realise* - depending on the parts of the world you live in, for example in the UK for a lot of words S's replace Z's. You ought to look up localisations of words next time before you "correct" a correct spelling.
What makes this so good is this is people telling you what you need to know and how to build things instead of acting and get you to buy product from a sponsor.
I already had a fairly solid understanding of compound turbos but Al's explanation is just so simple and straightforward! Love it. Makes me want my own setup! I like AC though so it's not gonna happen..
Many places in Australia have limited resources for fabrication. That's what makes them so creative. Give this man a job and I guarantee you one way or the other he's going to get it done! Good on ya mate, cheers
I am absolutely loving these videos where we just sit and listen to a master of his craft talk about what he knows best. It's informative, and interesting, and it really showcases not just how much you guys know, but how smart y'all really are. You explain things in a way that makes a layperson like myself be able to understand, and that's a real skill. They don't call you Turbo Yoda for nothing! What you're doing is great. Keep up the awesome.
This was the best lesson learned. To see hand hear Al & Woody explain how mechanical parts function and how they relate is "PRICELESS" Thank you MCM😎🏁🏁🏁
I love compound turbos! The tractor pull guys have been doing them for a long time, and really have some extreme setups. The one I remember most was on an International 466 that had 4 turbos in 3 stages. Two in parallel, blowing into stage 2, then blowing into stage 3. He said it made 240 psi boost. Not an intercooler in sight. So I asked him why he didn't have an intercooler, then he said "it's the pressure that makes the horsepower." So I went home and did the math, and figured out that his intake manifold temperature would be 1000F. He could have gotten the same intake manifold air density with two-stage turbos and a good intercooler. And he wouldn't have been changing engine blocks every 20 passes.
You are a true Legend Al, I'm from Cape town but I can tell you I have learnt so much watching your videos and you and Woody are EPIC, the way you figure out solutions to all problems you faced and I hope one day that I can make my way over to Australia and maybe one day meet you guys and maybe become your apprentice. KEEP UP THE GREAT WORK GUYS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! TRUE LEGENDS!!!!!!!!!!!!!!
Boys.... I would be really interested in watch the dyno of the compound turbo set... It would great to see how the tuner uses the 3 controls and what issues are thrown up. Another nice episode
Congrats on your first year of Skid Factory boys. It's been great following the progress of your builds and hope for many more years of success for you.
Knowledge is pow...TORQUE Compound turbocharger is exactly as a gas turbine engine, hot side exhaust go through small blades first , then expand through bigger blades to recover more energy. On cold side air gets compressed by big compressor blades first then smaller compressor blades the closer it gets to the combustion cans. Exactly like compound turbo , hot side small turbine to big turbine. Cold side big turbo then small turbo
@@msengineeringdavid3702 are you talking about gas turbines or turbochargers? Because in turbocharging 'staged' and 'compound' are two different things.
Aweseome video my guy. Was getting a chuckle listening to the complaining of mounting t3's and the wastegate when im trying to figure out how to mount an s400 under the hood with a v8 taking up most of the room. You do clean work and i like the no bullshit.
It makes me happy I just so happen to have the same shield as Al I didn’t think anything about it when I bought it I’m just lucky, you guys are a huge inspiration
Congrats on the one year anniversary! This is easily one of my favorite series to watch. I enjoy the low-key atmosphere, and especially the knowledge packed into each episode. Good work Al and Woody!
First off i know very little about diesel turbo engines, but i'm glad i watched this video. I was always under the impression that compounding meant that the small turbo was on the manifold then feed the larger turbo with the pressured fresh air (or what would usually go to the TB).
Similar concept to steam expansion engines, Al - smaller high pressure piston exhausts into a lower pressure cylinder to utilise spent energy. Great vid, thoroughly enjoyed nerding out in a straight-foward way and look forward to more :)
Turbo Yoda Al and Woody Happy 1st year. Hopefully we'll enjoy your vids for many many more years to come, Great to see the evolution of Al becoming someone who was initially camera shy in MMC to becoming a top class presenter in his own right, big love from Ireland
I always thought Turbo Compounding was when the exhaust gases drive a turbine that is directly connected to the crankshaft thus increasing efficiency and lowering fuel consumption. I.e. Wright R-3350 radial aircraft engine. Great vids chaps! Massive fan of your work!!
Never heard of this before and its very fascinating to me, I've heard of a turbo and supercharger combo before. Thanks for sharing and as always Keep Building👍
The reason you would want to go to triple turbo setups is to allow for better spooling speed vs one very large atmospheric charger. It also allows for lower smoke output on the street during transient throttle on non emissions diesels making above about 1000hp while making throttle more like a factory truck.
Compounds are probably the hardest to tune, making the transition smooth is double the tablespoon have to modify basically. When tuned correctly it can drive like stock and be a monster, my Cummins runs compounds and now limited by fuel… it tows like tug boat, it’s a beast, and being able to have the air for your engine is awesome. The Cummins guys run compound just like this but they run triples just for the dyno numbers, but you will notice when they sled pull, the run compound, or just one big single cuz your literally pegged, those big singles though take nitrous to spool the turbo but the triple doesn’t need nitrous to spool. Because the primary turbo helps, but you will be limited in dyno numbers overall on a compound your power band will be 5,000 rpm of usable driving instead of spooling up at 4400 rpm on a Cummins and using 1500 rpm of usable power.
Al, have you guys ever considered mounting the external wastegate on the outer portion of the Turbine housing??? The net result is you (if you installed in the right place) increase the turbine size at the same time you bleed off boost. Make sure you mount it at an angle so the turbine gasses don't make a sharp turn. The turbine housing is cast steel not iron, so it welds easy.
And there I was remarking in the last eps comments that it was a pity you didnt touch on Compound Turbo set-ups..... :v Glad you saved it for a separate, more in-depth & practical episode- thank you!
Great stuff guys! Just some useless info, the original compound turbo charger was a complicated set up that was used on radial aircraft engines like the engine in the super constellation, it was coupled directly to the crankshaft through a weird clutch set up ie; not used for boost but introduced more torque directly to the crank.....
Yeah. these guys would make great ads for Australia I reckon. An anodyne for all the crassness that often seems to be what people are shown. I think I've said it before in other words, but it's relaxing to see the calm competence applied to problems.
Hey guys I have an idea for a video for you guys. I see a lot of videos focusing on the basic tools you'll need to complete a job but you hardly ever see a professional like Al explaining what tools he has bought that make his life easier when working on so many different cars. I see Marty fell in love with your multi tool with the ratchet head attachment. I would be very interested in seeing what tools or power tools you have bought and will never go back to the old way type of thing. No matter how expensive they may be what tools have paid for themselves ten fold. That kind of thing. I am slowing getting use to wrenching on my own cars and Id be very interested in seeing what someone like Al considers his most worth while purchases for his shop. Or personal garage. And I'm sure a lot of people would too. Cheers guys love the show.
f**king top show al and woody, love kicking back smashing lemon aids and watching the skid factory... gotta do more skids in the shop, fill it full of smoke..
With the setup shown in this video, there's no wastegate dumping to atmosphere. Every kilo of air that enters the exhaust manifold is going full speed ahead through that secondary turbo. I get it, works great on a diesel application, but gasoline/E85 applications require any excess of energy to be dumped to atmosphere in order to keep the boost in check. By using an exhaust manifold reference for the primary turbo wastegate and using an intake manifold runner reference for the secondary turbo wastegate, we can both keep backpressure under control across the entire spool range and rev-range; and we can also control boost in a linear fashion without dips in the curve. Your backpressure and boost curves would look like a flat line after 3000RPM because everything would be set mechanically in a controlled fashion. Even if you wanted to rev it to 9000RPM, you would still have the possibility of seeing 30lbs of boost from 3000 RPM to 9000 RPM, and that makes a damn fun and damn efficient street car and effective race car.
I love compound set ups, so cool. Although, I though the intake going from the primary to secondary went the other way around..? So, the primary actually sucks the air in through compressor intake which then directs its boosted air into the intake of the 2nd?? That’s how I thought they worked, but obviously I could be wrong. Great stuff fellas!
The real benefit amounts to lower boost threshold and lag minimization, but the cost, complexity, weight, and space required for compound (i.e., sequential) setups is such that many people choose to go the single-turbo route.
I believe the reason why they are now using 2 turbos as the secondary instead of one is because it fixes what you said about it takes more time to build boost having one large turbo as your secondary. By having two smaller turbos for the secondary, when your building RPM's you can direct the air thru one of the smaller secondary turbos to quicker reach it's maximum range of boost efficiency quicker than the increasing exhaust gas can be used to reach the primary range of efficiency for the 2nd smaller turbo, thus making the system as a whole work more efficiently.
Awesome job looks much better, hope it brings results. Keep up the good work Skid Factory is one of my favorite channels. Wish I could have made the meet and greet in Dunville but it was the same day my girl friend was getting bone marrow transplant :(
Another well presented tech topic. Al Im sure you know more about turbo charging than I will ever know. This topic got me thinking about how compound turbo could work. Obviously carefully selecting housing and compressor size and so on is the first hurdle. In the area of control, could the smaller/primary turbo boost pressure reference the outlet of the second turbo to appropriately manage final boost pressure rather than let the primary go max all the time??? Would that possibly help reduce the exhaust pressure load? I would love to see an episode or series on R & D of a compound setup to see what methods and size combinations delivered the best output. I guess this is where manufacturers spend millions and the tuning world has to do our best to modify the work they do...
I have a genuine question for turbo Yoda. I (thought) I understood the basics on how turbos work. For this compound setup, I understand that both turbos use the exhaust gasses to get spinning, but why is it that the smaller turbo is getting fed through its intake from the charge port on the large turbo. Shouldn't it be the other way? Spin up that small turbo first, use the charge that it creates to spin that large turbo quicker, then use the charge from the large turbo to feed the engine. In your demonstration, you were feeding the small turbo with the big turbo, which meant that the small turbo was going to be feeding the engine. Am I just misunderstanding what is being accomplished here and all compound turbo setups are like this where it goes big->small->engine? Shouldn't it go small->big->engine?
The large turbo needs to be the one that breathes from the atmosphere because the bigger compressor inlet diameter can flow a higher mass flow of air before reaching the Mach limit.
I like the way you think Al.. i was always told is what you are saying about the pressures across the head best way is equal in and equal out across the head .. placing the external waste gate on the small turbo and allowing the restriction to move around it but still feed the bigger is the way i would do it
Don't forget that at high boost pressure your dynamic timing is significantly advanced.... You also need to shorten the length of time the fuel pulse is occurring and the only way to get the correct volume in a short time frame is larger injectors
You need a LOT more wastegate than a typical internal gate. Same for the big turbo, it should be 1.5-2x higher flow than the small. The reason the small turbo can flow so much more - it's ingesting compressed air, which takes up less space. It's also getting most exhaust bypassed thru the wastegate. I just hope you guys get some vids of it on the dyno!
Good explanation of how the compound system works. I think Alen misspoke at one point though, a turbine isn't using the exhaust heat to spin it is using the kinetic energy from the exhaust flow leaving the engine.
It uses both kinetic and thermal energy. The temperature drop across the turbine has a direct relationship to the energy recovered from the exhaust stream. Kinetic energy recovery is dependent on turbine blade design, and how effectively pulse energy is preserved in the exhaust manifold.
TurboYoda... Legend... I was trying to understand what you said, I still have no clue what you on about, but i think i learnt something... maybe later on... but that was some great info. cant wait for the barra bedford... sweet.
Hi Guys - I saw that Borg Warner had developed a twin scroll turbo with a variable diverted which could channel all exhaust gasses into one turbine housing and then progressively open up the second intake on the second larger scroll. It looked to have achieved a similar trick to the compound turbo but in a much simpler package. the diverted tab was also cast iron and very robust so very good for petrol engines with high EGTs. Have you seen these turbos in the marketplace? It was at SEMA a few years ago and it was covered on engineering Explained.
![[LIVE] : ONE ลุมพินี 86 | คู่เอก "คมเพชร vs ชาติพยัคฆ์"](http://i.ytimg.com/vi/m3q_dRYDuU8/mqdefault.jpg)
![3000HP, 150 PSI Of Boost | What Do YOU Know About Compound Turbo Systems | Shane T [TECH TALK]](/img/n.gif)
Al and Woody , I really hope you guys realise how good of a show you have.
*realize
I could watch it all day!
realise* - depending on the parts of the world you live in, for example in the UK for a lot of words S's replace Z's. You ought to look up localisations of words next time before you "correct" a correct spelling.
What makes this so good is this is people telling you what you need to know and how to build things instead of acting and get you to buy product from a sponsor.
Anyone else think Al largely says “Stuff the internet!”
Al is becoming such a good presenter!!!
This, x100.
a word from a clever professional is well worth your time listening too.
@@tommurray8312 couldn't agree with you more Tom. That's why I usually listen twice haha.
I was thinking the same thing.
He is! He's getting much more comfortable in front of a camera. He still is good ol' Al though
"People mess around with old junk engines all the time... It's a sickness" Shout out to all the toyota 4K family
Takes effort to destroy that engine lol
3S** family :P
JZ family
Pietrek L never
302* cam big lift 110* lobe seperation, solid roller lifters, roller rockers, bored out to 1550cc, 12:1 comp, LS1 coils, twin dcoe 45 Webber's, 130hp................ Not worth the effort
30 minutes, no shit just straight talk from someone who knows what he is taking about. Cheers
I already had a fairly solid understanding of compound turbos but Al's explanation is just so simple and straightforward! Love it. Makes me want my own setup! I like AC though so it's not gonna happen..
Wonder if he'll do sequential next...
Many places in Australia have limited resources for fabrication. That's what makes them so creative. Give this man a job and I guarantee you one way or the other he's going to get it done! Good on ya mate, cheers
"Its bigger then it looks" - my favorite al line
I am absolutely loving these videos where we just sit and listen to a master of his craft talk about what he knows best. It's informative, and interesting, and it really showcases not just how much you guys know, but how smart y'all really are. You explain things in a way that makes a layperson like myself be able to understand, and that's a real skill. They don't call you Turbo Yoda for nothing!
What you're doing is great. Keep up the awesome.
Look at him! He cant stop himself from smiling. He's right in his element. Love it
This was the best lesson learned. To see hand hear Al & Woody
explain how mechanical parts function and how they relate is "PRICELESS"
Thank you MCM😎🏁🏁🏁
I think we've just reached peak Skid Factory! This was the most interesting and informative episode to date in my opinion. Unbelievable stuff guys.
I love compound turbos! The tractor pull guys have been doing them for a long time, and really have some extreme setups. The one I remember most was on an International 466 that had 4 turbos in 3 stages. Two in parallel, blowing into stage 2, then blowing into stage 3. He said it made 240 psi boost. Not an intercooler in sight. So I asked him why he didn't have an intercooler, then he said "it's the pressure that makes the horsepower." So I went home and did the math, and figured out that his intake manifold temperature would be 1000F. He could have gotten the same intake manifold air density with two-stage turbos and a good intercooler. And he wouldn't have been changing engine blocks every 20 passes.
I'm running this exact setup on mine. It's frigging awesome. Would never go back to a single setup. Both turbos work brilliant together. 👌
You are a true Legend Al, I'm from Cape town but I can tell you I have learnt so much watching your videos and you and Woody are EPIC, the way you figure out solutions to all problems you faced and I hope one day that I can make my way over to Australia and maybe one day meet you guys and maybe become your apprentice. KEEP UP THE GREAT WORK GUYS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! TRUE LEGENDS!!!!!!!!!!!!!!
Boys.... I would be really interested in watch the dyno of the compound turbo set... It would great to see how the tuner uses the 3 controls and what issues are thrown up. Another nice episode
One of the best explanations of compound turbos ever explained by a bloke that works on petrol cars
Congrats on your first year of Skid Factory boys. It's been great following the progress of your builds and hope for many more years of success for you.
This was a pure master class in how to do some very intricate work. loved it. Yoda dropping some serious knowledge for the interwebs points
Knowledge is pow...TORQUE
Compound turbocharger is exactly as a gas turbine engine, hot side exhaust go through small blades first , then expand through bigger blades to recover more energy. On cold side air gets compressed by big compressor blades first then smaller compressor blades the closer it gets to the combustion cans.
Exactly like compound turbo , hot side small turbine to big turbine. Cold side big turbo then small turbo
Except it's not called turbo compounding but staged turbocharging.
@@msengineeringdavid3702 are you talking about gas turbines or turbochargers? Because in turbocharging 'staged' and 'compound' are two different things.
Just put a TD04H in my Subaru Outback! Got it for free from Albania, putting in a Japanese car in Canada! Great content guys!
turbo yoda talking turbos with two turbos, one turbo turboing another turbo!
bgdwiepp drinking game every time Al says turbo
i ran out of lemon lemon squash ;)
Mark M send help, I got alcohol poisoning
yo, dawg...
Aweseome video my guy. Was getting a chuckle listening to the complaining of mounting t3's and the wastegate when im trying to figure out how to mount an s400 under the hood with a v8 taking up most of the room. You do clean work and i like the no bullshit.
It makes me happy I just so happen to have the same shield as Al I didn’t think anything about it when I bought it I’m just lucky, you guys are a huge inspiration
Congrats on the one year anniversary! This is easily one of my favorite series to watch. I enjoy the low-key atmosphere, and especially the knowledge packed into each episode. Good work Al and Woody!
I've always been fascinated by compound turbo setups, thanks for taking the time to talk about this dark art
Excellent, authentic synopsis. Well explained in simple terms and concepts.
I’m really liking this diesel tuning tech stuff you guys are talking about.
First off i know very little about diesel turbo engines, but i'm glad i watched this video. I was always under the impression that compounding meant that the small turbo was on the manifold then feed the larger turbo with the pressured fresh air (or what would usually go to the TB).
Love the straight up tell it like it is approach.
Happy Anniversary Skid Factory
I sure appreciate you and the time taken to show your passion and knowledge.
..it's a sickness - yeah nah yeah
Nah yeah, it is. I am Aussie & this makes perfect sense, to most ppl here.
SOHC 4 Litre 4 lyfe!
Similar concept to steam expansion engines, Al - smaller high pressure piston exhausts into a lower pressure cylinder to utilise spent energy. Great vid, thoroughly enjoyed nerding out in a straight-foward way and look forward to more :)
Turbo Yoda Al and Woody Happy 1st year. Hopefully we'll enjoy your vids for many many more years to come,
Great to see the evolution of Al becoming someone who was initially camera shy in MMC to becoming a top class presenter in his own right, big love from Ireland
I've never fully understood these setups until now. Thank you.
I've never done any work to a car. ever. But I *will not miss* an episode of this!!
Tremendous stuff Al & Woody. :)
I always thought Turbo Compounding was when the exhaust gases drive a turbine that is directly connected to the crankshaft thus increasing efficiency and lowering fuel consumption. I.e. Wright R-3350 radial aircraft engine. Great vids chaps! Massive fan of your work!!
Never heard of this before and its very fascinating to me, I've heard of a turbo and supercharger combo before. Thanks for sharing and as always Keep Building👍
It's primarily a diesel thing, I can't recall any petrol cars using compound turbos...
Same same but different haha. I’ve had a compound turbo setup on my Subaru and it worked great! Until i starved my low mount turbo of oil haha
There are a number of gasoline engines that use compound turbo setups. The Toyota 2JZ-GTE comes to mind.
Subaru b4 legacy ?
Jacob Skinner that’s a sequential turbo setup. One is on then the other
Way to go Al I could listen to you all day mate and I usually fall asleep listening to people 😂
The reason you would want to go to triple turbo setups is to allow for better spooling speed vs one very large atmospheric charger. It also allows for lower smoke output on the street during transient throttle on non emissions diesels making above about 1000hp while making throttle more like a factory truck.
Compounds are probably the hardest to tune, making the transition smooth is double the tablespoon have to modify basically. When tuned correctly it can drive like stock and be a monster, my Cummins runs compounds and now limited by fuel… it tows like tug boat, it’s a beast, and being able to have the air for your engine is awesome. The Cummins guys run compound just like this but they run triples just for the dyno numbers, but you will notice when they sled pull, the run compound, or just one big single cuz your literally pegged, those big singles though take nitrous to spool the turbo but the triple doesn’t need nitrous to spool. Because the primary turbo helps, but you will be limited in dyno numbers overall on a compound your power band will be 5,000 rpm of usable driving instead of spooling up at 4400 rpm on a Cummins and using 1500 rpm of usable power.
Al, have you guys ever considered mounting the external wastegate on the outer portion of the Turbine housing???
The net result is you (if you installed in the right place) increase the turbine size at the same time you bleed off boost. Make sure you mount it at an angle so the turbine gasses don't make a sharp turn.
The turbine housing is cast steel not iron, so it welds easy.
And there I was remarking in the last eps comments that it was a pity you didnt touch on Compound Turbo set-ups..... :v
Glad you saved it for a separate, more in-depth & practical episode- thank you!
BLeeKiis Too haha me too
the bestest show down-under and the earthed antidote to the 2nd best show in oz!
the bestest show down under is on tomorrow "bathurst"
van the man.
Great stuff guys! Just some useless info, the original compound turbo charger was a complicated set up that was used on radial aircraft engines like the engine in the super constellation,
it was coupled directly to the crankshaft through a weird clutch set up ie; not used for boost but introduced more torque directly to the crank.....
Takes a mad man to invent the turbo. It takes a crazy person to mess with one. Nic video big lad👍
That was a great explanation of compound turbo charging well done Al
This show is awesome! I'd love to see the tuning process, the nerdier the better.
Great explanation on the working of compound units.
Keep up the good work, big hello from Portugal.
Yeah. these guys would make great ads for Australia I reckon. An anodyne for all the crassness that often seems to be what people are shown. I think I've said it before in other words, but it's relaxing to see the calm competence applied to problems.
Hey guys
I have an idea for a video for you guys.
I see a lot of videos focusing on the basic tools you'll need to complete a job but you hardly ever see a professional like Al explaining what tools he has bought that make his life easier when working on so many different cars. I see Marty fell in love with your multi tool with the ratchet head attachment.
I would be very interested in seeing what tools or power tools you have bought and will never go back to the old way type of thing. No matter how expensive they may be what tools have paid for themselves ten fold. That kind of thing.
I am slowing getting use to wrenching on my own cars and Id be very interested in seeing what someone like Al considers his most worth while purchases for his shop. Or personal garage. And I'm sure a lot of people would too.
Cheers guys love the show.
Yaaaay Bedford. You're very generous with your hard earned knowledge.
I love this stuff . I learn so much . Never any bullshit. Love it
Great work guys. I’m doing and have done before a compound setup on my Subaru Forester GT. Loved it!
f**king top show al and woody, love kicking back smashing lemon aids and watching the skid factory... gotta do more skids in the shop, fill it full of smoke..
Al’s an artist.
Awesome presentation Al! You've really become a great teacher. Please don't forget gloves when you weld mate!
Thanks for sharing all your knowledge Al!
I want a follow-up on this car!
With the setup shown in this video, there's no wastegate dumping to atmosphere. Every kilo of air that enters the exhaust manifold is going full speed ahead through that secondary turbo. I get it, works great on a diesel application, but gasoline/E85 applications require any excess of energy to be dumped to atmosphere in order to keep the boost in check. By using an exhaust manifold reference for the primary turbo wastegate and using an intake manifold runner reference for the secondary turbo wastegate, we can both keep backpressure under control across the entire spool range and rev-range; and we can also control boost in a linear fashion without dips in the curve. Your backpressure and boost curves would look like a flat line after 3000RPM because everything would be set mechanically in a controlled fashion. Even if you wanted to rev it to 9000RPM, you would still have the possibility of seeing 30lbs of boost from 3000 RPM to 9000 RPM, and that makes a damn fun and damn efficient street car and effective race car.
I love compound set ups, so cool. Although, I though the intake going from the primary to secondary went the other way around..? So, the primary actually sucks the air in through compressor intake which then directs its boosted air into the intake of the 2nd?? That’s how I thought they worked, but obviously I could be wrong. Great stuff fellas!
Would like to see it on the truck...and how much it makes...and of course some skids
Great explanation!! The triples are for exceeding 100-150psi. Crazy boost land. The fastest 4 cylinder is a trip compound Aussie rig I believe.
The real benefit amounts to lower boost threshold and lag minimization, but the cost, complexity, weight, and space required for compound (i.e., sequential) setups is such that many people choose to go the single-turbo route.
We also watch from Africa..
Mwangi Kanyoro tuko ndani ndani ndani
Do a 'my town' for the Unicorn circuit!
Where in africa bro
I am in Angola 🇦🇴 and love your channel
"More pipes, more glory." Brilliant.
Great channel. Looking forward to the rest of Bedford build and whatever else you got going.
I believe the reason why they are now using 2 turbos as the secondary instead of one is because it fixes what you said about it takes more time to build boost having one large turbo as your secondary. By having two smaller turbos for the secondary, when your building RPM's you can direct the air thru one of the smaller secondary turbos to quicker reach it's maximum range of boost efficiency quicker than the increasing exhaust gas can be used to reach the primary range of efficiency for the 2nd smaller turbo, thus making the system as a whole work more efficiently.
Awesome job looks much better, hope it brings results. Keep up the good work Skid Factory is one of my favorite channels. Wish I could have made the meet and greet in Dunville but it was the same day my girl friend was getting bone marrow transplant :(
Want to see this getting tuned!!!!!!!!!!! I know.. it won't be easy. Keep them coming!
Love it, someone knowledgeable talking on a great subject
Keen for the old before and after comparison, will eagerly await followup video
I love these videos. I mostly just wiz around, youtube in ears when doing stuff. These videos have me sitting still, ears and eyes perked!
These are my favorite videos. Love learning Al. Thank you.
Another well presented tech topic. Al Im sure you know more about turbo charging than I will ever know. This topic got me thinking about how compound turbo could work. Obviously carefully selecting housing and compressor size and so on is the first hurdle. In the area of control, could the smaller/primary turbo boost pressure reference the outlet of the second turbo to appropriately manage final boost pressure rather than let the primary go max all the time??? Would that possibly help reduce the exhaust pressure load? I would love to see an episode or series on R & D of a compound setup to see what methods and size combinations delivered the best output.
I guess this is where manufacturers spend millions and the tuning world has to do our best to modify the work they do...
I have a genuine question for turbo Yoda. I (thought) I understood the basics on how turbos work. For this compound setup, I understand that both turbos use the exhaust gasses to get spinning, but why is it that the smaller turbo is getting fed through its intake from the charge port on the large turbo. Shouldn't it be the other way? Spin up that small turbo first, use the charge that it creates to spin that large turbo quicker, then use the charge from the large turbo to feed the engine. In your demonstration, you were feeding the small turbo with the big turbo, which meant that the small turbo was going to be feeding the engine. Am I just misunderstanding what is being accomplished here and all compound turbo setups are like this where it goes big->small->engine? Shouldn't it go small->big->engine?
The large turbo needs to be the one that breathes from the atmosphere because the bigger compressor inlet diameter can flow a higher mass flow of air before reaching the Mach limit.
Great explanation on turbos. learned heaps.
I like the way you think Al.. i was always told is what you are saying about the pressures across the head best way is equal in and equal out across the head .. placing the external waste gate on the small turbo and allowing the restriction to move around it but still feed the bigger is the way i would do it
Interesting concept and i think this is the setup my Audi SQ5 3.0TDI biturbo runs.
I was thinking the Westgate is to small getting to much back pressure. Love your videos always.
Don't forget that at high boost pressure your dynamic timing is significantly advanced.... You also need to shorten the length of time the fuel pulse is occurring and the only way to get the correct volume in a short time frame is larger injectors
Glad I follow this channel, really cool to see how these things work and why!
Honestly, this was a great video on compound turbos.
Al has made a lot of improvements in presenting no where near as much “awkward” good on ya mate
Thanks for a particularly good episode guys; I learned a lot from this one!
Great episode! I hope to see this on the dyno. Keep up the good work.
Havnt watched its yet. But i already know its worth a thumbs up.
You need a LOT more wastegate than a typical internal gate. Same for the big turbo, it should be 1.5-2x higher flow than the small. The reason the small turbo can flow so much more - it's ingesting compressed air, which takes up less space. It's also getting most exhaust bypassed thru the wastegate. I just hope you guys get some vids of it on the dyno!
I was gonna ask about the Bedford but looks like you covered that at the end.
Best show on the tube!!! How is the new stainless pipe sealed to primary turbo. I noticed it moved when you put your hands on it... slip joint???
Al can we have a follow up on your buddy's compound turbo setup? What method is he using for wastegate signaling?
A year already wow, keep up the great footage can't wait till Monday 👍👍👍
Good explanation of how the compound system works. I think Alen misspoke at one point though, a turbine isn't using the exhaust heat to spin it is using the kinetic energy from the exhaust flow leaving the engine.
It uses both kinetic and thermal energy. The temperature drop across the turbine has a direct relationship to the energy recovered from the exhaust stream. Kinetic energy recovery is dependent on turbine blade design, and how effectively pulse energy is preserved in the exhaust manifold.
Excellent presentation. Thank you!
Brilliant job, mate!
TurboYoda... Legend... I was trying to understand what you said, I still have no clue what you on about, but i think i learnt something... maybe later on... but that was some great info. cant wait for the barra bedford... sweet.
Hi Guys - I saw that Borg Warner had developed a twin scroll turbo with a variable diverted which could channel all exhaust gasses into one turbine housing and then progressively open up the second intake on the second larger scroll. It looked to have achieved a similar trick to the compound turbo but in a much simpler package. the diverted tab was also cast iron and very robust so very good for petrol engines with high EGTs. Have you seen these turbos in the marketplace? It was at SEMA a few years ago and it was covered on engineering Explained.
secondary turbo should be 25% larger in: a) CFM, b) compressor "size", c) turbine "size" or just a happy medium between all 3?
Good question, I was wondering the same thing.
You guys are boost gurus!!! Thanks for making these gr8 videos!!
Al is such a master.. woody is really lucky to work with him