RX8 Engine into a 1st Gen RX7?
07-05-07, 08:28 PM
#27
The Renesis may not be able to take as much boost as a lower compression 13B but look at the horsepower advantage it has over a 13B sans turbos. The TII was either 182 or 200 hp with a turbo. The Renesis only needs a few pounds of boost to hit 300 hp if set up properly. If you are doing a straight engine swap, you can use a standalone ecu. No need to make it complex. Full control. Even Megasquirt can control a Renesis now. If you have a standalone, you don't need anything else that the RX-8 does to keep the ecu happy.
Install a lightweight flywheel on it and go. You can use the stock transmission. Mazda has used the same bellhousing since 1972 or so. It bolts right up. The RX-8 transmission is really no worse than any other n/a rotary transmission. Imagine a high 13 second n/a 1st gen that could pass emissions if it had to!
True it's not the cheapest option. It isn't any more complex than any other rotary engine swap into the car. Use the 1st gen front cover. I have a Renesis here right now that I'm porting for a guy from Detroit. My spare GSL-SE front cover bolts right on. Problem solved. You can also use the crank angle sensor from a 2nd gen so no need to worry about the weird crank trigger the RX-8 uses. That means any standalone works. Bolt on a 75mm throttlebody from another car and you're done. Use the mechanical oil metering pump (or premix). Use a bicycle brake cable connected to the tb to control it. Make your own oil metering lines. These are cheap and easy. It's an easy swap. Far easier than a 20B anyday and arguably as easy as a T-II swap. The only reason not to do it is because you could get a TII engine in good shape for cheaper.
Install a lightweight flywheel on it and go. You can use the stock transmission. Mazda has used the same bellhousing since 1972 or so. It bolts right up. The RX-8 transmission is really no worse than any other n/a rotary transmission. Imagine a high 13 second n/a 1st gen that could pass emissions if it had to!
True it's not the cheapest option. It isn't any more complex than any other rotary engine swap into the car. Use the 1st gen front cover. I have a Renesis here right now that I'm porting for a guy from Detroit. My spare GSL-SE front cover bolts right on. Problem solved. You can also use the crank angle sensor from a 2nd gen so no need to worry about the weird crank trigger the RX-8 uses. That means any standalone works. Bolt on a 75mm throttlebody from another car and you're done. Use the mechanical oil metering pump (or premix). Use a bicycle brake cable connected to the tb to control it. Make your own oil metering lines. These are cheap and easy. It's an easy swap. Far easier than a 20B anyday and arguably as easy as a T-II swap. The only reason not to do it is because you could get a TII engine in good shape for cheaper.
07-05-07, 09:45 PM
#28
Sounds like a plan. I have a 1st gen with a bad motor right here, and as an 8 owner I am not afraid of using a Renesis.
I will have to get with MM and see if a 12a rebuild is more expensive than a previously loved Renesis.
How about cooling? I have 1980, would the oil cooler be large enough?
I will have to get with MM and see if a 12a rebuild is more expensive than a previously loved Renesis.
How about cooling? I have 1980, would the oil cooler be large enough?
07-05-07, 10:05 PM
#29
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Sounds like a plan. I have a 1st gen with a bad motor right here, and as an 8 owner I am not afraid of using a Renesis.
I will have to get with MM and see if a 12a rebuild is more expensive than a previously loved Renesis.
How about cooling? I have 1980, would the oil cooler be large enough?
I will have to get with MM and see if a 12a rebuild is more expensive than a previously loved Renesis.
How about cooling? I have 1980, would the oil cooler be large enough?
lol...
Save your money, save the headaches, fix the 12a (rebuild it yourself), learn something in the process...
07-05-07, 10:41 PM
#30
Yep, I did. I have my pencil out and working it out now.
It depends on how cheap I can get the Renesis.
Where I live the 7 would have to pass emissions. And yeah there are ways to make that happen.
Looking at this option is a new thought and worth checking out.
It depends on how cheap I can get the Renesis.
Where I live the 7 would have to pass emissions. And yeah there are ways to make that happen.
Looking at this option is a new thought and worth checking out.
07-05-07, 10:45 PM
#31
The Renesis may not be able to take as much boost as a lower compression 13B but look at the horsepower advantage it has over a 13B sans turbos. The TII was either 182 or 200 hp with a turbo. The Renesis only needs a few pounds of boost to hit 300 hp if set up properly. If you are doing a straight engine swap, you can use a standalone ecu. No need to make it complex. Full control. Even Megasquirt can control a Renesis now. If you have a standalone, you don't need anything else that the RX-8 does to keep the ecu happy.
Install a lightweight flywheel on it and go. You can use the stock transmission. Mazda has used the same bellhousing since 1972 or so. It bolts right up. The RX-8 transmission is really no worse than any other n/a rotary transmission. Imagine a high 13 second n/a 1st gen that could pass emissions if it had to!
True it's not the cheapest option. It isn't any more complex than any other rotary engine swap into the car. Use the 1st gen front cover. I have a Renesis here right now that I'm porting for a guy from Detroit. My spare GSL-SE front cover bolts right on. Problem solved. You can also use the crank angle sensor from a 2nd gen so no need to worry about the weird crank trigger the RX-8 uses. That means any standalone works. Bolt on a 75mm throttlebody from another car and you're done. Use the mechanical oil metering pump (or premix). Use a bicycle brake cable connected to the tb to control it. Make your own oil metering lines. These are cheap and easy. It's an easy swap. Far easier than a 20B anyday and arguably as easy as a T-II swap. The only reason not to do it is because you could get a TII engine in good shape for cheaper.
Install a lightweight flywheel on it and go. You can use the stock transmission. Mazda has used the same bellhousing since 1972 or so. It bolts right up. The RX-8 transmission is really no worse than any other n/a rotary transmission. Imagine a high 13 second n/a 1st gen that could pass emissions if it had to!
True it's not the cheapest option. It isn't any more complex than any other rotary engine swap into the car. Use the 1st gen front cover. I have a Renesis here right now that I'm porting for a guy from Detroit. My spare GSL-SE front cover bolts right on. Problem solved. You can also use the crank angle sensor from a 2nd gen so no need to worry about the weird crank trigger the RX-8 uses. That means any standalone works. Bolt on a 75mm throttlebody from another car and you're done. Use the mechanical oil metering pump (or premix). Use a bicycle brake cable connected to the tb to control it. Make your own oil metering lines. These are cheap and easy. It's an easy swap. Far easier than a 20B anyday and arguably as easy as a T-II swap. The only reason not to do it is because you could get a TII engine in good shape for cheaper.
wow. you make it sound so easy
07-05-07, 11:33 PM
#32
It is easy! It's simple. People make it sound too hard. Keep the stock oil and coolant system from the RX-7. It's fine. It's very straight forward. I have a Renesis here and I own a 1st gen. While the engine isn't mine, believe me, I've figured out what to do to make the swap simple. Don't think a TII swap would be any less of a headache. My money is on the Renesis swap being far easier to accomplish.
No engine swap is cheap. At least not any swap that is done well. May as well use a current engine. Keep it n/a. That's about as reliable as you can get.
No engine swap is cheap. At least not any swap that is done well. May as well use a current engine. Keep it n/a. That's about as reliable as you can get.
07-05-07, 11:38 PM
#33
If you have to replace any housings in the 12A, the cost of the rebuild will match what you can probably get a used running Renesis for. Don't fall for the budget rebuild bs that you see around here. Why is there never enough time and money to do it right the first time but always enough to do it again? You'll spend nearly $1000 in seals alone on a rebuild. You can go cheaper such as RA seals or Atkins but I personally only use Mazda seals. They're the best unless you can afford Ianetti. I wouldn't use anyone else's seals. Others do but that's their risk. If you have to choose between using what's proven vs using what's cheap, be safe. Use what's proven. Ironically it's usually the cheapest option in the longrun.
07-06-07, 08:50 AM
#34
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The Renesis may not be able to take as much boost as a lower compression 13B but look at the horsepower advantage it has over a 13B sans turbos. The TII was either 182 or 200 hp with a turbo. The Renesis only needs a few pounds of boost to hit 300 hp if set up properly. If you are doing a straight engine swap, you can use a standalone ecu. No need to make it complex. Full control. Even Megasquirt can control a Renesis now. If you have a standalone, you don't need anything else that the RX-8 does to keep the ecu happy.
Install a lightweight flywheel on it and go. You can use the stock transmission. Mazda has used the same bellhousing since 1972 or so. It bolts right up. The RX-8 transmission is really no worse than any other n/a rotary transmission. Imagine a high 13 second n/a 1st gen that could pass emissions if it had to!
True it's not the cheapest option. It isn't any more complex than any other rotary engine swap into the car. Use the 1st gen front cover. I have a Renesis here right now that I'm porting for a guy from Detroit. My spare GSL-SE front cover bolts right on. Problem solved. You can also use the crank angle sensor from a 2nd gen so no need to worry about the weird crank trigger the RX-8 uses. That means any standalone works. Bolt on a 75mm throttlebody from another car and you're done. Use the mechanical oil metering pump (or premix). Use a bicycle brake cable connected to the tb to control it. Make your own oil metering lines. These are cheap and easy. It's an easy swap. Far easier than a 20B anyday and arguably as easy as a T-II swap. The only reason not to do it is because you could get a TII engine in good shape for cheaper.
Install a lightweight flywheel on it and go. You can use the stock transmission. Mazda has used the same bellhousing since 1972 or so. It bolts right up. The RX-8 transmission is really no worse than any other n/a rotary transmission. Imagine a high 13 second n/a 1st gen that could pass emissions if it had to!
True it's not the cheapest option. It isn't any more complex than any other rotary engine swap into the car. Use the 1st gen front cover. I have a Renesis here right now that I'm porting for a guy from Detroit. My spare GSL-SE front cover bolts right on. Problem solved. You can also use the crank angle sensor from a 2nd gen so no need to worry about the weird crank trigger the RX-8 uses. That means any standalone works. Bolt on a 75mm throttlebody from another car and you're done. Use the mechanical oil metering pump (or premix). Use a bicycle brake cable connected to the tb to control it. Make your own oil metering lines. These are cheap and easy. It's an easy swap. Far easier than a 20B anyday and arguably as easy as a T-II swap. The only reason not to do it is because you could get a TII engine in good shape for cheaper.
07-06-07, 12:07 PM
#36
yark79-- from what i read werent the rx8s "deturned" once they reached american soil due to the emissions regulations? if thats the case with a stand alone you could gain power if you ignore emissions regulations.
i think the renesis swap would be the best swap you could do for reliable, streetable power. hell, i dont think itd be too hard to hit 230 or so to the wheels with a renesis. that in a SA/FB would be a fun car. mind you it wouldnt be the fastest 1st gen out there, but it wouldnt cost anywhere near as much either. itd alos be a **** load more reliable and wouldnt be a hassle to drive everyday.
rotarygod- what about things ive read about the renesis having some reliability issues? something to do with the oil supply i think? if everything you say is correct, then this swap really isnt as hard as everyone make it out to be. hell, if you could use any of the rotary trannys then you could keep all your stock gauges working correctly..except mayeb the oil pressure and temp.
i think youre on to something....
i think the renesis swap would be the best swap you could do for reliable, streetable power. hell, i dont think itd be too hard to hit 230 or so to the wheels with a renesis. that in a SA/FB would be a fun car. mind you it wouldnt be the fastest 1st gen out there, but it wouldnt cost anywhere near as much either. itd alos be a **** load more reliable and wouldnt be a hassle to drive everyday.
rotarygod- what about things ive read about the renesis having some reliability issues? something to do with the oil supply i think? if everything you say is correct, then this swap really isnt as hard as everyone make it out to be. hell, if you could use any of the rotary trannys then you could keep all your stock gauges working correctly..except mayeb the oil pressure and temp.
i think youre on to something....
07-06-07, 12:12 PM
#37
I wonder, where is everyone managing to find used rensesis engines? They've only been out since 2004, I wouldn't imagine there are that many wrecks yet....
This is definatly something I'm intersted in doing someday, if rotarygod is right it might not be such a big job after all, I wasn't aware that the standalones were compatible, I thought I read something about the RX8 electronics system being different than other cars or something....
I agree, that amount of power would be a fun car, I don't think too much more would be needed in a SA/FB....
This is definatly something I'm intersted in doing someday, if rotarygod is right it might not be such a big job after all, I wasn't aware that the standalones were compatible, I thought I read something about the RX8 electronics system being different than other cars or something....
I agree, that amount of power would be a fun car, I don't think too much more would be needed in a SA/FB....
07-06-07, 12:59 PM
#40
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The biggest hurdle I see in trying to do this swap, is the exhaust. Remember, the renesis has 3 exhaust ports. No readily available headers for a renesis in a 1st gen chassis.
Of course, I know someone with a laser cutter, that happens to also be a car guy. Tubing benders are pretty easy to get ahold of.
Dammit, why do I have to be too stubborn to give up the simplicity of a carb/dizzy? I don't know of any carb intakes for the renesis, yet.........
One more thought. I know the stock FB trans will bolt up, but what about clutch and starter? Aftermarket flywheel for the 79-82 or 83-88 and an auto counterweight for the renesis *should* solve that, I would think.
Of course, I know someone with a laser cutter, that happens to also be a car guy. Tubing benders are pretty easy to get ahold of.
Dammit, why do I have to be too stubborn to give up the simplicity of a carb/dizzy? I don't know of any carb intakes for the renesis, yet.........
One more thought. I know the stock FB trans will bolt up, but what about clutch and starter? Aftermarket flywheel for the 79-82 or 83-88 and an auto counterweight for the renesis *should* solve that, I would think.
07-06-07, 01:15 PM
#41
Burning Oil-Grinding 3rd
07-06-07, 01:52 PM
#45
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07-06-07, 01:59 PM
#46
Check this out.
I especially like the part where they converted the throttle body to accept a 1st gen throttle cable using a rod from a stock nikki carb.
http://www.yawpower.com/renespic.html
Jon
I especially like the part where they converted the throttle body to accept a 1st gen throttle cable using a rod from a stock nikki carb.
http://www.yawpower.com/renespic.html
Jon
07-06-07, 02:25 PM
#47
Burning Oil-Grinding 3rd
The nice part about a new engine is They are new, 90 K miles before you start worring about them.
I have a guy that buys at the insurance sales, Can have him pick up a whole car any time I want.
I have a guy that buys at the insurance sales, Can have him pick up a whole car any time I want.
07-06-07, 02:54 PM
#49
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I just don't understand why it's ok to spend this much on swapping in a Renisis, but swapping in a 302 is wrong when it gives you more power and better reliability for less money with a proven swap.
07-06-07, 03:15 PM
#50
It's not about bang for the buck. It's about keeping a rotary in a rotary powered car. A 302 is not a rotary! I'm still waiting for someone to do the coolest swap of all and I guarantee it would **** off alot of American V8 loving people. I want to see a supercharged 3 rotor in a C6 corvette.