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It's been a few years, but I'm back (formerly 9G Redline). I had issues recovering my old name, but it's okay because I'm finally betraying my rotary love to swap to an LS. I have defended the rotary to haters and enjoyed explaining it to those who don't understand. I've never complained about oil consumption or maintenance as I knew what I was getting myself into, it's just time to do something different.
My car is a 2004 Winning Blue Touring 6-MT car that I bought brand new. I have had two engines in the car. First went at 83,147 miles (allegedly due to coils) and the second went with 100,472 miles on it.(overheated). I intend to document my journey once the admins allow me to post in that section of the forum.
It's been a few years, but I'm back (formerly 9G Redline). I had issues recovering my old name, but it's okay because I'm finally betraying my rotary love to swap to an LS. I have defended the rotary to haters and enjoyed explaining it to those who don't understand. I've never complained about oil consumption or maintenance as I knew what I was getting myself into, it's just time to do something different.
My car is a 2004 Winning Blue Touring 6-MT car that I bought brand new. I have had two engines in the car. First went at 83,147 miles (allegedly due to coils) and the second went at 103,--- (overheated). I intend to document my journey once the admins allow me to post in that section of the forum.
Hope to chat with some of you as time goes on!
Actually pretty ok with an LS swap. I get it and I dont get it at the same time. With the original engine the car is absolutely perfect. When you add the LS all you get is a watered down Corvette. Im personally of the opinion that if you want to LS swap, just buy a Corvette. The RX8 is magical with its original engine. Nothing else gives me the thrills this car can with just a stock engine on modern roads. Mods are cool, even a turbo, but the second you throw an LS in, all it is, is a drag car. Thats not what this car is about.
That being said, its your car and your decision.
Last edited by CaymanRotary; 12-18-2020 at 08:47 PM.
Actually pretty ok with an LS swap. I get it and I dont get it at the same time. With the original engine the car is absolutely perfect. When you add the LS all you get is a watered down Corvette. Im personally of the opinion that if you want to LS swap, just buy a Corvette. The RX8 is magical with its original engine. Nothing else gives me the thrills this car can with just a stock engine on modern roads. Mods are cool, even a turbo, but the second you throw an LS in, all it is, is a drag car. Thats not what this car is about.
That being said, its your car and your decision.
Hey Cayman, I agree with you! I believe my car is perfect as is. I will probably never be able to afford a Corvette and even if I could, I would never love it as much as I do my 8. So, deciding to put the LS in the car merges the two dreams/loves; good old reliable LS power and the perfect sports car from Mazda.
Hey Cayman, I agree with you! I believe my car is perfect as is. I will probably never be able to afford a Corvette and even if I could, I would never love it as much as I do my 8. So, deciding to put the LS in the car merges the two dreams/loves; good old reliable LS power and the perfect sports car from Mazda.
Well then, I say go for it. I'm not against the idea but it's just something I would never do. Totally get the appeal though. That power with this chassis will be an experience. You will definitely need to upgrade the entire drive train and suspension to accommodate the extra weight and power the original drive train was not properly equipped to handle. For me, it's just too much. If it was as simple as just doing an engine swap I would but this type of project will require some serious dedication to do properly.
Last edited by CaymanRotary; 12-18-2020 at 10:35 PM.
You're just down the road from me (in Gwinnett). Any thoughts on the LFX powerplant instead?
Mainly, I want the LS sound, power, and ridiculousness of it all. I'd kicked around doing a MS3 engine swap as well. They make great power and sound pretty mean for a 4 cylinder, but ultimately there's a lot of support and parts out there to choose from to do the LS. I do give Kudos to those doing the LFX swaps, I understand the logic and I know it will make the car even more fun that it came from Mazda.
The rx8 ace is the driving dynamics thanks in part to the renesis. Shoe horning a v8 just throw away what this car is about. Might as well get whatever v8 muscle car that abounds in craigslist.
The rx8 ace is the driving dynamics thanks in part to the renesis. Shoe horning a v8 just throw away what this car is about. Might as well get whatever v8 muscle car that abounds in craigslist.
Pretty much my opinion as well. That engine ruins what the RX8 is. You are left with a watered down corvette drag car.
Personally I wouldn't swap an LS into an RX-8 for the reasons stated above but that's me. I would have just gone with a 5th Gen Camaro or C5 Corvette instead.
Originally Posted by gooflophaze
You're just down the road from me (in Gwinnett). Any thoughts on the LFX powerplant instead?
IMO it's not a bad idea but you better be committed to staying NA if you go that route. Even in NA form, LFX should have enough power for a car like the 8. Once you start to turbo or supercharge it, you may as well just do an LS swap in the beginning as the weight and package advantages of the LFX all but diminish.
To give you an idea, the LF4(basically twin-turbo LFX) used in Cadillac ATS-V makes about the same power as the LT1 in the Camaro, gets around the same gas mileage, weighs about the same, weight distribution is more to the back but also higher(due to DOHC), possibly worse reliability due to forced induction versus a relatively unstressed NA V8. It's part of why that car flopped, people would just rather have a V8, especially in an American performance car. That's also why most people just trade their V6 Camaro in for an SS rather than force induction. Less work, probably similar amount of money to do the same thing.
Last edited by UnknownJinX; 12-21-2020 at 02:38 PM.
Love the LFX idea. Its pricey but seems worth it. Probably no more pricier than the V8 LS swap though.
Just comes down to if you think you will get greedy later. If you are happy with ~330 BHP and will stay happy with that, I think it will be a great idea, but if you think you will want more, then just start with an LS swap.
This is putting aside the whole revving thing, which some people prefer, though LFX really only revs about 700 RPM or so higher than, say, LS2 or LS3.
So, just to post an update since it's been a few months. I intend on doing a 5.3L swap over the standard LS1, 2, 3, etc. style swaps. It'll be a cheaper "less exciting" build, but it should get my car back on the road sooner. I do not plan to do anything crazy, like twin turbos, but may do cam, valve springs, an intake manifold, with a tune. I've been following some builds on YouTube, but if anyone has any useful information to throw my way, I'm all ears! I'm mostly curious if anyone has gotten the stock rx8 trans to work with an LS based engine. I thought I'd seen some stuff before, but can't find it now...guess I'll keep digging.
So, just to post an update since it's been a few months. I intend on doing a 5.3L swap over the standard LS1, 2, 3, etc. style swaps. It'll be a cheaper "less exciting" build, but it should get my car back on the road sooner. I do not plan to do anything crazy, like twin turbos, but may do cam, valve springs, an intake manifold, with a tune. I've been following some builds on YouTube, but if anyone has any useful information to throw my way, I'm all ears! I'm mostly curious if anyone has gotten the stock rx8 trans to work with an LS based engine. I thought I'd seen some stuff before, but can't find it now...guess I'll keep digging.
Here's a build thread where someone put a slightly modified 5.3 into a BMW. Sounds like very similar goals to yours:
He ended up with about 340hp/338tq to the wheels with absolutely no effect on curb weight or F/R balance.
Ignore everyone that says you should get a Corvette - the RX-8 is smaller and lighter than a Vette. You'd have to strip hundreds of pounds of of interior, sound deadening, and comfort items to get the Corvette down to RX-8 weight, plus you don't have a back seat in the Corvette, which is a dealbreaker for people like me.
The Camaro comparison is even worse - those things are pigs at 3600+ lbs., and they're stuck with a McPherson front suspension. They're fine for what they are, but nimble they are not.
And ignore what everyone says about the 50/50 weight distribution - those people are just drinking the Mazda brochure kool-aid. A specific car's number varies widely based on vehicle equipment, many RX-8s aren't actually 50/50 (mine is 52/48), and there's honestly nothing magical about 50/50. A car can be a fantastic handler at 52/48 or 60/40 or 32/68, as long as it's set up right.
Hey Laminar, thanks for your encouragement! Everyone has their way they want or think things should be done (opinions) and it's great we get to have them. I appreciate the link to the build and will definitely check it out! The mid-300whp range is definitely where I want to be because I don't have any crazy plans except to drive it and have a little fun messing with people.
I'll keep more information coming once I get deeper. I've only pulled back the harness to the firewall and removed all the accessories in the engine bay. Once I buy the 5.3 I'll start digging deeper.
I agree with Laminar that weight distribution is an overrated metric to measure a vehicles performance by and piston 'swaps' into any RX is a poor idea. I would search into the brand's history before desecrating their achievements; Kobayashi and Yamamoto would definitely agree. Rotary experiment number eight.
I agree with Laminar that weight distribution is an overrated metric to measure a vehicles performance by and piston 'swaps' into any RX is a poor idea. I would search into the brand's history before desecrating their achievements; Kobayashi and Yamamoto would definitely agree. Rotary experiment number eight.
Meh, its doable. The weight problem of a bigger engine is solved with a better suspension setup. To me, it's still ridiculous putting a V8 in this car but different strokes for different folks I suppose.
Alright, it's been a while since I've posted an update. I have gotten the engine bay stripped out so that all I have to do is evacuate the AC system, disconnect the drive shaft and a few miscellaneous hoses, unbolt the motor mounts, and pull out the old engine. I have purchased an LM7 5.3L for my build, so that's one item off my list.
I've attached a few pictures of the aftermath of the deconstruction process as well as some images from inside my throttle body and upper intake. I had the Mazdaspeed CAI on the car and kept the filter religiously clean, so I don't understand where all the crud came from... This is the current state of the car. Wiring harness has been completely pulled back (nothing was cut). She's pretty dirty, but keep in mind she's been sitting in a garage for over 3 years now. I was shocked when I took off my throttle body and saw this. Even more shocked when I saw this...
This is the LM7 5.3L I pulled from a suburban.
I will be posting my MS CAI, Racing Beat plug wires, and Agency Power Pully for sale at some point.
My plans for the 5.3 is simply to clean it up, inspect the cylinder walls, to ensure no major damage, possibly throw a mild cam at it, and then do what it takes to just get the car running so I can enjoy it. Serious upgrades/builds will be done later when it is required. I'll start posting in the engine swap thread when I'm allowed to do so or when the moderators move my thread for me. =)
Iron block is a bit unfortunate, 80lbs of extra weight with no power or durability advantage under 1000hp. I get that Pick N Pull selection is limited, but you can get the aluminum engines from car-part for well under $1000.
In the spirit of doing a true "budget build" I'm attempting to buy what I can, when I can, as it's available. I've attached my working spreadsheet of what I'm thinking of parts wise. I am interested in hearing others input who have completed the swap and also hoping to have some gaps filled in. I know I'll also have to address the suspension at some point.
I haven't been able to turn any wrenches since my last update as this is a back-burner project, but I am going to try to tear apart my 5.3 for examination over the next week or two. We'll see how that goes...
Congrats on venturing into the world of RX8 LS swaps. A couple of years ago now I finished my LS1 swapped RX8. Was an awesome project and I'm glad I did it.
I've always been a Mazda guy, having owned rotary vehicles since the late 80's, way before they were mainstream popular. I've personally built every type of Mazda rotary engine from 10A PP, through to 20B turbo engines and everything in between. So I don't hate on the rotary, they use to be cheap horsepower, but not anymore. Hence why it was logical to me to to LS swap this RX8.
I'm in Australia and I did my swap pre-covid, so prices of parts were way cheaper than they are today. My RX8 started life out as 4 port auto model, and I converted it to LS1 with manual T56 box. Given it was an auto RX8, with a dead motor, no-one wanted it and it was destined for the wrecking yard, and so I managed to pick up the complete car for $1K. I sold the dead motor, gearbox and catalytic convertor for $1K, so effectively it cost me nothing! I did all the work myself on the swap, no kit was used, and the entire out of pocket expense was $7K. I couldn't purchase a complete 13B REW motor and rebuilt it for that!
The car is awesome to drive. Weight distribution is 52/48, it makes 392rwhp and 370ftlbs. It's fast, it sounds tough, it's different and it turns heads. I'm now on my second version of the car and just about finished my rear mount turbo set up, which should easily see 550+rwhp.
Ignore the haters. Some people will just never understand the desire behind an engined swapped vehicle, and most of their comments are from a place of ignorance, not of experience. Keep us updated on your build....
@RX0004 I very much appreciate your words! As I stated in my initial post, I love the rotary (this is was my first) and will continue to defend it until my dying breath. With that said, money for money at this stage in my life the LS swap is the way to go. Right now in our market it would cost me a minimum of 6k to replace the engine with a reman. If I can spend 6k to have a running LS that won't let go on me again I'd call that a win. My 07 suburban has 267k on it right now on it's original engine and is still kicking. Your second to the last comment is what I'm looking for in my build and the turbo part could be fun too down the road.
@TeamRX8 I actually read Stubbs build thread all the way through yesterday (been meaning to for a while). It had a lot of good information and I used some of what I gleamed to help build my parts list. I've also watched any video on YouTube for anyone who has completed the swap to get ideas and will be piece-milling everything together for a unique build.
Again, I appreciate the support and words of encouragement!
Alright, it's been over a year and I haven't posted anything as there's still nothing to post. I'm still researching all my options and attempting to stick to a true junkyard build minus a few parts. I'm hoping to really get going on this in January of 2024 and have the car running by late spring. My target date is my kids last day of school so I can pick them up in it.
Over the past year I did take off all the accessories and opened up the valve covers, removed the intake and valley pan, along with removing the oil pan. I was pleasantly surprised at what I found! The valves and oil pan were extremely clean with no sludge and the cam appears to have minimal wear. From what I can tell the cylinder walls look good too. It appears that I found an engine that had regular oil changes and never had a problem. I'll try to dig up the pictures and post them here.
I still think I'm going to change the cam to the BTR 5.3 Truck Norris NSR and replace the lifters. I'm attempting to find the cheapest CTSV accessories possible as they will get me the tightest package to go in the already tight engine bay. I found an adapter for $160 that would allow me to keep the stock Rx8 throttle body and work with a GM intake, but the stock TB is only 70mm so that will keep my power down a bit. Decisions, decisions....
Looks like the engine didn't come with a throttle body. You can get a Summit 92mm cable-style for $170 or a GM DBW 90mm for $242. If you're using the GM ECU, it would be easy to either adapt the RX-8 pedal or use a GM pedal and let the ECU just control the DBW TB like it's supposed to. Otherwise there are any number of ways to run a cable-style pedal for a cable throttle body. No need to install a "restrictor plate" on purpose.
12-18-2020, 07:45 PM
Becoming Tr8tor
