Renesis Swap In Fc - NoPistons -Mazda Rx7 & Rx8 Rotary Forum

End3r · 12-13-2002, 08:18 AM

Hi, I'm relatively new to these forums and I've been wondering what the feasibility of swapping a renesis (from the upcoming rx-8) engine into a n/a fc would be. This is assuming that mazda will sell crate renesis engines once the rx-8 is released. If it's at all feasibile, how much would the entire set up be including the cost of a '90ish n/a, labor, etc? I've got a feeling that we won't know if it can be done easily until its' released, because the renesis handles exhaust differently or something than a 13b.

The reason I think this would be a good idea is that I want a fast rx7, but not all of the reliability/tuning hassle that goes along with having a turbo. The renesis has improved fuel economy and 250 hp, so that put in a lightweight (partially stripped down) fc would be fast and reliable.

turborotor · 12-13-2002, 10:26 AM

I bet u the engine block from mazda will cost over 4k alone. u know mazda and their prices.

C

1Revvin7 · 12-13-2002, 10:47 AM

4k i bet its way more than that. And you would need the tranny most likely. You could pick up that n/a from 500-3000, depending on condition and if its running. But s5 are hard to find. Labor would kill you, you would be better off doing it yourself, and wow, lots of money. IMO you would be better of buying the rx-8. 250hp is not worth 10k.

j9fd3s · 12-13-2002, 10:55 AM

on paper it looks good, 250rwhp na, it migh even pass smog with no cats.

its does present a few problems:

1. we dont know about the motor mounts yet, hopefully they didnt do anything wierd

2. the engine/tranmission bolt pattern needs to be the same, its been the same for 30years os cross you fingers

3. will it fit under the hood? it looks like it has a tall intake setup, it should fit (the 20b does)

4. it has drive by wire, are there any aftermarket ecus that will support that?

mike

cymfc3s · 12-13-2002, 12:13 PM

yah, drive by wire is a problem. I think only the motec supports it.

End3r · 12-13-2002, 01:21 PM

Hmm...sounds like a pain in the ***. I hope it can be done reasonably cheaply...I guess I/we will find out eventually once the rx8 is released.

j9fd3s · 12-13-2002, 01:25 PM

yah, we have to wait and see at this point. the only other bugaboo is that the renisis doesn't have a ton of torque (150-170lbsft) so unless you lighten the car its like a 14sec 1/4 mile, or the same as a t2.

so it get kind of involved, the renisis would let you get the car a little lighter, no ic/turbo/manifold etc.

mike

End3r · 12-13-2002, 01:34 PM

It isnt just about weight reduction, my primary concern is reliability and the added bonus of increased fuel economy is a good thing too

j9fd3s · 12-13-2002, 02:04 PM

yah, it has upsides there, it looks like a cool swap, its just not gonna be a 12second 1/4mile car, what it will be is a smog legal, quiet na thats got t2 speed.

mike

rotary>piston · 12-13-2002, 03:56 PM

you'd be better off rebuilding the existing engine and doing some wild porting, you could get some pretty impressive hp that way too.

12-13-2002, 10:26 AM	#2
turborotor Senior Member Join Date: Nov 2001 Location: LA, USA Posts: 1,622 Total Props: 0 Rotary Year: n/a Model: Mazda RX-7 Power Adder: Turbo	I bet u the engine block from mazda will cost over 4k alone. u know mazda and their prices. C
	+ 0 -

12-13-2002, 10:47 AM	#3
1Revvin7 Senior Member Join Date: Oct 2001 Location: Peoria, AZ Posts: 10,910 Total Props: 0	4k i bet its way more than that. And you would need the tranny most likely. You could pick up that n/a from 500-3000, depending on condition and if its running. But s5 are hard to find. Labor would kill you, you would be better off doing it yourself, and wow, lots of money. IMO you would be better of buying the rx-8. 250hp is not worth 10k.
	+ 0 -

12-13-2002, 10:55 AM	#4
j9fd3s Senior Member Join Date: May 2002 Location: California Posts: 22,468 Total Props: 1 Rotary Year: 1982 Model: Mazda RX-7 Power Adder: ITBs	on paper it looks good, 250rwhp na, it migh even pass smog with no cats. its does present a few problems: 1. we dont know about the motor mounts yet, hopefully they didnt do anything wierd 2. the engine/tranmission bolt pattern needs to be the same, its been the same for 30years os cross you fingers 3. will it fit under the hood? it looks like it has a tall intake setup, it should fit (the 20b does) 4. it has drive by wire, are there any aftermarket ecus that will support that? mike
	+ 0 -

12-13-2002, 12:13 PM	#5
cymfc3s Senior Member Join Date: Jan 2002 Location: San Jose, CA Posts: 1,145 Total Props: 0 Rotary Year: n/a Model: Mazda RX-7 Power Adder: Turbo	yah, drive by wire is a problem. I think only the motec supports it.
	+ 0 -

12-13-2002, 01:21 PM	#6
End3r Member Join Date: Sep 2002 Posts: 47 Total Props: 0	Hmm...sounds like a pain in the ***. I hope it can be done reasonably cheaply...I guess I/we will find out eventually once the rx8 is released.
	+ 0 -

12-13-2002, 01:25 PM	#7
j9fd3s Senior Member Join Date: May 2002 Location: California Posts: 22,468 Total Props: 1 Rotary Year: 1982 Model: Mazda RX-7 Power Adder: ITBs	yah, we have to wait and see at this point. the only other bugaboo is that the renisis doesn't have a ton of torque (150-170lbsft) so unless you lighten the car its like a 14sec 1/4 mile, or the same as a t2. so it get kind of involved, the renisis would let you get the car a little lighter, no ic/turbo/manifold etc. mike
	+ 0 -

12-13-2002, 01:34 PM	#8
End3r Member Join Date: Sep 2002 Posts: 47 Total Props: 0	It isnt just about weight reduction, my primary concern is reliability and the added bonus of increased fuel economy is a good thing too
	+ 0 -

12-13-2002, 02:04 PM	#9
j9fd3s Senior Member Join Date: May 2002 Location: California Posts: 22,468 Total Props: 1 Rotary Year: 1982 Model: Mazda RX-7 Power Adder: ITBs	yah, it has upsides there, it looks like a cool swap, its just not gonna be a 12second 1/4mile car, what it will be is a smog legal, quiet na thats got t2 speed. mike
	+ 0 -

12-13-2002, 03:56 PM	#10
rotary>piston Senior Member Join Date: Sep 2002 Posts: 282 Total Props: 0	you'd be better off rebuilding the existing engine and doing some wild porting, you could get some pretty impressive hp that way too.
	+ 0 -

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