Racer X-8

OK, all you previous RX owners!

We, who have never even driven a rotary-powered car need your advice, now more than ever!

Take me, for instance. You see in my sig that I have been driving piston poppers with HP in the mid to low 100 range.

When I first get in that RX-8, what am I gonna experience and what am I gonna wish I knew?

Many thanks in advance for all your help!

StealthTL

iTrader: (1)

The only advice I can think of is due to the rotaries low end character - it needs more revs and a good slip of the clutch to get a decent launch. Where you might be used to 1100 revs to get you rolling, the rotary might need closer to 1500, plus a slower clutch release.The only other thing is the caution about not shutting it off when it is still cold - let it warm up or don't start it, it may flood.

3Rotor

Many of the issues that existed in previous rotaries look as though they have been addressed with the Renesis. However, here are a few things that come to mind:

1) Follow the break-in procedures as listed in the owner's manual
2) Check the engine oil at each fill up (top off if necessary)
3) Change the oil often (every 3000 miles or 3 months whichever comes first)
4) Once the engine is started, keep it running until it comes up to normal operating range (this prevents flooding) before turning off. In other words, don't start up the car, pull it out of the garage or driveway and shut it off - let it warm up.
5) Once it is broken-in, regularly take it into the upper Rev zone 6500 to 8500/9K
6) Go to lots of Rotary events and gatherings - rotaries are very social cars :D

Since this is a normally aspirated (NA) engine, we all should get many miles of trouble free driving with just routine, but diligent, maintenance - nothing extraordinary.

Racer X-8

3Rotor, do you recognize my brother's champoin SCCA NorPac GT2 RX-7 in my avatar? He's in Seattle. (I claim NO credits here, except I was in his pits twice now. Once at Mission, BC & once at Road Atlanta. Wish I could do it a lot more!!!:D!!!)

Anyway, both of you guys mention the flooding scenario. What is the reason of why this happens? A better understanding of this might further help in preventing it. That would also dilute the engine oil with gas, right?

3Rotor

I believe it is because of the fuel that is required at ignition. It "floods" the housings. Letting the car run to operating temperature burns the fuel. I know that one of the only ways to unflood the car is what is known as the "ATF trick" (do a search on the RX7club.com forum for more info), or to pull the plugs. I am not a wrencher - so everyone who wants to flame me on this topic needs to know that there are many more people out there who had a lot more hands on knowledge than I do.

I do not know your brother. But that is probably because I am a collector of show and unusual rotaries, versus a racer. My Cosmo will be Mazda's featured car at their booth at the Hot Import Nights Show in Seattle on the 19th of July.

ZoomZoomH

iTrader: (1)

I think the flood issue is more or less attributed to leaky fuel injectors due to old age.

I doubt it'll be a constant issue with the BRAND NEW RX-8

but do let the car warm up before shutting down, to reduce general wear on the engine.

and yes, you will need to slip the clutch a bit more to get the car rolling from a stop.

other than that, I think you will be too busy enjoying 9000rpms of driving fun :D

Boozehound

Just remember, don't be afraid to spend some time keeping the RPMs above where you would normally fear to tread with a conventional motor. Keep the revs low till it warms up and then knock yourself out.

neofreak

iTrader: (1)

89+ RX-7s (FC and FD) can be unflooded by pressing the accelerator to the floor and cranking the engine.

rpm_pwr

Flooding: Only really plagued the earlier (84-91) injected rotaries. My FD is shut off cold regularly and I run cold plugs. Maybe if it was snowing you might have some trouble but I certainly haven't in years of owning FD's.

Warm-up: Can't stress this enough though. Don't get into it until it's warmed up. By that I mean both the engine and gearbox.

Servicing: Don't muck about with oil changes. If you're taking it racing, change the oil before you go.

Carbon build-up: Once it's run in, thrash it. It's not only fun it's good for it. The most common cause of death in 20b's was carbon lock-up (or so I'm told). ie not through not being looked after, but by owner afraid to go over 3000rpm

-pete

BRx8

i've never had a rotary myself, but from reading alot of you rotary owner's posts, it seems you guys are telling us to beat on the car once it's warm and that it's good for the car?

ZoomZoomH

iTrader: (1)

AFTER the specified break-in period, that is

and then go ahead and have fun at 9k rpm :D

rpm_pwr

I know it's hard to beleive but it's true. Nobody ever wears apex seals down to nothing, so you're not reducing the life of the engine. You are however, burning off buildup in the engine.

-pete

CERAMICSEAL

My take on the flooding issue is this;
rotary engines have relatively low static compression and the worst area of flame propagation of all engines (very long and thin space where explosions are taking place.) This is the same reason that rotaries will probably never set the pace in the fuel economy department.
Rotor speed is a third of shaft speed.This means when cranking at 300 rpms, rotors are travelling at a leisurely 100 rpms.(Comparatively slow rate when put against pistons.)
Most of these flooding complaints started when rotaries became fuel injected. I've heard it said that when cranking, the management system (P.C.M.) doesn't know the difference between 300 and 100 cranking rpms and instead focuses on other data for cold start.
To make a long story short, starting is not a rotary's favorite thing to do.It functions well if all systems are up to certain standards including battery,state of tune etc.

Racer X-8

On startup, any throttle? Hot/warm/cold? I've always used the no-throttle-unless-it-doesn't-fire-up rule. And then, only just a tad. This rule still apply?

Also, how radical is the no-load throttle response? I'm imagining almost too radical with very little inertia to tame it down. I'm asking this mainly in terms of how hard is it to master the smooth dead-stop downtown takeoff from, say, a stoplight, like with a cop next to you. Also easy to stall if you don't maintain 1500rpm? Of course, answer this as though we 1st timers have mastered this stuff on piston poppers, OK? Any difference at all?

eccles

With a fly-by-wire throttle, I'd assume that the ECU will determine the correct aperture when cranking. Makes it hard to clear a flooded engine by flooring it while cranking, tho'.

Haze

I have read that this is a big problem with rotary powered cars more-so than in pistons. If the car is started, then it needs to be run up to operating temp before shut off to prevent the risk of carbon lock. Apparently, the carbon lock can be so bad that the car has to be towed to a mechanic for work to break the engine free again. The FAQ seems pretty good to me, but I am hardly a judge as this is my first rotary car as well, but I'll list the FAQ location since it seems to be good reading for all new rotary owners. It's Felix's Own Rotary FAQ at:

http://members.ij.net/mrmazda/cfaqmenu.html

-H

3Rotor

Actually, the main problem with 20Bs was a weak eccentric shaft in the first 1000 engines, referred to as A-Spec engines. I have a stock A-Spec motor in my Cosmo with over 87K miles on it (142K+ kms). Because it is stock and it hasn't been overboosted, it is still running. 20Bs developed a reputation when A-Spec engines (the first ones) were tweaked, proded and poked, then put under greater than stock boost (9.37 lbs). The e-shaft were subject to flex, and BANG there goes your center rotor/housing and obviously your motor. That isn't to say that someone being gentle on a rotary couldn't cause cause carbon build up, but carbon build-up isn't the primary reason that 20Bs have a reputation.

RotorGeek

Hey 3rotor

Where and how do you go about purchaseing a 3 rotor cosmo.?

3Rotor

Pure, unadultered, blind, damn LUCK!

87Turbo2owner

Nice forum you folks have here. I was just searching this morning to determine if the 8 was out yet. Sounds like not quite yet. Also sounds like it might be awhile before anyone who didn't preorder can actually get one.

To your question. As others have mentioned, at least in my 7, the low end is pretty weak. I actually have found that to get a decent launch in mine I have to rev it to around 4-5. It's always been a better road car than stop-light drag racer. Hopefully the 8 will have more umph down low. Of course I have to deal with turbo lag as well. Also, realize that at least in my 7 the engine revs to around 3,500 for approx 15 seconds when initally started. This is by design. As others have said when you start it for whatever reason let it run until it's warm before shutting it down. Finally, be ready to be driving down the road at 6,000 RPM's not realizing you need to shift. Why? Because the rotary doesn't vibrate or make the noise a piston engine does. My 7 has a buzzer 500 before the redline to indicate it's getting close because the engine is sooooo smoooooth you may not realize it. That's probably the thing that made me most fall in love with the rotary.

It should be encouraging that my 7 is 16 years old with 124K miles, and still has the original turbo charger. In fact though it has a number of minor eletrical problems at this point the engine is still as strong as a bull.

TerenceT

help me out

where does the carbon build up take place?

at the "cyclinder" wall? where the apex seal sweep thru at every turn?

or on the surface of the triagular rotor?

cuz how come 4000 rpm sweep doesn't take out carbon but 9000 rpm does??

ZoomZoomH

iTrader: (1)

the carbon buildup is used to be at the intake/exhaust ports.

spinning up the rotors will supposedly break up any kind of buildup and send it out to the exhaust.

however, with the less use of oil to lubricate the seal and the use of side exhaust ports, i suspect the carbon buildup situation won't be as severe as the old RX-7s were.

BOOSTD 7

Flooding isn't going to be an issue ... neither is carbon build up.

All you need to know is that buzzing sound is your shift indicator. Wait until you hear it to shift, or you might get a leaky head gasket.

RX7 Guy

The flooding difficulties associated with shutting cold engines down was caused by a software glitch in the Engine Control Units (ECU's) of early second generation (1986 & 1987) RX-7's. The problem isn't related to the rotary engine design in any way & is a non-issue in the case of the RX-8. Having said that, all types of engines should be allowed to warm their oil prior to shut-down.

The Automatic Transmission Fluid (ATF) trick referred to earlier isn't required to un-flood an engine...just remove the fuel pump fuse, turn the engine over for a bit & install new or cleaned spark plugs...Vroom!!!

BTW, in sixteen years & 264,000 miles of operation, I've only managed to flood my 1987 RX-7 once so I think it's fair to say that the flooding legend is just another example of the ignorant propaganda bull crap that pistoncentric types love to fabricate.

RX Guy

A while back someone posted the Product Comparison Guide that is supposedly distributed to all dealers. Here is an extract from page 29, Section - "2004 Mazda RX-8 Delivery Tips ", Subsection "Rotary Engine":

During short periods of cold engine driving (such as backing the RX-8 out of a garage to wash it in a driveway) drivers should use the following procedure to help keep the spark plugs from fouling or the rotary engine from running rough:
· Turn the ignition switch to the START position and hold (up to 10 seconds at a time) until the engine starts.
· After starting the engine, let it idle for about 10 seconds, then move the vehicle.
· After moving the vehicle, let the engine idle for about 5 minutes.
· Rev the engine to 3000 rpm, and then let it return to idle.
Turn the ignition switch to the OFF position.

I would be a first time rotor-ite myself. But I have a friend who has a 3rd gen 7. He only experienced the flooding once in these past ten years.

What do you think?