TURBO VS BLOWER-WHO DOES BOOST BETTER? CAN A BLOWER AND TURBO MAKE THE SAME BOOST CURVES?

DOES A TURBO MAKE MORE HP THAN A BLOWER? DOES A BLOWER PROVIDE IMMEDIATE BOOST RESPONSE? CAN A CENTRIFUGAL BLOWER BE MODIFIED TO MAKE THE SAME BOOST AS A TURBO? WHAT HAPPENS IF YOU SPIN UP THE BLOWER THEN BLEED OFF THE EXCESS BOOST WITH A BLOW OFF VALVE? CAN YOU CHANGE THE RISING BOOST CURVE OFFERED BY ANY CENTRIFUGAL SUPERCHARGER AND MAKE IT FLAT-LIKE A TURBO? CHECK OUT THIS VIDEO WHERE I COMPARED THE BOOST CURVES OFFERED BY A COUPLE OF CENTRIFUGAL SUPERCHARGERS TO THE CURVE OFFERED BY A TURBO. CAN THE TURBO BE DUPLICATED?

[@baby-sharkgto4902]

I have a built 427 with an F1a Procharger and I thoroughly appreciate the centrifugal boost curve as it helps immensely with traction. I couldn’t imagine ANY more boost at lower RPM as it would not work in my application.

[@Bikemad24]

Are you in the uk with that car?

[@baby-sharkgto4902]

@@Bikemad24 on the U.S.

[@Bikemad24]

@@baby-sharkgto4902 only ask as there is a us airforce guy stationed here with a almost exactly the same car and setup as yours. Soo cool

[@YZFoFittie]

Nah, you just need proper setup and driver mods. Running an 09 Z06 with TVS2300...

[@baby-sharkgto4902]

@@YZFoFittie hahahahhaha thats cute. Add 4 or 5 hundred horsepower then come back and talk with the adults 👦

[@CraigPatersonII]

Well what if you use an oversized procharger in relationship with a target power? Like using an F1A94 to make 700hp. It can do that early on and then be wastegated to keep boost pressure at a target. You could also spin an oversized procharger faster, which would give even more ability to flatten the boost curve. The advantage of an oversized procharger would be it doesn't need massive displacement to spool it. Seems like the disadvantage to centrifugal blowers is the speed of the gear/impeller system. The thing that is overlooked is that the gear drive system has much more torque driving it than exhaust gasses. That means it can easily drive a larger impeller which moves more air. Which would result in higher airflow.

[@robvas]

Bigger blowers take more HP to turn and aren't efficient at lower boost levels

[@richardholdener1727]

and the bigger blower is often actually less responsive at lower impeller speeds

[@tunerdadtunerdad7927]

Smaller blowers overspun are almost always more responsive and more fun to drive than a bigger blower turned down. Even the smallest p1sc-1 procharger can make 700whp, and gets there quick.

[@TravisFabel]

You need a CVT like they use on go karts with big motors. You could set an RPM limit for the supercharger, with the weights and ramps... Then you could have a ratio that would spin it up quicker and then hold it there.

[@andyharman3022]

A continuously variable drive is the Holy Grail for centrifugal blower guys. Use a high step-up ratio at low engine rpm, and decrease it as revs build to keep the impeller speed nearly constant, or tailored to meet engine demand. The added weight, volume, and parasitic loss would be major problems to overcome. By the time you got done making the centrifugal act like a turbo, you should have just bought a turbo in the first place.

[@richardholdener1727]

I saw those at the store in the unicorn tear isle

[@kyletrautwein1676]

@@richardholdener1727 hey there Richard love your videos, just commenting on this post to hopefully get your attention. What are the best resources whether it be videos or books or youtube to learn how to build engines. I haven’t really done any engine work but it’s the most interesting thing to me and I want to do it so bad. By the way I have a 94 cobra with a 5.0. Please keep up the videos, your knowledge is invaluable I hope you know that.

[@mythos000000025]

Procharger makes an electronic controlled variable centrifugal supercharger, the i something

[@billclark5943]

If a CV or tunable drive isnt available it's probably because of cost. The technology is there. If that was resolved there would be little benefit if any in using a turbo. The trade off under the hood would be some parasitic loss and drive cost of a centrifigul vs exhaust system cost, complexity and thermal management for a turbo. Performance could be similar

[@4x4Mudmaster]

Go kart /snow mobile cvt with a small supercharger on smaller engine should work. M90 on a k24. Perhaps?

[@ElJefeUnderTheCarport]

First

[@kcdesignconcepts5216]

If you want instant boost and low-end torque, positive displacement supercharger all the way. No lag, no spikes ,no drama. Na power increased from idle all the way to redline. Without two-stepping, anti lagging, brake boosting, or any other trick to make your car fast. Turbos are more efficient. But everything you have to do in order to make big Power with a turbo is waste.

[@calvinevans8305]

The procharger I-1 has a CVT transmission built into it.

[@madmodsgarage1179]

I actually very often like to do the opposite, using an EBC, shaping a turbo boost curve into a rising one, limiting low end torque and saving fragile parts of the engine and drivetrain. That's also why I like turbos, combined with EBC, you can shape the boost curve however you want, in my case I had it flat to 4000, then lineary rising it to the redline, just to flatten the torque curve after it naturally wanted to fall off (thus rising and moving the power peak - results similar and better than camshaft swap)

[@pr0n5tar]

Best for ur engine life

[@kennethpowers8995]

That’s a good idea for SBE stuff, but for people actually trying to go fast/make power that isn’t really ideal.

[@madmodsgarage1179]

@@kennethpowers8995 yes of course, every solution has its place, I'm talking about street setup that needs to survive high milage use and quite weak motor - in my case the ford explorer 4.0 ohv. I'm getting close to 500 ft lbs @crank in a manual setup and start getting concerned about the flywheel to crank joint

[@4x4Mudmaster]

Do you have a build thread or video?

[@kennethpowers8995]

@@madmodsgarage1179 do you mean you are concerned with breaking the snout off the crank? I’ve seen guys make upwards of 800 ft lbs and not scatter anything related to the stock crank or flywheel. The key there is not setting the vehicle up to where your going to dead hook it when you dump the clutch. Keep it on a radial to where you get some tire spin if you plan to launch the vehicle aggressively, or just don’t come out of the hole super hard and you should be absolutely fine as far as the crank goes. I would be much more worried about stock rods/rod bolts at that power level.

[@chrisallmond6867]

Does the market want a centrifugal blower drive with multiple speeds? Should be viable with a planetary gearset and clutch packs. Managing the car during blower drive ratio shifts could be problematic.

[@brandonharze2133]

I’ve seen roots blower cars making 2-3 lbs😂😂😂😂 hell on a street car that’s a decent amount of power may not seem like much on a race car but 3 lbs on an already semi quick daily will make it damn near unsafe to daily depending on the driver lol

[@johnbrooks2122]

Well u add more boost at low end by closing off the bypass but then it puts lot pressure on a close throttle plate .I know I had 90 5.0 mustang without one at all it boosted at 800 rpms.

[@jasonandjenparks1523]

Have you done tests of similar sized Chinese vs name brand turbos? Do they make similar power?

[@JMiller317]

Beefcake Racing has been doing this for years with their coyote builds!

[@brandonharze2133]

All things equal a bigass turbo and nitrous to spool/cool it is the winning combo when rules aren’t a factor

[@brendavanorden9550]

Procharger made an I-1 blower capable of what you are trying to do.

[@adammoore5686]

You nailed it with last 60 seconds. You are like the Jedi master of engines. The racing community as a whole owes you a debt of gratitude.

[@michaelblacktree]

I always laugh when people ask those "how can I make apples taste like oranges?" kind of questions. 😛

[@sc1911acp]

A CVT transmission in the blower is only thing that would do it.

[@SazanD1]

Why dont theese things have an internal CVT to get a higher rpm at idle?

[@a807511]

so use a 10" crank pulley, and a 2" blower pulley.

[@Turbo_rito]

The i-1 procharger has a cvt to control the speed of the wheel

[@daverr8163]

The ratio 6.22:1 ,7.995:1 and 10.01:1 is misleading because its written backward. It would be ok written like this 1:6.22 , 1:7.995 and 1:10.01. This is how it should be written 0.16:1 , 0.12:1 and 0.09:1 , to show accurately the overdrive of the supercharger.

[@richardholdener1727]

it is written correctly

[@beartodrift5345]

Oh man, I was really hoping to see a dyno where the bypass valve opens and bleeds off the power at the top. We understand the turbos make more power. Some people just want to limit the boost amount, either they feel they don’t have a low enough compression ratio, components to match, or worries they’ll make too much power for the stock block. Good video but your opening statement had believe you’d show us a graph with bleeding off boost.

[@vintagespeedshop]

You should try a Rotrex centrifugal supercharger which have much higher impeller speeds than the Procharger. the Rotrex impeller speeds are as high as 240.000 rpm due to a 12.67 : 1 internal drive.

[@richardholdener1727]

THEY ARE VERY SMALL IN SIZE AND FLOW

[@177SCmaro]

You almost need a cv tranmission to drive the thing fast at low engine rpm and slower at high rpm or, you know, just put a turbo on it.

[@Rjpracingaususa]

nitrous oxide will sort out the problem.

[@ryandoyle4344]

Procharger I-1, if memory serves me

[@cz75tactical9]

Could i get away running a torque storm at 8psi with water to air on my 10.3:1 iron head 360 magnum on pump 93? It has forged pistons btw.

[@richardholdener1727]

yes but it might not make 8 psi on that motor

[@jdcarguy1242]

So, a cvt for the drive side. Not impossible, but likely too expensive. More possible would be an electric motor driven blower on some type of hybrid.

[@montycrain5783]

Do you think the reason the curve is rising so severely because the power drain of the centrifugal at low speeds vs no loss turbo ? In other words the centrifugal almost eats up more power than it increases until higher engine speeds where it’s more efficient.

[@richardholdener1727]

the parasitic losses increase with engine speed

[@TheProchargedmopar]

Procharger drives more "naturally" without electronics. 😋

[@phillipchastain2295]

I always thought the point of a centrifugal blower was to get top end when you were already torque limited at the bottom. Like it is a high end piece of gear and turbo was street/inexpensive power.

[@wadehatle5121]

How about engineering a cvt style drive to try to keep a more consistent blower speed?

[@richardholdener1727]

procharger has that for 1 blower

[@zrsnopro97]

Stall converter in an auto helps with getting the RPM’s up quick which equals more boost quicker. I have a 3200-3400 stall in my pro charged truck and I can hit the throttle at almost any speed and basically have an instant 6lbs of boost, it will wind out to 10lbs from there

[@heavydhit56]

ATF cooked me up a converter with a 5500 stall for my f1r combo. I'm hoping it keeps my in max boost for as long as possible

[@darkshine5]

Gday Richard mate...um whiteboard........7.995 x 2000rpm= 15990.......................hehehe

[@richardholdener1727]

listen for the word "about"

[@asherdie]

Need a CVT belt drive

[@thomaszwanink5158]

a mini cvt between the crankshaft and the blower????

[@richardholdener1727]

procharger has that for the small D1

[@lildno2007]

Would be great to have Variable Supercharger Pulleys! Like it be 3” at lower rpm to speed up blower speeds. Then with rising RPM IT EXPANDS TO A MAX 5” to slow blower Down 🤯

[@seancollins9745]

I'm up for the challenge to design this

[@lildno2007]

@@seancollins9745 I’m sure in today’s world somebody can. Some kind of variation of a clutch

[@robvas]

Wish some would loan you a wastegate so you could test this out for real!

[@richardholdener1727]

I have plenty of waste gates

[@wingnutks]

I think the cool thing about centri blowers is that they basically turn a 400ci small block into a 600ci higher revving small block lol. I was surprised at how weak the D1X was though. I have a D1SC on a 400ci sbc and with a 4.75" pulley it was at 11.5psi at 7000RPM and made 847hp on an engine dyno. With the 3.70" it was around 16psi and 950hp. I would think a D1X pullied like that would either make more than 800hp or more boost than that(because of restriction).

[@RyTrapp0]

I guess when you look at where you really see this kind of thing being done, it's in BIG HP race cars with the largest head units on the market(try to run "too big") so there's a real meaningful amount of CFM at lower RPM. Then we get into another problem with centrifugals... ...(breaking them)...

[@patlandymore7035]

I like the idea of the snowmobile type pulleys with a manual controller on the main pulley. It should work. Believe either Ford or Studebaker used something similar in the late 50’s with a blow thru Paxton setup. Another interesting supercharger drive is from a German WW2 aircraft. Look up the DB-601N engine. It had a fully variable speed drive centrifugal supercharger on a very large engine. Kind of like a variable stall torque converter.

[@maxwolthuis]

Dude that intro music always gets me hyped no matter how crappy my day is going

[@blainerd53549]

Although cost prohibitive, I'm thinking a dual stator AC induction drive motor utilizing 'linear' program controllers with an electronic drive clutch and a 2nd belt to drive the PC head pulley would be more than sufficient for precise, nearly limitless variable impeller speed to engine rpm ratios, up to clutch cutoff speed when the engine has reached an rpm capable of supporting pulley speed. Conversely, the lessened amount of drive power required to create usable boost pressure at lower engine rpm itself could create an inversely proportionate declining torque potential that in itself could be then reapplied to the engine crankshaft, increasing low speed combustion effectiveness and potentially decreasing fuel consumption.

[@hostilehemi9740]

Not sure the goal in trying to mimic a "flat turbo boost curve" with a centrifugal, we all know the curve is linear, and the boost increase is not, a goal for me at least, or not at least interesting, what I am interested in, is the increase in torque, say around 3,500-4,000 RPM range with 3.5" pulley vs a 3.1"....what are the power gains at the same RPM? Wastegate is merely to limit total boost on factory pistons and rings

[@b20vtec83]

It could potentially work if the centrifugal supercharger has a miniature CVT box/housing designed into it. This way over speeding the blower at the top end and generating excess heat for IAT's and parasitic loss won't occur. And you won't need a boost by pass valve. So at low rpm we could spin it at 160000rpm like a turbo and the CVT would taper the drive ratio down to 65000rpm at the top end for example.

[@ryandoyle4344]

Procharger I-1, this was available a few years back

[@b20vtec83]

@@ryandoyle4344 was it cvt or step geared?

[@richardholdener1727]

only for a very small blower and try to actually get one

[@phillipchastain2295]

People forget about the extra work with higher ratios. But I never thought about the daily driver aspect of less air (so less fuel) at lower rpm, then when the engine climbs you can get the power you want. Makes me think.

[@angelovasilikos7980]

So why wouldn’t the manufacturers design them to do that????

[@richardholdener1727]

TO DO WHAT?

[@angelovasilikos7980]

Thinking about it now I guess it would not make sense to but to design a centrifugal supercharger work more like a turbo.

[@augustinlopez5662]

if you put a 469 comp cam with a summit racing turbo do you have to change heads, rods or pistons ?

[@corndoggerman]

You would also most likely lose top end power using a blower at that rpm since you are wasting a significant amount of the generated air flow on top of taking the impeller out of its efficiency range.

[@rancherlee]

Tried this with my little Vortech 3.8l Ford, didn’t work nearly as well as I thought it would. It definitely has more midrange but lost top end power just as Richard explained. It was a fun experiment but the insanely loud air bypass and trying to manage belt slip killed the idea in a hurry.

[@notbuyingit8047]

Put a CVT drive on the blower pulley, LOL

[@brandonallison2617]

You heard it from the horse's mouth, "You should just get a turbo."

[@scudzuki]

That flat torque curve from the turbo ran from 4500 to 6000 RPM. That's a pretty narrow powerband. What does the turbo boost curve look like for the entire RPM range? I'm interested in driveablity as well as power.

[@richardholdener1727]

you can size the turbo to make it flat through 90% of the curve

[@fascistpedant758]

It was about time that you turn the intro music back up! Moving from a 4.5" to a 3.5" pulley isn't a humungous change. The pulley change and blow off valve idea is rather simplistic, you can't expect much from it.

[@richardholdener1727]

a change from 4.5-3.5 pulley is several hundred hp!

[@ericschumacher5189]

I think if a very large centrifugal blower was on a smaller engine in these tests, the effect of higher boost at lower engine speeds would be more pronounced, and get a little closer to matching the turbo characteristics.......I’m not disagreeing, but I think comparing an engine with twin s475’s to the Procharger you mentioned, is “kneecapping” the supercharged combo, because the airflow that two s475’s can move is much greater than the Procharger referenced in this test......I can’t complain because this info was supplied for free, but if the test was repeated using a 4.8L (like the Big-Bang engine), I bet the results would be more favorable for what you were trying to accomplish with the centrifugal blower.

[@richardholdener1727]

a single turbo on the big motor would have even more low-speed boost and torque-the cent will always have a rising boost curve because of the difference in impeller rpm from 2000-6500 (as smaller motor will would help its situation)

[@ericschumacher5189]

Hey Richard; yes, I agree with you in the example you just gave. What I was trying to articulate is if you compared the 4.8L Big-Bang, to the SAME 4.8L but with a Procharger that could move as much air as the twins from the Big-Bang combo, the boost response / boost threshold of EACH setup would be a little closer together for this type of test......I’m saying this because a large turbo setup would have a higher boost threshold on a small engine, and a big Procharger may “catch-up” a bit quicker if overdriven a LOT on a smaller displacement engine......additionally, if done on a chassis dyno, where you couldn’t steady state load the turbo setup to get up in the boost before the acceleration event begins to occur, the boost response / threshold may be a bit closer between these two setups (ex: on the street)......I’m not arguing with you, or trying to say your wrong in any way (I really enjoy your work), I just was trying to point out that on a different combo, the difference may not be as large as shown in this video......I have no dog in this fight.

[@ericschumacher5189]

@Richard Holdener, for better clarification; I mean in the example I gave, applied to the graph you had hand drawn at 14:30 in the video, the curves could be closer together between the two combos.

[@keything8487]

im glad you put that myth to bed !!! thanks for the videos !!!

[@yolofullsend]

Honestly, I don't think people should rate cars on max horsepower.. average horsepower paints a better picture.

[@noncog1]

Area under the curve considering gear ratios

[@richardholdener1727]

that's why I provide the whole curve

[@robvas]

What do the IATs look like when you're spinning a blower to make 12psi but bleeding it off to only make 8psi, vs spinning it slower?

[@richardholdener1727]

air temps should be similar

[@kennethpowers8995]

I think to accomplish this with a centrifugal you would basically have to change the internal step-up of the blower, not the pulleys.

[@kennethpowers8995]

Made the comment too early in the video lol, now you’re at the whiteboard basically talking about what I was speaking about.

[@mauricecooper176]

Is there a way of Changing the gears inside the centrifucal charger to overdrive it

[@normp3273]

I have a question. I have a bone-stock 1967 225 Slant 6 engine that I want to install a Torque Storm blower. I'm not looking to race the thing I just want a little passing power when I'm on the freeway. And maybe roast the tires every once in a while. Do I need to take apart the engine for re-ring or can I just install the blower? Do you have any tips for me? Thanks in advance.

[@richardholdener1727]

you can run low boost without ring gap-but it is always a good idea.

[@rushweaver2807]

This all makes sense but my question is what's the difference in science for the turbo? Does the motor not have such a significant change in exhaust gas between these rpms?

[@richardholdener1727]

a turbo does not experience the parasitic losses associated with driving the blower (it makes more per psi)

[@davidresar8256]

A turbo operates at much higher shaft rpm, a centrifugal would blow up before ever getting to the speed of a turbo.

[@ChurchAutoTest]

There are some centri's operating in the 80-90k rpm range, which is in the vicinity of a bigger turbo. Yeah the little micro 20-25 series turbos can go well over 100k, but they can't make much power.

[@aaronliddell4280]

The real question is why not just run a turbo if you want “turbo like” characteristics?

[@joseiracheta3817]

Less complicated install and less heat under the hood

[@aaronliddell4280]

@@joseiracheta3817 there was nothing simple sounding about dealing with all that was going on to try and replicate the turbo boost curve, not to mention the associated costs

[@joseiracheta3817]

@@aaronliddell4280 I was just pointing out why someone would attempt this. Not sure if can be done

[@michaelallen2501]

Have you had a chance to document and test one of the Procharger units with the CVT internals?

[@richardholdener1727]

NO SIR

[@yolofullsend]

Belt boi problems

[@richardholdener1727]

that too

[@krakhedd]

What's the difference in intake temps across that RPM range? I'm curious how much of that boost is due to heat aka inefficiency, and after all it's all about maximizing air mass. And you could maybe flatten the curve out a little with some meth, and hopefully bring those higher-rev boost numbers down I'm also curious how a CVT-type clutch would do, something to help keep the compressor shaft speed similar across the RPM range; granted this is probably leaving the realm of "practical" and approaching the realm of "R&D"

[@richardholdener1727]

procharger has a cvt drive for the d1 blower, the boost from a turbo is not heat

[@krakhedd]

@@richardholdener1727 I was talking about the centrifugal, apologies that wasn't clear. Will look up the D1 thanks

[@sw20indy]

Would love to see this comparison the other way: set up a turbo to have a rising boost curve to match a centrifugal s/c and compare.

[@richardholdener1727]

we plan to do that with the big bang motors

[@unclesquirrel6951]

Personally I blame squirrels

[@phillipchastain2295]

I thought of a similar thing, where you still keep the rising boost curve but then waste gate at the top to flatten out your top end boost. To keep it safe. Then you route the waste gate to back in front of the charger intake in order to lighten the load on the charger and maybe free up some top end.

[@phillipchastain2295]

Just trying to get there quicker but keep it top end and not blow it.

[@ChurchAutoTest]

I'm a little late to the party on this one, but I can say we have done several cars with centri blowers and a wg on the charge pipe to control boost. But it wasn't for a flatter boost curve. It was for (a) traction management in lower gears on cars where we couldn't pull out enough timing to get the torque reduction we wanted without making engine behavior wonky or (b) in situations where a car was tuned on a higher octane fuel (E85) and the boost was simply too high if the customer wanted to run 91 octane, so we reduced boost for the low octane fuel map. And note I say we used a wastegate instead of a BOV. For various reasons the response and controllability of a wg is much easier to manage than the somewhat binary behavior of a typical BOV.

[@richardholdener1727]

agreed-a WG works better and traction management is an interesting application

[@ChurchAutoTest]

@@richardholdener1727 If you're ever interested drop me an email and I'll show you the 3-level system we're using to control boost by gear on PD blowers with a bypass valve. My 900 hp CTSV is amazingly tractable even on street tires.

[@CanadaBud23]

I use a Rotrex Centrifugal on my 4.7 I6 and it seems to be pretty matched up with the motor. I get about 1.5psi around 2000rpm at 20%TPS up to 12.1psi at 4800rpm at 82%TPS. From 2-3Krpm it'll fluctuate between 1-3psi because the system is pressurizing after stabbing the throttle but that's less than a second. Then from 3-3.5krpm it'll ramp from 3-7 psi roughly. from 3500 and up it'll will gradually climb up from 7-8psi to 12psi (so far lol). I use a cogged primary drive and then use a 8rib between the jack shaft and the actual blower pulley. I can run up to 6000rpm but the belt slips quite a bit and it will jump around the 12psi mark when I do that so I haven't bothered to go that far yet. I want to do a cogged sprag for the back belt system because I hear they are good to 18psi. But yeah after all that you still only make a few pounds at the bottom. I can make a smaller cog for the front to bump that up (33t-29t cog) but the math just shows a negligible 1psi increase all the way to 3000rpm. I don't see too much of a point to drastically overspin a blower to make that huge gain at the bottom. Centri's don't really like being bled off at the top much either makes a lot of heat.

[@richardholdener1727]

the only true measurement is boost at wot at the various engine speeds

[@CanadaBud23]

@@richardholdener1727 Those few pounds at the bottom is more than enough. It'll blitz the tires quite handily. I've machined pulleys, changed drives made different ratios and it all maths out the same just at little bit different levels. It's very predictable and can figure out exactly how to set them up if needed. I myself just wanted more. So I made the drive ratio smaller and smaller but it like chasing a rainbow lol. The numbers are not true but the reference they make is accurate. I've got dozens of logs that reflect this. It's a pretty nifty idea but it would require a lot of work to just get it close to what a turbo does. In the end for most people it's just a numbers chase and is unnecessary, better to use it like traction control instead.

[@joshjenkins3815]

ALWAYS CARBURETED! Every single 454 has been CARBED! Give us EFI!!

[@joshjenkins3815]

My apologies, but still! Nobody does an ls style fuel injected 454 it’s always a single or dual plane carb :(

[@richardholdener1727]

i have efi 454 videos up

[@jhonnilund3.blystkjrskolen511]

I was thinking about a compound system, using a centrifugal and blowing it through a smaller sized turbo. I think the torque characteristics would be great. I would love for you to try it, just remember to use a BIG wastegate to eliminate the backpressure on the top end.

[@richardholdener1727]

compound is better with a roots or other PD blower and turbo-better low-speed response

[@jhonnilund3.blystkjrskolen511]

Off course it is on the low end, i was thinking for mid/top-end. But I watched the Banks monster truck series pt. 13. He found that the blower robbed some serious power when fed boost, but that may be because it was a twin screw. He even said as a closing remark that the turbo first and blower next is backwards. He hasn't said anything about it since, but I think he's right. not only is the blower restricting, it is working overtime when fed boost. Now that i'm thinking about it, maybe a PD blower into a big turbo would be the way to go. I just wanted to see you experiment with the idea, thank you for the response.

[@philipmacduffie7612]

I'm assuming most guys expected this behavior. The discharge temp will go up and the parasitic loss goes up. But two questions remain unanswered. One will the blower itself be damaged in this behavior. When running at high pressure and modest flow the torque input to the blower shaft is a value that is within it's operaitng envelope. If you open the wastegate the instantaneous load, as the flow rises to it's max free flow rate, is huge. What happens? Two when operated like this does it actually make substantially less on top due to drive belt slip. As it will at some point slip unless it's a cog.

[@richardholdener1727]

it still has to process the air that is released by the BOV/Gate, and the bearing rating it both load and rpm

[@philipmacduffie7612]

@@richardholdener1727 Yes but you are operating down and right of the choke limit on the compressor map. I would not expect the blowers internal gear box to be designed to operate there. While it may not damage the compressor itself will the belt stay on?

[@andyharman3022]

Here's a general question for everyone out there in Boostland: What is the minimum amount of boost that you would run to make it worthwhile to supercharge your engine?

[@aaronliddell4280]

All of it 😉

[@yolofullsend]

Depends on what's going to break on your car..

[@Mastermindyoung14]

I'd say 1

[@pr0n5tar]

One bar

[@4x4Mudmaster]

5psi Most can handle that

[@Ugurtosunoglu]

Just what i search 🤩

[@deanstevenson6527]

2nd. Welcome El Jefe.....👀

[@omarrfigueroa715]

Does parasitic loss increase with rpm?

[@andyharman3022]

Yes. Drive power increases with the cube of impeller speed.

[@joshlewis5065]

A turbocharger, in my opinion, is and will always be better than a crank driven supercharger, even if a CVT blowers gets invented. Here is why: 1. The turbocharger was originally made because crank driven superchargers couldn't perform well in high altitude bombers and interceptors due to a fixed compressor rotation ratio to the engine. A "turbo-supercharger" was fitted with a manual external wastegate and air/air intercooler. 2. Turbochargers are easier to control boost with and you have a larger window of dynamic boost as well as the ability to instantaneously change boost levels like in a boost by gear or boost by speed setup. 3. Turbochargers can have a lower center of gravity, as well as more mounting options. 4. You can have 3 types of anti lag to really keep the turbo spinning. Rolling, staging, and bypass. 5. From a credibility standpoint, all of the fastest production cars since the 1997 McLaren F1 have been turbocharged cars. 6. From an engine standpoint, turbochargers can keep your engine lasting longer because you can stay out of boost more often than a procharger. The dragsters running superchargers is not an argument for them, if you think that is, stick to top fuel racing

[@TheProchargedmopar]

👍💪

[@High_Desert_Tanner]

Guys in Miata circles are doing this. Using a Rotrex centrifugal that's oversized and spun fast, then putting a wastegate between the blower and throttle body. It CAN work, but the key apparently is having a much bigger blower than you would normally use. Now I've not seen this in person, so take it with a grain of salt but I've read about it in forums. The reason they are doing it is the torque limits of the factory bottom end is surprisingly low, so they are trying to get the flat curve of a turbo with the on track response of a supercharger.

[@utahcountypicazospage5412]

centri torque curve is good for not making power/torque early.turbos make torque earlier if properly sized. So I think you have it backwards

[@kylecurry6841]

Torque tax... spinning up Centrifugals at any RPM to mimic a turbo has a cost almost linear when trying to do what a turbo does that has no parasitic losses..nevermind the efficiency range the compressor was intended for, often times for flow ranges better suited at mid-high rpm's. I'm not saying centrifugals aren't worth it... They benefit from least complications in setup, but if you're really going to get the best from a supercharger, you're better off getting a Whipple IMO.

[@utahcountypicazospage5412]

Lol whipples have a power delivery similar to a centri.I think you meant tvs supercharger because if you didn’t you got it all wrong

[@richardholdener1727]

the boost curve of a Whipple TS would not be like a centrifugal-the PD blower will have much more boost down low

[@timbrwolf1121]

So if you were to twin charge that would it flatten the curve? If so what turbo setup would work the best?

[@brandonharze2133]

Doubt it’d make much sense.. these are low boost applications twin charging would only help if your turbo is making 50lbs and you’re just wanting some low end until it comes on lol but no point twin charging if you won’t even let the pro charger eat

[@Ilovegirlfights2]

1a