There is a lot of people wanting a turbo Renesis. I'm just curious, what do you guys think a NA Renesis is capable of, and how much did Mazda leave out for future upgrades? For example, from the prototype data it looks like Mazda might be able to increase the compression ratio a little bit. If it has the potential to get something like 300hp then there wouldn't really be a need for a turbo except for the extreme dragsters.

 

Well the need for a turbo stems for the need for more Torque from the engine. The car has a great HP to weight ratio, but the TQ is what is bothering some people. Breathing the Car better would allow us to get more HP, but thats all through the high ends of the gearing.

 

We'll see what a huge street/small bridge port will do to the renesis, although i'm also not happy with the 160lbs of torque, if there's a reason why i wont get the Rx-8 its because of the torque numbers. Here's what the car runs:
1/4: 14.5
0-60: 6sec flat.

 

I'd be very surprised if the ultimate horsepower potential of the REnesis is much better than the current style of engine.

The capacity is the same, the inlet ports dont really have the potential to flow any more than a normal engine that has been ported, and while the exhaust ports might be larger in combined area then the old peripheral style exhaust port, it will be interesting to see if the actual flow capabilities are that much greater.

Lighter rotors will allow a slightly higher rev limit, although the further up the rpm range you chase the power the narrower the power band becomes.

The best numbers I have seen, absolute honest engine dyno figures for a 13B Bridge or Peripheral Port are between 320-330hp at the flywheel at around the 10,000rpm mark.

The turbo sollution, although achieving more hp, does great things for bottom end torque. My own 12A Turbo engine which is a std Jap import engine with a few simple bolt on mods produces 170ft/lbs of torque at only 3000rpm with only 6psi (and is a 12A remember).

Campare this to the 160 odd ft/lbs expected out of the REnesis 13B at around 7000rpm and you will see the potential for improvement in the torque area.

 

actually renesis is supposed to have 90% of torque avail after 3300 rpm, so it shouldnt be much of an issue although it is still a bit thin in that dept compared with 350Z

 

I was curious about the power curve of the Renesis so I did a little research last night. First I wanted to compare an existing production vehicle to the upcoming RX-8 renesis powerplant. I'm assuming the torque curve is fairly flat on the Renesis given the 90% at 3250 RPM. That eliminated the S2000 (from what I hear, lets hope so) for comparison, although they have very close peak torque-to-vehicle-weight ratio. However, the 2770lbs RSX Type S with a peak 142lb/ft or torque actually matches up quite well in torque-to-vehicle-weight ratio, and it's new variable cam timing (not the valve stepping of VTEC, but the "i" part of the i-VTEC) makes for a surprisingly flat torque curve. Quick calculations show that each foot/pound of torque needs to grunt 19.53 pounds of RSX. The RX-8's 2970 (let's hope she goes on a diet!) with 162lb/ft results in 18.33 of chassis per foot/pound of torque, a slight improvement over the RSX. I know tire size and gearing can alter actual torque to the wheel, but both have 6 speeds and I imagine they'll be quite close.

To see what the Renesis will be like in terms of "driveability", test an RSX Type S, paying particular attention to the powerband in the 2000-5000 range. It's actually not that bad, given the Renesis peak NA output.