loco4rx8

Heh. I don't suppose I'd be surprised by anything Mazda does at this point, BUT....

Do we really think they'd revise the numbers from 247 to 238, then make a big deal by offering the buyback or service/$$, and then tell a baldfaced lie and STILL be wrong on the horsepower?

I think they've probably got it right this time. If you take ChurchAutoTest's dyno, which seems to have been done the most carefully and accurately, the rwhp was rated at ~190. That's a 20% drivetrain loss from 238. That seems a little high, but entirely possible.

Keeper

Don't forget that the dyno used by ChurchAutoTest removes the weight of the wheels/rims from the equation. The expected drivetrain losses with that type of dyno are lower than if you had used a dyno where the car was on rollers.

Mazda's statement indicated that they didn't do an engine dyno. They did say they dyno'd several production cars, came up with an average, and used that to estimate crank hp. This means they "chose" how much drivetrain loss the car had. They also made a point to mention that they're allowed a 5% tolerance (5% is +/- 12hp on a 238hp claim) on the number they publish.

Based on the information available, I'm forced to conclude that they made a decision to thread the needle -- ie: change the published numbers as little as possible while still being within 5% of the real power output of the engine. But that's just my opinion, and nobody here can really prove what their intent is.

But honestly, I don't care what power rating the car has at the crank -- the power that gets to the wheels is what matters and in that respect the rx8 isn't doing so well.

loco4rx8

Hmmm, yes. That's true.

I still think we may see some higher dynos after the cars get a few more miles on them. Maybe that 180-184 number will go up to 185-189 eventually....

Really, I am pleased with the performance of the car. I bought the car a little over a week ago knowing full well that there was a hp controversy. I based my decision on how the car performed during my test drives. I can see, though, how someone who ordered the car without knowledge of this would be very disappointed.

TurboSE

Mazda said they estimated the crank hp? Who on this earth would buy such bullshit?? All the years they spent to develop the renesis and they never put it on an engine dyno??? How stupid does Mazda North America really think the average US consumer is? I am an engineer and I find it absolutely impossible to believe the mazda engineers could not arrive at an accurate HP number. They know exactly how much Hp the engine makes with each and every fuel map and emissions set-up out there. They have put the engine on the dyno for hundreds of tests believe me. There must have been a deliberate campaign to misinform consumers by the company execs so that the advertised numbers would look to be in the same league as the competition and would justify the $30K + price tag for the "performance model" I think even the 238HP number is inflated. I really don't care now if it still meets performance numbers, I just won't give my money to a bunch of unethical SOBs. They got away without too much damage to the miata popularity the last time around so they pulled the same stunt again.

RX-8 Zoomster

I don't think that Mazda is minforming no one. That had to inform the consumer that the HP's changed, which they did. I do believe that Mazda engineers DID have an accurate HP rating at the flywheel BEFORE this car had to enter the U.S. It's my belief that because of emissions, the ECU had to be remapped (Euro3 ECU) to meet the stricter U.S. emissions. The HP is there and always will be, it is just throtteled by a detuned ECU.

In regards to giving your money to Mazda, I feel sorry you feel that way. I think you are being unfair to Mazda and your attitude is unjustified. If you don't want to buy the RX-8, that's your perogative. There are plenty of people that want to buy the car if you do not.

5Gen_Prelude

I just wonder if all of this was done at the port. By the way, it takes MAYBE a day for a corporation to release a memo to its members. The change was done several months ago, not yesterday - that's what would **** me off - finding out long after the process of detuning had taken place.

Lensman

They ARE misleading us one way or the other because they claim the performance hasn't changed (still 5.9 0-60). If the performance hasn't changed then the engine hasn't changed and they were misleading us about the bhp. If the bhp has changed then the performance has changed and they are still misleading us.

RX-8 Zoomster

To offer a healthy counterpoint, I do not think they are misleading us. The stated flywheel HP was correct before it entered port. After it entered the US, the stated HP was revised by Mazda.

The performance hasn't changed (at least not much). As evident by the recent performance runs by Speed Racer. Those are very close to the pre-production tests. I bought the car based on performance not on the stated HP rating (although it was 247 at the time). My point being, if the car only put out a stated 150Hp and had the 0-60 performance it was tested at, I still would have bought it. It's HP efficiency and performance, not stated HP numbers. It's why the BMW 3-series smaller displacement engines come close to the same performance as engines larger in displacement.

TurboSE

To be honest the 238HP number is inflated if the average dyno reading is around 180-185 HP. They are still trying to get away with what they can. Ofcourse the engineers know the capability of the motor as well as which emission requirements it meets, it's the corporate execs that lie and deceive.
As for the HP being there, i'll believe it when I see it. In stock form, I doubt very much now that even the japanese version can make 250HP. I hope it does and they continue to develop the bigger rotary engine as the future of the new rx7 is at stake.

Sputnik

Okay, this thread is moot now...

---jps