Does anyone know the weight of the Renesis engine? I heard it is something like 30% lighter than the twin turbo motor in the late RX-7 but this still means nothing to me because I do not know the weight of either.

The reason I ask is it seems that a Renesis swap into the last RX-7 would be relatively easy awesome. Same power as the turbo but lighter and more relaible. Couple the lighter engine in front with some miscellaneous rear biased weight reduction (Ti muffler can cut about 15 lbs, etc) to keep a 50/50 balance and the RX-7 would be awesome. Think about it; a 2500 lb, 250 hp RX-7. Sweeet!

Of course another option could be a nonbiased weight reduction with a three rotor Renesis that probably weighs about the same as the twin turbo setup. Now we have a 2700 lb, 375 hp RX-7. Damn!:D

Well... I have no idea about weight....

But I think a Renesis swap with an FD RX-7 would be sweet! Since the only way I'll be able to get an FD would be to buy parts and put it all together, I could get an RX-7 with a blown motor (hopefully for cheap) then wait a year or two, then buy a Renesis to throw into her.

Whatever the weight, it is substantially less than a piston engine.

remember though that the 13B also had about 50 lbs/ft more torque too, so while a renesis swap would yield almost the same power with maybe 100 less pounds, you also have far less torque. Ill take the 13B.

Originally posted by velociti
remember though that the 13B also had about 50 lbs/ft more torque too, so while a renesis swap would yield almost the same power with maybe 100 less pounds, you also have far less torque. Ill take the 13B.
I'll take the Renesis because of better gas mileage :)

Not worried about the torque.. it's RWD and the dash to 60 at around 6 seconds makes it plenty quick for me.

oh, please stay away from the torque issue... you'll burn out a fuse here, somewhere... it doesn't really matter but tenths of a second in a short acceleration run as driveability, longevity (going on past spec NA's), fuel economy, and emissions cleanliness are superior to the 13BREW (please make that distinction, otherwise you could be mistaken for talking about an FC or even SA...), not to mention that weight loss... if that weight at the back too was removed to again achieve perfect balance, the RENESIS retro-fitted FD would wipe the floor with the factory spec FD around any road circuit you can think of (all other things being equal, of couse... :D)

-Andrew

Originally posted by babylou
Does anyone know the weight of the Renesis engine? I heard it is something like 30% lighter than the twin turbo motor in the late RX-7 but this still means nothing to me because I do not know the weight of either.

I bought a used RX-7 TT engine a few months ago. The shipping weight was 390 pounds. The shipment contained: A wooden pallette, a used tire, the complete engine, all intake and exhaust manifolds, turbos, alternator, power steering pump, water pump, ignition coils, solenoids, and intake hoses. So, without the pallette and tire, I'd guess the engine weighs about 350 lbs. This would put the Renesis weight right around 245 lbs....dunno if that's right or not, but it gives you a ballpark idea anyway....

the palette itself should weigh at least fifty plus another 25 for the tire

Wow, 350 lbs less the AC compressor so maybe 375 with the compressor. A Chevy LS6 V8 weighs 450 lbs fully dressed.

If Mazda says the Renesis weighs 30% less I am sure they mean not including alternator, AC and PS. This leaves the Renesis at about 255 lbs for a 90 lb weight reduction.

Now we have to find 90 lbs of rear biased weight reduction. I think this is very hard but possible. We would need to eleiminate the spare tire and jack, and go with some sort of Ti muffler. might have to eliminate the energy absorber in the bumper too.

All right who is gonna be the first to total their RX-8 so we have a donor Renesis?:eek:

Originally posted by babylou
...Now we have to find 90 lbs of rear biased weight reduction. I think this is very hard but possible... Actually, it's not necessary. Most street cars are weight biased to the front to begin with, so moving as much weight off of the front as possible is the trick to acheiving 50/50 distribution. That's why a Miata has the battery in the trunk. ...All right who is gonna be the first to total their RX-8 so we have a donor Renesis?:eek: Hey Hey Hey!!! You vulture! Talk like that might get you banned here ;).

---jps

I replaced my FD motor a few years ago, I was able to pickup the bare block with my own hands and put it on the front seat of my wife's car to go get the flywheel torqued on.

The block included the oil pan and front cover (covering the water pump...). I couldn't believe how light it was so I placed it on a bathroom scale (try that with a V8!) and it read 220 lbs. AMAZING!!!

Originally posted by FritzMan
I replaced my FD motor a few years ago, I was able to pickup the bare block with my own hands and put it on the front seat of my wife's car to go get the flywheel torqued on.

(try that with a V8!)

Believe it or not I have done it with an iron block Chevy 350. Just grabbed the main caps as handles. I guess you are just a big ol' sissy boy!:p

Originally posted by Sputnik
Actually, it's not necessary. Most street cars are weight biased to the front to begin with, so moving as much weight off of the front as possible is the trick to acheiving 50/50 distribution. That's why a Miata has the battery in the trunk.

Most cars maybe but not a third generation RX-7. The FD was equally balanced front to rear; one of the major reasons they are a blast to drive.

Of course after reveiwing a few other posts today it is possible the RX-8 may come in at about 2800 lbs. This means the spin off RX-7 could get down to 2600 lbs. Sounds like Mazda is doing the work for us.

Holy thread resurrection!

Ok, I've searched all over the forum and the internet, what is the actual final dressed weight of the 6pt Renesis engine? Has anyone seen it?

On the subject, how much did the old 13B TT engine weigh?

In a thread a couple days ago I saw a weight of 302 lbs, I think. I'm not sure what weight that referred to though. For comparison, they also listed the S2000 engine weight at 330 or 350 lbs.

I don't think my 8 would look good in a dress.

the largest chunk of weight difference between the 13B-REW and the 13B-MSP is the fact the it's N/A... the twin turbo system is heavyyyyyyy

Dunno the exact weight of the 13B-MSP, but it should be roughly the same as the 13B:
13B block: 180 pounds
13B fully dressed: 260 pounds
13B-REW fully dressed: 327 pounds

13B-MSP vs 13B-REW should have the MSP engine coming in a few KG lighter thanks to weight saving production techniques.

Fit the 35kg turbochargers onto the side of the 13B-REW & the 13B-MSP becomes a featherweight

REgards

Sport Compact Car said the Renesis weighs 87 lbs. less than the RX-7 engine.

Per Jim Merder at Racing Beat, the fulled dressed Renesis engine with all attachments sans airbox weights 267.5lb.