The problem with a supercharger is that if you overdrive them enough to get the boost right off idle, they choke pretty quick on the mid-range through the top end. You need a way to bypass it and shut it down so the charger doesn't have to "suck" through it!

Chris

 

Chris.
I have a new product in the works for getting the turbo to spool instantly. I'm building it into my front bumper. It is basicly 2 large coil springs that work a bellows assembly that is inside my front bumper. I use a hydraulic jack to move the front section of the bumper forward. That elongates the bellows and at a point it ***** a trigger type sear mechanism. When I'm driving around and want to get fast spool up, I put my foot in it to get the fuel in and pull the lanyard attached to the trigger mechanism. The bellows rapidly collapses and forces a large quantity of air into the secondary charger causing it to take off. I'm going to call it the Bumper Spring Bellows Spooler. Or Bs Bs for short. Have a good day.

RonA

 

You don't live in the mountains do you Ron?? If so, either the thin air, or lack of company is getting to your head

What happens when you have a wreck?? Does it cause the truck to lurch forward and "power through" the object at the time of impact??

You've got to start thinking things all the way through Ron
Chris

 

Ebay had a scam going a few years ago about 'electric turbochargers'. Basically, someone tried selling a $10 bilge fan for a boat as an electric turbo.

Your idea can be done, but you will be surprised at how many HP is required to push the required CFMs at even a modest 5 PSI. If I remembered it was about 10 HP or thereabouts. A supercharger will be the ticket if you can disengage it at higher RPMs. The older Detroits used an optional turbo which fed into the stock Roots blower for added power.

Years ago I remembered reading about people dumping raw fuel into the exhaust manifold to get the turbo at 20 PSI at idle! I believe it was used in racing (somewhere) and it was outlawed because the sanctioning body said any fuel burned outside the cylinders constituted a secondary engine--which was not allowed.

Don't blow yourself up.

 

Cool, an added bonus.

 

See what happens when you use your head

Chris

 

Thats great......the bs bs........I think I peed my pants.

 

#1: To deliver 500 CFM and only 10 Psi requires about 35 HP using a fairly typical efficiency for these small compressors.

#2: 35 HP would pull about 2,175 amps at 12 volts.

#3: End of story.



For the record, Holset has turbochargers with extremely high power density electric motors inside of them to help with spoolup. This is being developed for diesel rigs to adress new totally-smokeless diesel legislation that is expected to come down the pike soon. The motor has a very high power rating but a duty cycle of less than 1% if I recall. It has leads the size of starter motor leads. The idea is that the motor is there to cover the 'hole' for inital boost, thus eliminating the puff of smoke prior to the turbo spooling.

As you can see from the above numbers, a continous run setup is not practical. P Gilles has nailed it... The waste heat from the engine is free, volts and amps are not.



Kp

 

Interesting idea in theory, but I would think fairly hard to engineer and put into practical use. Actually I have thought about this some myself.

Like 600 says anything in front of the turbo compressor has to keep up or get out of the way. Otherwise it can be a restriction to air flow.

Maybe a engine driven or an electric fan / compressor that could some how feather the blades like an airplane propreller? Might also be a possible way to couple the design into a reasonable engine brake for a diesel.

Another option, sort of like what RonA suggests (LOL but not quite), would be to install air nozzles in the turbine casing. From a large on board air tank, dump a massive and sudden burst of air into the turbine to get it spooling.

Jim

 

At one time big rig drag racers used compressed air from an air tank to spin the turbo to aid spooling. Collins Diesel in Stockton Ca. (ask for Larry) can explain the concept. Scary stories about what happens with boosted launches with big trucks. Heck, you could even create your own mixture. 20percent oxygen, 70percent air, 10 percent acetylene. Yehaaaawww,bring a dip net to the drag races, person who catches the biggest piece wins a chili dog.

 

There is alot of great idea's here... I think , but it sounds a heck of alot easier to run a set of twins with a somewhat tight turbine housing and a couple external gates, and maybe a small shot of nitrous to get everything going faster...

 

I am an automotive engineer by trade and have studied forced induction for quite some time now. I attended an SAE meeting a few years ago where the topic was the electrically assisted turbos. The key word there is assisted, they are not self spooling, as said the motor is a low 1% duty cycle motor that gives the turbo an initial push helping nonetheless.

Yes, an electric turbo with the proper amount of airflow would require 30-50 hp to run it and as said at 12 volts would take an enormous amount of current to run it. The electrical supply cable would need to be nearly the size of your wrist to handle the current and then you would still need some type of reserve on board to supply that current.

I do remember 3-5 years ago a collegue of mine showing me an electric air ram blower on the internet that they claimed would build 3psi and flow 800cfm. It was a video in which this thing was shooting around the shop floor as he hooked it up to an automotive battery. I don't remember the name of it or if it ever made it anywhere.

Speaking to a couple of collegues, one who works in the turbo industry and the other who works in the performance automotive industry and has set a world record in his turbocharged drag car, they both concur on what is the best, cheapest and quickes way to build boost. Both of them introduce raw fuel and nitrous oxide into the exhaust manifold just prior to the turbo. They both said this was the best thing that they ever did. It allows you to get the free heat with out the undue stress on the engine in terms of cylinder pressure. In so many words, it is easier on the engine altogether.

In the case of the guy with the drag car, he took the nitrous of the engine altogether, as his turbo was so grossly oversized when he spooled and ran with the nitrous in the exhaust it made the engine seem like a 10 liter v12 was driving the turbo when it was actually a 1.6 liter Honda. Incidentally, this 1.6 liter Honda (Vehicle was a CRX front wheel drive) went 157 mph in the 1/4 mile.

Just some information I thought I'd pass on...

JSF

 

Pgilles that is true, but I figured out the maximum amount of air that the engine can process at 3K and then acted as if 1 CF of air was in a closed system and how much it would have to be compressed to raise it from 14.7 psi=0 boost to 54.7 psi= 40psi boost. I then used that ratio of required volume change to determine that 1057 cf of air compresses to 40 psi (relative pressure) in a space of 312.5 CF. I factored out number of moles(# of molecules of air which can be equated to a mass weight in grams) and the R. The math is solid. The numbers will change if your charge air temp is higher. Higher temp of boosted air requires less mass of uncompressed air, b has fewer molecules or fewer grams of air per unit of volume. The after cooler actually causes the boost pressure to drop as the temp drops but the same mass of air molecules is there to combine with #2 and combust. Lower intake temp and lower boost can net the same power as higher temp air at higher boost pressures.

 

As for cut out of the supercharger, that's easy, just run a twin air filter set up, one feeding the supercharger and one separate filter running off of a 4" tee with a large neoprene check valve and or one way valve that will close when the supercharger pressures up the pre turbo intake tube, and will open when the turbo requires more air than than the supercharger can flow. This checkvalve would work like a hanging baffle that can close under pressure/ air flow from the blower and open when no pressure/ suction from the turbo is present.

Sounds good to me! Any thoughts?

 

Great, I need a bew beer and a cloth to clean my screen...