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Mazda RX-8 with a LS1 V8

Mazda RX-8 with a LS1 V8

This Mazda RX-8 from Iceland is powered by a 5.7 L LS1 V8 from a 2004 GTO. The project began after the RX-8 had a blown engine and took about 3 weeks in the owner’s spare time. The engine mounts are custom and they could only use the header from the right side of a Camaro while the left side needed to be custom built. The car also uses a stock 4.44 differential and a Camaro steering rack and oil pan. Overall the car weights 3240 pounds with 53.2% bias in front. The owner is still trying to figure out how to get the gauge cluster to function. I know there is some interest in a kit for this type of swap so lets hope someone builds one.

Update: This project completed and added videos of it below.
Update 2: The owner was kind enough to expand more on this build in the comments below. I have updated the article to reflect his comments.
Update 3: Hinson Super Cars is developing a RX-8 LSx swap kit.

Mazda RX-8 with a LS1 V8

Mazda RX-8 with a LS1 V8

Source: LS1Tech

46 thoughts on “Mazda RX-8 with a LS1 V8”

  1. I want to do the same in my car. please email me with any details that would be helpful, motor mounts and ect……… thanks

  2. Hi guys, I did all this swap at my workshop in Iceland. It took us 3 weeks to complete the installation in spare time. We made all the engine mounts and used header from camaro on right side but had to build the left one. The weight of the car with gastank allmost half is 3240 pounds, 53,2% in front and 46,8 in rear, whitch is allmost the same as the Corvette C5. We used steering rack from camaro 1995 and the oilpan and the pickup from Camaro LS1 allso. Regarding the cluster, I still have to figure things out. I will probably put the PCM from the mazda in again and the sensors for oil pressure, water temp and engine rpm on the LS1 engine, then I will have full function cluster again. Thanks for your interest in this project, it has bin a real fun driving the car since we completed the swap. Before I had never driven a Mazda RX8 . Regards to you all, BOGGI

  3. We are currently waiting on an LS-1 and trans for the same swap. ANY of the swap documentation wouls be greatly appreciated.

    Micah Baudoin
    Owner of Redline Motorsports
    Bryan Tx, 77808

  4. helloo there ,
    I’ve got a car rx8
    But no engine because some of the cylinders did not and I better change my engine
    Is it possible to Help..

  5. Hello,
    Would it be possible that you would make and sell me the header that is needed and the motor mounts? Please email me the prices for each. On another note, did you get the gauge cluster to work after? If so, how?

  6. If you go to, they are in the process of making a Ls swap kit for the RX-8, which I am waiting for. They also will do the swap for you if you ship the car to them.

    1. Thanks. The last I had heard was they were preparing to work on the kit but hadn’t started. It is great news to know they are working on the kit now. Can’t wait to see it completed.

  7. I am concidering selling my daughters 05 rx8 automatic. I bought it from a salvage yard. It has never been wrecked or smoked in. It supposedly was struck by lightning. I paid 7900.00 for the car, spent 2200.00 replacing the modules. she has driven the car approx. 10-15000 miles and the engine is giving trouble. it has about 60000 miles on it. what should I ask for it?

  8. Hi guy´s, I built a new engine LS1 this winter with Lingenfelter cylender heads and a camshft from Hitec motorsports. I allso put another ring and pinion in the rear, got 3,90:1 from RX7 automatic. Allso I put new shocks front and rear from Koni. I did the 1/4 mile this weekend in 11,992@118,47mph. 😉 Put a big smile on my face this weekend. (still smiling) Now I´m going for NOS!!!! fun fun fun!

  9. Hey Boggi,
    Any updates about the swap? I’m interested in putting an lsx in my rx8 but don’t have time for fabrication etc.. I would luv to know if there is any kit available to make the job easier.. Thanks

  10. my 04 rx8
    im in the works on how to do ls1 swap out. i need someone to talk to on this that has done it. how did it go. what all do i need to do to the car. ie new mounts ex what parts. and can i do it myself i have a good crew. but will we get in over our heads.

  11. We currently fit LS1 motors to Porsche 944’s and as we currently have two
    RX8’s with motors with broken apex seals, I would really appreciate any info that you guys who have done the LS1/RX8 conversion could supply me with.

  12. Hey BOggie did you get the cluster fix. I am going to do the same swap on mines, I already have a fully stock built ls1 and a t58 tranny in my barn and im going to start the swap in the near future but i don’t want to sit on this for no more than 1 week. Any ideas on what might be a problem or if there is something i’m going to need let me know i’ll pay ctsellersjr ( at )

  13. hey i was looking into buying an rx8 love the look and interior, i wanted to put a 3 rotor in it but iv heard lotta problems with the rotor engines and crap milage. but i saw a few ls1 swaps one here really wanna do it, wonderin if theres anyway you could email or call me and give me any tips/help like prices how to mount…ect

  14. Hi guy´s. I have done few things for RX8 like build a new engine in it. I´m running LS1 as before with lingenfelter heads, compression around 11,2:1, 3″ exhaust system with Borla muffler from Camaro. I have done the 1/4 mile with 75hp NOS in 11,52@128,xx miles 🙂 This summer I´m going for new fuel pump ( still running stock RX8 pump which is incretible, and running 150hp NOS!! Allso my latest product is my wifes car, Hummer H3 2007, which I´m swapping LQ9 from Escalade engine in. The engine is in, all cluster working, just need to program the ECM for best driveability! Regards, Boggi
    Burnout MAZDA RX8 LS1 in Iceland 😉

  15. I always loved the look of the rx8, especially with a body kit but the looks did not go with the power. If this kit becomes avaliable I’m definetly going to buy a used rx8 and buy this swap kit after I come back from my deployment.

  16. This is awesome. If a kit can be made like grannyspeed’s kits including cross-member driveshaft and a modified/stronger independent suspension that is complete bolt in, you would sell hundred’s. There are droves of current RX8 owners just salivating at the chance to purchase a nice kit that is at a decent price point, then you have a winner. I feel that it is harder to do this kind of swap as cheap as an FC/FD would be though, so that is what it really comes down to. The RX8 is the best car I have ever owned. The only problem being the lack of low end grunt. LSX/RX8 problem solved
    Now I wonder how a 347 stroked SBF would fit in here………..

  17. You dont need to go through all that trouble for a vette engine its pretty sweet though. I just put a twin turbo system in mine and don’t rev over 8k rpms.
    The talk about the seals isnt true you just need to know how to maintain a performance car. I change only 5w20, 94 octane only. 120,000kms no issues 35 psi boost. The engine is good for over 10k rpms but the transmission is not. 0-60 mph 3.6 secs, top speed 300 kmh. The smoothness of the rotary and the 50/50 weight ratio you dont want to mess with that in my opinion. The gas mileage is pretty terrible on this car worse than any 8, 12 cylinder I have drove. Approx 80$ every 3 days.

  18. I am building an rx8 for To Formula D specs, Im wondering with the engine tryouts that you did, would the Ls1 from a 2003 corvette fit? i know mounts and hardware would have to be fabricated but i plan on doing this build with my self and other students while attending college at Wyotech~ Just looking for insight, and did the firewall have to be altered or cut in anyway, because if so I can not put the car into Formula Drift! Thanks Boggi

  19. Mounting the ls and T56 in the 8 chassis is the easy part, need details on the electrical side of things to get the cluster to work. did you keep the stock pcm in too?

  20. Boggie
    Please email me I have an ls1 swapped rx8 but I’m having trouble with the instrument cluster / gauges can you tell me what you did to make them all work?

  21. How much hp would I get by swiping my RX8 engine to an LS engine & what can the top speed be ?
    Also if my car is an automatic can the swap work ?

    1. The 1.3 L 13B-MSP produced 189-249 horsepower depending on which generation and power level. The base LS1 makes 305-350 hp, LS2 makes 390-400 hp, and the LS3 makes 426-436 hp. The torque difference is even greater between the 13B-MSP and LSx. Top speed is a lot more difficult to estimate because it depends not only on power but transmission gearing and wheel size. Automatic transmission is fine as long as you switch to a GM automatic transmission.

  22. Hey boggie i have done questions about how you got the factory gauge cluster working with the swap. I have a lm7 and t56 combo in my rx8 and im trying to button the swap up. If you could email me at david.b.cook17 at that would be fantastic. Thanks in advance!

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