?

[@slamdvw]

How about the "out of the hole" lag? Lots of fun to attempt to jump a gap in traffic - stand on the throttle and just.. idle across 2 lanes of traffic waiting for the horses to be strapped to the crankshaft..

[@sutherlacd27]

Launch from higher rpms instead of idle

[@slamdvw]

@@sutherlacd27 kinda hard to do in city traffic.. the 21st century, shouldn't have to either.

[@drthik1]

Wheres the dpf and scr on this engine ?

[@TheBeardedMiracle]

this is why i run a 3800rpm stall. 76mm turbo

[@kidsythe]

let's be real here. the red boost curve looks perfect for a gas engine 3-4k and then slam it. darn shame this is probably a diesel application

[@Lazerecho]

Deal with it!

[@yaseenbshina3140]

That's not turbo lag, that's boost threshold. People mix up the two. Turbo lag happens when you floor while the engine is already at the optimal speed for turbo to give full input

[@FailingAtFarmChores]

This is probably a dumb question, but I've always wondered why you don't see fixed geometry turbo diesels equipped with the same type of anti lag that you see in a rally car. Does anyone know if it can be done? Safely?

[@georgewashington1106]

Do you think we'll get to a point where a VGT is reliable enough to justify engineering a retrofit for older engines? I'd like to have the benefits of a VGT on a 7.3

[@martinmallasch2814]

So why don't we use an electric clutch on a electric motor, to turn the turbo at low rpm, and auto disconnect at higher rpm?

[@John637]

You lost me after torque converter 😂

[@Symphony_gamestream]

What does that mean when you say loosening up the torque converter calibration?

[@henrydawson6960]

👍

[@JohnSmith-xu7ev]

Im going to flash my mechanical torque converter to adjust for turbo lag

[@nickwells20]

This is probably a dumb question but can a lightweight flywheel improve lag by speeding up revs?

[@Ticklestein]

European here, how would you solve it without messing with the torque converter? We drive manuals with clutches 😝

[@humblehummus3956]

Tempted to put a diesel v8 in my Subaru just to add banks parts to it and haul ass everywhere