Supercharged v NA
03-05-2016, 09:55 PM
#51
Platinum Member
Platinum Member
What does it cost for supercharger rebuild and how often? And how often replace intercooler? Think you will still win with supercharger. But what is the cost difference to do a 900hp motor charged and not? Cost for maintaining valve train over time vs supercharger and maintaining other parts plus investment for supercharging. As far as HP and speed HP is HP unless you cant get it to go from the start. Diesel makes a ton of torque but that wont seal the deal for speed!
HP wins!
Anyone that says different on the HP to speed back it up or don't post it!
HP wins!
Anyone that says different on the HP to speed back it up or don't post it!
Last edited by 14 apache; 03-05-2016 at 09:58 PM.
03-05-2016, 11:07 PM
#52
Registered
Here's a real world example that I have experienced in the past....
I think it has to do a lot with how a boat is set up as well...drives, drive height, x-dem, nose cones, etc. I have said this before on here a few years back when I once owned a 32' AT....and my buddy owned a 32' AT. I had 565cid naturally aspirated engines that made about 615hp on Dave W's dyno with very mild hydraulic roller cams. My buddy had 557cid engines with some 871 roots style superchargers on them that supposedly made about 750+hp. He could not pull away from me at midrange at 3500rpm up with both of us at WOT.....and while at top RPM of 5600, he could still not pull away from me. We both had Bravo drives...I had XR's and he had another type of X...we both were running 1:5 gear ratios. I always had my fuel tanks topped off....while he was always looking for one of the gas docks to refuel his tanks.
That's 615hp vs 750+hp....we both turned the same RPM up on top @5600rpm. He would ask me to open my engine hatch and he would just stare at my engines for several minutes....probably trying to hopefully catch me red handed with finding a NOS hose and bottle somewhere. But I told him that it was probably the way my drives were set up on my boat.....extension boxes, -2" IMCO shortys with a nose cone integrated into the IMCO shorty...compared to my buddy's boat not having any of these things. It seemed to be as if it was worth another 300+hp on my boat compared to my friend's same boat....difficult to believe...I know, but we ran raced each other several times over on different days...we do our boating out of the same area.
All else remaining the same and CID for CID, etc, I would still find it very difficult to believe that an NA engine would outrun/perform a supercharged engine within the same RPM power band in the same hull, etc. And if it did, I would have to think it would be very rare...few and far between.
The other funny thing is that I eventually sold him my XR drives.....he said they slowed his boat down by about 2-mph.
I think it has to do a lot with how a boat is set up as well...drives, drive height, x-dem, nose cones, etc. I have said this before on here a few years back when I once owned a 32' AT....and my buddy owned a 32' AT. I had 565cid naturally aspirated engines that made about 615hp on Dave W's dyno with very mild hydraulic roller cams. My buddy had 557cid engines with some 871 roots style superchargers on them that supposedly made about 750+hp. He could not pull away from me at midrange at 3500rpm up with both of us at WOT.....and while at top RPM of 5600, he could still not pull away from me. We both had Bravo drives...I had XR's and he had another type of X...we both were running 1:5 gear ratios. I always had my fuel tanks topped off....while he was always looking for one of the gas docks to refuel his tanks.
That's 615hp vs 750+hp....we both turned the same RPM up on top @5600rpm. He would ask me to open my engine hatch and he would just stare at my engines for several minutes....probably trying to hopefully catch me red handed with finding a NOS hose and bottle somewhere. But I told him that it was probably the way my drives were set up on my boat.....extension boxes, -2" IMCO shortys with a nose cone integrated into the IMCO shorty...compared to my buddy's boat not having any of these things. It seemed to be as if it was worth another 300+hp on my boat compared to my friend's same boat....difficult to believe...I know, but we ran raced each other several times over on different days...we do our boating out of the same area.
All else remaining the same and CID for CID, etc, I would still find it very difficult to believe that an NA engine would outrun/perform a supercharged engine within the same RPM power band in the same hull, etc. And if it did, I would have to think it would be very rare...few and far between.
The other funny thing is that I eventually sold him my XR drives.....he said they slowed his boat down by about 2-mph.
Last edited by KAAMA; 03-05-2016 at 11:17 PM.
03-06-2016, 12:08 AM
#55
Platinum Member
Platinum Member
Here's a real world example that I have experienced in the past....
I think it has to do a lot with how a boat is set up as well...drives, drive height, x-dem, nose cones, etc. I have said this before on here a few years back when I once owned a 32' AT....and my buddy owned a 32' AT. I had 565cid naturally aspirated engines that made about 615hp on Dave W's dyno with very mild hydraulic roller cams. My buddy had 557cid engines with some 871 roots style superchargers on them that supposedly made about 750+hp. He could not pull away from me at midrange at 3500rpm up with both of us at WOT.....and while at top RPM of 5600, he could still not pull away from me. We both had Bravo drives...I had XR's and he had another type of X...we both were running 1:5 gear ratios. I always had my fuel tanks topped off....while he was always looking for one of the gas docks to refuel his tanks.
That's 615hp vs 750+hp....we both turned the same RPM up on top @5600rpm. He would ask me to open my engine hatch and he would just stare at my engines for several minutes....probably trying to hopefully catch me red handed with finding a NOS hose and bottle somewhere. But I told him that it was probably the way my drives were set up on my boat.....extension boxes, -2" IMCO shortys with a nose cone integrated into the IMCO shorty...compared to my buddy's boat not having any of these things. It seemed to be as if it was worth another 300+hp on my boat compared to my friend's same boat....difficult to believe...I know, but we ran raced each other several times over on different days...we do our boating out of the same area.
All else remaining the same and CID for CID, etc, I would still find it very difficult to believe that an NA engine would outrun/perform a supercharged engine within the same RPM power band in the same hull, etc. And if it did, I would have to think it would be very rare...few and far between.
The other funny thing is that I eventually sold him my XR drives.....he said they slowed his boat down by about 2-mph.
I think it has to do a lot with how a boat is set up as well...drives, drive height, x-dem, nose cones, etc. I have said this before on here a few years back when I once owned a 32' AT....and my buddy owned a 32' AT. I had 565cid naturally aspirated engines that made about 615hp on Dave W's dyno with very mild hydraulic roller cams. My buddy had 557cid engines with some 871 roots style superchargers on them that supposedly made about 750+hp. He could not pull away from me at midrange at 3500rpm up with both of us at WOT.....and while at top RPM of 5600, he could still not pull away from me. We both had Bravo drives...I had XR's and he had another type of X...we both were running 1:5 gear ratios. I always had my fuel tanks topped off....while he was always looking for one of the gas docks to refuel his tanks.
That's 615hp vs 750+hp....we both turned the same RPM up on top @5600rpm. He would ask me to open my engine hatch and he would just stare at my engines for several minutes....probably trying to hopefully catch me red handed with finding a NOS hose and bottle somewhere. But I told him that it was probably the way my drives were set up on my boat.....extension boxes, -2" IMCO shortys with a nose cone integrated into the IMCO shorty...compared to my buddy's boat not having any of these things. It seemed to be as if it was worth another 300+hp on my boat compared to my friend's same boat....difficult to believe...I know, but we ran raced each other several times over on different days...we do our boating out of the same area.
All else remaining the same and CID for CID, etc, I would still find it very difficult to believe that an NA engine would outrun/perform a supercharged engine within the same RPM power band in the same hull, etc. And if it did, I would have to think it would be very rare...few and far between.
The other funny thing is that I eventually sold him my XR drives.....he said they slowed his boat down by about 2-mph.
03-06-2016, 12:14 AM
#56
Platinum Member
Platinum Member
Back when my 272 only had 675-700 procharged hp I raced a 272 open bow with a big NA motor that supposedly 750 hp, I had 4-5 mph on him. Hard to compare different boats, could be as simple as guy bolted on box stock prop and faster guy tried 5 different props labbed several times. I raced a 33 avs last fall that had 575 hp NA 540s (from what I been told) and crept away from him with my 33avs with stock 500 efis that have rev limiter turned up, I also bought a set of labbed 30's that were spot on, he said he was only turnoing 5200 or so, I would bet he had props that were slightly off, I was also running on fumes, fwiw, Smitty
03-06-2016, 10:28 AM
#57
Registered
Back when my 272 only had 675-700 procharged hp I raced a 272 open bow with a big NA motor that supposedly 750 hp, I had 4-5 mph on him. Hard to compare different boats, could be as simple as guy bolted on box stock prop and faster guy tried 5 different props labbed several times. I raced a 33 avs last fall that had 575 hp NA 540s (from what I been told) and crept away from him with my 33avs with stock 500 efis that have rev limiter turned up, I also bought a set of labbed 30's that were spot on, he said he was only turnoing 5200 or so, I would bet he had props that were slightly off, I was also running on fumes, fwiw, Smitty
03-06-2016, 05:18 PM
#58
Registered
I have heard that Dave Wesseldyk's dyno has a reputation for being on the conservative, unforgiving side, but he always says, "It's not conservative---it's correct, and I always keep a crying towel hanging next to it!" and he's willing to calibrate his dyno for a customer if they want.
Last edited by KAAMA; 03-06-2016 at 05:21 PM.
03-06-2016, 05:33 PM
#59
Banned
For longevity it's always an issue. Roots/centrifugal blower engines are making more power at the piston to have equal power at the crank compared to an equal powered NA engine.. The parts are seeing more abuse...they won't last as long. Simple physics. Most of these engines get rebuilt long before they really need to so it's pretty much a moot point.
03-06-2016, 07:34 PM
#60
Registered
Here's a real world example that I have experienced in the past....
I think it has to do a lot with how a boat is set up as well...drives, drive height, x-dem, nose cones, etc. I have said this before on here a few years back when I once owned a 32' AT....and my buddy owned a 32' AT. I had 565cid naturally aspirated engines that made about 615hp on Dave W's dyno with very mild hydraulic roller cams. My buddy had 557cid engines with some 871 roots style superchargers on them that supposedly made about 750+hp. He could not pull away from me at midrange at 3500rpm up with both of us at WOT.....and while at top RPM of 5600, he could still not pull away from me. We both had Bravo drives...I had XR's and he had another type of X...we both were running 1:5 gear ratios. I always had my fuel tanks topped off....while he was always looking for one of the gas docks to refuel his tanks.
That's 615hp vs 750+hp....we both turned the same RPM up on top @5600rpm. He would ask me to open my engine hatch and he would just stare at my engines for several minutes....probably trying to hopefully catch me red handed with finding a NOS hose and bottle somewhere. But I told him that it was probably the way my drives were set up on my boat.....extension boxes, -2" IMCO shortys with a nose cone integrated into the IMCO shorty...compared to my buddy's boat not having any of these things. It seemed to be as if it was worth another 300+hp on my boat compared to my friend's same boat....difficult to believe...I know, but we ran raced each other several times over on different days...we do our boating out of the same area.
All else remaining the same and CID for CID, etc, I would still find it very difficult to believe that an NA engine would outrun/perform a supercharged engine within the same RPM power band in the same hull, etc. And if it did, I would have to think it would be very rare...few and far between.
The other funny thing is that I eventually sold him my XR drives.....he said they slowed his boat down by about 2-mph.
I think it has to do a lot with how a boat is set up as well...drives, drive height, x-dem, nose cones, etc. I have said this before on here a few years back when I once owned a 32' AT....and my buddy owned a 32' AT. I had 565cid naturally aspirated engines that made about 615hp on Dave W's dyno with very mild hydraulic roller cams. My buddy had 557cid engines with some 871 roots style superchargers on them that supposedly made about 750+hp. He could not pull away from me at midrange at 3500rpm up with both of us at WOT.....and while at top RPM of 5600, he could still not pull away from me. We both had Bravo drives...I had XR's and he had another type of X...we both were running 1:5 gear ratios. I always had my fuel tanks topped off....while he was always looking for one of the gas docks to refuel his tanks.
That's 615hp vs 750+hp....we both turned the same RPM up on top @5600rpm. He would ask me to open my engine hatch and he would just stare at my engines for several minutes....probably trying to hopefully catch me red handed with finding a NOS hose and bottle somewhere. But I told him that it was probably the way my drives were set up on my boat.....extension boxes, -2" IMCO shortys with a nose cone integrated into the IMCO shorty...compared to my buddy's boat not having any of these things. It seemed to be as if it was worth another 300+hp on my boat compared to my friend's same boat....difficult to believe...I know, but we ran raced each other several times over on different days...we do our boating out of the same area.
All else remaining the same and CID for CID, etc, I would still find it very difficult to believe that an NA engine would outrun/perform a supercharged engine within the same RPM power band in the same hull, etc. And if it did, I would have to think it would be very rare...few and far between.
The other funny thing is that I eventually sold him my XR drives.....he said they slowed his boat down by about 2-mph.
