Retrofit and rx8 engine in...

Sh00bs · 03-12-2015, 10:58 AM

My friend loves his 8, but hates the rotary engine.
Buying an rb25 to put in it... Yeah ikr

My question is, how hard would it be to put a msp engine in a fb rx7?

I'm a certified welder so fabricating engine mounts and making it fit wouldn't be an issue

Just concerned with the engine working properly

He said engine (complete) trans ecu for $450... It works fine, he just doesn't like it

Fendamonky · 03-12-2015, 11:03 AM

I'd talk with Brian (TitaniumTT) for specific difficulties involved in the swap. He's got some first hand experience sticking more modern engines into the FB.

reddozen · 03-12-2015, 04:46 PM

If you want to keep the stock ECU etc:
I would say full dash harness, engine harness, immobilizer, key, and all related OBD2 Stuff. The immobilizer, ecu and key have to be from the same car. I think racing beat can remove the immobilizer (04 models) from the ECU with their flash, but then you'll be limited to something like an adaptronics piggy back ECU to tune. You wouldn't be able to reflash it, but you wouldn't need the immobilizer or a specific key.

With a standalone you'd just need to wire up the basics. This would probably be the easiest / cheapest option.

Nutsid · 05-10-2015, 03:01 PM

Difficult. Extremely. The actually engine itself can work with a modified FC front subframe, but getting all the electronics to work properly in order to run the engine optimally (ie - the same as it does in the Rx8) you'd need to run the stock ECU with a piggyback (Adaptronic, COBB Accessport, or use the MazdaEdit program). Even with those things holding true, there are over 90 wires that have to be ran for the stock ECU to operate.

That is just the engine. Then you need to worry about brakes for the increased speed, suspension, and chassis upgrades for the increased power. Tires, blah blah blah.

For the sake of simplicity, there are far better options for a swap. Like any turbo rotary. Get an S4 TII engine. A much more simplistic swap with a much higher potential.

Having said that, and I've been noted as saying it since the Rx8 was announced - A Renesis swapped FB is a fantasy of mine for a daily driver/street driven car. I love how smooth that engine is and the power delivery of it. Those things combined with the light chassis of an FB and I'd be happy.

03-12-2015, 10:58 AM	#1
Sh00bs I5's Doritos & dualsports Join Date: Dec 2014 Location: Pasadena, MD iTrader: (0) Posts: 24 Rep Power: 0	Retrofit and rx8 engine in... My friend loves his 8, but hates the rotary engine. Buying an rb25 to put in it... Yeah ikr My question is, how hard would it be to put a msp engine in a fb rx7? I'm a certified welder so fabricating engine mounts and making it fit wouldn't be an issue Just concerned with the engine working properly He said engine (complete) trans ecu for $450... It works fine, he just doesn't like it

03-12-2015, 04:46 PM	#3
reddozen Gold Wheels FTW Join Date: Mar 2008 iTrader: (0) Posts: 744 Rep Power: 17	If you want to keep the stock ECU etc: I would say full dash harness, engine harness, immobilizer, key, and all related OBD2 Stuff. The immobilizer, ecu and key have to be from the same car. I think racing beat can remove the immobilizer (04 models) from the ECU with their flash, but then you'll be limited to something like an adaptronics piggy back ECU to tune. You wouldn't be able to reflash it, but you wouldn't need the immobilizer or a specific key. With a standalone you'd just need to wire up the basics. This would probably be the easiest / cheapest option. __________________ My Cars: 1974 RX4 Coupe 1991 FC3S RX7 - Sold 2003 ZZW30 MR2 (Rotary swap after RX8) 2004 SE3P RX8 (20B Swap in the works)