Kasmiur

I was wondering if anyone has a picture of the rx8 without the plastic cover? I know mazda has said that turbo versions of the renesis produce too cool of air for catilatic emmisions(misspelled for your pleasure) but would that also include supercharging?
Man I can't wait for the mods for this thing.

Hercules

It has been mentioned that turbo/supercharging the Renesis aftermarket would be an EXTREMELY expensive and difficult proposition, because the engine is very tightly packed.

That doesn't mean however, that Mazda won't do it.

bern

Here you go.. courtesy RotaryNews




Cheers,
-Berny H.
http://rotarynews.com

rotarynews.com

And here is another one.. rather long download, bit you get a good feel of how things are packed in there...

bern

uno mas...

Sputnik

Hey Dan,
Was the X-men car an automatic or stick? I've only been able to see two intake paths in this engine so far.

---jps

Kasmiur

hmm.. I am assuming since two intake paths = two rotors in the motor... havnt kept up on tech details of the renesis..

some thoughts

1. Would have to remove the plastic cover completly over the radiator and such. I could imagine some space would be avaible there. Perhaps move a fluid container to another spot.

2. With the alternator right there and the belts too would be a ideal place to bolt on a supercharger and it would also be in direct path to both intakes

3. would have to replace the intake tubing with something better. Perhaps a HUGE Y pipe. More and likly may have to put indentation in the hood like a Esclipse has. Heck it is almost in style with american cars to put a fake ram air vent.

4. Would have to ditch also the plastic cover on the top Perhaps that would give the extra room without having to change the hood design

5. gotta get a new suit for this guy. Need to tell him not to shop at thrift stores.

Kasmiur

this picture looks like there is some space. its not a lot but I could see definitly fitting something there. Why am I so intersted in a supercharged rx8? Its simple. Generally a supercharger will add 30-50hp. With the light weight already of the rx8 a supercharger... and a few other small mods I could see it at 300hp. It is not much but with its current torque and if the handling is good this would be a fun vechile to drive plus have some power underneith the hood for other things.

Now to only get a picture without the other black cover.

circled part of the area that looks like I could fit a few things there. It all depends on exactly what is under the black area and if it can be moved.

RotorMotor

Here's a full shot of the RX-8 at the LA Auto Show with most of the covers removed. The battery is really crammed in there. Not too sure how much space you'll actually have....

DrKillJoY

battery relocation is an EASY mod.

RotorMotor

This may sound like a stupid question (I'm a Mazda enthusiast not a gear head), but wouldn't it be really easy to relocate the batter to the trunk considering you'd only have a few wires to run through the firewall? That'd open up a lot of space for a larger intake and probably create enough room behind it for the supercharger to be next to the alternator. Like I said, if I wan't to put any aftermarket parts on this car I have A LOT to learn (I got all excited that I changed my own oil a few months ago :D ) but that seems like it'd work.

Sputnik, the X-men car was a stick.

Rx4FUN

Sputnik- In the pick on page 22 of the press kit that shows the intake it appears as though the auxiliary intake path comes in from the opposite side of the motor from the other two (primary and secondary) intake paths. I think the pathway for the auxiliary is buried under the other intake components so it's hard to see by just looking at the motor. I am also speculating that the auxiliary intake port is actually on the opposite site of the rotor housing from the other two intake ports.

All- Something to think about if you are looking to supercharge...you probably don't need or want all the intake pluming that is currently in the RX-8. The setup is specifically designed to take advantage of the naturally aspirated characteristics of air flow. Once you bolt on a supercharger, you will completely change these characteristics. By removing the multiple path intake you could gain quite a bit of space under the hood. The problem is that the Renesis is currently expecting air flow from three different ports so the intake would still have to split the output from the SC. Also, the Renesis uses a "Jet-Air fuel mixing system" to improve atomization of the mixure entering the intake ports. Basically it uses a stream of high speed air just upstream of the intake port directed into the rotor chamber which improves the intake flow and mixing of the intake mixture. I'm not sure how supercharging the intake air would affect this.

Needless to say...I don't think that adding a supercharger is going to be easy. A lot of the technology that the renesis uses is very specific to natural aspiration.


~Robert

wakeech

Kasmuir, space issue asside, you really need to get in the know with what you're going to attempt before you really put some time and effort into this, and maybe get disappointed... i don't know if you are!! :D and i'm not saying you will, but you saying "generally adds 30-50hp" kinda worries me, 'cause it's (obviously) never that simple.

in any case, when you thought that the two intake paths meant two rotors, you are right in that there are two rotors, but that's not exactly it... i'd strongly suggest going to the Tech Garage section and reading up on the "ins and outs" of this engine... some is speculation, but a lot is hard fact. i love that thread, please keep it going ON TOPIC!! please??

now, the thing about adding a belt driven supercharger (as opposed to an exhaust driven supercharger, or "turbo"charger) is that the speed of the impeller is directly related to the speed of the crank. at a certain rpm, it will ALWAYS give you a certain amount of boost, and thus you have to set your pulleys to your intended driving use... if you "gear" (it's pulleys, not gears as you know) it for low boost, then what you'll find is power robbing inefficiency at high rpm, and possibly horrible overboosting... if you "gear" it for high rpm boost, then you'll have extra drag on the power train until you get boost, not to mention an impeller in your intake... even in the middle, there are significant comprimises.
with the exhaust driven supercharger (a turbocharger), impeller speed is influenced by throttle position, rpm, load, and other stuff (hard to know when i'm not a turbo engineer)... the big thing is that you can control the amount of boost with an exhaust waste-gate, which is their big advantage (a certain amount of boost useable through a large portion of the rpm range).

also, we know absolutely nothing about the tolerances of this engine, and how much boost it's safe to run. we also don't know how the stock fuel curves will respond, even to a very small amount of boost in the middle of the rev range... there are so many questions, which is exactly why i cannot support your hope of 30-50hp... maybe, just maybe if all your boost was concentrating on the 7k-9k range, i could see that happening more easily... but don't be lookin' for 280hp at 3.5Krpm, friend: i honestly don't think it'll happen without SERIOUS work, work serious enough that the "space issue" is an absolute non-issue (you'd find a way to make it work).

wakeech

you're right about ripping out the variable length intake, it WOULD make a lot of room (over the top of the engine...), and yeah, it'd be easier to have a manifold fab'd than to try and get the whole system to work together (but it WOULD be glorious... )

anyhoo, the "jet-air mixing" is just using something extremely akin to direct port injection: in DPI, fuel is fired through the valve-ports into the combustion chamber, using the air swirling around the valves (and even the heat of the valve itself as fuel droplets land on it, and evaporate) to mix the fuel and air. in this instance, the RENESIS has its (primary, i suppose) injectors firing fuel across the air-flow into the combustion chamber, and the rotor face itself (it would seem)... i don't know how to get a jpg out of a pdf!! and so alas i can't post the beautiful picture from the presskit Dan (rotarynews.com) was so gracious to post... it's a big download, but it's worth it...

hey Boogdawg, how do you get the jpg's out of the pdf??? you're always the first to know... i can't believe YOU were scooped on the Mazdaspeed 8!! :D

Rx4FUN

The difference between DPI and the Renesis system is that renesis blows air into the intake port from a seperate high-speed feed that is seperate from the air entering from the intake path. I can't seem to figure out where the source of this air is coming from and what is giving it the higher velocity, but I'm guessing that this system might be effected by the higher pressure of the intake air created by a supercharger.

The low emissions technology diagram that follows the jet air specific diagram clearly shows the seperate "tube" passing the jet air into the intake path.

~Robert

Kasmiur

Thanks everyone for such intelligent answers. I admit i dont know anything but figured it was worth a shot to ask.

jeremy

i was skimming and might have missed someone saying this, but one of the biggest problems besides fitment is that you are trying to boost a 10:1 compression motor. boost is going to need to be kept fairly low and you are still asking for trouble. any rx7 fan nows what happens if you run lean. one decent ping and you will be looking for the apex seal in your rearview. also there were no good pics on the exhaust side for checking the room for a turbo. be nice if they would get some better engine bay pics. not sure the dimensional differences, but i can see someone building the renesis with 13b-rew rotors to lower compression then custom manifold etc. maybe a 3rd gen fuel pump and upgraded injectors. blah blah, i'm going off on a tangent now.

Fëakhelek

Wonder if NOx is a viable option.

Buger

Hi Wakeech,

You can use a special key that some people have on their keyboards called the "printscreen" key. It can actually put a "picture" of your screen into the buffer.

Dan is the man. He gets to drive RX-8s before they are released and can leap tall buildings in a single bound. I am like office boy Jimmy Olsen next to his Superman Dan! :D

What if somebody tried to supercharge a small path that tied into the primary intake paths near the ports? The intake system should still be functional and perhaps the supercharged air hitting the rotor as it closes the port may lead to a stronger pulse to charge the other port at low rpms? I'm sure somebody here would be crazy enough to try and make it work. :D

Of course they will have to find a way to keep the fuel/air ratios good...


Brian

jmanolov

Note that the pic above from the car without the shock tower brace is from an old prototype. Here are two pics from the new production car which was at the LA auto show.

The first one:

jmanolov

The second one:

jdachik

If it helps with airflow I guess that it's for the best, but why is the airbox so huge? And does anybody have a clue what's under the left and right covers toward the front?

Fëakhelek

I'd guess that at least one of them is a fusebox.

DrKillJoY

the oversized airbox is most likely there to hold what I remeber to be called by Subaru as a "quick intake charge"

Once air is passed thru "front" of the airbox... the air passes info an area where a mass air can collect, so when you stomp on the gas and the engine sucks.. it has a wealth of air to pull from and does not have to immediatley have to pull the air through the filter..

essentially reducing the bogging when you stab the gas...

DrKillJoY

...overheard in a busy room somewhere...is that where the Xenon "auto leveling hardware" is located..

:D