First performance shop to extract more power from the 918
12-02-2015, 07:43 AM
#16
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Hmm, no.
The architecture of the 918 engine was derived from the RS Spyder's V8, but outside of being a flat plane 90 degree V8, they have nothing in common.
Porsche cast a brand new block to enlarge the displacement to 4.6l, removed all auxiliary power take off, and swapped the intake and exhaust side. Basically a brand new engine.
Because of the bigger displacement, it can't possibly rev as high as the RS Spyder V8, so it's not easy to just add another 1000 rpm, the max speed is dictates by the peak piston speed and the total mass of the internal components. Making it go to 9150rpm right now is already a great achievement. There is no free lunch in tuning an engine, if they do manage to squeeze another 1000 rpm out of it, yes the HP will increase, but there will be a corresponding drop in low-mid range torque, something that's not desirable as the low-mid range 'punch' is what the 918 is famous for. The engine, as it stands right now, doesn't really have a lot of head room left, neither on the intake nor the exhaust side. It already breath through 2 giant K&N style air filters with some form of ram air effect from the side pods, and the exhaust is already coming out through equal length tube headers into a pair of giant cats, some 10 inches in diameter.
For the e-motors, Porsche while Porsche has rated them at a specific output, I believed those are sustained, not instantaneous. The battery pack will supply a sustained amount of current to the e-motors for their rated output, but has a higher peak current output and that could be counted as 'bonus' power, can't be sustained for long but momentarily will exceed the rated power.
The architecture of the 918 engine was derived from the RS Spyder's V8, but outside of being a flat plane 90 degree V8, they have nothing in common.
Porsche cast a brand new block to enlarge the displacement to 4.6l, removed all auxiliary power take off, and swapped the intake and exhaust side. Basically a brand new engine.
Because of the bigger displacement, it can't possibly rev as high as the RS Spyder V8, so it's not easy to just add another 1000 rpm, the max speed is dictates by the peak piston speed and the total mass of the internal components. Making it go to 9150rpm right now is already a great achievement. There is no free lunch in tuning an engine, if they do manage to squeeze another 1000 rpm out of it, yes the HP will increase, but there will be a corresponding drop in low-mid range torque, something that's not desirable as the low-mid range 'punch' is what the 918 is famous for. The engine, as it stands right now, doesn't really have a lot of head room left, neither on the intake nor the exhaust side. It already breath through 2 giant K&N style air filters with some form of ram air effect from the side pods, and the exhaust is already coming out through equal length tube headers into a pair of giant cats, some 10 inches in diameter.
For the e-motors, Porsche while Porsche has rated them at a specific output, I believed those are sustained, not instantaneous. The battery pack will supply a sustained amount of current to the e-motors for their rated output, but has a higher peak current output and that could be counted as 'bonus' power, can't be sustained for long but momentarily will exceed the rated power.
Today, we have a massive 6.2l V12 revving over 9k (once only the realm of small race engines) in a 'production' car. 8k rpm used to the end all be all for ANY displacement and cylinder count. And the units in the Enzo FXX's easily pushing near 10k while still offering superb reliability. Ferrari engineers have said their still current 4.5l unit is easily 10k rpm capable right now thaks to DLC and general quality of the aluminum and titanium they currently use...BUT, they would simply not meet the current warranty and reliability set forth without going to even more expensive metals from their sources, ie much lighter and stronger, and the price pt. of the cars would get out of whack. Lexus (or Yamaha I should say) has boasted the awesome LFA 4.8L V10 would comfortably do 10,500rpm if "Lexus reliability" was sacrificed merely 'some'. Simple motorsport push rod V8's over 4.5L easily tread past 10k rpm, and have done so for some time now. before artificial limits were imposed, the massive but very simple 5.8L V8 NASCAR CUP engines were run near 11k rpm without gearing restrictions) although 10k rpm was the typical cut off where they made nearly 900hp. granted, they are designed to run 1000 mile rebuild schedules, which is respectable considering no exotic alloys are used. today's metals allows motorsport 3.5l V8's to get past 14k rpm, around the limit before valve float becomes a problem and thus being the end point of max rpm. Pneumatic valves are then needed to get past that hurdle. desire + butt loads of cash can get a 918 well over 1000hp without resorting to forced induction.
Last edited by Scuderia980; 12-02-2015 at 08:07 AM.
12-02-2015, 09:32 AM
#17
It's is fast but could be faster. The p1 pulls much harder once it hooks up and it's rwd
Shops such as Techart usually warranty their performance software upgrades
12-02-2015, 12:22 PM
#18
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yes, I understand the 918 lump is entirely different. however, the ability to raise engine speed is still there...but with stock internals, not by very much. as I mentioned, the driveability would of course change...trade-offs, the power curve would of course be altered. the 4.6L is actually comfortably within limits given the bore/stroke, and it CAN run with/out rev the 3.4l race engine if someone wants that...its larger displacement is NOT a limiting factor vs the smaller lump. as I said, it would require bespoke race level internals on par with those in the RS Spyder engine. it would probably require 100 grand in components from folks such as Arrow Precision, and experts for the software side of things. I wish I still had that old magazine that showed a chart for displacement/cylinders/rpm, conventional vs pneumatic valves, etc. it discussed the general limits given the technology available at the time. it's surprising how large engines can rev A LOT higher than what we'd think was possible. it all comes down to acceptable life of internal components...which is dependent on the quality. and that means big bucks. What was once 'race cars only' coatings like DLC and Titanium nitride are now present in high end production cars. We now have superior metals even compared to just a decade ago (quality and consistency of production). exotic stuff like Titalium is even more exotic with modern tweaks.
Today, we have a massive 6.2l V12 revving over 9k (once only the realm of small race engines) in a 'production' car. 8k rpm used to the end all be all for ANY displacement and cylinder count. And the units in the Enzo FXX's easily pushing near 10k while still offering superb reliability. Ferrari engineers have said their still current 4.5l unit is easily 10k rpm capable right now thaks to DLC and general quality of the aluminum and titanium they currently use...BUT, they would simply not meet the current warranty and reliability set forth without going to even more expensive metals from their sources, ie much lighter and stronger, and the price pt. of the cars would get out of whack. Lexus (or Yamaha I should say) has boasted the awesome LFA 4.8L V10 would comfortably do 10,500rpm if "Lexus reliability" was sacrificed merely 'some'. Simple motorsport push rod V8's over 4.5L easily tread past 10k rpm, and have done so for some time now. before artificial limits were imposed, the massive but very simple 5.8L V8 NASCAR CUP engines were run near 11k rpm without gearing restrictions) although 10k rpm was the typical cut off where they made nearly 900hp. granted, they are designed to run 1000 mile rebuild schedules, which is respectable considering no exotic alloys are used. today's metals allows motorsport 3.5l V8's to get past 14k rpm, around the limit before valve float becomes a problem and thus being the end point of max rpm. Pneumatic valves are then needed to get past that hurdle. desire + butt loads of cash can get a 918 well over 1000hp without resorting to forced induction.
Today, we have a massive 6.2l V12 revving over 9k (once only the realm of small race engines) in a 'production' car. 8k rpm used to the end all be all for ANY displacement and cylinder count. And the units in the Enzo FXX's easily pushing near 10k while still offering superb reliability. Ferrari engineers have said their still current 4.5l unit is easily 10k rpm capable right now thaks to DLC and general quality of the aluminum and titanium they currently use...BUT, they would simply not meet the current warranty and reliability set forth without going to even more expensive metals from their sources, ie much lighter and stronger, and the price pt. of the cars would get out of whack. Lexus (or Yamaha I should say) has boasted the awesome LFA 4.8L V10 would comfortably do 10,500rpm if "Lexus reliability" was sacrificed merely 'some'. Simple motorsport push rod V8's over 4.5L easily tread past 10k rpm, and have done so for some time now. before artificial limits were imposed, the massive but very simple 5.8L V8 NASCAR CUP engines were run near 11k rpm without gearing restrictions) although 10k rpm was the typical cut off where they made nearly 900hp. granted, they are designed to run 1000 mile rebuild schedules, which is respectable considering no exotic alloys are used. today's metals allows motorsport 3.5l V8's to get past 14k rpm, around the limit before valve float becomes a problem and thus being the end point of max rpm. Pneumatic valves are then needed to get past that hurdle. desire + butt loads of cash can get a 918 well over 1000hp without resorting to forced induction.
Exactly, will need to change most if not all of the internals to gain rpm. Not a easy job or cheaper one.
12-03-2015, 01:55 AM
#19
Which tuner has the expertise to modify electric motors to generate more power?
Electric motor has a much shorter lifespan than gasoline engine. Once it is made to generate more power through higher voltage (thus more heat) its life expectancy goes down exponentially and most likely will result in premature motor failure.
The only way to do it reliability is to swapped out the electric motors with more powerful ones. Than you have to consider other variables like if the battery is powerful enough to support the more powerful motors, lifespan of the battery, heat dissipation, how the whole system works as a whole...etc
Electric motor has a much shorter lifespan than gasoline engine. Once it is made to generate more power through higher voltage (thus more heat) its life expectancy goes down exponentially and most likely will result in premature motor failure.
The only way to do it reliability is to swapped out the electric motors with more powerful ones. Than you have to consider other variables like if the battery is powerful enough to support the more powerful motors, lifespan of the battery, heat dissipation, how the whole system works as a whole...etc
12-04-2015, 02:52 AM
#20
Which tuner has the expertise to modify electric motors to generate more power?
Electric motor has a much shorter lifespan than gasoline engine. Once it is made to generate more power through higher voltage (thus more heat) its life expectancy goes down exponentially and most likely will result in premature motor failure.
The only way to do it reliability is to swapped out the electric motors with more powerful ones. Than you have to consider other variables like if the battery is powerful enough to support the more powerful motors, lifespan of the battery, heat dissipation, how the whole system works as a whole...etc
Electric motor has a much shorter lifespan than gasoline engine. Once it is made to generate more power through higher voltage (thus more heat) its life expectancy goes down exponentially and most likely will result in premature motor failure.
The only way to do it reliability is to swapped out the electric motors with more powerful ones. Than you have to consider other variables like if the battery is powerful enough to support the more powerful motors, lifespan of the battery, heat dissipation, how the whole system works as a whole...etc
Example: tesla is doing the exact same thing, without a motor upgrade they cutting 0-60 times by .5 second, that is huge.
There is much to be learned about electric motors and it's only a matter of time before we see software upgrades being offered. Will there be some bumps in the road? Yes 100% but it's the future of high performance.
12-05-2015, 10:07 AM
#21
I am not a electric motor expert like some, but I do know porsche and they are conservative and always leave a fairly large margin of error in their motors. So it later a performance shop will exploit and extract more power.
Example: tesla is doing the exact same thing, without a motor upgrade they cutting 0-60 times by .5 second, that is huge.
There is much to be learned about electric motors and it's only a matter of time before we see software upgrades being offered. Will there be some bumps in the road? Yes 100% but it's the future of high performance.
Example: tesla is doing the exact same thing, without a motor upgrade they cutting 0-60 times by .5 second, that is huge.
There is much to be learned about electric motors and it's only a matter of time before we see software upgrades being offered. Will there be some bumps in the road? Yes 100% but it's the future of high performance.
No doubt technology/software will move on, but I'd be waiting for the Porsche upgrade, as they have more knowledge and resources than anyone else.
The 918 is optimised and works cohesively. I can't think of a worse car to start working on 'aftermarket'
12-08-2015, 09:03 AM
#22
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Pretty sure Porsche wanted to hit 918hp at outset, and would have done so if it was reliably possible.
No doubt technology/software will move on, but I'd be waiting for the Porsche upgrade, as they have more knowledge and resources than anyone else.
The 918 is optimised and works cohesively. I can't think of a worse car to start working on 'aftermarket'
No doubt technology/software will move on, but I'd be waiting for the Porsche upgrade, as they have more knowledge and resources than anyone else.
The 918 is optimised and works cohesively. I can't think of a worse car to start working on 'aftermarket'
12-18-2015, 03:34 AM
#23
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would YOU ever do something like the EDO engine mod to a CGT? i know you are more than happy/satisfied with 918 as currently engineered, but would you ever consider modding CGT like that? and as always, thanks again for being so generous with your time and sharing your knowledge, the ins and outs. we've all gleaned a ton from just your 'delivery' story thread alone. are you still favoring the 991 RS more than 918 these days. i know you are completely enamored with that also incredible machine.
12-18-2015, 03:37 AM
#24
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Pretty sure Porsche wanted to hit 918hp at outset, and would have done so if it was reliably possible.
No doubt technology/software will move on, but I'd be waiting for the Porsche upgrade, as they have more knowledge and resources than anyone else.
The 918 is optimised and works cohesively. I can't think of a worse car to start working on 'aftermarket'
No doubt technology/software will move on, but I'd be waiting for the Porsche upgrade, as they have more knowledge and resources than anyone else.
The 918 is optimised and works cohesively. I can't think of a worse car to start working on 'aftermarket'
12-18-2015, 03:44 AM
#25
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Which tuner has the expertise to modify electric motors to generate more power?
Electric motor has a much shorter lifespan than gasoline engine. Once it is made to generate more power through higher voltage (thus more heat) its life expectancy goes down exponentially and most likely will result in premature motor failure.
The only way to do it reliability is to swapped out the electric motors with more powerful ones. Than you have to consider other variables like if the battery is powerful enough to support the more powerful motors, lifespan of the battery, heat dissipation, how the whole system works as a whole...etc
Electric motor has a much shorter lifespan than gasoline engine. Once it is made to generate more power through higher voltage (thus more heat) its life expectancy goes down exponentially and most likely will result in premature motor failure.
The only way to do it reliability is to swapped out the electric motors with more powerful ones. Than you have to consider other variables like if the battery is powerful enough to support the more powerful motors, lifespan of the battery, heat dissipation, how the whole system works as a whole...etc
12-18-2015, 12:24 PM
#26
do you remember what EDO competition did with the 980? they did what most sides do, they increase the swept volume (displacement) instead of increasing engine speed (which necessarily needs much more expensive components). they bored out the 5.7L V10 to 6L i believe. I don't know how many owners actually had the engine mod done, but me, personally, i think it ruined the harmonics of that amazing sounding engine!
Apologise for the video quality.