Federighi

iTrader: (7)

Hey 8Club!

Just messing around online. I was very interested in this set-up for my Time Attack project and contacted the 7Club member regarding his build some time ago. A serious build no doubt and awesome to see that it found a home in a RX8.

Impressive n/a numbers and that extra 70-80 whp would be profound when compared to a healthy, tuned Renesis.

Enjoy!

https://www.rx7club.com/race-parts-o...k-cad-1131090/

TeamRX8

iTrader: (25)

Actually not so much, makes not much more torque than a properly built and tuned Renesis, just that it occurs at much higher rpm to generate the higher HP output (HP = TQ x RPM/5252). So 298 hp @ 10.5k works out to about 149 ft-lbs. The difference is it can breath at that high rpm whereas a Renesis becomes exhaust port limited above 8500 rpm or so. You also have to temper those numbers some since it’s a hub dyno and not spinning 80 - 90 static lbs of rear wheel/tire mass.

I had one quoted back in 2010 built new from scratch with dyno tuned ecu package and it was just over $30k. That’s a full pro package deal. I was asked not to share the output numbers. However, it only makes sense in a racing class where chassis weight etc plays into the equation. Generally speaking today’s turbo technology is going to produce both superior HP and TQ without having to wring it into oblivion. Better have a scattershield or BH blanket on that thing for sure.

.

TeamRX8

iTrader: (25)

Brettus

iTrader: (2)

It's still going to be quicker than a Renesis in car of the same weight so long as the area under the power curve is greater. Would be good to compare the overlay though, I suspect the difference wouldn't be as much as it looks.

Federighi

iTrader: (7)

Yes I noticed torque values are very relative; seems no n/a 13b can get over 200 ft/lbs? FI is great (agreeably superior) but I prefer the simplicity and immediate response of n/a.

I have limited experiences as an extreme hobbyist / enthusiast and it seems most people at this level of performance are operating in competitive motorsports. Not trying to break any records or hearts

+1 to the shield for sure.

TeamRX8

iTrader: (25)

the performance of that engine is much more critically dependent on other factors, the support systems in particular. So it may or may not be faster, it comes down to the variables involved.

as an example, nothing will kill it quicker than your undersized NA exhaust system

.

Brettus

iTrader: (2)

The only other thing (short of mechanical issues) that will affect how fast it is will be gear ratios .... Get that right and it will beat a Renesis any day.

Harsh !

Brettus

iTrader: (2)

Keep an eye on my N/A thread ...............

Federighi

iTrader: (7)

WOAH your shattered fly pic is crazy!!! Hope everyone / thing was ok. Thanks for sharing Team!

And I certainly will do Brettus! Nothing better than n/a rotary imo, very much looking forward to it.

Some good points made and a set-up like this I imagine will require an immense amount of fine tuning like Team stated. I'm personally of the school of thought to bump the gear ratios similar to what a sprocket kit can offer a sport bike. Ime, you can gear a 600cc to have 1000cc 'equivalent' performance levels at / through lower speeds. Very cheap and low-tech solution and is what I'm hoping the 5.12 will offer me.

TeamRX8

iTrader: (25)

Well that’s an Iannetti/i-Rotary flywheel sold through Mazda Motorsports and select dealers (Mazmart is one) and it didn’t shatter like that until 32,800+ rpm during testing for that purpose. Speaks to it’s strength considering it only weighs 4 lbs. It gives you an idea what can happen if a crack develops and goes undetected, bolt comes loose/fails, etc.


.