BLOWERS vs TURBOS-THE TRUTH ABOUT BOOST

TRIPLE TEST-BLOWERS AND TURBOS, FULL RESULTS, DOES BOOST CHANGE THE SHAPE OF YOUR POWER CURVE? DOES BOOST HELP AT HIGH RPM? DOES BOOST HELP AT LOW RPM? ARE BLOWERS AND TURBOS DIFFERENT? WILL BOOST HELP IT REV? CHECK OUT THIS TEST WHERE I COM-PARED THE EFFECT OF BOOST SUPPLIED BY THREE DIFFEENT FORMS OF FORCED INDUCTION TO SEE IF THEY HAD AN EFFECT ON THE SHAPE OF THE POWER CURVE.

[@bretc9644]

Seeing this info laid out so succinctly really helps demonstrate why turbos have become so popular with manufacturers these days.

[@rdkoehn2330]

No nonsense teaching 👍 loving every minute

[@smokeum12]

What I love about your videos is that you don't give an opinion, you give solid information backed up with experience and repeated testing. I have been following your articles since early MMFF days and they have always been about information and results, with zero agenda to appease anyone.

[@erwinnijs1]

What I like to do, with all the build-in boost controllers in the ECU's these days, is to make the boost curve RPM dependent. This allows for a flat torque curve all the way up to red line. Since torque is the limiting factor for drive lines, and drive lines are usually the limiting factor in modern day cars.

[@RustyChevy]

This is by far the best car channel on KZbin.

[@MLFranklin]

My favorite channel on all of KZbin.

[@jasonguy9917]

I'm your Aussie brother from our 351 Cleveland mother , in the early 1990's I developed what could very,very loosely , be considered a factory type , pro stock , 2 bolt main M code , with our Aussie 4.9 litre , Geelong , 2 Venturi , 54 cc quench chamber heads , reversed gudgeon ( notch to firewall) location , ( this ends compression stroke a couple of crank degrees early , and starting power stroke early .) To this I designed my own cam profile that my friend Dean Tighe , from Ivan Tighe camshafts ground up for me , if you look up their catalogue and load up the Cleveland Solid Cams for grind #764 ( there is a typo on peak exhaust lift , basically both intake and exhaust have 5/8" lift . 4venturi sizes will contact each other on overlap , max intake diameter for min safe clearance @ 275 degrees Fahrenheit is 2.145" intake and 1.71" exhaust . This recipe yields a spectacular power torque shape .

[@200mphgt40]

Great test to illustrate how boost curves work to alter the engine output. Love your work Richard. So here's the boost curve of my factory fited MP62 roots blower on a Toyota-Yamaha 2ZZ-GE motor (Lotus). Mostly standard, just smaller supercharger pulley (75 mm), water/meth injection (pre supercharger) and free flowing exhaust. 4000 RPM = 8PSI, 5300 = 10.5 PSI (Just before cam change over from small to big lobes - like Honda V-TECH), 5500 = 9.8 PSI, 7000 = 10.5 PSI (around torque peak - motor most efficient), 8500 = 12 PSI. So you can see the boost slowly increases with RPM, except for a dip when the cam changes over to the big lobes and also a section around 7000 RPM where the motor is most efficient, before rising again at the top of the rev range as the motor becomes less efficient (past torque peak).

[@Knightmare-gz9ls]

Love the torque and grunt of the roots blower. 🤘🏻 lot of fun on the street and strip.

[@rotaxtwin]

Great objective comparison. I have a new appreciation for turbos, at least on the dyno. The three would have completely different feel on a road race, for example. Turbo lag and all that. Keep up the great testing.

[@patrickmontgomery6353]

Every time I watch a video, I learn something new. Thanks Richard. Your videos are always interesting and informative.

[@lsxtuner6126]

The procharger boost curve makes the power delivery much more manageable in high power street cars. It's consistent and linear to help the driver manage wheel speed with the throttle :-)

[@bobqzzi]

Interesting, as always. Love these comparisons. In the future, I'd like to see some stuff about the tuning process- particularly part throttle/driveability stuff. You've done some great EFI/Carb comparisons at full throttle, and I'd be interested to see differences at low RPM, part throttle and transients.. Keep up the great work.

[@richardholdener1727]

part throttle and transition is best done on a chassis dyno or the street

[@ghostrt1608]

@@richardholdener1727... do a twin Torque Storm supercharger setup on an engine... they have the kits available for all the popular engines... even the Gen3 Hemi (I own a Hemi Ram, so I really don't care about other engines)

[@someguy2741]

One more boost idea... how about a pure boost test with no parastic losses? Run a boost maker on another engine at constant RPM but plumb that boost into the dyno engine. This will allow you to show the losses of a turbo.

[@richardholdener1727]

ALREADY WORKING ON SOMETHING LIKE THAT

[@CRUSHFACTORPC]

Richard you are the best and it seems almost unfair me at my age and you at yours and so much time in the past developing content that you had no idea would be so informative in 2020 from way back when. Im 53 so I know you have been at this for a minute.

[@richardholdener1727]

I think Good data is always helpful

[@BLKMGK4]

@@richardholdener1727 Data is the best and these days computers sure make life easier! Love the way you drive things with data, so very much appreciated and so very important. Need to get you a really good backup system going lol.

[@calebdean2440]

Now you just need to borrow Roadkills Boost Caboose to give an engine boost without anykind of parasitic loss on the dyno.

[@richardholdener1727]

I have something planned

[@calebdean2440]

@@richardholdener1727 You should have a second channel just dedicated to Steve Brule's reactions when he walks in on your experiments.

[@craigreschke8921]

I’m a roots guy because I’m a street driver. I want all that power as soon as I step on it. If I was drag racing then I would use a procharger or a turbo to limit the low end and bring it all in the top end. Love the videos, keep it up!

[@albertgaspar627]

Generally speaking, "boost" measures how much resistance the intake and heads offer the power adder. A lot of boost on a 2bbl stocker can make power similar to lower boost with great aftermarket heads and cam. Something to consider when fuel octane is an issue. Want to measure "constant boost" and its effects? Run single stage nitrous with a bottle set up to keep pressure constant. It applies oxygen to the cylinder instantly and doesn't "build" with revs since its revs-independant. Turbos and blowers may homogenize the air/fuel mixture if the carb comes before the power adder, but otherwise its major influence (generally speaking) is pumping more oxygen into the cylinder than atmospheric pressure can do without the power adder. The higher compression also helps, but its the efficiency of cylinder filling, that creates the curve RH is talking about--it follows the regular curve, just higher. Nitrous replicates efficient cylinder filling, as well. the centrifugal blower is interesting, since a lot of Mustang owners cram it into a long runner intake and small port/small valve heads made for torque that run out of breath. That's when swapping the designs really pays off on the short stroke/relatively big bore compared to a Chevy 305 TPI.

[@jeeptk]

Excellent morning video! Boost and curves what could be better!

[@pjmccoy4216]

The turbo set up seems to be best for the street car crowd. I like the idea of building a street motor. Then adding turbo. Your you tube channel has opened my eyes. I would say thanks, but the kids might have to go to a community college now!!! LOL

[@LucoreAuto]

Another excellent video Sir, thanks for the entertainment and education! You are tempting us to start adding boost to some of our classics... especially the lower boost easy to "bolt on" setups that don't require extensive exhaust/intake modifications. Who DOESN'T want a 30%+ power gain on their healthy oldschool big block!?

[@Bradley_Clark]

This answered a lot of questions, before I had time to ask. thumbed

[@TwoLotus2]

In regards to turbos, that seems to be the way it works. Tried to bulk up my engines torque down low with more boost, etc. But the main effects are more mid range and top end. As the original head was getting soft, changed cyl head with bigger ports, valves. Hurt the bottom end, raised the peak torque RPM a lot, and gained a lot of top end. Oh well... change the cam timing next.

[@ziggybmw]

Hey Richard, have you experimented with using a "wastegate" on the intake side on a procharger/centrifugal blower? I've read some articles where this has been useful. Customer/shop didn't want to exceed "X" amount of boost up top, but wanted more power down low. So what they did was pulley up higher (smaller blower pulley) and put a wastegate on the intake pipe to limit boost to whatever their number was. The result was awesome, much more down low grunt out of the blower while still limiting top end boost. So they kept the same peak boost/hp number while drastically increasing torque down low. Basically a flat boost curve similar to a turbo. Weird to see on a centrifugal, but it worked. Obviously blower speed and increased heat can come into play depending on blower size and speed, but for a street setup it wasn't an issue. Just throwing out ideas!! Love the videos and all the data!

[@richardholdener1727]

IT WORKS

[@ziggybmw]

@@richardholdener1727 can't get enough of your videos! I couldnt ask for a better channel! How can people like me help you to keep making videos? Also, my comment of "millennial lsx454 vs boomer bbc454 was a big hit!" Wink wink LOL. Thank you for all you do!

[@julianbarreras4854]

I HAVE A 2014 SILVERADO WITH 5.3 TOTALLY STOCK, WITH 2.9 WHIPPLE SUPERCHARGER, 12 BOOST, WATHER METH INJECTION. AND EASILY MAKES 600 RWH.... I LOVE BOOST

[@paulmccoy8966]

This is an awesome video hope you keep putting them out

[@MJTAUTOMOTIVE]

Another Great Video. Thanks Richard. Those subs keep climbing. Almost at 100 000 subs. Hell Yeah. Cheers 👍👍👍

[@richardholdener1727]

Thanks 👍

[@manitoublack]

You could do what Cosworth did back in the 80's and use an external air compressor and large receiver to provide a very controllable level of inlet pressure :O getting held back by my turbochargers turbine wheel/housing :(

[@allen43d]

I love your videos! Boost curves, power curves, torque curves, but why no ignition curves? I'd like to see LS vs SBC vs BBC vs SBF, etc ignition curves. Maybe even open chamber vs closed chamber heads? Nitrous vs Turbos vs Centrifical curves?

[@busij44]

Interesting info....need to include a twin screw also.

[@GrimReaper528777]

Centrifugal superchargers are my favorite type of FI. Basically a belt driven turbo so that I can set the boost response at whatever rpm (by varying the stepper gear ratio and pulley size) that I want with the equivalent of a wastegate.

[@merylpelosi8485]

Not to throw another variable monkey wrench in, but don't forget the parasitic drive loss for the blowers. Another great video. I wish I had half your energy.

[@richardholdener1727]

i THINK WE TALKED ABOUT THAT

[@kcdesignconcepts5216]

Very cool stuff. Trying to manage boost in a turbo application is very tricky. Without a controller, a turbo would be a raised rate forced induction. The old 671 does look cool. But is extremely inefficient. I would like to see the comparison with a modern positive displacement supercharger. At the very least , the Eaton M series.( M122 ) or the more efficient TVS. Most of which have a built-in bypass valve, to manage boost. And also use the heat exchanger. And of course At the top of the supercharger food chain, the twin-screw. screw.

[@ronnywestberry9503]

Thanks for all your hard work. I am learning a lot. What I would like to know or understand better is when you run one turbo into another or run turbo into or with a supercharger.

[@richardholdener1727]

compound stuff coming

[@NBSV1]

Running a turbo into another turbo basically just means the second turbo doesn't have to work as hard since it's got air being forced in rather than having to pull air in. That's why most compound setups have the second turbo actually smaller than the first one. A turbo into a supercharger gets complicated. Since the supercharger can cover the low rpm you typically go for a larger turbo to cover the high rpm. Which means at some point you will want to switch from the supercharger to the turbo. They don't compound like two turbos can because the supercharger is belt driven so will only spin to a certain rpm. Which means the supercharger becomes a restriction. That's why basically any super/turbo setup will have a way to bypass the supercharger when the turbo takes over.

[@Spirited_Driver]

@@NBSV1 Interesting thought.. What about starting boost with 1 or 2 small turbos, then having a centrifugal supercharger take over? This thought came from one of my cars that has 2 very small turbos that start building boost at 1800rpm and kick in very hard at full boost at 2500-6000rpm. Then a supercharger could take over around 4500-7500...

[@NBSV1]

@@Spirited_Driver Usually the setup uses a positive displacement supercharger so it can provide boost nearly right off idle. But, those become less efficient at high rpm so that's were the turbos can come in. The centrifugal supercharger could also work in that way, but then you'd be wanting to have 2 superchargers. At the end of the day it becomes difficult to manage and make work right since you need something that provides low rpm boost but also won't be a restriction or power loss at higher rpm.

[@douggorton1482]

I love big blocks with a Procharger. For the HP they make they are very drivable with throttle response being very controllable. You keep your big block lower end torque for drivablity with huge power coming in with additional throttle. Of course is you just mash it your tires will die.

[@FOURCED]

Define "Properly Sized Turbo" Richard Please. What if I want full boost (15 Psi) on my Truck at 1500 RPM. Yes 1500 RPM. ???? Yes Gasoline!! Haha Great work as always.

[@richardholdener1727]

it can be done-look at what the OEMs do with turbos-but it might not support 15 psi on the other end

[@FOURCED]

@@richardholdener1727 Please try something along those lines when you get a chance. A couple of EFR 7163's with electronic boost control. ELECTRIC Powerband!

[@billybobaggins8820]

Richard I want you to tell us about some motors that you just couldn’t get to make much power. Be interesting to hear

[@19jody72]

Now THIS is good stuff!!

[@shanestewart1498]

Keep them coming!

[@joseiracheta3817]

I'm my opinion the centrifigal is the best. Simpler installation less heat and an awesome top end

[@Turbogto_guy]

Well in my opinion a turbo is best. When you load it, it makes more tq. There’s no belts to slip. Less power loss. I can change my power levels as the press of a button. I can limit boost down to 5psi in 1st gear for traction if I need it. I can control boost by gear. You can build boost on the line. A turbo is easier on parts, there’s no tension on the crankshaft, it’s more efficient. When someone rides with me, the extra weight is compensated for. It’ll build another psi because it’s being loaded more. Your turn. Tell me why you think a supercharger is better. O and if you want to change boost levels, I don’t have to mess with a pulley. I press a button.

[@tatehalpin5686]

@@Bozemanjustin Pressure in the exhaust before the turbo does reduce the power produced. Its not free energy That's why changing from a tighter turbine housing with high back pressure to a larger housing will produce more power.

[@Turbogto_guy]

Levi Dieter Thx! I try!

[@BrendanCBreen]

@@Turbogto_guy It doesn't appear that you understand how opinions work...

[@otm646]

@@Bozemanjustin by definition a turbocharger increases exhaust manifold pressure (back pressure). That increase in pressure means that the engine is doing work to compress that air, that means that's lost horsepower.

[@Parents_of_Twins]

I was at the hardware store this weekend and the young man behind the counter is telling me how he has a 1998 Dodge Cummins that putting out 1400 lb-ft of torque and he's rebuilding a Duster and is going put a supercharged 440 in it that's running 1200hp. I know the Cummins is capable of that kind of power without a massive amount of money however I don't know much about the 440's. I'm sure that power level is obtainable but what kind of money are we talking to make 1200hp supercharged reliable streetable 440? All I really know about them is my Dad told me when he worked at a gas station back in the early 70's the police would bring their cars to the garage to be tuned and they were always complaining about the lack of power. So Dad went through the engine and by changing the timing the engine really woke up. Dad said it went from laying 10' of rubber to keeping them lit across the parking lot. He also took it out on the interstate for a test and ran it up to 140mph by the cars speedo. Apparently someone noticed because after that he was allowed to work on the cars but not allowed to drive them.

[@richardholdener1727]

a 440 with good heads, cam and intake with a Procharger can make those numbers

[@Parents_of_Twins]

@@richardholdener1727 So it is plausible. Thank you for the answer.

[@bcbloc02]

And boost is just a number its mass air density that makes the power. :-)

[@tomhammer9476]

Love that music howbot Rush ACDC and or whatever you like

[@jr78racer]

Do you have any turbo sizing math that you could share with the class? As always, excellent video! Can't wait to see more 292, 455 Buick, and 500 Caddy videos! Maybe some more Pontiac 455 videos?

[@kevin9c1]

I would like to see a comparison of BSFC between all types of forced induction and compared to N/A. And maybe a bonus discussion on turbos, back pressure and its impact on overall efficiency.

[@angelovasilikos7980]

Awesome video! Thank you!

[@nastychevys]

Prediction, before I actually watch the video. The shape of the curve likely wont change at the bottom end, but at the top end it will push both curves farther out at the top. That is meaning if boost stays the same throughout the run.

[@killerb4202]

You should do a boosted Northstar engine....id love to see what one of those bombs would do lol

[@jbr496]

Have you ever seen a centrifugal supercharger set up to bring in more boost lower but with the benefit of a turbo style wastegate to limit max boost? It tends to make a flatter power curve like a turbo. I've only seen it done on a street type motor making around 750-800hp. Kind of a fun setup to play with.

[@richardholdener1727]

yes

After 10 runs, which one will have a more stable power band?

[@jakebutler7962]

Should do a header shootout fender exist and upright truck pull etc

[@n8dawg450r]

Hey Richard, kind of an interesting scenario came to me while watching this. What if you were able to supply a given motor a remotely boosted atmosphere. Like boost provided by a separate source, not driven by the motor it's beIN fed to, in any way. No parasitic draw from a blower, no exhaust side restrictions from a turbo. And have a constant boost setting. Then compare to all variations with the identical boost curve/level to calculate what the actual parasitic loss of each form of boost is. Not trying to dump more on your plate. But you are kinda responsible for influencing these outlandish thoughts and scenarios. Lol 👍

[@richardholdener1727]

working on something like that already

[@unclesquirrel6951]

Richard sir Can we get a caddy 500 update

[@richardholdener1727]

heading out next week if all goes well

[@unclesquirrel6951]

Richard Holdener lets keep our fingers crossed mr 😎

[@J3n555]

I got a cool idea. What if you drive a procharger on a different engine, but the boost is going to another. So you can really see how much the parasitic loss is.

[@richardholdener1727]

already working on something like that

[@gregertman6497]

I think it would be cool to see how bad a motor would run if you just made a top plate for the roots blower manifold and stuck a carb or two on the manifold by itself and ran it N/A with those ridiculous short runners.

[@mikef647]

The only thing about the Root and the Pro-charger is to install smaller pulleys and then see how the curve looks

[@jeremymurphy7320]

Any chance you can do some tests with twin screw and Roots blowers comparing boost and power curves?

[@richardholdener1727]

look at the Mod Ford video that compares all forms of forced induction

[@Drake5153]

@@richardholdener1727 It would be really sweet if you could compare brands of positive displacement superchargers like the new tvs, 5.0 3l whipple and kenne bell to show the different boost curves and efficiency ranges they make!

[@blair79bear38]

like to see a direct comparison between roots style to screw style blowers. aka the big 6-71 stye to stuff made by Edelbrock and Whipple.

[@richardholdener1727]

check out the mod motor Boost Bash where I ran all four forms of forced induction on the motor

[@blair79bear38]

@@richardholdener1727 Still looking. The titles don't give it away. But thats OKay. like watching all your videos.

[@robertkeime4907]

Great video

[@Riptidevulture]

Thanks. It would be best to overlay/combine all 3 power curves in 1 picture for comparison like you did with boost curves. And no, it wold not be confusing LOL. Only 6 graphs and 3 colors.

[@richardholdener1727]

thnx-this was not a comparison between the motors-only the boost curves and changes in each

[@RyTrapp0]

When you realize that "boost" is nothing more than an artificial change in the atmospheric pressure that an engine is inhaling, this all begins to make sense. Naturally aspirated engines aren't "un-boosted" engines; EVERY engine is quite literally "under boost" on earth because of the natural atmospheric pressure, what we know as roughly 14.7psi @ sea level. Your engine at sea level is, literally, "boosted" to 14.7psi by atmospheric pressure alone. Any 'boost' you add to an engine via a secondary compressor(turbo/blower; the cylinders are your primary compressor of air) is added ON TOP OF atmospheric pressure. This is the foundation for Rich's general rule about 'boost' after all - adding ~14.7psi of boost via a s'charger/turbo(that is appropriately sized & setup correctly) will essentially double the power output; because you're literally doubling the air density(at sea level) going into the intake, the SC/TC is intaking 14.7psi of atmospheric pressure, then it's compressing it another 14.7psi of 'boost'. So, if you increase the air density going into the intake equally across the RPM range(in other words, let's say you have 10psi of boost, having that 10psi equally across the RPM range means you have 10psi from the starting RPM of a pull all the way to the end of the pull at the top of the RPM range, or a perfectly flat boost curve), then the curve isn't going to differ AT ALL from the naturally aspirated curve - because the only thing that changed is the intake air pressure. It would be comparable to just running the same engine at a different elevation/altitude(running an engine at the peak of Mt Everest then running it below sea level - dramatically different air pressure).

[@wayneireland4802]

Your a champion mating👍🙏

[@niknasstie]

Anyone else notice your almost at 100k subs. There better be a viper v10 vs triton v10. Or a rotary vs a Cadillac v16 flat head. Twin procharge Something crazy for the milestone 🤣

[@gregdavis3324]

Richard, Since your video is titled The Truth About Boost, maybe we can discuss the way boost is measured? I believe using a simple pressure gauge to measure boost is misleading. The OAT and the manifold temp should be calculated into the equation. (Like a calculation for D/A) I truly enjoy all of your videos and find them informative and entertaining. Keep them coming!!

[@austindoud273]

You're talking about mad manifold absolute density

[@gregdavis3324]

@@austindoud273 Absolutely! Here's a link official.bankspower.com/density/

[@richardholdener1727]

Don't be bringing Gale Banks up in here

[@austindoud273]

@@richardholdener1727 what is he sue happy like sinister diesel

[@conwayfiddy4908]

Great video. An idea for a future video Might be turbo sizing. You kept saying the turbo needs to be properly sized, it would be good to see a future video with a turbo that is too small vs properly sized vs too big all run on the same engine.

[@austindoud273]

Check the videos he has done that

[@conwayfiddy4908]

Austin Doud oh awesome thanks. I’m going to go look for that right now.

[@derrelcarter9401]

How about a show on a late model efi "truck" that is going to tow, say up to 8000 pounds occasionally. Intercooled screw blower vs a moderate sized turbo or small twins(?) and an intercooler?? How would water/alcohol benefit either combo as a "driver"? How would fuel consumption be affected at cruise rpm with either combo as well??

[@joseebruno]

Richard could you make a video or tell me if you made it about high compression vs low compression under boost and when would be good to have one vs the other. Thanks! Great videos learned a lot!

[@allen43d]

Compression will always be limited by the fuel used

[@joseebruno]

@@allen43d thanks Allen, I get that. The thing I'm interested it's that with lower compression on the same fuel,(E85) we may be able to handle more boost and get more power. Or would be beneficial to get less boost and more compression, I believe this is just done for fuel economy but I'm not sure of this and if applies on a v8.

[@allen43d]

Jose Eduardo Bruno Your better off to keep compression higher, especially with E85. The engine will be much more responsive and come up on the transbrake/two step, much faster/cleaner.

[@joseiracheta3817]

Hi comp makes more power but it can't take much boost without detonation. Low comp makes less power but you can apply more boost and get even more power.

[@joseiracheta3817]

I think Richard has done this test before

[@bigjohn1948]

on the turbo you set it at 7lb but what if you let it run up to maybe 16lb you should have more of a curve to the higher pressure

[@richardholdener1727]

the power curves at 16 psi will be the same shape (as NA and 7 psi) if the turbo can support the power level

[@russelljackson7034]

Right on

[@CobraDBlade]

I'm assuming that screw type superchargers will act similar to the roots style?

[@NBSV1]

Yes. All the positive displacement blowers will act similar. The twin screw is more efficient so doesn't heat the air as bad and tends to remain efficient to a higher rpm.

[@dondotterer24]

I thought it was cool when the Detroit diesel 2 stroke had a turbo on top of the blower. With a roller cam if course

[@domusdebellum3042]

twin charged. check out the Lancia Delta S4. my favorite race car of all time, and it just happens to be a twin charged 4 cylinder.

[@alexlankford6301]

@@domusdebellum3042 not twin charged the blower on a detroit will add little to no boost it's there to move air through the engine due to it not having an intake stroke the turbo will add boost and the late model detroits will actually bypass the blower when at full boost for efficiency

[@dondotterer24]

@@alexlankford6301 Did the old MACKS use the Stater fan the same way? I can't remember.

[@alexlankford6301]

@@dondotterer24 my old mack has an air starter but I haven't seen anything like that every mack I've run across is a 4 stroke

[@dondotterer24]

@@alexlankford6301 Yep 4 stroke.

[@BLKMGK4]

Isn't "boost" just a measure of backpressure in the intake manifold? If you have a centrifugal blower making say 10PSI and then port the heads you'll see boost drop as power goes up. With a turbo no one ever notices this because the W/G just keeps turning it up. I used to laugh at Mustang guys that would compare boost pressure like it was pecker size and made a big difference. You want the air IN the motor not backed up in the manifold. That would be a pretty interesting test to demonstrate actually, swap or port heads and watch boost on a centrifugal with fixed pulley size drop as power goes up.

[@richardholdener1727]

take a look at the videos that are up that cover that

[@BLKMGK4]

Richard Holdener thought I’d seen most of your videos, I’ll look! I recall getting ported heads when I had a centrifugal and being upset at boost loss but the car was sure quicker. Fun stuff!

[@andyharman3022]

Would it be feasible to make a centrifugal combination that has a mild cam that would make peak power at 5000 rpm, then use the supercharger to extend the peak power to make it nearly constant to 7000 rpm? Somehow get the volumetric efficiency to fall off at the same rate the boost pressure is rising. Put really strong valve springs in to get valvetrain control to 7000 rpm.

[@richardholdener1727]

5000-7000 might be a stretch, but maybe with good heads and short runner intake and small cam

[@Mr1231mpw]

Love the videos, just wondering what does your head stud collection look like? Do you reuse a lot of the same bolts?

[@bobocaterpillar3697]

cool video! ... one question ... did the 671 have teflon sealed rotors?

[@richardholdener1727]

I think it did

[@spoolboiz204]

Just combine all three

[@sanchez_lsx1198]

I'll prefer a blower setup on the street and a turbo setup for the track.

[@masta51]

How much more power would each pound of boost take from the overall, we need the answers to the longest arguments out there. Is the diminished return worth the extra power and stress with belt driven adders. Obviously the easiest power would be all the nitrous lol

[@richardholdener1727]

THERE IS NO ARGURMENT ABOUT THAT

[@masta51]

Ahah right? Still comes up like which oil is the best.

[@motorosso3349]

Thanks for the boost overview. Why couldn't the centrifugal supercharger boost curve be controlled by a blow off valve?

[@richardholdener1727]

it can

[@BLKMGK4]

@@richardholdener1727 Can be done, sometimes accidentally, on screw blowers too. Used to see Mustang guys unhook their bypass solenoids and see power gains on the dyno lol.

[@andyharman3022]

Vortec sells blowoff valves if you want to do that.

[@7shoemaker]

What would happen if you used a supercharger and blew a turbo into it? Whould you grt the bottom end power and the top end or would the blower limit the amount of boost or fliw the turbo adds.

[@richardholdener1727]

we did that with an 03 Cobra Ford motor

[@remybrouwer8700]

I know nothing about this or anything else, but will it not be easier to keep the A/F ratio on EFI system based on rpm with a centrifugal supercharger vs a turbo based on boost since it can fluctuate if you peddle, what happens with the power recovery time ? and if you have to peddle what happens with the A/F ratio on a turbo engine, if I understand right the A/F ratio on the supercharger will track with the rpm and keep pase as the engine go up in rpm one can say butterfly position related almost, but what happens if you peddle on a turbo does the A/F tracks as well with the fluctuations and what is the recovery time of power of supercharger vs turbo in case you have to peddle, I know there is a lot of interaction between the ECU-rpm-tps-boost-O2 sensor, but is one system less susceptible than the other ?

[@richardholdener1727]

proper tuning can make the AF constant (or whatever you want) at every given combination of rpm and load

[@F22cCivic]

Very interesting video. I’m assuming during the turbocharger test, exhaust back pressure doesn’t exceed or is that much greater than the intake pressure?

[@richardholdener1727]

back pressure is almost always higher than boost unless you go to great efforts in your sizing and are not concerned about response or use other methods to improve it

[@LS__812]

Techno Techno! Good Good!

[@sammindell1090]

what would the effect be if you were to use a larger roots blower, like a 10-71 or 14-71?

[@knight0334]

You wouldn't need to turn the larger units as fast to provide the same amount of boost. 6-71=426cid, 10-71=710cid, 14-71=994cid - that is how much air they pump in on a single revolution(theoretical, not always 100%). However, the larger the roots blower, the more crank power is needed to turn it. It becomes a matter of depreciating gains. The pulleys I saw in the video on the 6-71 left lots of room for pulley swaps to increase boost. And with that - you don't want to overdrive a roots too much. There is a point where that becomes an issue. That is when you step up to the next size.

[@richardholdener1727]

those can supply more power-though not needed on this test motor

[@sammindell1090]

Might it work better on the 500 or another big block?

[@b00sted_SS]

Do you have a video of “boost types” , for instance say at a given RPM range with 10 psi boost , say 4000 to 6500 on the same engine , blower vs turbo vs pro charger ? With deduction the results would then tell us how much horsepower the blower and procharger are using to make the same boost . Does that make sense ? Have you already done it and if so what’s the video title ? Thanks

[@richardholdener1727]

YES-LOOK FOR THE 4.6l 4v VIDEO WHERE i COMPARE ALL FORMS OF FORCED INDUCTION-LOOK IN THE MOD FORD TURBO PLAYLIST

[@b00sted_SS]

Richard Holdener awesome ! Thanks Richard!!

[@williamjarman7466]

What about a blow off valve on a ProCharger to create a consistent boost curve

[@richardholdener1727]

it helps

[@YZFoFittie]

Centrifugal blowers, it's like a blower, but with lag...DERP

[@DullBoyJack]

Pro Mod cars with centrifugal blowers are deep into the 5's and trapping 270mph+. The right combo can be killer.

[@YZFoFittie]

@@DullBoyJack even so, that class is still ruled by turbos...

[@tofugypsy2021]

Would of been good to see the 3 different forced induction setups on the same engine with the same head and cams.

[@richardholdener1727]

take a look at the Mod Ford video-I tested four types on the same motor, same boost, same AF and Timing

[@jonathanduke8295]

Be one of the guys that invent something else besides nitrous supercharger and turbo

[@deadshotmotorsports7856]

So what if you use co2 to control the boost on a turbo and give it a Is linear boost curve like a procharger, will it carry the power through the rpm like a prochager dose or will it still loss its efficiency at the same spot?

[@DavidFraraccio]

Do you plan on doing a video on "How to Tune EFI"?

[@richardholdener1727]

I'M NOT A TUNER

[@DavidFraraccio]

@@richardholdener1727 who does the tuning on all of your EFI tests?

[@pache7216]

after adding boost, were u able to still use pump gas?

[@richardholdener1727]

no

[@andyharman3022]

How much boost can a plastic intake manifold take before it blows up? Would you ever run a plastic intake manifold without an intercooler? What is a safe intake air temperature to run with a plastic manifold?

[@richardholdener1727]

I've run Fast intakes to 26 psi

[@austindoud273]

People push the stock stuff to 30 psi

[@Troy_Built]

Have you ever tested a compressed air supercharging system on an engine dyno? I was wondering how the intake temperatures are affecting the power.

[@richardholdener1727]

YES-THE CAS BOYS RAN AT WESTECH AND THE AIR TEMP IS SUPER COLD

[@mortensandmoen5208]

Whay don't you try VGT turbo to get a low end torque and good flat boost curve? Is it to expensiv?

[@plepgeat]

Have you ever used a ProCharger i-1? I'm really intrigued by that blower...

[@richardholdener1727]

have not

[@TroyPatterson310]

@richard hey what about higher compression (11,12,13.1 whatever), boost, and stroke (408, 427, 468 etc.. maybe on pump gas, Race Gas, e85?😈🔥 people say it’s not safe, But they say a lot of things. You should test it!

[@richardholdener1727]

no thanks on pump gas-e85 works

[@rodrigodiaz1535]

Hey there is a demon carb 750 good for a 671 sbc 350 blower set up single carb ? What needs to be done to the car. To run ?

[@601performance5]

What’s the most effect intercooler set up?

[@richardholdener1727]

ice water (or liquid nitrogen) or no intercooler with CAS

[@minicooprc]

CAS???

[@matt59736]

I like your channel. I'm asking for your advice.I have a 77 Chevy half ton with a very tired 350 that I'm going to replace I'm either going to put a 383 or a 472 candy. at 2300 I'm at 55 miles an hour I toe with this truck.until seeing your channel I have never been interested in anything except naturally aspirated but now I'm wondering what do you recommend for a low RPM boost adder. I need power from 800 RPM to 3000.thank you.

[@bertvisser6423]

Sound like you should drop a diesel in that. low rpm torque..

[@richardholdener1727]

the caddy (even a 500)

[@NBSV1]

A positive displacement blower is about the only thing that would provide boost at 800rpm. You could go for a small turbo that would come on that low, but it would be maxed out pretty quickly as well. You'd have to be very careful though because heavy load at low rpm with boost can be hard on the engine if the tuning is right. And any power adder is also going to be adding more heat.

[@matt59736]

@@NBSV1 thanks. I'll just stick with naturally aspirated like always. That's what I know.