Lower Compression Rotors for the REnesis
12-28-2010, 11:44 AM
#176
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I am not so sure that Racing Beat isn't referring to the old S5 engine with 9.7:1 compression. Besides, that is just a broad statement not attached to any system, kit, or management. I wasn't around the turbo rotary world in 1986-1991 but I am sure the amount of engine management is nowhere near the AP
So not to discredit RB; they still know their stuff, but the 5psi is obviously outdated, and most likely aimed at the lowest common denominator.
So not to discredit RB; they still know their stuff, but the 5psi is obviously outdated, and most likely aimed at the lowest common denominator.
12-28-2010, 02:11 PM
#182
12-28-2010, 04:00 PM
#183
Rotared
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They designed completely different manifolds for turbo and non turbo cars. The staged intake hinders forced induction. Surely you can see why. I hope they are past the 8bit units 22 years later.
Again the MSP isn't as different as you guys want to claim. What is really funny is that you will use piston motors as a base for your CR and AIT's but refuse to look at prior rotary engines.
I can see not many of you have touched previous motors, and I know why the people who are pushing the limits are not on here.
There is more to the equation than you guys want to list. You readily dismiss someone who has a set up like olddragger wants after he posted results. Its too funny and the exact reason I quit posting information from building motors.
Continue on, I enjoy reading this as I need some entertainment.
Again the MSP isn't as different as you guys want to claim. What is really funny is that you will use piston motors as a base for your CR and AIT's but refuse to look at prior rotary engines.
I can see not many of you have touched previous motors, and I know why the people who are pushing the limits are not on here.
There is more to the equation than you guys want to list. You readily dismiss someone who has a set up like olddragger wants after he posted results. Its too funny and the exact reason I quit posting information from building motors.
Continue on, I enjoy reading this as I need some entertainment.
12-28-2010, 04:07 PM
#185
The msp doesn't differ from the previous rotaries? Absence of overlap, side exhaust ports, the possibility to use an advanced ECU etc all add-up. Yes, most of the parts are the same but still there's a world of difference when building those things. So I could quote you and say that there's more ot the equation than you want to list!
Have you ever looked at the complexity of today's computers?
Have you ever looked at the complexity of today's computers?
12-28-2010, 04:09 PM
#186
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The msp doesn't differ from the previous rotaries? Absence of overlap, side exhaust ports, the possibility to use an advanced ECU etc all add-up. Yes, most of the parts are the same but still there's a world of difference when building those things. So I could quote you and say that there's more ot the equation than you want to list!
Have you ever looked at the complexity of today's computers?
Have you ever looked at the complexity of today's computers?
12-28-2010, 07:16 PM
#189
Administrator
Thread Starter
hence the quotes around "recently". that is recent to me but i recognized that it might not be considered that way for others. plus it was the flappy vane kind with its own inherent flaws/limitations not the hotwire type used now. still it was better than not using maf.
05-09-2021, 01:12 AM
#193
Just read through this thread again after 11 years of it sitting stagnant. Now that I'm about to try some low compression (Renesis) rotors myself I thought I might get some useful info. Main reason for doing this is that I no longer have easy access to E85 and still want to run in the high 300s on pump gas.
Anyway , I found it quite hilarious that no-one through the course of the entire thread even mentioned something absolutely relevant to this discussion. All the talk of the engine being a more efficient compressor than a turbo totally ignores the fact that all air that comes from the turbo goes through an INTERCOOLER !!!!!! I mean WTF ... how did that little technicality get missed?!
Anyway , I found it quite hilarious that no-one through the course of the entire thread even mentioned something absolutely relevant to this discussion. All the talk of the engine being a more efficient compressor than a turbo totally ignores the fact that all air that comes from the turbo goes through an INTERCOOLER !!!!!! I mean WTF ... how did that little technicality get missed?!
05-10-2021, 04:43 AM
#194
maybe you missed that it was really relative to the Pettit supercharger from a topic started by OD. So that was a bit limited wrt the intercooler as compared to a turbo setup.
that said, the thread is a lot of the usual didn’t really understand the differences between the Renesis and previous 13B engines that was fairly prevalent at that time.
which a lot of people still don’t have a good handle on it to this day, even after having it spelled out in detail. They (general reference not aimed at any particular person) just can’t any more get over and past the hump of what they thought they knew any more than a lot of the people in this past thread.
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that said, the thread is a lot of the usual didn’t really understand the differences between the Renesis and previous 13B engines that was fairly prevalent at that time.
which a lot of people still don’t have a good handle on it to this day, even after having it spelled out in detail. They (general reference not aimed at any particular person) just can’t any more get over and past the hump of what they thought they knew any more than a lot of the people in this past thread.
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05-10-2021, 01:03 PM
#195
The thread was kicked off by ODs quest for a reliable 300 but maybe you should read it again because that was not the focus of the thread as a whole. But why split hairs? The effect an Intercooler has in relation to CR and safe boost levels should have been covered either way - but it wasn't.
There also seemed to be this idea through the thread by a few, that retaining the high compression Renesis rotors for boost was somehow a good thing. How ridiculous! IMO with the benefit of hindsight and experience, the guys that came in from rx7 land had more clues than the "Renesis is different" guys in this regard.
There also seemed to be this idea through the thread by a few, that retaining the high compression Renesis rotors for boost was somehow a good thing. How ridiculous! IMO with the benefit of hindsight and experience, the guys that came in from rx7 land had more clues than the "Renesis is different" guys in this regard.
Last edited by Brettus; 05-10-2021 at 02:46 PM.
05-10-2021, 02:55 PM
#196
honestly, I’m not really sure why you bumped the thread to make whatever point you’re trying to make, because again it was relative to the supercharger compressor is how I read it and they were also only talking about 300-350 whp too; which my first response to it back then was why even bother having this discussion for that power level 
Last edited by TeamRX8; 05-10-2021 at 03:32 PM.
05-14-2021, 09:37 PM
#198
well the answer to your question, or point, or whatever it was intended to be was right at the beginning
https://www.rx8club.com/series-i-maj...6/#post3824820
followed by my post about “why bother for 300 whp?” …
however, that post does in turn address the reason for pursuing this. Pretty much could of ended & closed the thread after I posted the “why-bother” comment immediately after it.
https://www.rx8club.com/series-i-maj...6/#post3824820
followed by my post about “why bother for 300 whp?” …
however, that post does in turn address the reason for pursuing this. Pretty much could of ended & closed the thread after I posted the “why-bother” comment immediately after it.
Last edited by TeamRX8; 05-14-2021 at 09:40 PM.
05-15-2021, 12:30 AM
#199
It's obvious to me that you are bored and just want to stir up an argument.
You also couldn't have read the whole thread , otherwise you wouldn't have made that dumb comment about ending the thread there. There is more to it than ODs 300 quest and there is no other decent discussion about CR on the forum so why wouldn't they carry it on?
But as to the point of my initial thread revival post:
Firstly : ... Kane's post has no mention of intercooling. Throw an efficient intercooler on both engines and his argument is null and void. IE it is ALWAYS (within reason) better to do more air compression outside the engine than inside.
Secondly : A 9:1 13b engine at say 14psi of boost makes approx. the same power as one at 10:1 . There is a small gain in efficiency in the 10:1 less a small loss from lower airflow due to slightly lower chamber volume. But power comes mostly from mass airflow. The amount of compression inside the engine has no effect on mass airflow and the small advantage from efficiency of the 10:1 is negligible.
So ... in a nutshell ... A lower CR engine is a better engine for boost. Kinda blows my mind that there was even any doubt about that!
You also couldn't have read the whole thread , otherwise you wouldn't have made that dumb comment about ending the thread there. There is more to it than ODs 300 quest and there is no other decent discussion about CR on the forum so why wouldn't they carry it on?
But as to the point of my initial thread revival post:
Firstly : ... Kane's post has no mention of intercooling. Throw an efficient intercooler on both engines and his argument is null and void. IE it is ALWAYS (within reason) better to do more air compression outside the engine than inside.
Secondly : A 9:1 13b engine at say 14psi of boost makes approx. the same power as one at 10:1 . There is a small gain in efficiency in the 10:1 less a small loss from lower airflow due to slightly lower chamber volume. But power comes mostly from mass airflow. The amount of compression inside the engine has no effect on mass airflow and the small advantage from efficiency of the 10:1 is negligible.
So ... in a nutshell ... A lower CR engine is a better engine for boost. Kinda blows my mind that there was even any doubt about that!
Last edited by Brettus; 05-15-2021 at 12:48 AM.
05-15-2021, 04:18 PM
#200
no, you resort to bearing false witness against me again
you also never mentioned it in any of your posts in this thread back then
trimming material off Renesis rotor faces was acted upon before it was ever posted on here for you to see and consider
there’s nothing to argue, I just don’t understand what you’re crowing about is all, and over something from 10 years ago when you also didn’t know then what you do today. Maybe you were bored or something.
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you also never mentioned it in any of your posts in this thread back then
trimming material off Renesis rotor faces was acted upon before it was ever posted on here for you to see and consider
there’s nothing to argue, I just don’t understand what you’re crowing about is all, and over something from 10 years ago when you also didn’t know then what you do today. Maybe you were bored or something.
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