Rotary engines ARE relatively fragile, and they DEFINITELY need MUCH more care/attention then, say the inline-6 Supra or a LS1. Not disputing that at all - that's not my argument here.

It's comments like this that spreads misinformation around the internet. An improperly tuned, 'low 200hp' rotary would probably not last past one race.

Comments like the above would give newbs the impression that 'Hey! As long as I don't try to make too much hp, I'll be ok! (wink)'.

Daniel

 

I think that the guy who originally posted this thread got a little more than he bargained for! LMAO!

 

So what 'empirical evidence' do you have to suggest that 'around' two hundred hp is what a 'reliable' rotary makes?

You've just stated above what every seasoned rotary enthusiast knows - that it takes alot more thought to build a high performance rotary then others.

The post began with someone with a untuned ecu trying to figure out why their engine blew. It had nothing to do with how much hp they made (and judging by his list of mods, it would have been on the low side - definitely within your 200hp range, tuned or not).

You made a statement that 200hp rotaries are more reliable then higher-output rotaries. Back it up with your empirical evidence, not with generalizations that any knowledgable rotary enthusiast should know.

 

Thank you!

 

back to the topic at hand....


this exact circumstance is why NO ONE SHOULD BE MAIL ORDER TUNING THEIR CAR.

you can NOT buy a pfc and plug and go....Ive dealt with the most respected shops in the country that do mail order tuning in the past. I got fucked every single time.

I had detonation each time...even though it was supposedly tuned rich (it wasnt...it was set up for non seq when i was sequential)

you should NOT buy a pfc without a commander....that is the only instrument that tells you at all what the hell the tuner did...unless you get a datalogit.

you cant soup up these cars unless you spend the money to do it right. simple fact. I had to learn the hard way too. we all did.

in your signature it said you were running fouled plugs???????????????????????????????????????

that is a sign of a big problem right there...if your plugs were white they are LEAN...if black...RICH...either way you can doom your motor.


Im sorry...I wish you luck with your future car.

For most college students...the FD is not a good car. If he or she has the cash...and a garage...it will work out...

i wish i had the car when i was in college...but Im glad I didnt...even if it would have gotten me laid.


j

 

that pointless argument about rotaries that is going on is as stale and boring....there is no use going over any of it anymore...do a search...the topic has been hashed out by people with a lot more experience than any of us.

its a waste of breath...and typing time.


later


j

 

well my FD lasted 87k miles with many bolts on and about 300rwhp..................... my 89 GTU that i bought from the second owner had a reman put in at 62k. reliability is all in the owner's hands. you can't blame an engine that breaks because the owner has no idea what they are doing. i agree a stock car is more reliable than a modded car that the person has no idea what they are doing but generally speaking all of my friends car with 400+ hp are reliable and driven alot

 

Well, getting a little OT, but here's a message posted by someone who races SCCA talking about sometime saying how crappy rotary engine are:

 

reliability is a relative term. only in the world of rotaries is going 87k miles before a rebuild considered a very durable engine. there are cars out there that make that much power, that'll easily run for over twice that number of miles. anyway back to the blown motor thing, was the pfc tuned for larger injectors? cause if it was, and he was running stock injectors that could be the culprit. also could all the stand-alone ecu's everyone uses be causing a lot of blown engines? there are a lot of failsafes in the stock ecu which may not be accounted for in all the ems units. there are people that have been tuned to absolute perfection yet have still blown their engines.

 

Right on man!!!!!!!!!!!!!!!!

 

Lets do the proven list for the middle to low 300 hp range:

Intake: 250
Intercooler: 700-1200
DP: 200
MP: 150
Cat Back: 400
ECU: 500

Total: 2200-2700

You being own3d: Priceless

 

I guess you'd better go kick Jo's ***
Then again, I'm the one that told him it shouldn'd be a problem for you to use it since he told me you also have a ported motor, with similiar mods as him, AND he said you were gonna run 13-14lbs.

He told me he had leaned it out, and was STILL getting A/F ratios of mid to high 11s throughout the RPM range on a wideband on a dyno.

Using someone else's ECU with similiar mods is no different than using someone else's maps. I told him to make sure you check your O2 voltage, though.

Question: WHO rebuilt your engine? Popping the engine with the PFC could be just a coincidence. I feel for ya man

 

this list isn't representative of everyone though. a lot of people go w/ the pfc, that's $1300. larger secondaries, $300 or so, fuel pump $100. then people usually need a new clutch, and maybe a new flywheel, that's $900 for clutch/fw combo. then the reliability mod's that everyone gets, rad- $400, silicone hoses-$100, ast-$150, etc. then there's just the general upkeep stuff like fuel filter $100, fpd- $100, sending out injectors to be cleaned-$100, new fluids- coolant, tranny/diff oil, engine oil- $100, new plugs wires- $80. add another grand or so if you want a shop to install all this stuff. so let's say you just bought a bone stock fd and you want to get a good running, reliable 300 hp, $5k+ is about right. that's all drivetrain stuff too, that doesn't even include the fact that motor mounts usually need changing, bushings and shocks are shot, interior needs refurbishing, etc. there's no question that it costs a lot just to mildly modify our cars.

 

will you guys PLEASE stop argueing with tbielobockie
hes just here to talk about some BS that he really doesnt know anything about, aside from rumors and horror stories hes heard on the internet, and through the grapevine.

Hes a troll, and needs to be treated like one,
his only reason for being here is to trash talk, so dont give him the satisfaction.

We all know there are PLENTY of fine running rotaries out there, and we also know that mazda put some less than satisfactory parts/materials in the FD(which is why alot of engines blow).
ANNNDDDD we know that you can make them reliable it you just do it right.

Thats all that needs to be said so lets end it here.

 

so how much do you want to sell your car for? i've been looking at these forums for about a year now just reading and studying all about rx-7's and rotary engines and i'm so ready to buy one it's not even funny.

 

oh yea just pm me if you want or if you haven't already sold it.

 

Right on man! I did the same that you did. . .researched the car for a long time before i felt confident about buying one.

Even with allllll the horror stories you dont take into account all the people that just love their cars. There are so many stories of love and joy when people talk about their rotary powered cars. Isnt it funny when people really like their cars and take the time and money to do everything right, their cars are reliable and they love them so much?? I love my FD sooo much. Yeah yeah yeah im on my second engine but the car had 86,xxx miles so its expected. All this crap this guy is saying about rotaries is revelant to all this. When people take the time to really learn about what they are doing....and take the time and money to do it right are less likley to have their engine blow on them. So let this noobie ramble on about how our engines are not reliable....if he owns a rotary he would know why we put up with them

later

bobby

 

i dunno my FD 416rwhp @ 13psi on regular old 93 octane..... i have the sheet to prove it

 

Since you're 16 1/2 years old, I assume you taken some science classes. Here is your statement, in case you've forgotten:

So what' this formula to calculate exactly how much life I can expect of modified rotary? I'd really like to know, so I can plan my future upgrade path. Where's your empirical evidence?

I'm looking for numbers - such as 'of 347 FDs that produce XXX number of wheel hp and suffered catastrophic engine failure, 240 were because of..." Scientists and researchers would be shunned like the plague if they ran around making statements with no numbers to support thier theories.

All you've done above is make a ultra-simplistic statement, based on no numbers (or empirical evidence). In fact you've realized you now have to distinguish between FD and FCs. Care to add any other disclaimers/qualifiers to your original, revolutionary/earth-shaking statement?

Well constructed sentences and use of fancy words do little except perfume over half-baked ideas.

Which leaves your inflamatory statement:

Given that the original topic was of a FD owner trying to determine why they blew thier motor- after doing what they thought was the correct - I can only imagine a question like this is meant to incite another rotary vs. piston debate.

It's also known as trolling. If you don't have anything meaningful to say to someone who's short on funds and may not be able to keep their pride and joy - don't.

Not sure who's worse - you, or the rotary pundits that scream 'blasphemy' every time somebody puts a V8 or SR20 in their RX7.

Daniel

 

try reading my post

This one takes the cake. Sell your **** elsewhere man, nobody here is buying it.

Sorry for whoring the thread, should've seen the troll alert much sooner.

 

oh yeah it would have been but my boost controller was still learning the boost curve since it was installed the day before we dyno'd

 

Actually tbielobockie has some merit to his statement...

Thermodynamically work is a function of specific volume and fundemental thermodymamics.

W = dV

There is also a well known adage in engineering:

"A candle that burns twice as bright, burns half as long."

This is a direct statement about efficiency in any system.

Sure gobs of hp can be extracted from a "candle" but not without compromising something else...in this case reliability and durability.

It does not matter what system you are talking about...more pressure, more fuel/air requires closer and closer functional tolerances and equally intolerances by the system to process deviation.

If you size a blower for instance, for a certain static pressure or rpm there will be an rpm specified as terminal rpm limit (and this is included whenever ordering blowers). If this limit is breached, the fan will literally fly in pieces (out of balance). A great example of this relationship are the FD turbochargers, sure they will put out 17psi in some cases but for how long?

In the end...there is not replacement for displacement.

 

well my car was put together to be reliable.... it cost alot but my car is reliable. i have broken lots of driveline parts from drag racing but that's to be expected. the engine is the MOST RELIABLE PART OF MY CAR !

 

Vosko, what's with your sinsusoidal torque curve? Thats one of the roughest power curves I've ever seen.

Cover8: Thanks for stating the obvious. Of course if you take ANYTHING, and apply more stress to it, it won't last as long. As far as no replacement for displacement, that's still one of the stupidest phrases I've heard. Sure, there are tons of replacement for displacement... like forced induction, nitrous, free flowing intake/exhaust, etc. Anything that will increase air flow can give you more power, including displacement.

 

I expect that there is some merit that the NA rotary is very reliable vs. boosted. I bought a '86 GXL with 44,000 miles on it and proceeded to drive it 7000rpm daily until it finally let go at 135,000 miles. That was with nothing but regular maintenance. I bet if you could get the stats from Mazda showing how many remans are sold to FD owners vs. FC/FB you would have some evidence. Sure, you may be able to get mega hp out of a boosted rotary but it will cost you to get it set up right and won't tolerate error. You will get well beyond the stresses the REW motor was designed for. This is why I remain relatively stock using the stock ECU. I need to spend the time to fully understand all the parameters of the PFC relative to the stock settings before I go this route. BTW - my FC motor would have lasted much longer but I blew one of the heater hoses at WOT and got the motor hot. It didn't last a month or so past that. I also owned a '79 SA which I also put well beyond 100,000. Now of course it is much more fun to have all the power the FD has vs the FC\FB\SA. I just don't count on it lasting as long...