SureShot

My injector count is 6 total - 3 intake runners X 2..
-Bill

(I'm hopeing the renesis kit will be available when my NA hit 250000 miles.)

SureShot

Here is the sound byte from the factory RX-8 Ad.

"http://208.62.166.66/guest/renesis/RX-8_sound-75k.swf"


Here is the engine annimation. (It's 3mb)


"http://208.62.166.66/guest/renesis/renesis-3m.mov"

You will have to cut and paste the address.
Bill

SureShot

Here we go:

RX-8 sound byte

HEVNSNT

iTrader: (3)

I don't usually like to misinform people but you guys are right about the mechanical water pump. I thought I read somewhere that it may be electric but I guess I am wrong. It wouldn't make sense for it to be electric anyway for reliability reasons. The grey injectors are the secondaries and yes there is 4. The red ones are the primaries, and there should be two.

Note the preproduction blocked off "flange", one at the lower center of the intake and one off the exhaust manifold. There is also some sort of actuator (black thing a little to the right). I assme these may possibly be the EGR setup. Any other ideas? Possible future connections for turbo?

drago86

Kiyokix, overlap is good for power at high rpm. True that its bad for low end, but who the hell buys a rotary for low end torque? If you dont believe me ask someone like Riceracing, the more overlap(to a point) the more high rpm power you have, true it does kill your low end, and you mileage, but again, who cares? i get 28 mpg with my overlap thank you very much. When you streetport a motor you make it open earlier, and close latter, increasing,... overlap. ive seen a graph of the duration and timing of the renissis, compared to a FC NA motor, and its is very very small, looks like a duratec econobox exaust cam timing, the periphreal exausts have twice the duration. And although it does open the ports latter, which increases the power stroke, this too only matters for low end torque, for high rpm power, you want the port to open while the mixture is still burning, creating blowdown which helps clear the chamber for the next intake charge. The renissis has very small exaust timming, the only way they get away with it is because of the increased exaust volume. I susspect people will do something similar to a bridge port on the exaust to INCREASE overlap and make more power

KiyoKix

Not to start an argument, but what's more important in racing...riding on a long straight and long sweeping corners, OR short straights and tighter turns. What gets you off a corner...horsepower or torque? If you have no low/mid range power to speak of then you will ALWAYS play catchup in racing. Torque is what gets you moving, horsepower keeps you there. If you have no real torque then you will have very bad accelaration unless you have a ridiculous power to weight ratio (f1/cart cars). I'm not speaking from opinion, I'm speaking from what Mazda themselves say. It's great to have awesome horsepower, but that's not what makes a car quick. Why is the TII faster than the N/A because of the extra horsepower...no it's because of the torque curve they have. The curve never drops below 145 lb*ft all the way to redline, whereas the N/A's doesn't ever hit over 140 and isn't as flat. Oh well I don't want to argue with anyone, I'm just stating facts and I hope nobody will be pissed off about that.

KiyoKix

Regardless of any facts that we state here, it's MUCH easier to create hp than tq in a rotary. It's a race engine that's pretty much tuned for the street so eventually we'll all have to realize that and optimize it for what it's for and not what we think it should have. I know that I'm not gonna get some ridiculous torque number out of the 13B, but I'm gonna try and find the compromise that I can. It was made to run at high revs so that's where it'll thrive (hell it we wanted a low rev engine we'd have gotten a Mustang). It's similar to the S2000, you might get one off the line and take him for a few thousand rpm, but when he gets around 4500...that's your ***. Same with the Celica...well not quite as bad since the whole powerband is between 6k and 8k (wtf). Sad, that car could be so much more. Anyway I'm studying (I think that's all I ever do ) the other rotaries especially the ones that never made it (21A anyone...) to see the settings they had (especially timing and powerband), and seeing how they relate to the 13B. I know the carbed 13B sports kit used in the '77 Fuji race had a peak power of 290+@9000rpm and used a peri intake (86/75) and exhaust (73/65). Same compression ratio as normal 13B DEI, it used no turbo or 6PI. Very nice...off I go to study again.

faster7

Someone needs to turbo one with a scratch built intake manifold....So I can steal the whole Renesis intake setup for a 6 port RX-7. Looks like it'd match up, or be close???!?!?!

KiyoKix

Haha, that someone would have to be good in order to turbo a RENESIS since you can't get them just yet. But people have gotten things before they were sold before, I remember reading about a new stereo system that Mazda made for the FB, and 3 hours after it got off the boat someone stole it from their OWN PARKING LOT...now that's desperate!

RETed

I've heard this many times, and I still don't believe it's true.
I believe the gains (from RICE RACING) are from the increased duration and not directly from overlap.


Under what conditions?&nbsp Normal city driving?&nbsp Bullshit...


Most "commercial" templates do, but this is not a general rule.&nbsp My streetport motors have ZERO increased overlap.




-Ted

faster7

I didn't say next week, I CAN wait until they're out in numbers.

drago86

na 28 highway REted :-), and overlap helps power because the exaust exiting at the same time as the intake comming in, creates a sorta vacume that sucks in more intake charge, very early in the cycle at high rpm. If you dont believe me look at a Mazda Factory Peripheral Port the exaust opens a little bit latter than an NA fc (2 degrees) but closes much latter, if you look at one next to a normal housing, it looks like the port has been relocatted upwards, this increases overlap. Kiyokix low end torque does matter for everyday driving, but once you throw a close ratio gearbox in and you keep the motor allways in its powerband. The S2000 motor is fast on a race track, not only because it has 240 HP @8500 rpm( i think thats the peak) but because it has a nice close ratio box that can keep the motor on cam no mater what speed the corner. F1 cars live solely off high rpm power, you never see an F1 car go much below 10,000 rpm, because the lower they go the less hp they have. the r26b was the same way, if it wasnt kept in its (high rpm) powerbad it wouldnt have won Le mans, once you have a close ratio gearbox low end torque doesnt mean much because you can make far more power with high end torque, if we could keep our na's making 120 ft pounds all the way up too 8500 rpm, wed be making about 250 hp. im also almost positive mazda put a close ratio box in the rx8, with 6 gears they better have. and none of this argument gets around the fact that the renissis has very a small exaust duration, which REted himself said duration increases power, im sorry if i come off mean or something, im not trying to start a fight or anything, just stating what i know. I had a website that had information on the renissis on it, timmings and such, ill see if i can dig it up

drago86

btw city is between 15 and 20 something, i usually end up with about 25 mpg mixed driving i do around in a normal week. on road trips i get 28 highway, i think i saw 29 once too, but only once, its usually quite consistant at 28, and i know the rennissis will be way better in this respect, they reduced fuel consumption at idle by 40 %, and by large amounts else where too, one of the reasons is they run it quite lean during normal driving, combinded with no overlap and a longer power stroke, it makes for great gas mileage

KiyoKix

running to the other side of campus...I'll post in a few...

KiyoKix

Overlap itself isn't what makes the power at high rpm, it's a long story on how this works (you have to understand pressure wave timing, port sizing, flow of air, and a bunch of other stuff, I'll give you guys some links in a little while).

KiyoKix

Alrighty here's a nice link to give you guys something to think about the next time you do anything intake/exhaust wise to you car (it'll also explain a lot, not to mention give you some good 'ol fashion knowledge)...

http://personal.riverusers.com/~yawpower/

Hit up the technical article section and while your at it check out the photos of the 12A he's working on. Not to mention if you want some work done on your car it'll give him some business.

SureShot

I have read some of Paul Yaw's articles. He's the man - especially when it comes to flow.
Bill..

slidingsky

Hey kiyokix I was wondering why you say torque is so important in racing. From what I read in that article and from what Ive experienced autoX and roadracing<only once actually> mid and low end barely matter. Seems like after I got moving I didnt see below 5k rpm anyways. Again my car has NO torque. SHould have decient HP though.

KiyoKix

You do have some torque or you wouldn't ever speed up. Horsepower is just the measure of "work done". Torque is the force at which the shaft actually rotates. Like I said torque gets you moving, horsepower keeps you there. It's takes a while to explain and I'm about to go home right now, but read on the exhaust portion of the Yawpower site (I think it's in there), I know it's there somewhere so you'll see what I mean.

drago86

hehe, yeah, ive read all of Yaw's stuff to allready, and i wasnt talking about torque, i was talking about low end torque, which i dont care to much about as long as i have the high rpm torque to make me a good amount of hp, so i am very much in favor of torque, so long as it peaks at around 8000 rpm or higher

drago86

http://www.mymazdarotary.com/mazda_...nesis_paper.htm

here is a paper on the rennisis, showing the very low exaust duration, bear in mind that on the graph is for 2 side ports, not the 4 of the production renesis, so the exaust port are would be increased by nearly 2x wich give it a little more volume through the port that the periphreal, which is how they get away with the geo metro exaust timing

drago86

theres one about the r26b on that site too

bingoboy

that link is messed up.

drago86

hmm ok gonna have to type it in i guess: mymazdarotary.com/mazda_rotary_general/renesis/html/renesis_paper.htm

drago86

btw this thread supports my feelings on overlap, and the renesis's lack there of https://www.rx7club.com/forum/showth...lap+riceracing