http://motoring.nzoom.com/motoring_d...88-390,00.html

just read this article in motoring magizine. What do you think possible we will be seeing a supercharged rx-8 from the factory. Heres a quote from the magazine:

Whilst Mazda's engineers are quick to deny that they will produce a turbocharged version of the RENESIS engine, principally because of the effect that process has on exhaust emissions, they do acknowledge that they are working on a supercharged version. This supercharged prototype is officially limited to 206kW, but produces an incredible torque, said to be some 375Nm at 4000rpm. Our sources also tell us that the supercharged version will in fact churn out 238kW, and in racing form will be easily capable of producing 298kW (400bhp).

There is also continuing but unsubstantiated speculation that Mazda is working on a larger-capacity, normally aspirated rotary to overcome the new engine's inherent lack of torque. Our guess is that if this is indeed the case, it will take the form of a three-rotor RENESIS engine. How a longer engine will fit into the RX-8 without raising its placement in the car is of course another issue

 

Hello x-mann. BTW, I would like to say welcome to the club . We had discussed the opportunities the RX-8 had for us, such as supercharging, turbocharging, nitrous, etc. After reading the article, and what you had posted, I strongly believe that the RENESIS would benefit more from a supercharger, though a turbocharger is more flexible in terms of changing boost. Improving the low-end seems to be the problem everyone here is trying to solve.

 

thanks for the welcome shelleys and the imput

 

welcome and forget that bit of speculation on a 3rotor. not going to happen

 

I agree zoom44. After having gone through a few discussions on it and some things i heard about the 20B... I seriously doubt a 3 rotor Renesis will appear. Maybe larger rotors for more displacement in the 2 rotor form, but most likely a S/C...

 

Here is some reading for you.
https://www.rx8club.com/series-i-major-horsepower-upgrades-93/sunflower-mazda-supercharger-info-27235/

 

man if they got the rx-8 more tourque and power in the low rpm's id trade mine in right away!

my moms accord has more torque, lol

 

Hell yea =)

 

For all the valid talk re lack of torque, did anyone notice that in the recent Road & Track comparo test the RX8 was QUICKER than the G35 to 40 MPH? Doubt such was the case before the M Flash.

 

I thought that the supercharged version of the RX8 was confirmed to be an electrically assisted one. Apparently, on this version at low RPM an electric motor assists the supercharger to produce boost (and torque), and at higher RPM the supercharger works in a normal way.

Can somebody please confirm this?

AND

How would this version of the supercharged RX8 compare to those under development on this forum? I am eagerly awaiting a good supercharged solution, and am following Richard Paul's Axial Flow Supercharger thread (https://www.rx8club.com/series-i-major-horsepower-upgrades-93/axial-flow-supercharger-29778/) with great interest.

What are the Pro's, and Con's of each of these systems (lets say the electrically assisted Mazda supercharger, and Richard Paul's Axial Flow supercharger)?,

Which one would be more suitable for road use?,

What rwhp figures should we expect from each of these???...

Thanks.

 

Um no. The electric-assist is a turbo, not a supercharger. A positive displacement supercharger has no need for electric assist as it is producing full boost all through the RPM range. The point of electric-assist for a turbo is to help spool it up faster to reduce lag and improve drivablility across the rpm range.

NOt much can be said about what Mazda is working on without more details... such as if this is a positive displacement supercharger or not. That will have a significant impact on this conversation.

 

Why is an electric-assist pump a turbocharger? Isn't a turbocharger by definition, an exhaust-driven supercharger? Either way, I believe they are both pumps.

I wonder why Mazda would go the route of an electric-assist pump? IMO, the idea would not only be costly, but time consuming. Positive-displacement superchargers are already available, so maybe Mazda can go that route. I don't know about the average power gain of electric-assist superchargers; personally, I prefer to trust a device that already exists.

However, at least the idea of an electric-assist supercharger is out there. I am always willing to accept new technology, as long as it has been thoroughly tested .

BTW, does anyone have any testimonials for Thomas Knight's blowers?

 

Use the search button...please.

There is no electric-assisted supercharger. It is a 100% electric supercharger, and there is the bogus one and the one that only provides a couple seconds of boost. To run it the alternator and battery have to undergo serious upgrades.

The idea of an electric-assisted turbocharger is a fact, no matter what you may think. period. It has been discussed several times and explained by rotarygod and maybe wakeech and Zoom44 as well. Not only Mazda is researching this for the rotary engine (reportedly for the next 7), but Nissan is looking at this in a twin turbo form for the GTR.

Why does a turbo need assistance? For the reasons I already posted. Turbos have improved alot, but the average turbo will never be the same as a positive displacement supercharger... you'll never get all the power on tap from 0 to redline (which you trade for other benefits). In order to reduce turbo lag and beef up the normally weak low-end they are assisting the turbo with an electric motor at low rpm only so it will spool up faster and give you more boost at low rpm as well as high rpm.

Then there is the emissions issue. Sure the rotary's exhaust is hot, but the emissions laws are getting tighter and tighter. They're demanding the cat to be warm and working in what... 5 min after cold-start? So manufacturers are moving the cats closer and closer to the engine to heat them up faster. Now drop a turbo in between the engine and the cat. There goes a lot of your heat, absorbed by the turbo. So let's move the turbo further down stream... opps, thermal efficiency is down.. less heat for the turbo, less Hp for the car... this is mazda's dilemma. So move the idea is to move the turbo downstream and strap on an electric-motor to help it spool up faster.

 

Oops. I must have misinterpreted what you had said. I know an electric-assisted turbocharger exists. It's on the hydrogen-powered RENESIS. It's old news, I know .

Were you talking about engine thermal efficiency, or were you talking about compressor and turbine thermal efficiency? I kind of got lost there :o.

The reason for a turbocharger moved further downstream's (gr) inability to work as efficiently lies in the exhaust velocity, I think. Low or a sudden change in exhaust velocity is obviously not going to help spool a turbocharger. You are right though. Moving a normal turbocharger downstream is going to affect how much power the engine is going to produce. I suppose the use of the electron will help in this.

This idea of an electric-assisted turbocharger may just outdo other technologies such as twin-scroll designs and VATN turbochargers. So far, VATN-type turbos, such as Garrett's VNT turbo, are what appear to be hydraulically-actuated vanes that vary the turbine A/R, which in turn helps it spool throughout the powerband. Of course, hydraulic actuation will never outdo electric-assist. Garrett is also working on an electric-assist turbo, the e-boost. Borg Warner also has its version as well.

That is my two cents.

 

I second that. The car will need more power in the future to compete with the elite sports cars. Personally, I'd like to be able to have power without revving the engine into high rpms. That is however, the way this car is, so I'm living with it until a more powerful rx8 comes out. When it does, there will be no hesitation, and I will own one.

 

Yeah it looks like a misinterpretation. No prob... it happens.

I'm no rotarygod, but I don't think it was compressor and turbine thermal efficiency, but I blieve engine thermal efficiency. Essentially what I was trying to say is that there is cooler (i.e. slower) exhaust gas avaialble downstream for the turbo, meaning lag lag lag. Putting it in the sweet spot means your cat is cold and you don't pass emissions.

Hmm. I've wondered how an electric-assist turbo would hold up under temperatures, but... probably no worse than the VATN in the end.

 

Agreed. Check out my VATN thread I started. Jeff had some choice words about his ideas on VATN's.

https://www.rx8club.com/showthread.p...576#post461576

Oh yeah, after clicking Hymee's link to Borg Warner, I stumbled upon their eBooster technology.

http://www.turbos.bwauto.com/en/products/t_ebooster.asp

It may be old news.

I believe that is a problem that Mazda is trying to solve. How does one isolate the electric-driving mechanism from the elements?

 

Well, I work for Mazda so I can tell you what we hear from the factory.

The last year RX-8 is going to be a supercharged Mazdaspeed version with a functional aero package, beefier suspension, and different wheels/tires.

The RX-7 is going to be a 3.2L naturally aspirated rotary. They were playing around with the idea of a single ball bearing turbo, but due to emissions they scrapped it. Its going to look similar to the 8 with regards to the front end (like the '99+ RX-7s in Japan), but the rear will be like the RX-7 we know and love. It should produce around 300 horsepower and weigh roughly 2800 pounds.

 

3.2L for 300hp huh? You should check a couple threads in the Tech Garage about the factory rotary racecars. They were talking more like 2.6L 4 rotor engine for 500hp race form.

 

Crentix- what do you do for Mazda?

 

When will the last year RX8 be out ~ ??

 

3.2 liter? Don't you mean 1.6 liters?

If this is true, then maybe my guess was correct (increasing the rotor width to 90 mm). Hopefully it's not the last year RX-8, whenever that is .

Oh yeah, I have a pic of an FD with an RX-8 front end. Looks weird, but it could be the future .

P.S. - This pic was adapated from the RX-7 Club.

 

Motoring magazine has reported those numbers in bold 6-9 months ago (don't know if this particular article is that old as well). But no one else has confirmed the supercharger rumor or those numbers in particular.

This is exciting but old news. And since no one else has confirmed such lofty figures from a supercharged factory RX-8, I am beginning to doubt the accuracy of the Motoring article.

-Mr. Wigggles