Rotary 818
01-02-2018, 04:13 AM
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Rotary 818
Not sure if this is the right section for this, but...
I'm researching engines to power the 818C that I will be purchasing soon. One that just keeps holding my attention is the Renesis (I know, it'll need an adapter plate for either the Subaru tranny or a fwd Mazda tranny). I prefer to keep things n/a (I count meth as still n/a, and I plan on including it in whatever build I decide to do). With meth, compression, port & polish, cai, tune, etc., can the Renesis reliably produce 300 whp? I love the rotary engine, but I'll stick with the subaru boxer if it can reach n/a 300 whp for less $$$ and reliably stay that way. I will check around the site for more information and maybe post this question elsewhere as well.
I'm researching engines to power the 818C that I will be purchasing soon. One that just keeps holding my attention is the Renesis (I know, it'll need an adapter plate for either the Subaru tranny or a fwd Mazda tranny). I prefer to keep things n/a (I count meth as still n/a, and I plan on including it in whatever build I decide to do). With meth, compression, port & polish, cai, tune, etc., can the Renesis reliably produce 300 whp? I love the rotary engine, but I'll stick with the subaru boxer if it can reach n/a 300 whp for less $$$ and reliably stay that way. I will check around the site for more information and maybe post this question elsewhere as well.
01-02-2018, 10:16 AM
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Wow. I know rotaries aren't quite as reliable as a GM to begin with, but I thought I was low-balling at 150k. My Malibu LS V6 is going on 300k miles with mostly proper care (I can't speak for the owner that put the first 150k on it, but it didn't seem to be in too bad of shape), and the transmission has been the only big blow out the last 20k miles.
How about I flip the question. With a good rebuild (raise the cr, throw in some more reliable apex seals, add some meth injection), can it be reliable for upwards of 150k miles? I can live with 200-250 hp, as long as it will be worth the time and effort that it's going to take to get the rotary to work with either the subaru 5 speed or a good fwd transmission.
How about I flip the question. With a good rebuild (raise the cr, throw in some more reliable apex seals, add some meth injection), can it be reliable for upwards of 150k miles? I can live with 200-250 hp, as long as it will be worth the time and effort that it's going to take to get the rotary to work with either the subaru 5 speed or a good fwd transmission.
01-02-2018, 10:27 AM
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Is it possible? Yes, in the same way it is possible that my wife would be cool with me dating Anna Kendrick.
Is it probable? Yes, in the same way as the above scenario is probable.
You don't want a Renesis. If you're dead-set on a rotary, you're going to want a 13B-REW.
Is it probable? Yes, in the same way as the above scenario is probable.
You don't want a Renesis. If you're dead-set on a rotary, you're going to want a 13B-REW.
01-02-2018, 10:34 AM
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NotAPreppie, thanks for your response on one of the other threads I asked this question in. I had pulled 150k from nowhere, and a little math has that 60k would be about 5 years for me. A rebuild every five years is definitely reasonable for having a n/a rotary-powered 818. For pricing... If the subbie donor and kit came in at around 20k (my current estimation, based on available n/a imprezas at auction and the ffr order form), and leaving 2k for my aftermarket cabin (small sound system, android radio, cordura seat covers, etc.), can the Renesis be had and made work for 7-8k? Either mated with the subbie tranny or another one that can handle 9k rpms and 250 hp. $30k is still a pretty reasonable cost for having 10lbs/hp.
Last edited by Jeff Womack; 01-02-2018 at 10:38 AM.
01-02-2018, 10:49 AM
#9
On a list of motors id rather have in an 818 other than the boxer four, the rotary doesn't strike me as the top 10 of engines id think about, side bar Im in for Anna Kendrick, dibs on the digis bro.
but that said your best bet is to confirm which way the rotary spins and how the Subaru trans Is mounted and go from there, the problem with the Ren is it has such a low following theres little support for it both in the fabrication world and aftermarket community. Now if the engine spins the right way, and you can adapt it to the Subaru trans it would be a spunky little engine with low weight and that rpm right behind your ear, but youll have to sort out the exhaust and probably find a way to mount the oil coolers in the best possible area for airflow since these engines have massive coolers, and then add a bigger fuel tank assuming you can get a rx8 for part out, youd want to pick up and S2, and find a company that can retune the engine, and up the oil mix or start premixing I go through an 80 dollar bottle every 6 months. youll also probably want to do an LS coil conversion to keep costs down but be wary they will need replacing sooner. the other thing is your intake will be backwards compared to the direction of airflow and these engines are highly susceptible to intake temps,
I honestly think 7k in just swapping alone is possible, but then you have the rest of the kit to contend with, for me 7k in swapping stuff Id be looking at a K24 or maybe even a J35 and bask in the plentiful power with a 7500 rpm redline
but that said your best bet is to confirm which way the rotary spins and how the Subaru trans Is mounted and go from there, the problem with the Ren is it has such a low following theres little support for it both in the fabrication world and aftermarket community. Now if the engine spins the right way, and you can adapt it to the Subaru trans it would be a spunky little engine with low weight and that rpm right behind your ear, but youll have to sort out the exhaust and probably find a way to mount the oil coolers in the best possible area for airflow since these engines have massive coolers, and then add a bigger fuel tank assuming you can get a rx8 for part out, youd want to pick up and S2, and find a company that can retune the engine, and up the oil mix or start premixing I go through an 80 dollar bottle every 6 months. youll also probably want to do an LS coil conversion to keep costs down but be wary they will need replacing sooner. the other thing is your intake will be backwards compared to the direction of airflow and these engines are highly susceptible to intake temps,
I honestly think 7k in just swapping alone is possible, but then you have the rest of the kit to contend with, for me 7k in swapping stuff Id be looking at a K24 or maybe even a J35 and bask in the plentiful power with a 7500 rpm redline
01-02-2018, 11:09 AM
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sort out the exhaust and probably find a way to mount the oil coolers in the best possible area for airflow since these engines have massive coolers, and then add a bigger fuel tank assuming you can get a rx8 for part out, youd want to pick up and S2, and find a company that can retune the engine, and up the oil mix or start premixing I go through an 80 dollar bottle every 6 months. youll also probably want to do an LS coil conversion to keep costs down but be wary they will need replacing sooner. the other thing is your intake will be backwards compared to the direction of airflow and these engines are highly susceptible to intake temps,
Last edited by Jeff Womack; 01-02-2018 at 11:12 AM.
01-02-2018, 01:50 PM
#12
Yeah the other thing is are you really going to daily an 818? If this is a hobby car, the miles driven per year goes way down.
About that Subaru 5 speed... what trans are you talking about that drives 2 wheels and fits in a mid-engine configuration? Or are you doing an AWD setup. What is the guy doing a REW in an 818 using? A trans that fits a REW will fit a Renesis. Here's the other thing.. how are you going to control it? The RX8 ECU needs a matching RX8 ignition key cylinder, otherwise the built-in immobilizer kicks in.
I'm with 9k, you could go down this road, but there be dragons, especially if you're the first one doing it. A K24 with its own transmission seems simpler, or a 3sgte out of an MR2. Either of those will give you AMPLE power and a strong aftermarket.
If you decide to go this way, I'd recommend a series 1 (2004-2008) renny. The series 2 have a different oil injection setup that is more advanced, but less modifable, which means your crankcase oil is always your injection oil as well. You can read up on the oil war threads and make your own decisions on whether to pursue modifying the injection system.
About that Subaru 5 speed... what trans are you talking about that drives 2 wheels and fits in a mid-engine configuration? Or are you doing an AWD setup. What is the guy doing a REW in an 818 using? A trans that fits a REW will fit a Renesis. Here's the other thing.. how are you going to control it? The RX8 ECU needs a matching RX8 ignition key cylinder, otherwise the built-in immobilizer kicks in.
I'm with 9k, you could go down this road, but there be dragons, especially if you're the first one doing it. A K24 with its own transmission seems simpler, or a 3sgte out of an MR2. Either of those will give you AMPLE power and a strong aftermarket.
If you decide to go this way, I'd recommend a series 1 (2004-2008) renny. The series 2 have a different oil injection setup that is more advanced, but less modifable, which means your crankcase oil is always your injection oil as well. You can read up on the oil war threads and make your own decisions on whether to pursue modifying the injection system.
Last edited by Loki; 01-02-2018 at 02:04 PM.
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