nkeehn

Ok, here's a question for everyone...
What would it take to get 350 NA horsepower on a 13B engine? No full peripheral or bridge porting and no nitrous. How's semi-peripheral coming along, anyone done it? Is it even necessary?

andrew lohaus

not gona happen without a p-port; the r26b made about 700hp with 4 rotors p-ported. so baisically youde have to replicate that in a 13b to get close.

RandomHero

iTrader: (2)

^ditto, you would be more than doubling the engines output from the factory. Couldnt be done without boost or nitrous. Maybe with a large peripheral port, high comp rotors and race gas.

Kenku

What would it take to get 350hp NA on a streetport 13B? An act of god.

peejay

Probably a large bridge would do it better than a P-port.

If you want a *****-envy dyno number, do it. If you're rules limited to naturally aspirated 2 rotor, do it. If you want to accelerate a car quickly and are not bound by rules, a lower revving turbo engine or a (gasp) boinger swap will scoot the car far better, even with less peak HP. Upside of the turbo is you can get way more than a mere 350hp. Downside is it is so hard to not turn up the wick and scatter the engine. Been there, done that, sticking with N/A because I know I have no self control when it comes to things like that.

nkeehn

What about semi-p ports? I've heard good things... though I doubt 350 NA power is streetable or reliable by any means.

peejay

Semi = half, or partial

Think of semi peripehral or half bridge as "half assed". Now before the flames begin, finish reading. For this instyance, where a peak HP figure is important and driveability or that is not an issue, then you need to gear the engine 100% explicitly for your goal. Doing any less is diluting it. Half bridges and the like have their place, but this is not one of them.

t-von

iTrader: (8)

You want 350 NA? No problem a 20b with a custom intake manifold and high compression rotors will make that power on side ports. NA 20b's aren't really expensive either. Plus you will have a crap load more torque down low for better drive ability.

nkeehn

https://www.rx7club.com/20b-forum-95/my-rx-7-done-cup-holders-3-rotor-semi-p-port-n-setup-stock-subframe-454580/

I've seen it and it's making about that. This post is more informative than realistic, I really started this to find out what people think about NA motors. I didn't know if 350 hp NA is possible or not and if not, how can be made.
GtoRx7's FD is very well done, he is a craftsmen of the highest order and he's reaping the reward. I'm not putting an engine together for an RX7 and there's no room for a 20b, but 13b will fit just fine. Anyway, how much power can be made out of an NA 20b with just steet ports? Theoretically, two thirds of that would be the max, right?

peejay

I have heard of as high as 270hp with a "street" port 13B, but it was a high RPM full race deal, again with *everything* geared to making peak horsepower. Probably about as "streetable" in that trim as your typical bridge or peripheral port engine, only street ports have peakier powerbands (less low end and midrange) than a bridge/peripheral engine.

karism

PP with 360hp?Not very likely,but it *might* be possible.

Like Peejay said;a BP might be able.


A 2 piece Eccentric shaft will be required,pref with some sort of a centre bearing.Carbon seals,balanced with the clutch assembly down to 1g.Injection with 2.5" + throttle plates etc.Expensive goal!!

(Pics are of a actual 12000 rpm Monsterport)
karis

ronbros3

HEY Jesus Padilla in Orlando makes 345whp N/A, Rolo does the tuning. and you know inspection techs are all over it to make sure it has no power adders.

ronbros3

OH yeh! padilla is a 13b