TT Rx7
Originally posted by rotary sports
You're contradicting yourself there. Read it again.
You're contradicting yourself there. Read it again.
It's not necessarily a problem. You'll see later.
EGR does play a big role in controlling emissions, no argument there but the overlap found on the pre-Renesis engines has nothing to do with EGR. Many people have already argued about this but the simple fact of this is that Mazda didn't engineer this overlap to happen. If they could have eliminated it like they did with the Renesis, they would have, but obviously the modification couldn't be done without a complete redesign of the engine.
To keep things simple, EGR simply recirculates some spent gases and introduces it with the fresh A/F mixture to keep hydrocarbon emissions down. Naturally, spent gases are harder to ignite and results into something similar to increasing the octane in fuel. However in the earlier rotary engines, too much spent gases would re-enter the combustion chamber and makes it much more difficult to ignite the intake charge even with the dual spark plugs. This is why Mazda at the time had no other choice but to enrich the incoming A/F mixture with a higher fuel content to help with a more complete combustion.
With the intake and exhaust ports now on the side, Mazda has more play into how they wish to tune their new engine. Sure, they can design it with a lot or less or no overlap now and this opens up the field of play a lot more. I'm certain that the RX-8 will be the start of a new class of rotaries to come.
... the main reason why Mazda moved the exhaust port is due to emissions. The FD got killed in the US in 96 because of it(can't comply with OBD-stuff) and I suspected the same reason it got killed in Japan recently.
Back to the topic. I have found a very good article about the Renesis in R&T June 01. Read it and come back again. In short, moving the exhaust port to the side plates PROMOTES spent exhaust gases back to suction cycle to reduce emission, just like an EGR valve. Why you ask ? Because the side exhaust traps the exhaust gases instead of letting all go with the peripheral port.
"Unlike previous mass-production rotary engines, which employed peripheral exhaust ports and side intake ports,the naturally aspirated RENESIS has intake and exhaust ports in the side housings. This configuration eliminates overlap between the opening of the intake and exhaust ports, enhancing combustion efficiency. The intake ports are 30% larger and their timing has been changed to make them open sooner than in previous designs. Moreover, the exhaust ports open later, resulting in a longer power (expansion) stroke and providing radically improved heat efficiency."
"The increased heat efficiency resulting from zero overlap between the opening of the intake and exhaust ports makes it possible for the RENESIS to run on a leaner fuel mixture than conventional rotary engines. When idling, the RENESIS consumes 40% less fuel than the current production rotary engine."
On top of this improvement, the increased number of ports, lightened components, higher compression just to name a few of many changes with this awesome new engine contributes to a much flatter torque curve and power output that rivals that of the OEM FD TT. To make a long story short, the increased breathing ability = more power output.
Think again dude. You only had your FD for 5 months, I'd suspected it's only 5 days.
And what current design has very little room for adding a turbo ? Care to explain more ? The FD and RX8 is very similar in size and the Renesis is slightly more compact than the 13BREW.
Hopefully this helps clarify a few points.
Originally posted by carrrnuttt
This clearly shows how made-up your claims are.
Take a gander:

Looks like Honda copied from itself
.
As for the rest of the thread, all you guys are doing is making calpilot7's trolling legitimate. Everybody was on the same track (S2000 slower than FD), until calpilot7's remarks. Don't you guys get it? calpilot7. Probably a seven driver himself.
This clearly shows how made-up your claims are.
Take a gander:
Looks like Honda copied from itself
.As for the rest of the thread, all you guys are doing is making calpilot7's trolling legitimate. Everybody was on the same track (S2000 slower than FD), until calpilot7's remarks. Don't you guys get it? calpilot7. Probably a seven driver himself.
In case you didn't see this :
What exactly triggered Honda's decision to release the S2000 after 29 years.
Probably because of Toyota (Corolla), which had an extensive history of high revving motors (with some decent power).
Originally posted by Hyper-X
I had the FC for 4 years, the FD for 5 months.
I had the FC for 4 years, the FD for 5 months.
You know what they say sometimes, once a Mazda, Nissan, Toyota or Honda fan, always a Mazda, Nissan, Toyota or Honda fan.
Let's not let this get out of hand guys, we're all sports car enthusiasts here
. Well, with the exception of Calpilot7 the oxygen thief, who I doubt owns a 7 and prolly rides a 70cc moped around town.
. Well, with the exception of Calpilot7 the oxygen thief, who I doubt owns a 7 and prolly rides a 70cc moped around town.
Originally posted by SHIRI
Well I'm surprised, I would think that you would actually back up the Fx a little more since you've had 2.
Well I'm surprised, I would think that you would actually back up the Fx a little more since you've had 2.
The info I've provided about the RX7/RX8 are facts, I even posted a link so anyone can read plus I've even cut and paste the relevant section for those who are lazy to read the entire web page.
I've not seen any facts from any of the "trolls" so far. By the definition of troll, it means those who talk crap and have nothing better to do but call people names and not provide any significant source of facts. If you question my comments, I've posted links so you can read for yourselves. I've proved that one person doesn't know anything about a car except for pulling "reliable information" out of his head and not using known facts. I've even referenced a very well respected tuner for RX7's and IS300's and they are open to any inquires that you may have.
Correct me if I'm wrong, but you yourself was unsure about why the 1.3 rotary had bad fuel economy?
Posted by SHIRI "Oh yeah, that was another thing I hated about the FD, fuel consumption, why is it so bad for a 1.3 lt engine?????"
I've went through a simple and easy to understand explanation as to the cause of the high fuel consumption. Like I said earlier, if you don't believe me that's fine. Do a search on the web yourself, email Mazda or call a respected tuner that works on RX7 engines. It doesn't matter who you believe in my mind, but a known fact cannot be disputed.
For what it's worth, I don't think you have any room to state how facts are backed up especially when your theory regarding who started the high revving motor scene in Japan was proven wrong to begin with. Since I wasn't aware of who the pioneer of the Japanese high revving engines were, I kept quiet then I think carrrnuttt posted that old article about the first "S" models. I'll admit, you almost had me there.
The digital dash layout of the AE86 that you posted is new to me as I've never seen that layout here. Around that same timeframe, Chrysler came out with the Laser that also had some kind of digital dash also, but I can't recall what it looks like in detail. For me, that was the first production car I've seen to have such an instrumentation and the name "Laser" at the time stuck in my mind.
BTW SHIRI, what do you drive? Have you really worked on a rotary engine before or owned an RX7 before? Just curious.


