Supercharger for a 6.0. Why not? There would be no turbo lag and you can change your boost by changing the blower drive pully. You would have to stud the heads, but other then that it would handle it fine. 
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just thinking here BUT!!!!!
- Thread starter Dogman
- Start date
MBRPCrazyford
Eat Some Smoke
Blower and turbo would be some serious S**&
Zookie400
I WANNA GO FAST
it would wear out extremely quick.....the old diesels with a turbo and blower setup, used the blower for scaving, not for charging the air. all it did was "blow", not create any pressure (thats what the turbo was for). if you were to supercharge your diesel:
a) for a roots type blower, it would be boosting 100% of the time, causing extreme parasitic draw under cruising/idle conditions, and i would bet money you would see a drop in mileage, as well as power. there would be NO lag however.
b) for a centerfugal type charger, you would have NO low end power, you would have lag based on rpms rather than throttle position. you could fix that by turning the crap out of the charger, and then we are back to the parasitic draw problem, as well as challenging the volumetric efficiency of the charger at the upper rpms.
c) any belt driven charger will require lots of maintenance, more belts to change, and honestly....who has the money to fork out for a HUGE supercharger (think....7.3liters, turning 3000rpms, boosting at 20-30 psi.....LOTS AND LOTS OF AIR THERE!!!), fab up the mounting, oiling, piping, pullies, and then keep up with the belts and oil changes (for sealed units).....NO THANKS!
im not bashing your idea, it would work, and maybe good for an all out drag race application...but i think if it were BETTER, you would see people doing it.
a) for a roots type blower, it would be boosting 100% of the time, causing extreme parasitic draw under cruising/idle conditions, and i would bet money you would see a drop in mileage, as well as power. there would be NO lag however.
b) for a centerfugal type charger, you would have NO low end power, you would have lag based on rpms rather than throttle position. you could fix that by turning the crap out of the charger, and then we are back to the parasitic draw problem, as well as challenging the volumetric efficiency of the charger at the upper rpms.
c) any belt driven charger will require lots of maintenance, more belts to change, and honestly....who has the money to fork out for a HUGE supercharger (think....7.3liters, turning 3000rpms, boosting at 20-30 psi.....LOTS AND LOTS OF AIR THERE!!!), fab up the mounting, oiling, piping, pullies, and then keep up with the belts and oil changes (for sealed units).....NO THANKS!
im not bashing your idea, it would work, and maybe good for an all out drag race application...but i think if it were BETTER, you would see people doing it.
02stroker
Full Access Member
I've seen Detroit engines with a roots type charger and a turbo mounted on top of it. The blower was used mostly for scavenging, but it did provide a few pounds of low speed boost. Once the turbo began to spool up, the charge air was routed around the blower to provide boost to the engine.
You'd have to do some serious design work to make this work anywhere close to right. Not to say that it couldn't be done...
First off, Turbo's aren't free power. They make their power from exhaust back pressure. I really hate when people think that a blower uses more power than a turbo to create the same pressure at the same volume of air. I'd be willing to bet, that if you measured two units of equivalent output, the hp in would be within 5% or less. Remember, PV=nRT? It takes the same amount of work to compress 5 cubic feet of air into 2.5 cubic feet, no matter what the pump is. Turbo's are more lossy in that they aren't positive displacement, blowers have better pumping efficiency, but give up some to the gear drive for both blades to run the same speed without crashing...
Belt life is no worse that any other belt. plenty of cars came with factory chargers, and they didn't eat belts any more frequently than their NA cousins. Even my cousin's 302 with a whipple charger on it never ate belts and that thing was beat hard for 70k miles, autocross, road race, track time... Blower lube was changed I think every 20k miles, pretty simple really.
Now... on to the fun part. This could work... You'd need a fast acting charger, the whipple comes to mind. It's a lysolm screw compressor, not the same thing as a roots, but kinda close if you've never seen one. The trick here as was done on the gas cars would be a throttle plate. Remember, we used to have one on the early 6 liters. You put it upstream of the blower, and the blower runs in a vacuum. When you open that plate, wham! you've got boost!
We have an advantage that we're running about half the RPM of a gasser, so we can use a more aggressive pulley ratio on the blower. I know the one on the 302 was an instant 7 psi from idle to 1100 rpm, then from 1100 to 6k, it was flat at 13 psi. This was on a stick, so whether the motor could pick up speed or not, it made boost. I don't remember if his was a 2.2 liter blower or not. They had two sizes, normal and "blowzilla". The latter being quite retardedly silly in it's output. I think they even have a model that would handle the 8 liter GM gas engine, so volume shouldn't really be a problem. We'd use the larger unit, and spin it with smaller pulleys.
So for us, I'd venture a guess that a stand alone module to operate the throttle plate would be needed, then that coordinated with the fuel tables and other nifty engine functions through SCT or whatever. I bet this is more doable than we think. The worst part would be getting the electronics to cooperate. We could even keep the intercooler!
First off, Turbo's aren't free power. They make their power from exhaust back pressure. I really hate when people think that a blower uses more power than a turbo to create the same pressure at the same volume of air. I'd be willing to bet, that if you measured two units of equivalent output, the hp in would be within 5% or less. Remember, PV=nRT? It takes the same amount of work to compress 5 cubic feet of air into 2.5 cubic feet, no matter what the pump is. Turbo's are more lossy in that they aren't positive displacement, blowers have better pumping efficiency, but give up some to the gear drive for both blades to run the same speed without crashing...
Belt life is no worse that any other belt. plenty of cars came with factory chargers, and they didn't eat belts any more frequently than their NA cousins. Even my cousin's 302 with a whipple charger on it never ate belts and that thing was beat hard for 70k miles, autocross, road race, track time... Blower lube was changed I think every 20k miles, pretty simple really.
Now... on to the fun part. This could work... You'd need a fast acting charger, the whipple comes to mind. It's a lysolm screw compressor, not the same thing as a roots, but kinda close if you've never seen one. The trick here as was done on the gas cars would be a throttle plate. Remember, we used to have one on the early 6 liters. You put it upstream of the blower, and the blower runs in a vacuum. When you open that plate, wham! you've got boost!
We have an advantage that we're running about half the RPM of a gasser, so we can use a more aggressive pulley ratio on the blower. I know the one on the 302 was an instant 7 psi from idle to 1100 rpm, then from 1100 to 6k, it was flat at 13 psi. This was on a stick, so whether the motor could pick up speed or not, it made boost. I don't remember if his was a 2.2 liter blower or not. They had two sizes, normal and "blowzilla". The latter being quite retardedly silly in it's output. I think they even have a model that would handle the 8 liter GM gas engine, so volume shouldn't really be a problem. We'd use the larger unit, and spin it with smaller pulleys.
So for us, I'd venture a guess that a stand alone module to operate the throttle plate would be needed, then that coordinated with the fuel tables and other nifty engine functions through SCT or whatever. I bet this is more doable than we think. The worst part would be getting the electronics to cooperate. We could even keep the intercooler!
Zookie400
I WANNA GO FAST
your theory is busted on this one, its already proven in the race world that the turbo engine will produce MUCH more peak power because it has MUCH less parasitic draw off the engine. if you dont believe me, hop on desktop dyno, build any engine, and run it with a turbo and with a blower, and again with a centerfugal supercharger....the turbo engine will blow them away, just not on the low end.
for a factory, down tuned, low boost engine, you are correct....the belts wont get beat too hard. for a "built" application, running 30 psi........THEY EAT BELTS!!! the cobra in my you tube videos is only pushing 20 psi, and the thing has an 8 rib gator-back belt, that is under extreme tension and it still slips and wears out quickly (10k miles to a belt) if he doesnt snap it at the track, wich is a known problem, and is why most supercharged mustang guys dont go anywhere without a spare belt and the tools to change it (like us and our CPS!)
now im not sure i understand this correctly, but you want to put a throttle plate and run a diesel under vaccuum? that would make a lot of heat (EGT's) and it would be very hard to even keep it running; think of the older diesels that had the emergency shutoffs....they were no more than a throttle plate, that when closed killed the engine.
im not saying it couldnt be done, or it wouldnt work, or that it couldnt make more power than a turbo engine.....im just saying that the cost effectiveness/reliability/fitment issues isnt worth it, especially when turbos are proven reliable, driveable, likely to make more power, and cost much less than a 4 liter blower.
You didn't read my qualifier... a turbo and blower of the same output. Work is work. Desktop dyno is a neat tool I've messed with it a number of times. Pretty cool stuff. Also, are we looking for average power that you can use while pulling, or peak power that the engine spends less than 5% of its life at? Big difference there, but again, I point back to my original statement, of same volume and pressure capacity. The HP to run a turbo from a V20 locomotive engine is certainly greater than the hp to run a 171 gm two stroke. Gross exagerations, but you see my point?
Throttle plate would be to regulate the amount of air going through the motor. It would probably never be fully closed, but necked down pretty good for the times when you're puttering around not needing anything more than 1-2 psi of boost just loafing. You're right you wouldn't want to run under a vacuum. But if you don't limit the air flow to the blower, it will try to make full boost all the time, needed or not. Most likely it would be software keyed to fuel flow rate at the injectors.
You might have a point on the belt, but I know my cousin's used the factory belt and he was getting at least 20k out of a belt. I think a lot depends on the pulley design, and the hp needed by the blower. Small diameter pulleys are hard on belts. Most cars don't have the room for a larger crank pulley, we do though. I don't know what kind of blower you're running. Cobra's picked up almost 100 hp just loosing the factory eaton blower in place of a KenneBell unit, at the same boost. More efficient pump. It's possible though, why gm gear drove most of theirs.
Not knocking a turbo, they do work well, but for beating out lag, they leave a bit to be desired. Dunno, it would be an interesting project if I had the money to play with it. Haven't checked my powerball ticket yet though!
Throttle plate would be to regulate the amount of air going through the motor. It would probably never be fully closed, but necked down pretty good for the times when you're puttering around not needing anything more than 1-2 psi of boost just loafing. You're right you wouldn't want to run under a vacuum. But if you don't limit the air flow to the blower, it will try to make full boost all the time, needed or not. Most likely it would be software keyed to fuel flow rate at the injectors.
You might have a point on the belt, but I know my cousin's used the factory belt and he was getting at least 20k out of a belt. I think a lot depends on the pulley design, and the hp needed by the blower. Small diameter pulleys are hard on belts. Most cars don't have the room for a larger crank pulley, we do though. I don't know what kind of blower you're running. Cobra's picked up almost 100 hp just loosing the factory eaton blower in place of a KenneBell unit, at the same boost. More efficient pump. It's possible though, why gm gear drove most of theirs.
Not knocking a turbo, they do work well, but for beating out lag, they leave a bit to be desired. Dunno, it would be an interesting project if I had the money to play with it. Haven't checked my powerball ticket yet though!
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