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So , there has been a bit of talk lately on building a 20b Renesis and it got me thinking. If I were building one , how would I do it ? So I devised a concept which I believe will deliver 320-350whp in a fuel efficient/street-able/affordable package.
Assuming those goals are achievable, my question to the forum before I pull the trigger is:
IS IT WORTH THE TIME AND EFFORT BUILDING IT ?
I've been teetering over whether it's worth pursuing for a while now, as I know I can make more power/torque and have a more efficient street friendly engine on a turbo setup for less money. But we all know how cool a 20b sounds so ...give me your opinions please.
PS : this isn't meant to be a technical discussion on HOW .... more about the WHY ?
I am putting a 20 b turbo, half bridgeported in 08 rx 8 with sequential 6xd tranny, Starting to get into the wiring, does anybody know do I need the computer under the engine managementt one? Using Haltech everything. The tranny can do wide open throttle and blip for downshifting, just a street car. I still want to maintain, cruise, air, steering wheel functions, remote entry, etc.
Team - I was laughing cause your response reminded me of Mel Brooks “Silent Movie” where Marcel Marseau (spelling?) the famous mime says the only spoken word - NO.
It would be interesting to see it done. I don’t agree with the whole electric car thing. Just feel they’re an environmental disaster looming. The mining of mineral nodules from the abyssal plain (deep ocean) is causing unknown havoc all to source battery material .
The green attitude of new owners grates on me. The tailpipe has been moved from the car to the coal fired power plant or gas powered plant.
Damn I’m getting to be a grumpy old fart
Did anyone else have a good laugh at my expense? I did and it’s ok to point fingers.
I guess I need to be less rabid when the word “hybrid” comes up. Sometimes it’s not another battery car.
Sorry for polluting your thread.
Brettus - ignore my crap and proceed. I’ve enjoyed and learned much from stalking your other posts.
Not sure how this turned into an environmental discussion, but I'll just point out that while the above is true, it's not like sourcing petrol is environmentally friendly and not all electricity comes from oil. It's a matter of degrees.
As for why you would build a 3-rotor Renny: I can see a couple of pros:
- more torque
- potentially better top end bsfc than a twin renny
- more return on your turbo investment (if you're going to do all that work, may as well feed a bigger engine)
It sounds like some kind of endurance race car to me
Loki , I'll be keeping my turbo setup for track. This engine would just be for my street car, the blue one I put the PP Renesis engine into.That engine gets huge attention from the boy racer crowd due to the pulse ....but that's not really my demographic ...lol
It will costs as much or more than a regular 20B for starters and it will require a lot more work to achieve that power level target out of it as compared to one too.
What is the actual context for making that power though? 1-port (PP) per rotor 2-port (Std) per rotor, 3-port (High) per rotor, etc.? Because those details are going to matter wrt effort and cost even if we don’t get into the technical merits.
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I'm not going to go into that.
I gotta say , I was going to delete this thread after no-one posted anything for a while because I pretty much had the answer I was looking for from the the Purely forum. But then I found I wasn't able to so had to leave it here.
We can just let it die a natural death ...
I wasn't looking for advice on the build ... I have that part figured out. I have a builder itching to do it (that has built plenty of 20b s and believes my idea could work) , I have a car to put it in , I have most of the parts I need already.
I was just looking for a reason to do it! If the general vibe was .... nobody wants to see a 300+whp Renesis based rotary that could work well in a street car . Then I would just forget the idea.
With all due respect to every opinion given here, but here in UK a bunch of wannabe's managed to build a 3 rotor out of renesis housings and plates and it worked.
Any engineer in his right mind would have looked at that engine and said this is not going to work since the mid rotor would not breath as well as the others, is it ideal ? Hell No, but then again what exactly is ideal about a bloody rotary??!!
it worked and they have videos of it in an rx7 drifting and ripping wheels.
i am not sure what the design would be but judging by your documented work, I believe it will be you that pull this off purely based on success statistics.
best of luck.
You were giving advice based on what you think is achievable . I asked what you thought putting all that aside. You can't do that and that's fine. I don't need to hear anymore from you. Byeeeee !
You are the only person that didn't understand what I meant... because you can't look past your current paradigm of what's possible and assumed it couldn't work.
Childish ? You do remember that you banned me from your sandpit (aka turbo thread) because you couldn't take the criticism?
You are the only person that didn't understand what I meant... because you can't look past your current paradigm of what's possible and assumed it couldn't work.
Childish ? You do remember that you banned me from your sandpit (aka turbo thread) because you couldn't take the criticism?
Assumed what wouldn’t work? We haven’t even established that yet. I don’t assume it won’t work. I don’t see how it makes sense to put that time and effort into a Renesis 20B just to get a lesser result from a real 20B, as per the that dyno graph. Or go choose an NA 20B graph if you think that matters.
I did get frustrated and asked you to leave back then. It’s not the same thing at all. That was when I was in the peak of the chemo and radiation treatment. I’m content enough to say I’m not the same person now either, even if you refuse to recognize it.
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I don’t see how it makes sense to put that time and effort into a Renesis 20B just to get a lesser result from a real 20B, as per the that dyno graph. Or go choose an NA 20B graph if you think that matters.
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Ok ... that's the kind of answer I was looking for ! Thankyou.
Have you ever driven a PP rotary 13b or 20b? If you have ...how was it for driving around town ? Stopping in traffic , taking off from the lights slowly behind traffic? Crawling along the freeway ? How was the fuel consumption ? I don't know the answer to these questions myself BTW ....but i'm sure you can see where i'm going with them.
Also ...did you know : a STOCK Mazda 20b makes around 230whp?
I already told you that in my second reply to this thread.
The factory stock 20B intended for a luxury car ... how many years ago was that? I guess all those details matter now. You’re something else.
Doesn't really matter ...no . But what can a normal 20b make and still be a practical street engine? Again ...I don't know .... but that's what we would need to compare the Renesis 20b to. If a normal 20b can make 320-350 and be a practical street engine then my proposal is a waste of time.
Which, there’s a reason why throwing 13B housings together with Renesis plates doesn’t result in herds of unicorns and lucky charm leprechauns springing forth out the exhaust pipe.
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I agree 100% ,and I'm not thinking of doing anything like that.
It might be you whose mind explodes when you do see what I have planned though ...lol
but to answer your question, 20B NA can get about 300 whp 200 ft-lb streetable, addition of staged ITB semi-PP can get 350 whp helping flow more at high end without hurting lowend, higher if you’re will to sacrifice some driveability.
With PP it just depends what you call streetable. I’m not convinced it will work well with side ports because they only support so much hp/flow. You could see that with the one aviation PP motor that was built compared against a well built stock port; it made an ok number within the side port limitation, but only for a 1000 rpm range and suffered a lot below and above it. Which the 20B Renesis center rotor will be limited siamese only exhaust ports. A staged semi-PP might be ok to a point. The biggest hurdle is the intake system. Without the S-DAIS it will suffer at lower rpm. The semi or full PP might help it make a peak number, but torque on either side of that will suffer.
So I stand on my claim that it won’t be worth it even if it makes that output range in comparison, but based on the basis of my general understanding since I’m not clear on what you’re plan is. A standard 20B engine is quite expensive. A Renesis 20B engine might initially cost less, but you have to spend money in other areas since there was never a factory version, like intake and such. Even if you position the PP to not have overlap, I don’t think it will be able to handle the exhaust flow requirement, but maybe. Overlap is not a solution to anything, but again based on all the configurations I’m familiar with.
I can see how thinking the addition of a PP to a 4-port would help it transition to 6-port like power and the addition of the 3rd rotor help to offset the mid-range TQ loss of not having a staged SSV, though you can stage all that with enough $$$, but the effort and overall cost still has me in the “no” category.
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but to answer your question, 20B NA can get about 300 whp 200 ft-lb streetable, addition of staged ITB semi-PP can get 350 whp helping flow more at high end without hurting lowend, higher if you’re will to sacrifice some driveability.
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Going off those numbers ,I would expect it to do better that a ported 20B down low and equal to a ITB semi-PP up top, with better driveability, better fuel consumption and a lower all up cost than either of those two engines.
09-03-2020, 07:08 PM
