This 20B triple rotor RX7 is a 1000hp flame thrower!
While at the Adelaide Motorsport Festival, we shared a garage area with a number of absolutely insane time-attack cars. One of which was impossible to miss, being that it was literally was shooting flames everywhere and making enough noise to rival a military jet fly over. Arrival of the car into the pits sent the crowd either running for cover, or running towards the beast to snap a quick video while it was still brapping away.
That car was none other than the Rama Racing 20B triple rotor Mazda RX-7.
During one of the gaps between time-attack sessions, we caught up with Brad Trenwith, the owner of the mental rotor and got some details of the build.
The RX-7 started life as a completely bog-standard prime example of a clean, fresh import. Straight out of Japan with only 12,000km on the clock, you can bet the previous owner of the lightweight sportscar had no idea what was in store for it once it landed on Australian shores.
Being that it was a non registrable import, for use as parts or race only, Brad decided to strip it down to a shell and build one seriously mean track weapon.
Initially sporting a mildly modified 13B engine with a T04z, Brad dabbled in a bit of local hill climb and time attack competitions, before some fuelling issues saw two motors give up the ghost during the 2011 World Time Attack round.
Brad returned to WTAC in 2012 where this time the engine held together thanks to Morpowa’s work on the replacement, carrying them to a very respectable 3rd place, fastest rotary, and fastest RWD in class.
But, as any real car fanatic knows, you can never have too much power. As such the old 13B was soon after retired and a 20B triple rotor took it’s place.
Air is stuffed into the three rotor by means of an absolutely monsterous GTX45 turbocharger, which Brad says is actually not big enough.
The extreme flame throwing function is thanks to some wild peripheral porting.
The fire breathing beast takes no prisoners. As you can see from the video she even turned on her owner, leaving Brad recoiling away from the sudden ball of fire out the driver's side.
Word to the wise, if you’re going to check this car out in person, steer clear of the driver’s side-exit exhaust pipe when walking by!
Reliability is something that most rotary owners don't want to talk about, but when we asked Brad, he surprisingly replied by saying the engine has been untouched in over 18 months. That's right, 18 months of racing. How? Well, apparently it was screwed together by Jerry from Direct Clutch, who certainly is quite handy with the old rotor, being that he has a few of his own, including a rather impressive wide-body Veilside 3-rotor FD RX7.
On the dyno, the remarkably reliable rotary lays down a healthy 627kw (840hp) at the wheels, putting flywheel horsepower somewhere around 1000hp.
With the car weighing in at 1200kg, that's a very decent power to weight ratio right there.
Many thanks to Brad for the chat and information about the RX7.