All out stock block Renesis.
#76
Originally Posted by Mazda-Rati
You might have a harder time reaching your 300hp goal if you use the umnitza/simota intake.
https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/attention-people-umnitza-carbon-fiber-intake-must-read-103692/
seems like this intake loses power
https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/attention-people-umnitza-carbon-fiber-intake-must-read-103692/
seems like this intake loses power
#78
Yesterday i receive a Simota 10" by 5" "500" hp air filter. I flow test it on my Flowquick the maximum flow with the cylinder free flowing was 452 cfm@28" with the Simota filter it was 448 cfm@28" compare that to a similar KoN filter only 422cfm@29"Simota filter was 6% better. I don't know what that means in real world conditions but i will test it on a 500 hp REW engine in the near future.
/Lasse
/Lasse
#79
Are you using a simota filter only or the intake aswell? I have the intake and filter. It was my car that was dynoed and lost 5whp with the simota filter vs unfiltered. I know there will be an increase in power of filter vs no filter. However, if it was only a 4cfm difference that shouldnt have lost 5whp. Scott down at Mazsport concluded that it was a really odd filter thats is more or less no good. It looks just like the all the filters on their website. Just an FYI.
#81
Unfortanetly not. I have some 10 rotary engines to do and can only make a few hours a week with the Rotrex kit. I can not now say when the prototype is finished, becausse of all the engine works.
/Lasse
/Lasse
#82
Some updates. Now i only have 6 more 13B to do before i can begin the work with my Project "300 hp" all out stock block. Mikael is almost finished with the complete new built from scratch Renesis inlet manifold. It contains a simple mechanism that open full or closed complete the 6 -ports runners in the side housings. Then shall we build a ver 2 of the exhaust manifold that shall be put to the test on the dyno. I will post some pics on my website that shall be up in a few weeks.
/Lasse
/Lasse
/Lasse
/Lasse
#84
I don't think the intake flow and port timing is no problem. The big issue lies in the tiny exhausts ports. No port timing and bad flow hurts the power output of the Renesis. That is the real challenge of this project. Main concern is to build some good header systems that will perform to 300 hp.
/Lasse
/Lasse
#87
260Hp na is a well known fact. One interesting thing that Lasse has mentioned is something i brought up about a year ago. Surprised no one else has spoke of it.
The electric water pump.
The lack of the parasidic draw of our fast turning pump I truely believe that an electric pump can give us 10hp. Especially in the higher rpm ranges. So that is 270hp. Getting close.
Electric pump has other much desired features also. Lasse can you share with us your plan with this part?
olddragger
The electric water pump.
The lack of the parasidic draw of our fast turning pump I truely believe that an electric pump can give us 10hp. Especially in the higher rpm ranges. So that is 270hp. Getting close.
Electric pump has other much desired features also. Lasse can you share with us your plan with this part?
olddragger
#88
Here is a nice link to info on proper rotary cooling as seen from the eyes of an aircraft rotary engine user. Great info. Somewhere in there he deals with electric water pumps and why not to use them.
http://www.rotaryeng.net/how-to-cool12.html
http://www.rotaryeng.net/how-to-cool12.html
#89
Here's the part RG was talking about
Now, I understand that in an aircraft this is true. But in a vehicle the engine will only be making peak power for a very short amount of time. The author makes a big point of this early on in the article. The cooling needs on an aircraft are going to be much, much more demanding than those on a car.
Regardless, this is an easy one to test. OD already had a water temp guage, so it's merely a matter of swapping out the pump and taking it out on track and watching the guage.
Electric coolant pumps
Some have advocated replacing the mechanical pump with an electric pump. The Mazda 13B rotary requires about three HP to drive the mechanical pump at 6000 RPM and provide the coolant flow necessary to keep the metal temperature near the combustion chamber within bounds. The flow rate required is on the order of 30 to 40 gallons per minute. In the last 100 years there have been no break troughs in impeller shapes that would allow a significant improvement in water pump efficiency. Therefore it would also require about three HP from an electric motor driving a coolant pump to provide sufficient water flow. There are 746 watts in one HP so three HP is a minimum of 2,238 watts. Since the electrical system voltage is 12 volts and watts is equal to voltage times current it would require about 186 amps out of the alternator to provide the required coolant flow. None of the after market car electric coolant pumps available claim that magnitude of current drain so obviously they cannot pump enough coolant to keep the metal temperature within bounds in a rotary engine generating 150 HP continuously. This is not just an opinion. It is based on the laws of physics. If one wants to reduce the water flow rate in the engine one must install thermal couples near the combustion chamber to monitor the metal temperature.
Unfortunately Mazda mounted the pump on the top of the engine. This means if the coolant level drops in the system the pump will cavitate by sucking air. Some builders have installed mechanical water pumps lower down on the right side of the engine to forestall this potential problem.
Some have advocated replacing the mechanical pump with an electric pump. The Mazda 13B rotary requires about three HP to drive the mechanical pump at 6000 RPM and provide the coolant flow necessary to keep the metal temperature near the combustion chamber within bounds. The flow rate required is on the order of 30 to 40 gallons per minute. In the last 100 years there have been no break troughs in impeller shapes that would allow a significant improvement in water pump efficiency. Therefore it would also require about three HP from an electric motor driving a coolant pump to provide sufficient water flow. There are 746 watts in one HP so three HP is a minimum of 2,238 watts. Since the electrical system voltage is 12 volts and watts is equal to voltage times current it would require about 186 amps out of the alternator to provide the required coolant flow. None of the after market car electric coolant pumps available claim that magnitude of current drain so obviously they cannot pump enough coolant to keep the metal temperature within bounds in a rotary engine generating 150 HP continuously. This is not just an opinion. It is based on the laws of physics. If one wants to reduce the water flow rate in the engine one must install thermal couples near the combustion chamber to monitor the metal temperature.
Unfortunately Mazda mounted the pump on the top of the engine. This means if the coolant level drops in the system the pump will cavitate by sucking air. Some builders have installed mechanical water pumps lower down on the right side of the engine to forestall this potential problem.
Regardless, this is an easy one to test. OD already had a water temp guage, so it's merely a matter of swapping out the pump and taking it out on track and watching the guage.
#91
good info --thanks RG. I really feel that the ewp has a place here. The flow rates are there. I would advocate more than just installing the pump. More of a package deal. it will be interesting to see what Lasse has in mind. One drawback is no one makes a ewp specific for the renasis----yet. fabrication can be done especially by someone with the knowledge and skill that lasse has.
Guys---just think of the increased cooling at city speeds in very hot weather, think about continuing the circulation of the coolant for 30 secs(or whatever) after shut off--and other things come to mind. Hope he can follow through with this.
olddragger
Guys---just think of the increased cooling at city speeds in very hot weather, think about continuing the circulation of the coolant for 30 secs(or whatever) after shut off--and other things come to mind. Hope he can follow through with this.
olddragger
#92
It could be that whee a car engine is most of the time that an electric water pump would work just fine. Since an aircraft rotary is always running at full load at 6000 rpm or so, they need to have a cooling system designed to cool for long periods of time at that power level. In a street car you can make some sacrifices as most of the time you aren't at these levels and when you are it is only for a few seconds. This wouldn't give the coolant system enough time to completely heat up. For extended track use however you would need more cooling ability than on a street car but maybe not as much as an airplane. It depends on the track.
#94
Water pumps are centrifigal impellers. Whether its pumping gas or liquid they have a varying efficiency across the range of RPM. In a cooling system the purpose is to move enough coolant to cool. If it moves too much the thermostat provides a bypass.
Liquid introduces a new problem with cavitation. Turn the "prop" fast enough and the liquid vaporizes in turn reducing the flow volume.
Water pumps are designed to flow just enough to cool at an idle which generall ends up pumping far more then is really required at say mid range operation. At higher end operation most water pumps succumb to cavitation. Hook a pressure gauge to the radiator spout on a warm engine and wind it up - eventually you'll see the pressure increase by about 1 psi - then back it down and the pressure drops. Thats where it's cavitating. Once it begins to cavitate the flow rate drops and will never increase above that point.
Whats even more interesting is depending on how the system is designed too much flow will actually result in higher engine temps. Heat absorbed by the water has to be balanced out with the heat removed by the radiator. Without getting into a lengthy dissertation on that there are systems on production cars (common on some Fords) where the time spent in the radiator is more important to cooling then the time spent in the block. Not sure which models, but on some of the older Fords it was known that removing a thermostat actually made them overheat. I think they called that "reverse flow", but it's been a while maybe someone else can elaborate.
Electric water pumps provide a more efficient method of coolant pumping then a motor driven one can. The drawback is they cost more and they invite another failure point. Water pumps don't sap much power so the improvement in fuel mileage is negligible. The only real benefit is they flow a consistent amount of coolant and are designed to avoid cavitation - that allows the control of heat exchange to be almost entirely with the thermostat.
Several years ago I installed a 1/2 HP DC motor on a small block chevy water pump. That pumped more then enough water to keep the motor cool.
Liquid introduces a new problem with cavitation. Turn the "prop" fast enough and the liquid vaporizes in turn reducing the flow volume.
Water pumps are designed to flow just enough to cool at an idle which generall ends up pumping far more then is really required at say mid range operation. At higher end operation most water pumps succumb to cavitation. Hook a pressure gauge to the radiator spout on a warm engine and wind it up - eventually you'll see the pressure increase by about 1 psi - then back it down and the pressure drops. Thats where it's cavitating. Once it begins to cavitate the flow rate drops and will never increase above that point.
Whats even more interesting is depending on how the system is designed too much flow will actually result in higher engine temps. Heat absorbed by the water has to be balanced out with the heat removed by the radiator. Without getting into a lengthy dissertation on that there are systems on production cars (common on some Fords) where the time spent in the radiator is more important to cooling then the time spent in the block. Not sure which models, but on some of the older Fords it was known that removing a thermostat actually made them overheat. I think they called that "reverse flow", but it's been a while maybe someone else can elaborate.
Electric water pumps provide a more efficient method of coolant pumping then a motor driven one can. The drawback is they cost more and they invite another failure point. Water pumps don't sap much power so the improvement in fuel mileage is negligible. The only real benefit is they flow a consistent amount of coolant and are designed to avoid cavitation - that allows the control of heat exchange to be almost entirely with the thermostat.
Several years ago I installed a 1/2 HP DC motor on a small block chevy water pump. That pumped more then enough water to keep the motor cool.
#97
Originally Posted by MegaLoL
Well, Astra Racing do 270hp N/A RX-8. Sth about 210 whp. So I think, that 220 whp is quite more than 260 hp.
#98
Astra 's numbers are suspect because they made an approximation based off RWHP so you can't accurately draw that conclusion, BTW Alex is no longer there ...
different dynos make different readings, you can't just throw out numbers without referencing them and even then there's no guarantee of continuity among same brand dynos, there are so many factors ....
the Sun dyno Lasse is using connects directly to the hubs in place of the wheels & tires so it does not output numbers that are relative to a Mustang or Dynojet, in theory it should read higher than a Dynojet all else being equal
different dynos make different readings, you can't just throw out numbers without referencing them and even then there's no guarantee of continuity among same brand dynos, there are so many factors ....
the Sun dyno Lasse is using connects directly to the hubs in place of the wheels & tires so it does not output numbers that are relative to a Mustang or Dynojet, in theory it should read higher than a Dynojet all else being equal
Last edited by TeamRX8; 04-07-2007 at 10:35 PM.
#99
Awake from the"dead"! No it just that i am very busy with my Rotary jobs and some more. I have been to Swedens biggest car racing and style manufactor exhibition where i had a little boot displaying 3 rotary engines and some parts. Can say that the interest was big! My plan was to dyno the Renesis engine this spring but unfortanately i haven't got the time. I am working hard to get the engine dynoe'd in June with some more parts to test on the Super flow 901 engine dyno. I have good results with the EWP 80l/h electrical water pump and i am plan to use it on the Renesis engine. At least i want to test 3 headers and 2 exhaust systens to see what's gives the most hp.
/Lasse
/Lasse
#100
Lasse--hope you enjoyed that trip. !
Can you give us a little bit more details concerning ewp for our car.
1-- is it attached to the engine via stock wp connections or is it a stand alone attached to the hoses?
2-Type thermostat you use?
3- how wired--any variable speed?
Got a lot more but i will have mercy---and thanks!
olddragger
Can you give us a little bit more details concerning ewp for our car.
1-- is it attached to the engine via stock wp connections or is it a stand alone attached to the hoses?
2-Type thermostat you use?
3- how wired--any variable speed?
Got a lot more but i will have mercy---and thanks!
olddragger