When it Runs Best WITHOUT The Belt! - SuperChargers - Joe Abbins w

[@Jagg61]

Years ago I specialized in carpet cleaning truck mounted machines. They normally had a Suterbuilt blower ran reversed for suction rather than air charge. We always had to do the math for cfm.

[@BarryTsGarage]

That’s interesting, I had no idea they used a blower for suction in that application. 👍

[@DeVoNmotorsports]

If the blower is too big then it will be trying to flow too much AIR/CFM at a specific speed/pressure of the blower, can disconnect the blower and measure cfm using a mass airflow sensor, with it disconnected and then add a restrictor plate to simulate intake valves open,

[@Lou2024-b8j]

Just proves the old adage Sometimes... Less is More Too funny....blower works better not even turning..🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣 How do you work that into a sales pitch???😅😅😅😅 .

[@Lou2024-b8j]

Just occured to me... Knowledge really is Power 😅😅😅😅😅😅😅😅😅😅

[@BOBHLDRMN]

The answer is simple. ::: With today's technology you use A brushless motor to drive your blower or turbocharger.. and you can set up your boost pressure through your RPM's too wherever you want it to be ... !!!! ... the best for horse power... !! Not so much economy.. is my Opinion

[@BarryTsGarage]

That sounds pretty cool!😎

[@dukecraig2402]

This is the same problem supercharged aircraft engines had because of the changes in altitude and air density as an aircraft flies, it also has to do with the myth of the Merlin engine being more powerful than the Allison engine, it wasn't, in all reality the Allison was actually more powerful than the Merlin and is why the P38 was the first fighter in the world to break 400 MPH in level flight, but when the P51 was designed the Allison didn't have a 2 stage 2 speed supercharger as the US Army has funded development of the Allison engine and up to that point had only paid for the development of a single stage supercharger on the Allison engine because they wanted all their aircraft to have engines with single stage superchargers that were compounded with turbos for high altitude performance, that was the best way of dealing with the changes in air density at varying altitude and gave superior performance at all altitudes. Because they climb when they fly aircraft have to deal with the same problem a supercharged Pikes Peak racing car would have to, if you put a supercharger on one of them and tuned it to have max boost at the base of Pikes Peak then half way up the mountain you'd be down on power and at the top ⅓rd you'd really be down on power, likewise if you tuned the blower to make max boost at the top ⅓rd of the mountain you'd be way down on power at the bottom ⅓rd because of "overboost", down that low the driver would have to watch the boost guage and could only depress the gas pedal far enough to make max boost, say 30 psi for example, down lower in the thicker air you may be able to make 30 psi by being careful and not pushing the gas pedal down too far but that's where you run into an issue aircraft had to deal with called "throttling power loss", even though you're making max boost of 30 psi power will be down because your throttle plates are partially closed and the engine is being drug down because it's fighting a vacuum between the throttle plates and the blower, that's what "throttling power loss" is, max power can only be achieved when max boost is being made AND the throttle plates are wide open, so the best way to tune the blower on a Pikes Peak car would be for the middle ⅓rd of the way up the mountain, at the bottom ⅓rd you'd have throttling power losses but not so bad, during the middle ⅓rd of the run the driver would be able to hold the gas pedal all the way down and make max power throughout that range and at the top ⅓rd would still be holding the pedal wide open, power would be starting to drop because of the thinning air but it's the best all around compromise for what you're doing. In the earliest days of supercharged aircraft engine's that's exactly how the pilots had to fly them, down low he'd have to keep his eyes on the boost guage, as the aircraft climbed he could keep inching it forward until it was opened all the way while simultaneously making max boost, that would be the sweet spot where it was making the most power, then eventually he'd climb to altitudes where because of the ever thinning air eventually power would be low enough that it didn't have enough forward thrust for the wings to achieve lift, but since oxygen systems for pilots didn't exist yet that didn't matter because the human couldn't go any higher. But eventually by the 30's with the advent of ever increasingly powerful engines combined with all metal aircraft, enclosed and heated cockpits with oxygen masks for the pilots altitude once again started being limited by the engines, really their supercharger systems, so basically there was two ways of doing it, multiple speed and eventually multiple speed/multiple stage superchargers, or a single stage/single speed supercharger that was compounded with a turbo for higher altitudes, that system produces max power at all attitudes but is more expensive, more complex, is bulky and takes longer to design and develop an aircraft around all the ductwork involved, the P38, P47, B17, B24, B29 and several other USAAF aircraft of WW2 had the turbo compounded single stage supercharger aircraft engines and is why they were all unequaled in performance for their classes at the highest altitudes, but once again those systems and the aircraft that used them cost more, but like everything else in life you get what you pay for. Multiple stage/multiple speed supercharger aircraft engines leave the pilots with the same problem our Pikes Peak racer has, overboost and throttling power loss issues at lower altitudes but because the supercharger has multiple speeds and stages that phenomenon happens multiple times while climbing to the highest altitudes, every time it shifts into a higher range the throttle has to be reduced to prevent overboost, then eventually climbing up to a sweet spot then doing it all over again, there's also another issue and that's parasitic power loss, every time a system like that shifts into a higher range it's about a 150 HP drag on the engine, at the highest altitude it's around a 400 to 450 HP drag on the motor, but not with the turbo compounded system of the type US Army aircraft of WW2 because the engine was only ever driving a single stage single speed supercharger, the turbo was basically free from being driven off of exhaust gasses, it took a little power to drive them but it's negligible compared to the multiple stage and speed mechanically driven supercharger systems and their massive parasitic power losses. The way the turbo compounded systems worked was at low altitude the turbo did nothing, its waste gate dumps diverted exhaust out of them and didn't even drive the turbo, then at around 9 to 10 thousand feet where a single stage single speed supercharger can no longer make max boost the waste gate valves would start to close directing exhaust gas to the turbo to drive it, the turbo in turn kept the inlet pressure at the supercharger at the ideal level for that sweet spot performance all the way up to maximum altitude, no up's and downs on power while climbing like with superchargers that shifted through different ranges, which by the way experienced the same issues while descending, with the turbo as the plane climbed anywhere past an altitude where the throttle lever was "firewalled" the pilot had a boost lever that the more it was pushed forward the more it closed the waste gate valves and diverted more exhaust driving the turbo faster and faster the higher he climbed, while climbing he'd just keep bumping the boost lever forward a little at a time keeping the supercharger at max boost (actually they had automatic systems, which could be shut off and run manually, for the sake of explanation it's just easier for people to understand the system if thinking about having to have run it manually). No additional parasitic power losses from shifting into higher ranges and no "up's and downs" with power while climbing is why the US Army wanted all their aircraft designed with the turbo compounded supercharger system, but the P51 wasn't designed for them, and when it was designed the British didn't want a turbo involved with the system, whether or not that was a mistake is debatable, but the reality is when it was developed the only engine available to North American Aviation was the Allison engine, and because the US Army had been the only customer up to that point for the Allison it only had a single stage single speed supercharger as no one had ever paid them to develop anything else, the RAF desperately needed every single Merlin that was being produced by all the British contractors and couldn't spare any for its development, which really didn't matter anyway because as of when the P51 was designed and developed the 2 speed 2 stage supercharger variant of the Merlin wasn't being produced yet anyway, at that point the Merlin still only had a 2 speed single stage supercharger variant which was only good for medium altitude, Packard hadn't started producing their variant of the Merlin yet either, it was in the developmental pipeline but wasn't being produced yet, so it was simply a matter of developing the P51 with what was available at the time knowing that an engine swap would be happening sometime shortly down the road. The myth that the Merlin being more powerful than the Allison comes from an abbreviated version of the true story of the P51's development, it ignores timelines and supercharger types and is just an easy sell to people who don't understand and know about the different supercharger types on aircraft engines and the entire story of the P51's history, the reality is the Allison is 60 cubic inches bigger than the Merlin so given the same boost levels and same octane fuel it's going to make 60 cubic inches more power, it's also vastly superior for military applications, it's a truly modular engine and can even have its direction reversed in the field by mechanics, unlike the Merlin which requires specific reversed direction camshafts, the Allison doesn't, by dropping the crank and turning it around, along with rearranging 4 of the cylinders sparkplug wires only in one engine bank and installing a small gear on the back of the engine that turns all the pumps and accessory drives in the correct direction it was simple to reverse it's direction, it was a very well thought through engine when it was designed, and by the end of the war Allison had indeed developed a high altitude supercharger system for it, ot was used to upgrade the P39 to the P63 which was essentially a high altitude version of the P39, the same engine when put in the Twin Mustang and experimental models of the P51 had much higher performance ratings than the Merlin versions, but during the war they weren't going to shut down production to swap engines.