ricky356

i got the new turbo mag this month and on the cover it had a rx-7 equiped with a 1.3 liter 13b. im new but this is the same engine we have in our rx-8 right? if so why are there no 500+ hp rx8's running around ...unless i havent heard about it.

just wanted to know if anyone has seen this and if they have why is it necesary to swap to a 20?

thanks

rick

I8U

iTrader: (1)

Anyone else wanna handle this one? All I'm gonna say is...yes and no!

Digital_Damage

No not the same engine.

but 500hp will be coming.

ricky356

what do we have a 13-a?

expo1

13B RENESIS

Mazda-Rati

the differences of the 13B and the 13B renny are posted everywhere on the internet and on this forum.

If you care about your feelings....don't come back to this thread. I think a lot of flaming is about to take place.

rotarygod

Go easy on the guy. It's an honest question.

rotarygod

Here's one that did 711 hp and 566 ft lbs of torque.

http://www.rx7club.com/showthread.php?t=633482

Red Devil

I'd be happy with seeing a proven, reliable 400whp Renesis.

GT34

This is all you need to know my firend


The reason the typical rx8 owner isn't running around with 500bhp, is because he'd be rebuilding his engine every 20k. Judging by the turbo mag you're looking at, they're probly pumping a lot of air into that engine. Only a handful are capable of properly tuning the 13b. It's not reliable enough to do.

If you wanna get technical about our engines they are 13b. It even says so on the side of the engine. However they're not the same as the previous generation rx-7s 13bew. The apex seals and the porting is done differently. However the rotars housings are mildly the same. Please read before attempting to flame me. http://www.mazdamaniac.com/direct_dl.htm

rotarygod

Just for the record, the 711hp 13B in the link above is a streetported 13B using 9.0:1 compression ratio. He's got Atkins apex seals (which I wouldn't use but that's just me) that are cryotreated. He's also got a Guru Racing eccentric shaft that has the center bearing which I've been preaching about for some time now. He's got a stock intake manifold (and admits it's holding back power), a big single turbo, large intercooler, and some damn good tuning. The C16 gas helps too.

Out of the above list about the only thing that really helps with the strength of the engine is the eccentric shaft. The rest of it was really a result of good tuning. Keep in mind he's also got a full point lower of compression. High compression like the Renesis at 10.0:1 will reach it's limits much sooner on the power game. It will still be over 400 hp though with good tuning.

I'm not sure we'll see 500 hp out of a Renesis without some good money being spent internally on the engine. You don't see that out of a 13B on a stock engine. Yes it has been done but there are always extreme cases out there. Most can't do it.

rx8frank

To get those number some of them run on the 13B-REW of the past cosmo....I know two guys who own rx-7 have the 13B-rew in them and One of them pull 450hp out of it. Here his link...it's in french but most of it's mods are written in english...
http://rotaryrocket.monchar.com/

ricky356

[QUOTE=Mazda-Rati]the differences of the 13B and the 13B renny are posted everywhere on the internet and on this forum.

If you care about your feelings....don't come back to this thread. I think a lot of flaming is about to take place.[/QUOTE

Care about my feelings? how old are you?

thank you to everyone who took the time to school me.

Rick

Cody Red

yeah, we have a 13b renesis, and that 500hp 13b you're reading about is a 13b-rew

it's all good, a lot of us still don't know EVERYTHING about Rotary engines. we all gotta start somewhere. I've seen 700hp out of a 13b-rew, but i'm more than sure it won't last more than 10k miles. but having that much power isn't your typical daily driver anyways.

-Cody

Mazda-Rati

[QUOTE=ricky356]Does age really reflect maturity level?....silly question though, but I'll answer, I'm 12 years old

A very good sticky to read is here..https://www.rx8club.com/series-i-tech-garage-22/rotary-specific-sae-papers-105067/ It may answer some of your questions

Detrich

thanks for answering his question. i learned a lot from reading this thread too.

california style

Is there any reason why Mazda called the Renesis a 13b?

especially as they changed the ports etc, which is quite a fair change from my understanding...

Why not a 14B or something?

rotarygod

13B is technically what the engine is. We throw the terms 13B and Renesis around separately since it's easier to understand which engine we are talking about. We generally refer to a 13B engine s a side intake port, peripheral exhaust port configuration while we think of a Renesis being a side intake and exhaust port engine. What about an all peripheral port configuration? We still call this a 13B. The Renesis is a 13B based on how Mazda names their rotary engines. Everytime a dimension internally changes in regards to displacement, they give it a new name. "13" refers to the displacement which is 1.3 liters. The 12A engines were 1.2 liters. The letter designation generally (but not always) refers to the generation of this size range. "A" would be the first incarnation of that engine size. Again, generally as they have broken that rule before.

There was a 13A engine. It was only available in one car for 2 years. That was the Luce and it was the only front wheel drive rotary powered Mazda ever made. That was in the 70's. That engine differed from the 13B in that it's rotors were taller but not as wide. Think of this engine as the stroker of rotaries. It's overall displacement was 1310 cc which is a fraction larger than the 13B at 1308 cc. Mazda just rounds the numbers so they both appear as "13". When Mazda changed to the wider rotors that had the same shape as the 12A rotors, they changed the name to reflect the second incarnation of this size range which was naturally a "B".

The engine size hasn't changed at all with the Renesis. Only the porting has so on these grounds it is still a 13B. Just a 13B with different porting. This is no different than an all peripheral port engine being called a 13B as well. For the sake of clarity we do use the terms independently when referring to them though.

GT34

You are the rotary god

rotaryWizard

what would if you were able to lower compression on the renesis, would boost and hp be more accessible?

Red Devil

Absolutely. Now the trick is getting lower compression rotors that work with the Renesis.