Digisan

Wrong, it's brand new! Why would I beat on it? It's quick, no doubt, but it's not broken in yet, therefore I have no idea about it's full potential. After the breakin I expect it to perform as advertised. The car thus far has been fantastic, on the other hand, I don't like being lied to or kept in the dark my $30K+. Some of us, (me), care about what we spend our money on. RX-8s don't grow on trees and they damn sure ain't cheap. The RX-8 package, as advertised, is what makes the 8 so appealing.

D-san

RomanoM

I understand what your saying and I would be happy with the car as is.

But why (if) is the engine down on power? I what to be reassured that there isn't a defect in design of manufactur.

If Mazda comes out and says, sorry we made a huge mistake and the engine can only make 210bhp, but the engine is within specs. I'd be pissed, but I'd keep the car.

Gord96BRG

I just find it funny that so many people here are assuming that it's Mazda keeping you in the dark. We have 2 dyno tests on green engines, with no real proof that they were even tested properly (ie the first one probably didn't have DSC properly disabled - and does anyone know technical details on how DSC would affect a dyno run?), and everyone is in a panic.

Why would you all be assuming that those two tests of green engines are absolutely accurate and that a gun-shy (burned once, maybe twice if you include parent Ford's Cobra experience) major corporation is going to risk everything by trying to pull another fast one by exaggerating HP numbers? I put a lot more faith in Mazda's engineers than these two tests, that's for damn sure.

The uproar this is all generating is quite hilarious - well it would be, if it weren't also so sad. Other auto forums are picking up on this and laughing at the RX-8 already - The RX-8's supposed enthusiasts are running around like chickens with their heads cut off and are ruining the reputation of a great car when it's barely off the showroom floor.

Relax, be patient, and don't be so ridiculous in all this overreaction!

Regards,
Gordon

BillK

Just to be fair, there is at least one vehicle that has been dynoed that has well over 1000 miles on it - almost equivalent to the mileage on at least one magazine test vehicle.

Also, I find it interesting that concern about what other auto boards may think of the RX-8 keeps coming up here. Is this really a big issue? Did people here really buy their cars based on what owners of other cars think of the RX-8? That seems silly to me...

Charleston

I finally got to test drive the 8 yesterday afternoon. The dealer let me take it out on the freeway and let it go. The AC was fine. The car never seemed hot and I did not notice the AC cycling.

It was great and I did hit 8500 rpm a couple time in low gears (2nd and 3rd). I had it up to 85 mph at one point and it just sings. The salesman I was with had it up to 140 on his first drive and said it felt more like 70. That is when I realized how easy it is to drive at higher speeds. When I have been in non-sports cars 85+ can be scary from a stopping and handling perspective assuming you are sane enough to think about stopping in an emergency. In the 8 it was just plain fun. I wonder if you can get the car to 140 btw if you only have 183 horsepower? I hope someone will get out on a track and discuss the performance then.

I don't know what the true delivered horsepower is, but I was surprised at the push you into the seat take-offs. The car is pretty strong above 7000 rpm IMO. Please no flames, I am a novice but I play a pro on video games

I drove a car with the touring package FWIW. I'll comment on the stereo on another thread.

RomanoM

I think anyone making ANY conclusions at this point is being very premature. And I would be absolutely SHOCKED if there was any deception on Mazda's part.

I also think that anyone, like myself, that is waiting to take delivery should do so. IF there is an issue I have no doubt Mazda will remedy the situation somehow. The Ford/Mazda actions on the Explorer/Firestone, Cobra and Miata show that.

And even though the dyno runs are insufficient to come to any conclusion, they are enough to simply ASK what if anything is going on.

I have been in more than one situation where weeks before launch or even during the first weeks of a new vehicle launch, major problems pop-up not caught in development. It's not the engineers, it's the budget and time constraints. All cars are built to a cost and that cost includes testing, development, personel, and program time. Priorities are set and corners are cut.

The automotive industry is a bitch. That's why I left.


It's not the DSC part of the system that would cause problems. It's the traction control.

The DSC (ESP) is a yaw control program and only effects the car when it's spinning or pitching.

The TC on the other hand controls wheel spin. It does this by reading the TPS (throttle position sensor) and the ABS wheel speed sensors and the reference velocity sensor (usually a sensor on the drive-shaft). It then compares all and decides if the wheels are doing what they should be. If it concludes there is wheel spin then it can use the brakes or cut ignition spark to rectify the issue dependent on the severity of the wheel spin.

So, if you are spinning the rear wheels on a dyno and the front wheels are doing nothing the TC will read that as major wheel spin and cut-in dramatically.

This intervention will be very prominent on the torque curve. There would be no hiding it. You would see a major drop in power at the moment the TC activated and it would keep dropping since the only way to get the rear wheels to spin as fast as the front on the dyno is to stop the rear wheels from spinning at all. And even though there is an allowed amount of rear wheel spin, it's too small to go unoticed.

ggreen29

I'll try to restate my amusement with this whole situation.

I don't have a problem with the situation, but Mazda does. But however Mazda handles it will benefit us. We will get a stronger car when it reaches the mileage trigger, or we will get compensated by Mazda in some way.

But prior to reading these dyno threads we were all happy, numb-butted drivers enjoying our cars, passing cars with glee, completely unable to tell the difference between 180rhp and 210rhp. Now we know our butts are unreliable and we're afraid of what the neighbors will say.

Digi-san, if you had hopped into your car and driven for months, never visiting this website until Christmas after next, you'd still be loving your car, ignorant of the missing rhp, because in 99% of driving conditions it just doesn't matter.

You drove your car, you accelerated, braked,and cornered your car, you got in and out of your car, you looked at your car and you listened to your car.

You loved your car...

............then you read some dyno results.....

....................and now your car sucks.

Forcing yourself to dislike your car isn't going to make the answer come any sooner, and it will probably bring you less satisfaction when the answer arrives. So sit back, re-enjoy your car, and if anyone asks how much hp it has, just say "Hop in. Let me show you." They will be as impressed with the car as you were a week ago.

Lensman

Uhmmm, no.
Most people who own RX-8s haven't been able to check whether the upper power range is missing because they are making an effort to run their engines in at lower revs. It IS, therefore, a big deal to them because some day they WILL want to redline the engine and they'll be sorely disappointed if nothing useful happens. This is a PERFORMANCE car! It's marketed as 'A Sportscar like no other'. Regardless of how well it drives with the (hypothetical as yet) problem it would still be missing a significant part of its reason to exist if the engine is not what we were sold. There is a law in the UK called the 'Sales of goods act' what ensures that the specification of an advertised product matches the specification of the purchased item. If the Renesis IS down on power then the RX-8 would contravene that law. I presume that the US has a similar law so this is not trivial. Look, it doesn't matter if the car seems plenty fast enough even though it's missing a bit of power and therefore we should all just put up with it and not worry, this is an expensive product and we want the specification we ordered and paid for!

Gord96BRG

Absolutely agree - I just think it's waaaaaay too early to conclude that we haven't got the spec that we ordered and paid for.

Sure, the early green engine dyno runs raise a few questions, but at this stage that should be all. Talk of boycotts and lawsuits and conspiracies and ripoffs are all incredibly premature.

Regards,
Gordon

TybeeRX-8

Quote:

It's not the DSC part of the system that would cause problems. It's the traction control.

The DSC (ESP) is a yaw control program and only effects the car when it's spinning or pitching.

The TC on the other hand controls wheel spin. It does this by reading the TPS (throttle position sensor) and the ABS wheel speed sensors and the reference velocity sensor (usually a sensor on the drive-shaft). It then compares all and decides if the wheels are doing what they should be. If it concludes there is wheel spin then it can use the brakes or cut ignition spark to rectify the issue dependent on the severity of the wheel spin.

So, if you are spinning the rear wheels on a dyno and the front wheels are doing nothing the TC will read that as major wheel spin and cut-in dramatically.

This intervention will be very prominent on the torque curve. There would be no hiding it. You would see a major drop in power at the moment the TC activated and it would keep dropping since the only way to get the rear wheels to spin as fast as the front on the dyno is to stop the rear wheels from spinning at all. And even though there is an allowed amount of rear wheel spin, it's too small to go unoticed.

To me, this sounds like a very possible explanation of the deficit experienced in some of the dyno tests to date. TC/ECU reads what the front wheels are doing as well as the rear. The RW only dyno tells the computer that there is a massive amount of wheelspin taking place when the fronts aren't turning at all.

Racer X-8

I for one am responsible in writing my opinions of this topic which has so easily been hitting nerves.
Since this thread IS about dyno results and NOT opinions, lets take our opinions to the more appropriate thread, shall we? No offense anyone, it's just hard to chatch up on dyno results with all these opinions too...
http://www.rx8forum.com/showthread.php?s=&threadid=8003
See ya there too
(The poll is dead-even as I write this. Hmmmm......)

RomanoM

Yeah, but you won't be able to miss the intervention.

The dyno would be similiar to being on slick ice. The engine would practically shut off.

The the torque curve would look fine until probably 4000RPM and then it would drop off the cliff.

No way to miss it. The guy making the dyno run would immediately notice the RPM's drop as the engine cuts out.

There is only one possiblity. If the TC is shut off the engine management computer (through the CAN) may read the wheel speed sensors and if it sees the large difference between front and rear wheels it will decrease engine power to try and "save" itself.

In essence to enure you don't accidently do a 9000RPM launch if the tires suddenly get traction.

But I've never heard of any car actually being set up that way. And I don't see how reducing power only by 20% would make a difference. Instead it would lower the fuel cut-off to something like 5000RPM.

It's not the DSC/TC causing the problem.

pelucidor

The solution is simple for the buyer: just test drive a demo RX-8 and rev it to redline in first and second (like I did) and ignoring hp numbers etc. My demo car had <100 miles on it and was damn fast with four on board.

If you are happy with the performance then buy it (like I am doing). And perhaps it will even improve later or Mazda will give you some nice incentives if there is a mistake. 'Woohoo' to quote ggreen.

If you are unhappy then try again in a few months when power may be better, or just buy another car.

The problem is tougher for Mazda from a PR perspective - the longer they wait to make a statement (assuming things are working as designed) the more people will think there is a real issue.

RomanoM

OK, I'm cleaning the BB-Q for tonight, having a Corona w/lime (a Corona w/o lime is a crime) and thinking about this.

Yes I am a dork! Can't help it, makes me a good engineer though.


Anyhow, the RX-8 has an electronic throttle. Did anyone that ran the car on a dyno check the throttle position?

With E-throttles it's somewhat difficult to calibrate the pedal to ensure WOT (wide open throttle) at full pedal travel.


I know more speculation. Oh well!

MrWigggles

Doctorr brings the issue up towards the top of the 7th page.

-Mr. Wigggles

1stRX8

Not true for me. The biggest reason for going to the dyno was that I expected the 8 to be only a bit slower than a fresh/stock FD. My first impression in an FD was "WOW!" My first impression of the 8 was more like "It's Zippy" I was expecting a firmer push in the seat feeling. I burned off a thousand miles and went straight to the dyno. I don't dream I'm amazingly sensitive but 25 - 30 hp is hard to go un-noticed! I think my mom could tell the difference if she could A/B compare identical cars with one being 30hp less.

I am still quite excited about the car! It turns heads big time. It starts converstions. It looks better than any other car (my opinion). It really has great performance. It should be faster. The first time an S2000 pulls away from me before I can blink - I will be extremely upset. Half of the fun is knowing "what she can do"

99% of my driving conditions use 100% of available HP. Not that I am racing the thing all the time. Just passing a soccer mom van makes me put the pedal all the way down. I enjoy passing quickly then calming down to a reasonable speed. Any car can go 90. My car should get there quickly.

I repeat: I WANT MY 247 F*&@$%G HORSEPOWER.

....... Patiently waiting for a mere 20,000 miles to pass me by waiting for my HP to arrive from the dark side of the moon.

PS. My GSL-SE never got any quicker after the 700 or so miles I gave it to break-in.

BillK

On the other hand there have been numerous interviews with the Mazda engineers who have said since January if not longer that they did not want the "kick" of the RX-7 and instead deliberately went for a softer, smoother acceleration curve for the 8.

That doesn't excuse any potentially missing HP, but it does signify that the acceleration characteristics the car seems to have now match perfectly with what we read the designers' intentions were...

BOOSTD 7

You obviously have no clue who I am ...

lefuton

wow, that's really funny...just about made my week =) and it's only monday

BOOSTD 7

Glad I could help

dcfc3s

Thought of another thing -

What with talk of there being a set point where power is "unlocked" to allow a good breakin, there's another possibility besides fuel and timing. Since the throttle is totally controlled by the ECU, the ECU could easily not open the throttle fully. So, you have your foot to the floor, but the ECU is only giving it 80% throttle.

One positive aspect of this - down the road, as more RX-8's show up on dealer floors, people are gonna go beat the crap out of them test driving. Having the ECU electronically hold back until the engine is broken in would be a Good Thing. This way if you end up buying the one that was heavily test driven, you'll still have a motor with a long life ahead of it.

Dale

RomanoM

2nd page:p

Anyway, well it's a good question.

If some one could have the TP checked to see if it goes to WOT it would be nice.

This does not require a dyno, just a diagnostic tool. Any good shop or the dealer can do it easily and quickly on the spot.

Sputnik

This has been brought up before.

But realize that simply holding the throttle back to 80% won't cause overrich problems. It might be part of it, but not all of it.

---jps

Skyline Maniac

Just a quick question:

Base on the recent dyno results, the RX-8 6MT seems to be making 210-215hp at the crank. If this information is indeed accurate, how does it affect your purchasing decision on the RX-8? For those who have purchased the car already, would knowing such information prior to your purchase change your ultimate decision in buying the car? Be honest and hopefully some people from Mazda USA would be paying attention to your responses. (Better yet, start a new thread focusing on this issue)

I truly wonder how many people on the fence are holding off their RX-8 purchase because of these recent dynos. 30hp differential is huge when it comes to a performance oriented car.

BillK

The question about what effect this may have on a purchase decision should probably go in a different thread, but at least for me I don't care - I loved the way the RX-8 felt on a test drive and I'm not going to beat the car any harder than I did going down a freeway onramp.

That having been said, my interest in this issue is more in Mazda's response to it than the issue per se. I want to see how Mazda would react should there be some other major issue that comes up...