Fiero vs RX7 (Page 1/2) Csjag SEP 23, 07:28 AM I saw an ad for an 85 RX7 yesterday on craigslist that looked nice so I looked up the specs on the RX7. It only had 101hp and 0 to 60 was over 10 seconds. I was surprised' and it puts my 85 Fiero 2M4 and 85 GT in a different light to me. carnut122 SEP 23, 07:35 PM Did it also mention the need for new rotor seals every 50,000 miles? Csjag SEP 23, 08:36 PM quote Originally posted by carnut122: Did it also mention the need for new rotor seals every 50,000 miles? I remember reading that when they were new and also that they got lousy gas mileage. jaskispyder SEP 24, 10:30 AM quote Originally posted by Csjag: I saw an ad for an 85 RX7 yesterday on craigslist that looked nice so I looked up the specs on the RX7. It only had 101hp and 0 to 60 was over 10 seconds. I was surprised' and it puts my 85 Fiero 2M4 and 85 GT in a different light to me. Yup, general HP numbers were pretty low when the Fiero came out, but that was the times.... thesameguy SEP 24, 03:00 PM An '85 RX7 will either be a carb'ed 1.1l or an injected 1.3l, but of course since rotaries have two combustion cycles per rotor per rotation (versus a reciprocating engine's one per four) a lot of folks "weight" the rotary as double it's actual displacement... ie, a 1.1l Mazda 12A has characteristics of a 2.2l boinger. Until fairly recently, neither power output nor fuel economy of a rotary compared terribly unfavorably to reciprocating engines - the 12A in an '85 RX7 would make 115hp which is not dissimilar to a 110hp 2.5l Iron Duke. The '85 13B would make 135hp, splitting the difference between a 2.5l Duke and 2.8l 60V6 nicely. Fuel economy for both motors was low 20s in the city and high 20s on the highway, which was pretty typical for sporty cars in the '80s - though maybe slightly low. OTOH, these engines weigh nothing - 150lbs to make 135hp is a benefit to itself, and rotaries offer very, very flat torque delivery making them exceptionally drivable for their size, displacement, and weight. Driving a rotary is not like driving a reciprocating engine - the torque peak and petering power delivery isn't nearly as dramatic. The small torque numbers you'll see on a dyno chart really don't tell the story, since they make more of it more often than a conventional engine. The result is a very useful, very wide power band. Especially in the context of the '80s, driving a rotary was a kind of crazy feeling. As for their apex seals, 50,000 miles is quite an exaggeration. While apex seals *can* fail early, they'll typically last upwards of 100k - unless you do lot of short drives or run too much boost. But rotaries have only a handful of moving parts (like, three) so they are far less complicated to rebuild than conventional engines. Rebuilding a rotary in its entirely is generally easier than a head gasket on a reciprocating engine. Unfortunately, with 1.3l being out of production for 20 years and 1.1l for 30, finding replacement housings can be a real problem - so you may not want to even tackle the job. I understand the Renesis (RX8) cured some of these issues, but I'm ten years out of touch on rotaries, so I'm not sure to what degree. If you've never driven a rotary and you're any sort of gearhead, you owe it to yourself to give it a go. 2.5 SEP 24, 03:35 PM quote Originally posted by jaskispyder: Yup, general HP numbers were pretty low when the Fiero came out, but that was the times.... Yep 1985 Mustang: The 2.3 liter inline 4 cylinder remained at 88 horsepower, while the 3.8 liter V6 provided 120 hp Camaro: 2.5L 88 hp I4, 2.8L 135 hp V6 (Same as Fiero, Yet weighed something like 500lbs more than Fiero.) Fiero84Freak SEP 24, 10:10 PM I think the biggest issue is just finding one - really either generation RX7 pre-FD - that hasn't been ragged completely out. Sure there are some good FC examples out there, but most of the time they tend to be convertibles as so many coupes have been run ragged. And the exorbitant price hikes of the rather rare FD in the United States means that finding one that is unmolested is possible, but more like $10,000-$20,000 possible depending on mileage. It's a bit hard for even enthusiasts to drop nearly 20 Gs on a car that can be upwards of 20 years old. I have driven a ton of FCs. I've never a 1st gen SA, nor the beloved FD (although I dated a girl in high school for a bit that had a silver non-turbo FD). There's a ton of SAs and FCs in the world though, I think together they combined for something like 750,000 total units world-wide produced. thesameguy SEP 24, 11:25 PM I've had an SA and an FB, and drove a few FDs (with the intention of buying one). I've only driven one or two FCs - I never really cared for them as they added a ton of weight and not much power. My SA was my favorite - mild engine work, headers, exhaust, suspension, sticky tires, grippy seats (and harnesses to keep you there). It was like a little, slow race car and was just as happy drifting a corner as sticking it. A rotary nut friend of mine says the FC GTUs have a lot of that in them, but they are so very, very rare these days! The RX8 is also quite a blast - I keep thinking I'm gonna buy an RX8 R3 but it never actually happens. I need to stop thinking about them before I start shopping. Fiero84Freak SEP 25, 11:11 AM I'll be honest I've heavily considered an RX8 as just a fun toy car. With them having a readily accessible rear seat it would also be quite practical. I have seen sub six figure mileage cars go for around $5,000, which honestly I thought I would NEVER see since I assumed so many rotary fans would be all over the 8s. The big turn-off for me though is I've noticed that a mess load of RX8s received new engines at relatively low mileage - like I've seen some with only 30,000 miles have new engines in them. I'm no RX8 expert or enthusiast by any means but if what I've read is correct I'm guessing that there was a big recall on the RX8s and many received new engines? That's good and all I guess, but seems rather concerning. Still though, the low cost of getting into one seems rather alluring. thesameguy SEP 25, 03:03 PM Rotaries have different care needs than piston engines, and unfortunately Mazda never really represented those needs to their customers for fear of scaring them off. Because rotaries inject a small amount of oil into the combustion chambers keeping oil full is a task that must be carried out reliably, and because rotaries run very rich when cold they don't respond well to start-stop-start scenarios or short drives. Both are very hard on the apex seals and with continued abuse those seals will fail. The first few years of the Renesis motors were tuned for, how shall I say, a more intelligent customer base and some number of engines failed early, necessitating replacement. In order to ease potential customers' minds, Mazda extended the warranty on the -'08 (IIRC) cars - which also gave people a free license to abuse the crap out of them. That's why you tend to see early cars with low-mile engine replacements - people scrambled to get their <100k engines replaced by whatever means necessary. In '09 (again, IIRC), they adjusted some of the tuning to make them a little more resistant to this type of abuse and restored the warranty to its original terms. Since The Car is an '09+ RX8 R3, it's never really affected me. In any case, there is nothing more fragile about the Renesis than any of the engines that came before - and it takes only a modicum of care to keep one happy. Buying used, you always gotta wonder if the PO abused the mill, but you need to do that with any car. It probably just calls for a little more careful selection when shopping. They are great cars and amongst the best drives to be had in the last ten years. While they may seem down on power on paper, real world performance is top notch. They are the scalpel to the 350Z's hammer and - IMHO - a superior choice to a BRZ/FRS (though they're certainly nice too!)