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-   -   Max HP on a 13b ? (https://www.rx7club.com/new-member-rx-7-technical-256/max-hp-13b-1057060/)

crzlito 02-11-14 01:59 AM

Max HP on a 13b ?
 
Hello rotary fans just wondering does anyone know how much hp.can you get out of a 12a or a 13b engine all motor,and I mean max hp with all the goodies ? Thanks

Aaron Cake 02-11-14 10:53 AM

Over 1000 in a drag situation.

About 250 in what most people would consider the limit of streetable.

You're going to need to provide a bit more info on what you want to do to get a better answer.

Mr rx-7 tt 02-11-14 01:24 PM


Originally Posted by Aaron Cake (Post 11677470)
Over 1000 in a drag situation.

About 250 in what most people would consider the limit of streetable.

You're going to need to provide a bit more info on what you want to do to get a better answer.

You are not going to get 1000 horsepower out of a n/a motor.

diabolical1 02-11-14 02:54 PM

i'm sure Aaron probably missed the N/A part. :D

i know 13Bs have eclipsed 400 in all-out race trims - i honestly don't know if nitrous was involved or not though. as Aaron Cake alluded, you're looking at the mid-200s for the street.

crzlito 02-11-14 03:57 PM

Well my goal is to make 300 hp all motor is that possible ? Thanks

placd1 02-11-14 04:09 PM

Its an ambitious goal. 300whp on an NA motor is going to be extremely expensive,extremely loud and not very street-able. I don't think I've ever seen or heard of anyone hitting more than 230-250 hp NA on a rotary engine without spending a tonload of money and sacrificing everyday driveability.

Aaron Cake 02-11-14 04:10 PM


Originally Posted by Mr rx-7 tt (Post 11677591)
You are not going to get 1000 horsepower out of a n/a motor.

Nitrous. Though I guess that's not "all motor" and some people don't consider nitrous breathing to be NA.

But full peripheral port, nitrous, alcohol and you can get 1000HP out of a 13B for a few drag runs.


Originally Posted by crzlito (Post 11677700)
Well my goal is to make 300 hp all motor is that possible ? Thanks

Possible, yes. For a full peripheral port engine, 300HP is easily achievable. It will not, however, be considered what most would say is "streetable". Primarily due to exhaust volume. It will be stupidly, incredibly loud.

You want 300HP an something you don't need ear plugs for and won't get 5MPG? Then turbocharge it and have a reliable 300HP all day long.

IamWill 02-11-14 04:47 PM

An NA 13b won't go further past 250 without breaking or deciding to eat itself. 13b T, easier to get your 300 hp out of.

Aaron Cake 02-11-14 06:52 PM


Originally Posted by IamWill (Post 11677740)
An NA 13b won't go further past 250 without breaking or deciding to eat itself.

The Renesis makes nearly that power stock. It's a 13B by dimensions. It's pretty easy to get more than 250HP out of an NA 13B with a big set of bridgeports, and peripheral ports will take it 100 - 150HP higher. Of course you better drive with earplugs...

Evil Aviator 02-11-14 07:22 PM

A 13B in all-out hill climb configuration would be around the 700-800hp level.

diabolical1 02-11-14 07:51 PM


Originally Posted by Aaron Cake (Post 11677707)
But full peripheral port, nitrous, alcohol and you can get 1000HP out of a 13B for a few drag runs.


Originally Posted by Evil Aviator (Post 11677835)
A 13B in all-out hill climb configuration would be around the 700-800hp level.

good God, where have i been? :(

Mr rx-7 tt 02-11-14 08:00 PM


Originally Posted by Aaron Cake (Post 11677707)
Nitrous. Though I guess that's not "all motor" and some people don't consider nitrous breathing to be NA.

But full peripheral port, nitrous, alcohol and you can get 1000HP out of a 13B for a few drag runs.


Aaron,
N/A=normally aspirated so nitrous a supercharger a turbocharger etc. are not considered N/A.

Evil Aviator 02-11-14 09:45 PM


Originally Posted by diabolical1 (Post 11677849)
good God, where have i been? :(

I don't know where you have been, but the guy who built them was in your neck of the woods for decades. Unfortunately, he passed away suddenly in 2010. One of his engines was on display at DGRR last year.
http://www.caradviceusa.com/tag/jim-bonsey/


Originally Posted by Mr rx-7 tt (Post 11677856)
Aaron,
N/A=normally aspirated so nitrous a supercharger a turbocharger etc. are not considered N/A.

NA = Normally Aspirated or Naturally Aspirated, depending on which term the engine manufacturer prefers.

N2O is an oxidizer. It is not forced induction because it does not increase the manifold pressure.

Also, a turbocharger is a type of supercharger, more properly called a turbosupercharger.

neit_jnf 02-12-14 08:46 AM

street ported side ports, semi peripheral ports staged with independent throttles, 9.7:1 lightened and balanced rotating assembly, 2-pc eccentric shaft with center bearing, increased oil pressure, ceramic apex seals, rev it to 10-12k rpm.

300whp NA streetable and durable.

Mr rx-7 tt 02-12-14 01:37 PM


Originally Posted by Evil Aviator (Post 11677924)
N2O is an oxidizer. It is not forced induction because it does not increase the manifold pressure.

A 3000 psi tank of nitrous being forced into the intake system isn't normally aspirated. It's why nitrous isn't allowed in normally aspirated race classes.



Originally Posted by Evil Aviator (Post 11677924)
Also, a turbocharger is a type of supercharger, more properly called a turbosupercharger.

A supercharger is generally belt driven whereas turbo charging systems are exhaust gas driven and both aren't naturally aspirated.

Naturally-aspirated engine - Definition | WordIQ.com

The bottom line is you aren't going to get a 1000 hp out of a normally aspirated 13b, period.

Aaron Cake 02-12-14 03:16 PM

Haha, I knew my comment would start this discussion!


Originally Posted by Mr rx-7 tt (Post 11678324)
A 3000 psi tank of nitrous being forced into the intake system isn't normally aspirated. It's why nitrous isn't allowed in normally aspirated race classes.

Except, the engine naturally aspirates the nitrous/air/fuel mixture. Whereas with forced induction, the manifold pressure is raised past atmospheric to "force" more air/fuel into the engine when it aspirates.


A supercharger is generally belt driven whereas turbo charging systems are exhaust gas driven and both aren't naturally aspirated.
As Evil Aviator said, "supercharger" refers to any device which crams air into the engine. A "turbosupercharger" is one driven by a turbine, powered by exhaust gasses (well, it could be powered by other things as well...like a honking huge tank of CO2).

It's just that in the automotive world, people use the term "supercharger" or "blower" (even though "blower" refers specifically to a roots style supercharger) to describe "supercharger" while they use the term "turbo" or "turbocharger" to refer to a "turbosupercharger".

Sgtblue 02-12-14 06:08 PM

lol, I tend to learn stuff when two big brains debate. Now I wonder.....is the true 13b displacement 1.3 or 2.6 liters? ;)

Mr rx-7 tt 02-12-14 07:18 PM


Originally Posted by Aaron Cake (Post 11678396)
Except, the engine naturally aspirates the nitrous/air/fuel mixture. Whereas with forced induction, the manifold pressure is raised past atmospheric to "force" more air/fuel into the engine when it aspirates.

It is considered a "power adder" which we are talking about. Many race classes let you use either or. (turbo/supercharger or nitrous oxide).


Originally Posted by Aaron Cake (Post 11678396)
As Evil Aviator said, "supercharger" refers to any device which crams air into the engine. A "turbosupercharger" is one driven by a turbine, powered by exhaust gasses (well, it could be powered by other things as well...like a honking huge tank of CO2).

It's just that in the automotive world, people use the term "supercharger" or "blower" (even though "blower" refers specifically to a roots style supercharger) to describe "supercharger" while they use the term "turbo" or "turbocharger" to refer to a "turbosupercharger".

Yes we all know what the terms mean, it's not 1940 and that's why I used the term "generally". I think some of you just want to argue to argue. If you want to get technical using the term nitrous is also a misnomer.

We know what the OP was asking and ~300 hp is about all you are going to get out of an N/A 13b and the last 20 or so hp doesn't come cheap.

Evil Aviator 02-12-14 07:40 PM


Originally Posted by Mr rx-7 tt (Post 11678324)
A 3000 psi tank of nitrous being forced into the intake system isn't normally aspirated. It's why nitrous isn't allowed in normally aspirated race classes.

By that flawed reasoning, fuel being injected into the engine at 40psi isn't normally aspirated either. Much like fuel, nitrous reaches pressure equilibrium shortly after it is injected, and therefore it supplies no boost whatsoever to the intake manifold. You are more than welcome to test this for yourself with a MAP sensor if you wish.

Whether or not nitrous is allowed in a race class is based on competitive or safety rules. I raced in an NA class that didn't allow fender flares, but that doesn't mean that fender flares are forced induction.

The OP did specify "all motor", which typically means no nitrous.


Originally Posted by Mr rx-7 tt (Post 11678324)
The bottom line is you aren't going to get a 1000 hp out of a normally aspirated 13b, period.

I think it could be done with modern technology and stratified-charged hydrogen fuel injection. However, I am not sure how much it would still resemble a 13B at that point. As it was, Jim Bonsey's engines leaked like crazy when cold, used special oil, and had all kinds of custom internal tricks engineered into them.


Originally Posted by Aaron Cake (Post 11678396)
Haha, I knew my comment would start this discussion!

:cursing:


Originally Posted by Sgtblue (Post 11678512)
Now I wonder.....is the true 13b displacement 1.3 or 2.6 liters? ;)

After subtracting the internal capacity lost to all the unburned oil, ATF, and fuel from leaky injectors, there is only about 0.5L left inside the engine, lol.

crzlito 02-12-14 11:00 PM

Well how about J-bridge port is that too much for street use ? Is it still too loud ? And how's the MPG on it ? What I mean about street use is using the car just in the summer time,running it around for 40 miles a day and taking it to the track maybe once a week..

Aaron Cake 02-13-14 09:15 AM


Originally Posted by crzlito (Post 11678729)
Well how about J-bridge port is that too much for street use ? Is it still too loud ? And how's the MPG on it ? What I mean about street use is using the car just in the summer time,running it around for 40 miles a day and taking it to the track maybe once a week..

A J-bridge is the worst possible port ever designed. And it was only designed to get around rules banning peripheral ports in certain racing classed. J-bridge engines typically have lifespan of a few hours, a few races, or a few months. With the typical failure being water leaking into the engine through the intake port as the port extends into the water jacket, meaning the water o-ring needs to be cut.

It will act worse than a bridgeport with a high lopey idle and in order to make any sort of power, it will be stupid loud. It will be far worse than a peripheral port for the same amount of pain in the ass factor.

You'll get about 8 - 10 MPG on a J-bridge around town.

Porting

For the same amount of effort, swap in a 13B-T, perform basic upgrades, and have 300HP all day long.

At 40 miles a day, assuming city driving, you'd be filling up the tank of a j-bridge every 3 days.

neit_jnf 02-13-14 09:24 AM

staged semi-peri is more street friendly than bridge with more power potential

Evil_Sephiroth 02-13-14 03:10 PM

The best choice if you want power and a near streetable NA 13B is aiming to RPM

Then follow precedent tips: half bridgeport (more became LESS streetable), lightweight rotors (you can "easily" machine rotor to a lighter state then most of the aftermarket lightweight assembly, 2 piece E-Shaft with bearing, go with sohn all the way, new fuel rail+ injectors and new ECU....

BTW just buy a 13B-REW or a Turbo kit...less work if you only want 300HP no matter what

rotary_FD3S 02-13-14 07:25 PM

If u guys want to get technical about it the NA S5 has a VDI valve ( variable dynamic intake ) which forces air into the engine in a way. Technically forced induction haha. FWIW...

Evil Aviator 02-13-14 08:44 PM


Originally Posted by crzlito (Post 11678729)
What I mean about street use is using the car just in the summer time,running it around for 40 miles a day and taking it to the track maybe once a week..

In that case, you are asking the wrong question. What you need to do is find a rule book for the racing class in which you intend to compete, determine the engine modifications that are allowed in that class but are still street legal for your local area, and then ask for tips in our racing subforum. Your budget, skill set, and access to tools and equipment will also factor into what you can accomplish. However, nobody can help you until you determine what is allowed in your race class.


Originally Posted by rotary_FD3S (Post 11679248)
If u guys want to get technical about it the NA S5 has a VDI valve ( variable dynamic intake ) which forces air into the engine in a way. Technically forced induction haha. FWIW...

Forced induction means that it produces a significant amount of boost, which the NA S5 does not. Nice try though. FYI, the other 13B DEI (Dynamic Effect Intake) engines use a similar effect, as do many other automotive engines that incorporate a Helmholtz resonator or similar inlet effect.


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