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although i love the R26B at least as much as any other member your comparison is still a bit unfair.it is a very radical full race engine.(good power coming after 7500 even with variable length intakes and intake duration well beyond 400 degrees) a better comparison would be to a formula1 motor which actually puts beating on our favorite piece(800hp from 3liters of displacement)but as for an old tech ohv beating a rotary i dont think so.by the way the comparison of a dressed s2000 motor to the renesis is truly fascinating
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Originally posted by babylou I bet if 500 hp were easily achievable GM would go ahead and do it.
i seriously doubt they would go from 405hp to 500hp in one model. That doesnt mean they can't and many vette owners tune their cars with basic mods that bring them close to 475-480 hp.
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'99 Mazda Protege
Upgrading to RX-8 in a year.
It would not be fair to compare the 4-rotor R26B against ultra-expensive 900hp Formula 1 car engines. IndyCar and Sportscar engines are relatively cheap.
A rotary racing engine cannot be fully stressed due to its inherent low stiffness. An engine support frame is required to transfer chassis loads, which increases weight and size. This is another rotary disadvantage.
A V-type piston racing engine (V6, V8, V10, V12) has high torsional stiffness and acts as a fully stressed member of the chassis. It is bolted directly to the tub and gearbox.
Originally posted by Supercharger It would not be fair to compare the 4-rotor R26B against ultra-expensive 900hp Formula 1 car engines.
uh, not really... how can you compare an engine which has to run for tens of thousands of kilometers over 24 hours straight to a GP engine which is tuned to last somewhere in the range of 350-400kms, with (in current rules) a fresh engine for both qualifying and the race???
it would in fact be most fair to compare it to Judd enduro V10's, the newest Audi/Panoz Turbo V8's, or other long-run race engines, like in the Deutche Tourenwagon Masters... don't they only get like 2 or 3 engines for the whole year?? anyways, my point is the level of tune, not to mention the basic function of the engines is quite different between enduro sports cars and GP karts.
ah, yes... but they're still allowed to tear it down and replace a faulty part (like a broken valve: BMW, in Austria, i think...??) with the stewards breathing down your neck, so yeah, they're definitely getting closer to the eventual "one engine per weekend" rule, or even one engine per multiple weekends (that'd be a nightmare to police).
It's amusing seeing everyone calling pushrods "ancient tech"... What would that make OHC models? "Prehistorical tech"? One thing that was not mentioned in this debate were the engine's fuel efficiency, which also takes gearing into consideration. An LS1 6MT F-body can get in excess of 30mpg on the highway on a long trip, and an LS6 can probably get mid-20s at least under the same conditions (not sure what the exact specs are). Now, for an engine that's more than four times the size of the Renesis and puts out half again the power and two and a half times the torque of that motor, its fuel efficiency, when compared to the 1.3L rotary, is impressive.
As far as the GM 3.8 OHV V6 that was mentioned earlier goes, that engine really was meant to be boosted. From the Buick GN of the past to the Grand Prix GTP of the present, the engine really only sees anything close to its full potential when being force fed air. Any comparisons made should be made using the L67 stats, and I think it would be interesting to compare it to a rotary that breathes an equal amount of air.
with all of this talk, it makes one wonder...what would a new "super rotary" (by this i mean 4 rotor or like, races-that-you-guys-are-talking-about competetive) be like?
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Originally posted by P00Man with all of this talk, it makes one wonder...what would a new "super rotary" (by this i mean 4 rotor or like, races-that-you-guys-are-talking-about competetive) be like?
Originally posted by babylou I was thinking that a comparison to a comparable power engine would be good. Here is a comparison with the "super high tech" Honda S2000 engine (F20C):
.................................................R enesis Specs...........................F20C Specs
Dressed Weight (lbs).............................303............. ..........................326
Max Power (hp)............................250 @ 8,500 rpm....................240 @ 8,300 rpm
Power/Weight (hp/lbs)..........................0.83................ ......................0.74
Specific Power (hp/lbs/1000 rpm)...........0.097.............................. ......0.089
Max Torque...................................159 @ 5,500.........................153 @ 7,500
Torque/Weight (ft-lbs/lbs)......................0.52.................... ..................0.47
It seems to me that the S2000 engine does not look as impressive as it used to or the Renesis looks a real sweet. Of course there are a few other metrics that I have not compared that the Renesis would be strong or weak in because I do not have the data. Things like cost, fuel efficiency, CG, size, durability, NVH, reliability, emmissions, etc.
They're actually pretty close. Remember that F20C engine is 4 years old!! Mazda is just now catching up.
They're actually pretty close. Remember that F20C engine is 4 years old!! Mazda is just now catching up.
:p the RENESIS concept is left overs from 1995... not to mention it's been in the R+D refinement process for something like 3 (??) years... not to mention that the F20C was the top of the heap, and with the RENESIS this good, i wouldn't say that Mazda's "catching up" now.
Re: Re: Re: Re: Rotary loses vs. OHV Piston Engine?
Quote:
Originally posted by wakeech
:p the RENESIS concept is left overs from 1995... not to mention it's been in the R+D refinement process for something like 3 (??) years... not to mention that the F20C was the top of the heap, and with the RENESIS this good, i wouldn't say that Mazda's "catching up" now.
IMHO, the rotary still lags behind Honda in terms of overall efficiency (i.e. power, handling, braking, etc. taking into account fuel economy and emissions). See the attached thread where I posted some metrics that illuatrated this.
The S2000 came out in 1999 and I'm not sure how long it was in R&D, but I do know Honda, like Mazda takes a pretty long time to bring a model to market (which is a good thing usually). I know they tend to be pretty tight-lipped about future models as well. I think the S2000 is the last VTEC model for Honda as they are transtioning their vehicles to I-VTEC, which is more efficient than the prior generation VTEC. There have also been recent rumors about the new S2000 (possibly called the S2200) being I-VTEC and being unveiled at either the Tokyo or Detroit auto shows.
Still, I hope Mazda makes significant strides in improving the rotary's efficiency as they and Honda seem to be the only major manufactures focused on lightweight (i.e. smallest displacement to produce a given level of power) in their sporty vehicles.
considering the clear disadvantage the rotary has had with research compared to the billions (probably) spent on piston engines, it's no surprise that they are more efficient/powerful.
Considering the same scenario, and the revolution in the rotary world that the Renesis is, if double the money was put into rotary design and research as is present, it would easily surpass most piston engines maybe as fast as in 2 rotary generations.
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'99 Mazda Protege
Upgrading to RX-8 in a year.
Since Mazda seems to have group of pathological liars running the joint I have been forced to redo the calcs for the Renesis. Again! 260 hp (Mazda claimed "goal") to 250 (I have a brochure stating this 250 as SAE net) to 247 and now 238 even though it really appears to be closer to 225.
No one has mentioned engine vibration. This is one of the things I miss the most about my first-gen. Smooth as butter. You really notice when you've been driving a rotary beast for a long time, then take a recipicator out for a spin and wonder what all the racket is about. Something to be said for 3 moving parts that just spin.
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1985 RX-7 GSL-SE in 1986 red - donated to charity @ 255k miles
1998 Subaru Impreza 2.5RS - Green w/stock Rally-gold wheels(The Mythical Unicorn of Imprezas)
Originally posted by Keshav No one has mentioned engine vibration. This is one of the things I miss the most about my first-gen. Smooth as butter. You really notice when you've been driving a rotary beast for a long time, then take a recipicator out for a spin and wonder what all the racket is about. Something to be said for 3 moving parts that just spin.
I like the racket! To each his own I guess. One of the major reasons I bought the WRX rather than waiting for the EVO and paying a little more was the boxer rumble. The STi was still a couple months away and there was a long list, I think they just now caught up with demand. It's tough to find anything this side of a good ole V8 with such a sweet exhaust note.
Originally posted by IkeWRX I like the racket! To each his own I guess. One of the major reasons I bought the WRX rather than waiting for the EVO and paying a little more was the boxer rumble. The STi was still a couple months away and there was a long list, I think they just now caught up with demand. It's tough to find anything this side of a good ole V8 with such a sweet exhaust note.
There is also something to be said about 19.5 pounds of boost whistling like a missle.
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2003 Rally Red Mitsubishi Lancer Evolution VIII
1999 Honda Civic LX Sedan (Daily Pothole Absorber and Thief Avoider)
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