How many of you think the rx8 new motor will fit in the 3rd gen FD or plan on doing it? and do you think that it would mate with the trans?

 

I'll comment on the planing on doing it - hell no. it's makes good HP, but has nothing for torque. Not only that, but it doesn't make any power until the revs get really high. It would be like having an S2000 motor... They are kinda fun, but only if you spank 'em... for regular driving, you may as well have a Vtech Del Sol.

gotta have some low end.

 

In agree with BrianK, I think it has 250 HP but only 150 ft lbs of torque.

 

but this is 250 HP N/A power...and u know there is always room for turbo =) but then i heard US is only coming out with the auto tranny version only

 

Wasn't there something about the way that its setup that makes it really difficult to turbo charge?

If you can get a turbo on there that would probably be one hell of an engine.

 

It' s gonna be hard to turbo because it's a high compression rotary engine. high compression = not good for turbo charging

 

The RENESIS engine probably isn't a good one to turbocharge because of the side exhaust ports. I predict that the really wild modified and turbocharged RX-8s will use older, peripherial exhaust ported rotor housings (like all previous rotarys). That's why the old rotary responds so well to turbocharging, the peripherial ports produce very high velocity (and hot) exhaust pulses which help to spool up a turbo.

Also, what's this crap about the RENESIS engine having hi-rpm hp, but low torque a bad thing. Seems like another rotary to me. They just don't make torque until you turbocharge them. Remember that the FD has only 217 ft-lbs of torque in stock trim. Naturally aspirated rotarys don't make power until you rev them up, they've never had good torque. What do you think the low 4.10 gear is for, to give it some power off the line by keeping the revs up?

The biggest contribution of the new engine will probably be things like the oiling system, intake manifolds, seals and other little stuff like that.

Sorry for being so long winded.

 

15 years later - Id have to call you a fortune teller

 

Except the Renesis made VERY good power when turbo charged.

Because it has no overlap it is much more like a piston engine. More lag on a given turbo, but more power. You just size the turbo back down to something more piston engine like.

The real problem ended up being EGTs killing side seal springs and causing excessive side seal wear.

This was even a problem with supercharged or NA Renesis engines.

Mazda knows this and on the new rotary re-design (as seen on the range extending generator for Mazda 2) the side seals are moved back away from the edge of the rotor and the rotor bevel is eliminated.

 

They dont make 250hp..
The HP figures of the rx8's were WAY overstated and they actually only make closer to 187hp..
The info is everywhere.

Im simply disgusted by the whole idea. Do not proceed

edit; oh crap didnt realise someone had bought this thread back from the dead. Im still disgusted though.

 

^Yeah, in a 2,880 to 3,050 pound RX8, the RX8's real world 187 or 190ish horsepower doesn't exactly set the world on fire.

Adding a 190hp Renesis into an FD would have been a recipe for... bland...

 

I had an RX8

rwhp on these was 170 to 185, tq like 110 to 120

but it has a big *** powerband and handled like a dream


its bad enough to put the 8 front end on a 7, but swapping in the motor.... yeah not worth it

 

The rotor bevel offers no benefits in the range extender with its peripheral intake but moving the side seal tips away from the side exhaust port surely must improve their life

 

The rotor bevel offers no benefits in the range extender with its peripheral intake but moving the side seal tips away from the side exhaust port surely must improve their life

Yes.

My point was the rotor bevel was another detriment to side seal spring life in the Renesis since it reduces the thermal mass of the surrounding rotor material (oil cooled) and contributes to attached (hot) exhaust flow to the rotor as it exits the exhaust port (thinner insulating turbulent layer).

That detriment to sideseal spring life has been eliminated in the new motor design along with further improving the situation by moving the seal track back toward the rotor center.