Cat's out of the bag now...
09-13-2007, 04:59 PM
#16
Drifting
SuperCharging...
Have you given any thought to eliminating the throttle valve via using a "primarily" engine driven positive displacement SC through a Toyota hydrid e-CVT concept/arrangement?
No pressure bypass would ever be required.
e-CVT/SC:
Belt driven input to one end of a differential gear set, variable frequency AC inverter powering a permanent magnet rotor AC synchronous motor through a ~3:1 reduction gearset into the opposite end of the diff'l. Diff'l output drives the SC.
The engine could turn at 6,000 RPM with zero boost if the AC motor were turning in the "opposite" direction at 18,000 RPM.
Continuously variable, FULL RANGE, boost level from idle to max RPM.
With a positive displacement SC that requires, say, 10HP at full boost the ICE would contribute 7.5 HP and the AC motor only 2.5HP/2000 watts.
No pressure bypass would ever be required.
e-CVT/SC:
Belt driven input to one end of a differential gear set, variable frequency AC inverter powering a permanent magnet rotor AC synchronous motor through a ~3:1 reduction gearset into the opposite end of the diff'l. Diff'l output drives the SC.
The engine could turn at 6,000 RPM with zero boost if the AC motor were turning in the "opposite" direction at 18,000 RPM.
Continuously variable, FULL RANGE, boost level from idle to max RPM.
With a positive displacement SC that requires, say, 10HP at full boost the ICE would contribute 7.5 HP and the AC motor only 2.5HP/2000 watts.
Last edited by wwest; 09-13-2007 at 05:14 PM.
09-13-2007, 05:55 PM
#18
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i'm a big subaru guy (4 since 2001) and remember dusting a 993 with my WRX wagon as he tried to grind through the gears. i'm following your build too, and would do it in a second, if a bolt in kit was available. it's the fuel tank/front end modifying that gets me. i don't want to cut the chassis, though not much difference in that vs replacing sheetmetal from rust issues.
09-13-2007, 11:42 PM
#19
Okay, I'll try and answer everyone's questions. Hope I don't miss anybody...
The cooling system plumbing is going to be stainless braided with AN fittings throughout. -20 and -16 to be exact. I'm planning on running the cooling lines the same route as the factory oil and AC lines (along the rockers). I made the radiator myself specifically for this project so I was able to dictate exactly where everything goes, and there is a bleed valve at the highest point of the radiator to vent any trapped air.
As far as engine weight goes, I know for a fact that the Subaru engine is lighter than the Porsche engine... even with the adapter plate. How much lighter I'm not sure yet. From the research I've done, I'm guessing it will weight in at just under 400lbs NA, but I don't want to blindly throw out numbers. Also, there is less oil weight , and the oil weight is down lower because of the standard style sump. Yes there is some added weight with the radiator and water, but I still think the front end will be lighter than stock because everything is made out of thin wall aluminum. Also of weight savings by getting rid of the heavy stock fuel tank, battery, and spare tire with jack kit.
As far as forced induction... When I designed the headers, I designed them with future turbo chargers in mind. You just can't beat the simplicity and horsepower availability gained with this kind of forced induction. For now though, I am going to stick with normal asperation because I'm not sure if I want to deal with a tranny swap yet. We'll see how long it takes for me to start looking for more power though
As far as "bolt-on ability" of this kind of conversion kit. Everything is being designed to work with the 911 chassis with no permenant modification to the chassis. The only acception to this is the hole that has to be cut in the nose of the tub to get air to the radiator duct work. However, anyone who has installed a descent sized oil cooler in the front of a 911 knows that this kind of hole is made when you "box in" the front for air flow behind an oil cooler. If someone wanted to convert their Subaru powered 911 back to air cooled, they would just have to box in the nose and either leave it that way, or install a front mount oil cooler. Everything about this kit would be something that any mechanically inclined person could do in their garage with no special tools or welding. I'll have pictures of the custom fuel tank in a few days. I have been working on it here and there the past few days. It's almost ready for final welding. It will use the factory fuel fill, vent, and fuel pump location.
The cooling system plumbing is going to be stainless braided with AN fittings throughout. -20 and -16 to be exact. I'm planning on running the cooling lines the same route as the factory oil and AC lines (along the rockers). I made the radiator myself specifically for this project so I was able to dictate exactly where everything goes, and there is a bleed valve at the highest point of the radiator to vent any trapped air.
As far as engine weight goes, I know for a fact that the Subaru engine is lighter than the Porsche engine... even with the adapter plate. How much lighter I'm not sure yet. From the research I've done, I'm guessing it will weight in at just under 400lbs NA, but I don't want to blindly throw out numbers. Also, there is less oil weight , and the oil weight is down lower because of the standard style sump. Yes there is some added weight with the radiator and water, but I still think the front end will be lighter than stock because everything is made out of thin wall aluminum. Also of weight savings by getting rid of the heavy stock fuel tank, battery, and spare tire with jack kit.
As far as forced induction... When I designed the headers, I designed them with future turbo chargers in mind. You just can't beat the simplicity and horsepower availability gained with this kind of forced induction. For now though, I am going to stick with normal asperation because I'm not sure if I want to deal with a tranny swap yet. We'll see how long it takes for me to start looking for more power though
As far as "bolt-on ability" of this kind of conversion kit. Everything is being designed to work with the 911 chassis with no permenant modification to the chassis. The only acception to this is the hole that has to be cut in the nose of the tub to get air to the radiator duct work. However, anyone who has installed a descent sized oil cooler in the front of a 911 knows that this kind of hole is made when you "box in" the front for air flow behind an oil cooler. If someone wanted to convert their Subaru powered 911 back to air cooled, they would just have to box in the nose and either leave it that way, or install a front mount oil cooler. Everything about this kit would be something that any mechanically inclined person could do in their garage with no special tools or welding. I'll have pictures of the custom fuel tank in a few days. I have been working on it here and there the past few days. It's almost ready for final welding. It will use the factory fuel fill, vent, and fuel pump location.
09-17-2007, 10:50 AM
#23
Legacy Flounder
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I ask because a friend of mine has a Contour SVT & they had known problems with sweeping turns & oil starvation. I figure the Subies aren't doing corners usually nearly as much as a 911 is expected to.
09-17-2007, 08:31 PM
#24
"nothing special about the 911 engine"
Wow - there is a LOT that is special about the 911 motor. I hope that was a joke.
Nonetheless, no reason why you shouldn't put a Subaru back there. Others have also. I'd like to see somebody do a Mazda RX-8 install tho. Wanna do that next?
Wow - there is a LOT that is special about the 911 motor. I hope that was a joke.
Nonetheless, no reason why you shouldn't put a Subaru back there. Others have also. I'd like to see somebody do a Mazda RX-8 install tho. Wanna do that next?
09-17-2007, 11:02 PM
#25
one word.... FORD!!!
Not exactly a company known for going fast around the turns lately. On the other hand, Subaru has made their reputation hauling *** around turns.... sideways..... in the dirt. But still.
The only way I would consider a rotary would be if it was a 20B 3 rotor.
09-18-2007, 01:10 AM
#27
Rennlist Member
Well, you know how to fabricate, so hats off to you and your creation. It's a unique piece and I hope it goes well for you. It probably will.
I wonder what other engines will fit back there beside the SVX and the Chevy V8...
I wonder what other engines will fit back there beside the SVX and the Chevy V8...
12-15-2007, 10:11 PM
#30