Peripheral Port Renesis dyno's
12-19-2007, 05:08 PM
#27
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I know of only 1 other one but it didn't hold up. The owner switched to 13brew PP config and now making 340 rwhp @ 9500rpm lol.
12-19-2007, 05:51 PM
#28
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12-19-2007, 06:07 PM
#29
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12-20-2007, 02:00 PM
#32
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Well the 16x should be an improvement without any doubt just based on the displacement increase alone without Direct Injection or the Larger Ports. (assuming emissions are met) Now include DI and LP along with better fuel economy ...how can Failure even cross your mind? RX8 sold solely on marketing so improve it in all areas a bit and why would it not sell well again?
If your referring to the RX7 well that is a different story, they have so many directions they can take the car but which will they choose. I'm sure R&D will figure it out and lets hope its not the way of the new Miata.
If your referring to the RX7 well that is a different story, they have so many directions they can take the car but which will they choose. I'm sure R&D will figure it out and lets hope its not the way of the new Miata.
12-20-2007, 02:04 PM
#33
Destroying Threads
i was merely saying that the 16X BETTER be better, if not mazda would be failing big time because of all the reasons you listed
i highly doubt it would though, but still, I highly doubted mazda rx8 sales could have gotten any lower and here we are now
i highly doubt it would though, but still, I highly doubted mazda rx8 sales could have gotten any lower and here we are now
12-23-2007, 11:35 AM
#35
The Professor
Kind of makes you wonder why mazda doesn't just make a new small suv and stuff a 4 rotor in it.
1) would get around emissions laws for sedans/coupes
2) could be easily swapped into the 8 or 7 or whatever
1) would get around emissions laws for sedans/coupes
2) could be easily swapped into the 8 or 7 or whatever
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12-23-2007, 03:08 PM
#39
The Professor
91 is used to combat the high temps the engine experiences in stop and go daily driving and fouling of the plugs, etc.
12-23-2007, 07:42 PM
#40
Registered
Thread Starter
Naturally aspirated rotaries have always loved low octane fuel. The only reason the Renesis doesn't doesn't have anything to do with the engine. It has everything to do with the tuning. Retune a Renesis and it would love low octane too.
12-24-2007, 05:26 AM
#41
Registered
PP on demand
I've always wondered whether a PP + side intake rotary would work.
That is, at low speeds a butterfly valve in the PP intake runner is shut and the engine works just like a regular side intake engine, then above a certain point the valve opens and the PP starts doing its dirty job... It could possibly be used instead of the aux side intake port.
I know that a similar setup was used many years ago for a racing engine (possibly a 12A), but would it be feasible for a road engine?
Also, would a similar butterfly valve controlled exhaust Peripherial port be possible? I've been thinking about it for a while, and while carbon deposits may be an issue, the actuators could be instructed to flip the valve 180° every time the engine goes to deceleration fuel cut-off, so that the valve "sweeps" its seat and keeps it clean. Any thoughts?
That is, at low speeds a butterfly valve in the PP intake runner is shut and the engine works just like a regular side intake engine, then above a certain point the valve opens and the PP starts doing its dirty job... It could possibly be used instead of the aux side intake port.
I know that a similar setup was used many years ago for a racing engine (possibly a 12A), but would it be feasible for a road engine?
Also, would a similar butterfly valve controlled exhaust Peripherial port be possible? I've been thinking about it for a while, and while carbon deposits may be an issue, the actuators could be instructed to flip the valve 180° every time the engine goes to deceleration fuel cut-off, so that the valve "sweeps" its seat and keeps it clean. Any thoughts?
12-24-2007, 10:53 AM
#42
BDC Motorsports
MazaManiac, it's not about peak power; it's not about spending (x) dollars on a setup to "get 60hp". It's about the torque and horsepower band, it's about when torque begins to rise and how quickly it rises per (x) RPM, and it's about peak torque and horsepower. Not to mention it's a nice experiment that gives some very useful data that's worth much more than the money spent to do it.
B
12-24-2007, 11:32 AM
#43
BDC Motorsports
Fuel is a funny thing. It's the catalyst that allows for the combustion of O2 molecules. Along with charge density and air/fuel mixture, it determines the rate of deflagration (speed of the flame front). It can have a positive effect on pulling heat out of the chamber overall. It dictates when the spark plug can be fired and how strong that spark must be. It also dictates not only what kind of spark plugs must be used (in terms of heat range) but also what effective compression ratio can be used in the motor.
In terms of the use of a non-turbocharged motor like the stock 10:1 Renesis, of course a lower octane fuel will yield more power. One of the greatest misconceptions the unsuspecting public has is that 91-93 octane fuel, which is more expensive at the pump, is somehow more powerful and better to use in their grocery-getter, putter-putter cars. Infact, it's not, even though there may be certain additives and detergents added to that higher octane fuel that may lend towards longer engine life (depending on the manufacturer and vendor). Octane rating in a nutshell is an established measurement of an engine's resiliency to engine knock, be it pre-ignition or detonation, depending on the circumstance. The lower the octane rating, the more volatile and easily lit the fuel is. Lower octane fuel yields greater power per stroke (in the form of BTU's; heat energy). In the case of the Renesis N/A motor, like the older non-turbocharged 13B's preceeding it, a more volatile fuel is perfectly fine to use, will produce more power, and will cost alot less too. Boosted is a different story however in that not only will intake air temperatures (IAT's) be higher but also the load on the motor will be more severe in that the density of the charge is greater, requiring a more stable fuel due to the fact that once the denser charge fires, it will burn with more rapidity.
The things that determine a fuel's efficacy as a heat exchanger in a combustion chamber is its latent heat of evapouration (how much heat it draws when it flashes from a fluid to a gas) and its specific heat (how much heat it can "hold" prior to heating up itself. Lower octane fuels usually have lesser of both of these. Gasoline in general isn't high on the list at all. Infact, it's low and is comparatively-speaking a very poor heat exchanger. Alcohol fuels are the anti-thesis of all that is bad about using fuel as an anti-knock agent. Methyl and ethyl alcohol fuels are through the roof on latent heat. Water, although not a fuel, is amazing on the specific heat index. The main deterrant to knock for a fuel will be its auto-ignition temperature which is challenged in its fullest fury just prior to TDC (during the end of the compression stroke) and thereafter once the charge is fired and when both pressure and temperature rise. Gasoline fuels range from mid 400*F to mid-high 600*F. Alcohols are in the high 700*F's to low 800*F's.
Hope this helps elucidate some of this sometimes-complicated topic. On a side note, once you understand all of this, you'll also understand why E85 is such a bad idea for any heavily non-FI'd vehicle.
B
12-24-2007, 02:48 PM
#44
The Professor
I understand what you're saying Staticlag, but I wouldn't think of it in terms of "combating" but instead consider it more as a part (not only a part but a critical part) of a system with several parts that have to be "well-balanced" concerning the goal of the system (creating (x) power or producing (x) load).
Fuel is a funny thing. It's the catalyst that allows for the combustion of O2 molecules. Along with charge density and air/fuel mixture, it determines the rate of deflagration (speed of the flame front). It can have a positive effect on pulling heat out of the chamber overall. It dictates when the spark plug can be fired and how strong that spark must be. It also dictates not only what kind of spark plugs must be used (in terms of heat range) but also what effective compression ratio can be used in the motor.
In terms of the use of a non-turbocharged motor like the stock 10:1 Renesis, of course a lower octane fuel will yield more power. One of the greatest misconceptions the unsuspecting public has is that 91-93 octane fuel, which is more expensive at the pump, is somehow more powerful and better to use in their grocery-getter, putter-putter cars. Infact, it's not, even though there may be certain additives and detergents added to that higher octane fuel that may lend towards longer engine life (depending on the manufacturer and vendor). Octane rating in a nutshell is an established measurement of an engine's resiliency to engine knock, be it pre-ignition or detonation, depending on the circumstance. The lower the octane rating, the more volatile and easily lit the fuel is. Lower octane fuel yields greater power per stroke (in the form of BTU's; heat energy). In the case of the Renesis N/A motor, like the older non-turbocharged 13B's preceeding it, a more volatile fuel is perfectly fine to use, will produce more power, and will cost alot less too. Boosted is a different story however in that not only will intake air temperatures (IAT's) be higher but also the load on the motor will be more severe in that the density of the charge is greater, requiring a more stable fuel due to the fact that once the denser charge fires, it will burn with more rapidity.
The things that determine a fuel's efficacy as a heat exchanger in a combustion chamber is its latent heat of evapouration (how much heat it draws when it flashes from a fluid to a gas) and its specific heat (how much heat it can "hold" prior to heating up itself. Lower octane fuels usually have lesser of both of these. Gasoline in general isn't high on the list at all. Infact, it's low and is comparatively-speaking a very poor heat exchanger. Alcohol fuels are the anti-thesis of all that is bad about using fuel as an anti-knock agent. Methyl and ethyl alcohol fuels are through the roof on latent heat. Water, although not a fuel, is amazing on the specific heat index. The main deterrant to knock for a fuel will be its auto-ignition temperature which is challenged in its fullest fury just prior to TDC (during the end of the compression stroke) and thereafter once the charge is fired and when both pressure and temperature rise. Gasoline fuels range from mid 400*F to mid-high 600*F. Alcohols are in the high 700*F's to low 800*F's.
Hope this helps elucidate some of this sometimes-complicated topic. On a side note, once you understand all of this, you'll also understand why E85 is such a bad idea for any heavily non-FI'd vehicle.
B
Fuel is a funny thing. It's the catalyst that allows for the combustion of O2 molecules. Along with charge density and air/fuel mixture, it determines the rate of deflagration (speed of the flame front). It can have a positive effect on pulling heat out of the chamber overall. It dictates when the spark plug can be fired and how strong that spark must be. It also dictates not only what kind of spark plugs must be used (in terms of heat range) but also what effective compression ratio can be used in the motor.
In terms of the use of a non-turbocharged motor like the stock 10:1 Renesis, of course a lower octane fuel will yield more power. One of the greatest misconceptions the unsuspecting public has is that 91-93 octane fuel, which is more expensive at the pump, is somehow more powerful and better to use in their grocery-getter, putter-putter cars. Infact, it's not, even though there may be certain additives and detergents added to that higher octane fuel that may lend towards longer engine life (depending on the manufacturer and vendor). Octane rating in a nutshell is an established measurement of an engine's resiliency to engine knock, be it pre-ignition or detonation, depending on the circumstance. The lower the octane rating, the more volatile and easily lit the fuel is. Lower octane fuel yields greater power per stroke (in the form of BTU's; heat energy). In the case of the Renesis N/A motor, like the older non-turbocharged 13B's preceeding it, a more volatile fuel is perfectly fine to use, will produce more power, and will cost alot less too. Boosted is a different story however in that not only will intake air temperatures (IAT's) be higher but also the load on the motor will be more severe in that the density of the charge is greater, requiring a more stable fuel due to the fact that once the denser charge fires, it will burn with more rapidity.
The things that determine a fuel's efficacy as a heat exchanger in a combustion chamber is its latent heat of evapouration (how much heat it draws when it flashes from a fluid to a gas) and its specific heat (how much heat it can "hold" prior to heating up itself. Lower octane fuels usually have lesser of both of these. Gasoline in general isn't high on the list at all. Infact, it's low and is comparatively-speaking a very poor heat exchanger. Alcohol fuels are the anti-thesis of all that is bad about using fuel as an anti-knock agent. Methyl and ethyl alcohol fuels are through the roof on latent heat. Water, although not a fuel, is amazing on the specific heat index. The main deterrant to knock for a fuel will be its auto-ignition temperature which is challenged in its fullest fury just prior to TDC (during the end of the compression stroke) and thereafter once the charge is fired and when both pressure and temperature rise. Gasoline fuels range from mid 400*F to mid-high 600*F. Alcohols are in the high 700*F's to low 800*F's.
Hope this helps elucidate some of this sometimes-complicated topic. On a side note, once you understand all of this, you'll also understand why E85 is such a bad idea for any heavily non-FI'd vehicle.
B
Why is a low octane fuel more volatile than a high octane fuel?
How does lower octane generate more power per stroke?
How does this specific heat work?
why is E85 such a bad choice for non-heavily FI'ed vehicle, isn't it cheap?
12-24-2007, 04:19 PM
#45
BDC Motorsports
http://en.wikipedia.org/wiki/Deflagration
How does lower octane generate more power per stroke?
How does this specific heat work?
http://hyperphysics.phy-astr.gsu.edu...ermo/spht.html
Gasoline fuel's specific heat sucks, IMO, where alcohol and water far excel. The reason why it's common for tuners to run such rich air/fuel ratios while under boost (for example: 12psi of boost running 11.5:1 AFR) is because the extra fuel in the charge, making the chamber awash, is used as a heat exchanger to pull heat out of the chamber that's being created because of running boost (high loads) in the first place.
why is E85 such a bad choice for non-heavily FI'ed vehicle, isn't it cheap?
B
12-24-2007, 05:31 PM
#47
BDC Motorsports
B
12-24-2007, 05:36 PM
#48
BDC Motorsports
I really love Wikipedia, Ray. http://en.wikipedia.org/wiki/Combustion
I hope I'm not ruining this thread.
B
I hope I'm not ruining this thread.
B
12-24-2007, 05:44 PM
#49
I wish I were able to load-tune the car but I can't because the clutch is finally starting to slip. I've got an ACT un-sprung 6-puck disc that I bought and installed in August of '99. I've had it in there for over 8 years and it's finally starting to see sunset. I can't load the car out past about 9-10psi of boost because it begins to slip off. Oh well. I'll replace the disc soon (got a good deal) and get back to load tuning. I hope to break 500 to the wheels with this new turbo and methanol.
B
B
I told my wife that what I wanted for Christmas was NO hassles about putting the engine back in my car before dinner
12-24-2007, 08:22 PM
#50
Brian - I applaud you for answering this stuff.
I didn't have it in me to do it again.
And again.
And again.
I think this is a sticky somewhere, isn't it? Oh, that's right:
https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/so-you-wanna-tuner-100333/
I didn't have it in me to do it again.
And again.
And again.
I think this is a sticky somewhere, isn't it? Oh, that's right:
https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/so-you-wanna-tuner-100333/