Mazda RX-8

duke15

The folks on another message board have figured out that the picture in this month's CR issue is that of the mazdaspeed 8 - you can see pics by doing a google of mazdaspeed 8 under the images tab. They don't mention the mazdaspeed trim line like they do the base and shinka, so it might just be that they grabbed the wrong picture. Or maybe this will add to the speculation of a mazdaspeed 8. As far as looks go, I like the base model with GT, appearance pkg & rear spoiler better than the looks of the mazdaspeed 8 - but it would be interesting to see what is under the hood.

mfenton

Any speculation as to whether or not Mazda will have special pricing incentives on the 2006 RX-8 since it is coming out so late? I would think that with the 2007's hot on their tail they will want to move their stock quickly.

duke15

I was told that they are only making a limited number of 2006's so that (hopefully for Mazda) won't be a problem. There are still quite a few 2005's on the lots in the DC area.

duke15

I know some of you are due to get yours any day now, or maybe you already got them and that is why this thread is moving so slowly right now.

Buunygirl - did you get yours yet?

mfenton

As far as I know the 2006 RX-8's are not here yet and I am in Los Angeles. I got a call yesterday about an 05 that was equipped the way I want it, but now I may just wait for the 06 because it has more HP and it is a 6-speed automatic. I have been told to expect them here around the end of April

bunnygirl

Mine is at the dealership in the back lot. It hasn't been prepped or anything yet, though. Still has plastic covering most of it. The 2006's officially went on sale at dealerships in Portland on Friday. My dealership said they have 60 vehicles that need to unloaded, inventoried, and prepped to go out onto the lots (I'm sure not all RX-8s). Mine isn't as high a priority as some of the other vehicles since I already bought mine so I am just waiting for them to get it ready, most likely by next week Thursday. I do know that my dealership has four 06's right now on their lot that have been prepped and I am not sure how many others are coming in that haven't been prepped yet. They have three Galaxy Gray and one Phantom Blue. Then there is my Winning Blue in back but it isn't going onto the lot. It may be ready tomorrow but probably not if they are still dealing with all those other vehicles. Next Thursday would be my best bet to get it, since it is my day off.

So, aside from it actually being in my possession at this time, my car is here, along with several other 2006s in the area, just in time for Spring Break.

joedirt

My friend just bought an '05 Mazda RX-8 in brilliant black, and now I want one!

Amazing cars, that are amazingly smooth, and that make amazing sounds! No other car is as unique - 9,000 rpm redline!

duke15

I am guessing that the answer is that you can't do this, but I'll ask anyway. Is there a way to track your car through the build process via the order number - maybe through the website, or email alerts, etc? Or do you have to go through your salesman?

moadh

Just out of curiousity, how does the keyless ignition work for the MT RX-8? i have an MT and the only way to turn the car on is by pressing down the clutch, so i was wondering how it works if your out of the car and the clutch is de-pressed? thanks

rorr

Keyless ignition is NOT the same as remote start.

I'm not sure how it works on the RX-8. My dad has keyless ignition on his Prius; with that car, the keyfob STAYS in your pocket. The car senses the fob and unlocks itself as you approach and when you get in you just hit a start button. I'm assuming the keyless ignition on the RX-8 is similar. No need to ever take the 'key' out of your pocket.

modock

Just a question about this system. Anyone know how it works if you are going to let your car warm up in the mornings. Can you lock the doors and walk away with the FOB in you pocket and the car keeps running. Or do you have to stay in the car for it to keep running??? I think this would be cool to have on my car but there may be problems with the logistics of the thing.

Modock

rorr

"...but there may be problems with the logistics of the thing."

Why? Do you frequently lock the doors and walk away from your current car with the engine running?

If you insist on doing this, I suppose you could leave the keyfob in the car so it keeps running and then use a spare key to lock/unlock the doors. How would you do it with a standard ignition system?

lhess

my 8 doors won't lock with the key in the ignition. So, there's no locking the door once you start it to warm it?? Am I missing something??

modock

In my current car, and my previous one for that matter, I use the valle (sorry i never took french) key to turn the ignition on and then use the key on my key chain to lock the doors. This way I can let the car run for 10 minutes and melt the ice off the windshield and rear window before driving to work. I guess I could sit in my car when it is freezing out but I see no reason to.

This was not directed specifically at the 8 but at Mazda and for that matter any of the manufacturers keyless ignition systems.

Just my thoughts.

Modock

bunnygirl

I'll have to try it but according to the 2006 owners manual the car won't start unless the transmitter is inside the passenger compartment and I believe the doors need to be closed to start it. Of course, it tells you to close and lock your doors before starting, so who knows how much is a safety issue or a requirement. The only thing I can see me doing with the car on and me not in it basically is knocking snow off the window if there happens to be any but it only snows here about twice a year so I can't say that it is a big issue.

lhess

of the keyless ignition thing, but am starting to get the feeling of some real aggravations with it. I think it could end up being a little restricting.

I know no one actually has it yet, but what if you start the car, decide you need an extra pop-tart to eat on the way to work, hop out of the car, run back into the house and have the fob in your pocket? Does the car just die? If so, let's hope they really have fixed the flooding problem.

bunnygirl....not picking on the specs of your "soon to be had" car - I just don't know anything about the keyless ignition.

pathstar1

I don't think hers will have the system. Only certain models come with it. Look back in these postings and you'll find her description of what models have it.

A lot of people confuse this sytem with "remote start". It isn't that kind of system. It's just a convenience system that allows you to operate the car without having to use the key in the ignition or door lock. If you want to go back into the house to get something while leaving the car running, (not a very smart thing to do if you leave it unattended) you can just leave the fob on the console. Beware though, the RX-8 likes to lock the doors on its' own (they will lock 10 sec. or so after you close the trunk for example). Better have a key in your pocket!

bunnygirl

I got the Grand Touring package so it will have it. I don't know if it shuts off or what it does. The only need I can see for me to have to get out of the car after it is running is to get ice off the window (depending on how quickly the car can thaw it on its own). I figure I would not close the door completely, just push it to the point where it is almost closed but not catching.

On a side note, I can't believe you are going to eat in your car!!!!! Especially a pop tart. Those things are so sticky!!! Poor car. LOL

bunnygirl

My car is here and I will pick it up this weekend!!!!

ninjaman

I just found this informative forum and I'm on the fence. RX8 or G35 Sedan. I actually owned a 83 rx-7 many years ago and really liked the car.

In my research I've read alot of horror stories in reference to reliability with the rx-8. Have these issue been resolved? I understand the flooding problem has been addresses.

I've read posts (not here) about engines needing replacement, seats wearing quickly, and all the recalls. Even though we're fans of the car, what's the honest verdict? Do we put ourselves at risk getting one? Any car can break, but what's the bottom line for this car? Also, I have not been able to find any specific information on the changes for the 06 model other than the AT having more gears and more power. Like many here, waiting to squeeze the dealers on an 05 may be worth it if the 06 is not so much different. Any thoughts you may have will be appreciated.

plekto

Good car.

1:Warm it up in the morning until the gauge starts to creep to the first line.

2:Let the engine rev down when you stop, plus tap the gas as you turn it off.(it should rev to 2-3K for a brief moment)
(note - if this sounds suspiciously like you old cars with carbs, you're spot-on)

3:Check the oil every time you fill up. Religously. This is like an old diesel engine in how it tends to burn some oil with the gas - a nesessarry evil of the design.

4:Don't do silly things with it, of course. The car will happily rev up to speed faster than most anyone needs - just give let it get there as it wants(whomping on it only decreases the lifespan at the gain of a couple of tenths of a second). It's not an engine that you can abuse and beat the crud out of. Think old Mercedes, Old Jag, old Porsche. Small, refined engine that goes really fast, but you can't expect to pull hard off the line.
(That said, my friend's 968 starts off a bit slow at the light, but the second it hits 2nd gear, it's a blur from there on out. He's had it to 140mph, btw )

5:oil changes every 3,000 miles. Works better with normal oil instead of synthetic(as some gets burnt while running)

bunnygirl

You can get most of these questions answered very well by tons of people at the RX8club, if you go over there. Read the manual. You need to periodically drive it hard to keep from getting carbon buildup. It is recommended to redline it periodically. The car doesn't get the greatest gas mileage but if that isn't your biggest concern, than don't worry about it. The car seems to require about 1 quart of oil per 3000 miles. The manual recommends an oil change every 7500 miles or six months, whichever comes first. I think part of this long is because you need to add oil periodically. However, I would still recommend doing it closer to 5000 miles instead since when they drain and change the oil you still have over 2 quarts left inside. Don't shut the car down cold and it shouldn't flood. Remember to check the oil. It is recommended every three fillups or so to check the oil to make sure it isn't too low.

It's a great car. It just requires a little extra attention to ensure it stays well maintained.

bunnygirl

I just love it!!!! I made the discovery that I really suck at taking off in a stick but it shifts so smooth and easy once I get the clutch engaged and start moving. I'll need to practice starting. A few times I did it perfectly, a couple times kind of jerking, killed it numerous times, and peeled out a few times. Oops. LOL

The keyless thing isn't so bad. My mom and I went to a store after I picked it up and for the life of me I couldn't get the doors to lock. It just kept making a beeping noice at me. I then realized it was because the second transmitter was in the car. I took it out, put in my purse, and then it locked up just fine!!! I felt like such a retard.

I'm not sure how this would work when the car is running, though. I haven't checked it yet. I would say to just close your door enough so that it isn't completely caught, slightly ajar and do whatever it is you are going to do.

lhess

from another female who loves her 8. I still remember how exciting it was to bring Rex home that first time. I just hit my 1-year anniversary with him and it's still exciting.

Don't worry about the take-off thing. I had taken about 4 years off from driving a stick and when I got my 8, it was ugly for a while.

Yeah, I admit, I do eat in my car, but I'm very careful and keep it clean. I've been known to pull over and chase a fry from under the seat.

Just a side note that you already know about, but according to the Mazda website, the keyless op comes on the Grand Touring models.

bunnygirl

I haven't named my baby yet but the navigation is female, so it needs a girly name. I take it back in to the dealership tonight (mom won't let me drive it there until around 8 p.m. after rush hour and then only if she follows me there LOL) to get her Teflon-coated inside and out over every square inch to seal and protect everything from staining, fading, cracking, water spots, bird poop marks, et cetera.

This is my very first car and it only took me until I was 25 to get it!!! LOL

jeff209

I have just purchased a 2005 Shinka Black Cherry. I never thought I would ever fall in love with a car so fast. It has 11000 miles on it. Only thing I see I am not keen on is you can see rust or discoloration on the edge of the rotor brakes through the wheels. I am going to get a speeding ticket I see right now from the speed of this sweetie. I want to take care of my baby any ideas how to clean up the inner rotor paint? Thanks jp

wantmb

pathstar1

The inner edge of the brake rotors gets hot but not really hot. Clean off the rust using sandpaper or steel wool - very important as the paint you are going to apply will come off with the rust if you don't get rid of the rust first. Degrease it (there are many degreasing choises including spray ones - just remember your hands will add oil if you touch it after degreasing), and use "Testors" model paint - it's the "hot setup" most of the guys with RXs use on calipers. If you think the temp. is too high you can get exhaust paint (usually flat black) at motorcycle parts places. Be careful to keep the paint off the rotor surface the pads touch - it will contaminate the pads and decrease braking.

wantmb

CarMan,

Can you please let me know what the April residual and Money factor is for the 2006 RX 8 manual transmission in Maryland. I understand they have a $500 cash rebate and $1000 Dealer cash as well as a lease special. I am in the market to lease 24 or 36 mos 15k. The vehicle MSRP i'm interested in is $32,135. What would be my payment pre tax and post tax (5% in MD)with $0. Thanks for you help in advance, I've been following your advice which has served to be very helpful with our MB 350 several months ago.
Thanks Again!

56bartman

I am contemplating making a change from my 01 TT to a slightly used rx8. The question.... will I be happy with the change? I've been driving the TT for 3 years and I'm getting a little tired of driving with a stick ( cell phone and coffee juggling plus a wife who doesn't want to learn a stick, making road trips my exclusive driving pleasure!) I love the TT but am drawn to the rx8. Has anyone made this switch or have any comments on this move?

Thanks

jeff209

Hey I need some guidance. I have been driving a 95 Honda five speed and now have a 2005 RX-8 Shinka six speed Manual Transmission. I seem to be shifting very jerky and need help from you pro's how to make this car purr without as much jerking. Its me and not the car. Mabe I dont understand RPMs vs shifting and when this baby needs to shift? Or is it that I am pushing the clutch in too far. Any tips are appreciated to a green horn. Thank You a Million jp

ukjim

I am sure you will get lots of good advice but here is my guess (ps, I'm 54 yo and have road rallied, owned umpteen different cars including an old Lotus, and qualified for an IMSA licence):
If you are used to a relatively low revving reciprocating engine it's possible you are shifting too low in the rev range for the Rotary motor. The Rotary has a) poor low end torque and b) is a free revving engine where the revs not only rise quickly but also drop quickly, so if you are shifting too low in the rev range the engine will "bog down" when you let the clutch out after the shift. This is also true in just normal driving(not during the shift), the motor slows down very quickly (low inertial mass) once you are off the gas.
If you read past postings you will see that this engine loves to rev and it is recommended that you redline it periodically (this shouldn't be a problem,:) )Also, from my experience, to get a smooth start, I had to get the revs up to at least 2500 to 3000 rpm before letting the clutch out. 1st and 2nd gear are relatively short so I found that it does help to shift quickly to be smooth. If you are having trouble shifting quickly it may be that if you car is new the gearbox may still be a bit stiff and it will get better as it wears in. I hope this helps and have fun.

lr3rx8

Here's my shifts in town just commuting
1-2 5K
2-3 4.5K
3-4 4K
4-5 3.5K
6th - never need it.

Here's my shifts in town commuting and driving it like it should be. (not racing let's just say spirited driving.)
1-2 6K-7K
2-3 6.5-7.5K
3-4 4.5K
4-5 3.5K

Mileage difference is only about 0.5mpg worse the "spirited" way.

emeraldhue

Congrats on to Shinka. I bought one last September as well.

As for the shifting, this is my first stick ever. And let me tell ya, I can't recount the number of times I stalled the car in first gear trying to get it off the line. It took quite some time for me to develop the sense to feel when the clutch catches on. I consider myself to be a convert from auto to stick now. The only time I would allow myself to drive an auto is when I'm driving someone else's car.

At first I would try to keep my RPMs between 2.5K to 3.5K in order to save gas. But my dealer mechanic said it driving in low RPMs actually hurts the engine. So now, I keep it between 4K to 5K, eliminating the need to ever use the sixth gear. Shifting seems to be smoothest in that range. I'm stilling a bit jerky with first to second throw though. But I've found that I can reduce the jerking tremendously with an extremely quick shift while letting off the gas only slightly, but not completely as I would with other gears. Also, I don't engage the clutch all the way in when I shift. About 3/4 way should be sufficient.

trispec

OK, being an RX-8 AT owner, I know it's not the same as shifting a manually six speed, but in the AT manual mode shifting works pretty well, all be it, at a lower power level.

That being said, here's what I've noticed. The 3500 RPM level seems to be designed as the reasonable minimum RPM or cruising level. Being just below the level 3800 RPM second intake opening point for available power boost when needed. In full AT mode, and under full acceleration, it appears the AT is designed shift at 6000 RPM and dropping to 3500 RPM in first gear and then up to 5000 RPM and dropping to 3500 RPM in second. 3rd and 4th gears, each with overdrive behavior, seem to like the 3500 RPM reasonable minimum level.

So, when using the AT in manual mode, if one mimics the above pattern using the paddle or stick shifters, the added control and performance, in all driving circumstance is very much enhanced. Pegging the 3500 RPM level as the minimum and working the manual shifts up and down from that point, looks like the best balance of economy, performance and most important, fun driving.

rx8wannab

My 05 AT came with the emergency tire flat repair kit, which includes a small air compressor. Does anyone know if you can use it to add air regularly to your tires? Other than warning you not to run it for more than 10 minutes at a time, the manual doesn't say it can't be used for non-emergencies.

Gas stations in California :shades: make it so inconvenient now to use their air machines (remember the days when air and water were freely available at the central pump stations?); this would be quite useful to use instead.

Anyone tried using this thing?

mdw1000

Interesting post about shifting. As you may remember, I've got an AT as well. I was wondering where you got your info about the engine characteristics (second intake opening port rpm, etc). I would like to read up on info like that.

Thanks!

trispec

PathStar said the ports open at 3800 and 6800 (MT) only. I think you can hear them open during revving in neutral. Also I think the tach is designed as a racing tach where the horizontal and vertical indicate cruise points.

Don't recall ever seeing actual Mazda spec info on any of this. I wonder if a real Mazda engineer from Japan would ever chime in here to speak to the uneducated masses.

Actually, I'd pay money to talk with the RX-8 design engineers about the RX-8. On second thought, I'd just worship them.

aviboy97

We just received our 2006 RX-8 Shinka's in. They are quite nice. We have 2 in Copper Red Mica, and one in White. Also, the leather is a vast improvement over last years. I would definalty say this is one of the nicest cars on the road.

e_ric

A Rx8 need more power. Its competitor 350Z its blowing it away. Mazda should have a 1.3L rotary engine with a 2.0L turbo and has about 290+ hp then it could probably match up with the 350Z and the new supra thats toyota bringing back.

plekto

The RX-8 wasn't ever EVER made to be a 350Z - it's a sports sedan with a sportscar looking exterior. That it even comes as close as it does to the Z is amazing, since auto magazines seem to love matching the two up - as if it's a Z.

Now, compare the RX-8 to an IS250 or an Audi A4 or simmilar - and it's a whole other story.

rorr

Anybody catch the writeup on the turbo kit available for the RX-8 in the July issue of Car and Driver? I don't remember the details but it was around 390hp with a VERY healthy bump in the torque.

mkoll

This may be one for the problem / solution forum but I was wondering how everyone's experience has been with the RX8 and vibration. When idling at a stop with my foot on the brake the car seems to vibrate more than is desireable. I have an '04 GT with auto trans. The dealer tells me that this is a common complaint witht the automatic trans. Can anyone verify this?
Another point to ponder, tire noise? The car is pretty noisy on the road even at low speeds. Of course it gets louder as you accellerate. The 18" Potenza tires are lousy if they become that loud after barely 20,000 miles. The dealer has again told me that this is a common complaint. Can anyone comment on either of these items.
Any suggestions on a quieter performance tire?

rotorrocket

the rx-8 has vibration at idle. it should dissapear as soon as you step on the gas a little bit (in neutral in the case of a manual)

The potenzas are a miserable tire in terms of wear +/- 20K, and noisy as hell. Mine wore out and i switched to goodyear Eagle F1 GS-D3. They should last twice as long and are very quiet and comfortable.

Your size would be the 245/40YR18. They should fit well in spite of being slightly different from originals.

Check out this review from the Tire Rack.com

http://www.tirerack.com/tires/survey results/surveydisplay.jsp?type=MP

trispec

I call up Jon Etheridge, from the Car and Driver article on the PTP RX-8 Turbo kit. He said they were still getting the kit parts together. Everything is coming in from other places around the country and the world it seems.

I asked Jon if the kit would fit on the RX-8 AT models. He said he didn't know if the 80% torque boost would burn up the AT tranny. He thought there might an issue with space need for the pipes down below, but they had not been able to get an RX-8 AT to work with. I offered to drive my RX-8 AT, Boston to Austin over the next two days in exchange for a big discount.

Question for the group: "Is the auto tranny in the RX-8 AT limited to 7500RPM strictly because of torque and horse power limits? OR If a turbo kit develops higher torque and horse power, say 200 lb of torque and 250HP over 4000 to 6000 RPM, will the same 7500 redline hold up?

Anyway. Nice to see huge-ish torque and horsepower, now available for the RX-8. Bragging right over the tiny Rotary's 13B Renesis producing 375 HP is worth something to me even if I don't have the $9000 minimum (turbo kit, engine management unit, dash gauges, and installation) to make it happen.

pathstar1

I believe the RX-8 pre-2006 AT is derived from the Mazda mini-van and if so it should handle the extra torque (torque is the only thing you really have to worry about - the extra HP will heat up the transmission more but you can deal with that with a transmission cooler).

The 7500 RPM limit is due to the torque converter - it will fail if operated above that for extended periods. By fail, I mean explode.

My comment, (I know, unsolicited) on adding a turbo to the RX-8 is it's a "bad idea". I'll bet half the conversions will result in a destroyed engine within two years. To be done properly (read reliably) the compression must be lowered. This entails machine work on the rotors (or replacing them with different ones).
I passed on adding a supercharger to our RX-8.

trispec

Wow, I didn't know the 4 speed RX-8 AT used the mini-van tranny. Paddle shifting too? The transmission oil cooler in the driver side grill doesn't cool the tranny, just the oil?

The extra turbo compression causes the apex seals to break down? Or do things just get so damn hot that the oil cooks? Or both?

Is it hopeless for the 13B rotary to be a brute force? It must be damn near impossible or they would have done it by now?

pathstar1

You can add paddle shifters fairly easily to any computer controlled automatic transmission. They are just switches supplying control inputs to the computer.

The existing trans. oil cooler might have to be enlarged, or perhaps an electric fan added to it, to handle a larger HP load (more watts of heat to dissipate).

Compressing the intake charge has several effects:
1. It adds heat to the intake air and this can take the intake charge (once the fuel is added) too close to detonation making it unstable. You might think cooling it is not difficult (intercoolers), but I've not seen effective intake cooling on turbo or supercharged vehicles very often (my 3rd gen RX-7 is a perfect example, with intake air temps often far above 60C, even with 20C ambient temps).
2. It increases the amount of oxygen and fuel in the chambers putting the molecules much closer together and thereby increasing the chance of them combining before the spark creating detonation.

The result of all this is you increase the chance of detonation occuring. In a rotary where the apex seals are basically in direct line of sight to any explosions in the chamber, any detonation is death to the engine - it shatters the apex seals. In a piston engine the rings are hiding over the edge of the piston - shock waves hit the cylinder walls and only secondary shocks reach the rings through a tiny gap between the piston and the cylinder wall. Hence the detonation has to be really bad before it does damage, and that usually is a hole punched in the piston. Mild detonation puts "peening marks" in the piston - it looks like someone has taken the round end of a tiny ballpeen hammer to it - I've seen this too often on performance piston engines. A rotary wouldn't survive this "mild" detonation.

Finally, no, it isn't hopeless for the 13B renesis to produce a lot of HP - it just takes proper engineering. They (the engineers) must design the engine for forced induction, and they must target it for a specific pressure. The current engine is optimised for normal aspiration. It can be taken "over the edge" without pressurizing the intake (we've done it and been saved by the wonderful "detonation prevention" system built into the renesis computer). Pressurizing the intake of the stock engine is asking for serious trouble unless proper engineering is done to protect it.

What needs to be done? Look to previous rotary models for guidance - the second gen RX-7 turbo engines had lower compression. The third gen RX-7 had lower compression and some enhancements in the fuel injection system to ensure there was always "too much" fuel. The extra fuel acts as a coolant if the charge approaches detonation conditions.

The fact that Mazda haven't added a turbo is a hint - it probably isn't cost effective with the rotary. The third gen RX-7 was a classic example - see how few have survived and how short the average engine life is (typically less than 100,000 mi whereas the second gen normally aspirated engines go for well over 200,000 mi).

Perhaps we'll see a turbo or super charged rotary in the future. However, with fuel prices going the way they are, I'd be surprized.

trispec

Nice entry. Depth and breath of knowledge. Thanks.

So do the detonation protections in the Renesis 13B detect conditions prior to any detonation or would a single detonation event then trigger the shut down (check engine light and loss of power resulting).

I've been running various octanes of Shell gas, 89 and 93 with no problems. One time however, I tried a tank of 87, just to see how millage would go. But with that one tank of 87 there was a single event of a loudish popcorn/rattle that occurred just above 5000 RPM. The noise was much louder than the popcorn/rattle at low RPM noise I hear less and less often. The event did not cause a check engine light or loss of power, but I backed off the gas. Was that likely an episode of a detonation? Could that single event damage the Apex seals.

pathstar1

I'm beginning to suspect the automatic PCM (the engine control computer) is very different than the manual one. The manual cars' PCM will immediatly drastically retard the timing when it receives a knock input from the sensor (the sensor is basically a microphone bolted to the engine). If further knock inputs are seen, it will set the car into "limp mode" for about 15 min. I guess the thinking was the first knock events are mild, though they will "set up" the engine for destructive knock by increasing temps - so correct the situation before it gets out of hand. On the several times we triggered this protection scheme we didn't notice the popcorn noise, so it wasn't violent yet.

From your reports and reports of others it sounds like the automatic PCM doesn't have this effective knock prevention system. Perhaps this is what they are adding when they rebuild the PCM in California (as per reports from previous members).

I suspect in a normally aspirated engine, you would have to hold it in the knock event for at least 5 sec. before it could cause potentially fatal physical damage to the engine. This is the difference between normally aspirated knock and forced induction knock - there is so much more energy with forced induction often the first knock events or the beginning of the event is enough to destroy the engine. It's a bit funny, because with my RX-7 if you knock it cracks the apex seals, and the pieces subsequently are ejected through the turbos. Cost of new/rebuilt engine - $3000. Cost of new/rebuilt turbos - $4500. Thankfully I know of this from reports by others - I have kept my mixture rich enough to avoid knock! So "knowledge of when to richen the mixture - priceless" .