DARKMAZ8

meh, I'm fine with the 1.3L. Adding a turbo would weigh less than another rotor(or 2)

Glyphon

it bugs me when people say the engine in the FD was unreliable because of the turbos. The engine itself is perfectly fine, with the turbos and all. the "problem" that the FD had was a whole bunch of mooks went out and tried to modify them without having the slightest clue as to what they were doing and ended up detonating them. after enough of these morons kill their engines, the car ends up with a perceived reliability problem.

it still happens to this day. not too long ago, i read a thread on the 7 forum about some moron asking if he damaged his engine because he was out drifting his FD and ran out of oil.

tuj

There are 3 options for making the rotary make more power:

FI: this is a pretty good option, except that people will start mucking around with the boost levels, ignore proper enrichment, detonate, blow an apex seal, and blame Mazda for making an unreliable engine. Probably more realistic to do FI safe nowdays than when they made the FD3S thanks to more computer control rather than a vacuum line mess. However, this option is the cheapest for Mazda. The power potential in the side-port configuration may be HIGHER than peripheral port exhaust motors since the side-port motor has zero overlap. This would result in reduced exhaust gas velocity, slowing spool, but allows for more efficient pressurization of the chamber. But without lower compression rotors, detonation is likely to be an issue.

2 rotor, larger displacement: not so good due to flame propagation issues. The only dimension that would change would be the rotor width. This still requires all new rotors, housings, and at the very least, enlarged ports on the end and center housings. Its likely that emissions would be worse, as would fuel consumption.

3 rotor: Mazda has experience with this in the 20b, which had side intake ports. They would have to develop a new intermediate housing to accomodate the center rotor's larger ports (the current ports on the end housings are bigger than the center housing ports). The two-piece e-shaft doesn't seem to be such a big deal as they've used it on the Cosmo for a while. This option is the second cheapest for Mazda, and removes the potential for large power gains that FI has, alleviating many of the reliability concerns. There's plenty of room to fit a 3-rotor in the 8, so that's not a big issue.

A fourth option is a 3-rotor or 4-rotor with reduced displacement per rotor. This isn't a bad idea, in the sense that smaller rotors would yield improved fuel economy and less stress on the multi-piece e-shaft. But, it would require all new housings and rotors.

tuj

Controlling the turbo system with a maze of vacuum lines prone to cracking in the high underhood temps didn't help either.

Nemesis8

iTrader: (3)

Yep, that is correct. I know an FD owner is Seattle that had a perfectly running single turbo '93. He just could not stand tinkering with the boost, and turned it up on Highway 161 thius year and blew the apex seal from running to lean - detonation will kill you.

LucasET

Kinda what I was getting at in post #7.

fullsmoke

Yep... Vacuum leaks are a b*tch...

l008com

Based on the fact that all the other mazdaspeed cars are turbo, and especially based on the fact that the mazdaspeed 6 has WAY more power than the rx8, I'd assume a turbo probably is coming. I'd be happy with 300 hp and a few more mpg. Regarding sales, i LIKE being the only kid on the block with an rx8...

namasan

BK motorsports ALMS car...3rotor. Not sure how much power it's putting out, but that thing sounded amazing on the track.

zoom44

Renesis is only used for marketign - it is not a Renesis based 3rotor.

KYLiquid

correct the ONLY renesis engine you can get is in the RX8 and the Mazda Star serries race cars. there is no turbo version made by mazda and no 3 rotor version.

Its the same thing as the chevy impala in NASCAR, its not really a chevy impala, nor is it a FWD v6....but that doesnt matter, cause durring the race you keep hearing the words "Chevy Impala" ect

l008com

UGH

tuj

Difficult to say. The first Mazdaspeed car was the Protege, done by Calloway. After that they brought the development in-house and did the MS MX-5 Miata, which Mazda insiders swore for YEARS would never get a turbo (of course it did take nearly 15 years and will only be around for a few years). Now we've got a MS6 and rumors of a MS3, both turbocharged.

So the general sentiment against turbos at Mazda seems to have gone away, however the rotary is a different beast. The MS cars are equipped with knock sensors and special ECU tuning, and are in general tuned quite conservatively. But even with an FI rotary mildly tuned, one ping can still blow an apex seal. The knock sensor will hear it, but by then its too late. Maybe Mazda would do it if they could use 3mm seals and lower compression rotors. They almost certainly will not use FI on the Renesis as it is now. Heck, even the MS Miata motor has lower compression and stronger internals and that motor had already been proven to handle boost well in stock form!

But the one thing they can't afford is another FD3S-like debacle of warranty claims and blown engines. That's why they're watching the engines so closely. My take is that there probably was plans to release the MS RX-8 with FI earlier, but concerns over the longevity of the powerplant pushed it back.

staticlag

I wonder if anyone has ever turbocharged a lawnmower?

That would be pretty sweet....

Rotarian_SC

Of course people have turbocharged lawnmowers :p

The problem with a 3 Rotor is really its weight. Maybe if Mazda could figure out how to build aluminum rotaries then we would see another 3 rotor. There's also a problem with increasing 2 rotor displacement, which is igniting the charge. I'm betting we'll either see a supercharged rotary (turbos seem to be running too hot, especially when some of these engines have been running too hot without turbos) or basically a factory ported Renisis with better intake, exhuast, headers, etc.

Nemesis8

iTrader: (3)

Atkins Rotary has a rotary powered lawnmower. I think there is a vid on their website.

No More Oldsmobiles

Factory turbo would be nice, but I think some people are expecting too much from Mazda.
Stock Miata used to be 142 hp. MazdaSpeed turbo Miata, 178. New MX-5 Miata, 170 hp, no turbo.

mjd

I have a feeling I'm going to end up with a 350Z if I want more power. All there seem to be on here are rumors, and Mazda has remained totally tight lipped about a possible MS rx-8. I know the rotary is quirky and it may take more time and R&D to get a higher power version right and reliable, but you would think they would have had something in the works right from the get go, and we have seen the supercharged 8 from Speed magazine. I'll admit I don't have a ton of patience and if there is not a MS 8 by the end of '06 or at least word of something the Z will be my next car.

rx8wannahave

Nice...thanks people, as always it's great learning more about the rotary.

OK...so, I say go with a 1L 3-rotor 300+ HP rotary...sounds fair? Come on Mazda...do something???

zoom44

why is that? you guys at JIC cant figure otu how to tune an engine properly? maybe ill just stay away from your products then

rotarygod

It's not the Atkins but it was a real production mower from the '70's.

http://www.rx7club.com/showthread.php?t=449488

drifter_d

ouch! zoom44, that was harsh! don't know 'bout their engine tuning, but the FLT-A2 coilovers work great for me.

l008com

Rotary lawn mower, I have a 6.5 HP go kart and I'd love to swap a rotary on it. But even more than that, i want a rotary outboard motor on the family speedboat. Seems like boats are perfect for rotaries :-D

therm8

http://www.freedom-motors.com/

(no, they're not French :p )

tuj

To add more fuel to the fire... Mazda sold the 13B-REW engine in the Eunos Cosmo (with slightly reduced hp) over 18 months before that engine was first used in the US, in the FD3S. Speculation is that they wanted to test the reliability of the 13B-REW (and derrivatives, like the 20B that also powered Cosmos). Perhaps the same is happening with the Renesis?