1stRX8

I put my 8 on the Dyno Today with unexpected results:

Best pull was 184HP and was expecting 205 or so. Has anyone done Dyno's?

DSC was off
93deg F (results temp corrected)
ABS freaked but had no apparent effect
DSC light still came on solid but only after accidentally tapping the brakes.

I will scan the dyno results tonight.

Lensman

Uh-Oh! Here we go again.
Conspiracy theorists: "START YOUR ENGINES!"

1stRX8

I put my 8 on the Dyno Today with unexpected results:

Best pull was 184HP and was expecting 205 or so. Has anyone done Dyno's?

DSC was off
93deg F (results temp corrected)
ABS freaked but had no apparent effect
DSC light still came on solid but only after accidentally tapping the brakes.

I will scan the dyno results tonight.

wakeech

interesting: your torque was a scarily smooth curve, with a range of ~100 - ~125 ft.lbs... hmmm...

btw: what's your milage, how did you break her in, and what fuel are you running?? have you had your post-break-in tune up??

DisneyDestroyer

Let me see if I can remember some of the comments from the last individual who put their car on a Dyno:

a) The car is still pretty new, even if you've put on the 600 miles. Try again at a few thousand.

b) One car, one machine, one test. Not necessarily valid enough to conclude anything.

c) You would do that to a car that's so new???

I think that covers quite a bit of the comments...

brothervoodoo

So, two dyno's now and both fall well below what the high-power should be, and that's taking into the effect the expected loss of power to the back wheels. I hope we start getting a definitive answer on what is going on...

ZoomZoomH

iTrader: (1)

give it another try when you got a few THOUSAND miles on it.

someone mentioned rotary engines don't make full power until a few thousand miles and the compression builds up?

Lensman

I don't believe this. It's a myth.

ZoomZoomH

iTrader: (1)

then i don't know what to say....

someone with connections care to ping Mazda about this???

Lensman

Which Pro-Technik dyno did you use please? Where was it (in Texas?) please?

daedelgt

Max torque seems right on the money. Asuming its about 130 ft/lbs with 17% drive train loss (from the graph) you get about 157-158 ft/lbs of torque at the flywheel. Sound right to anyone else?

I think it's genuine. You can see some marks around the top left, and bottom left sides of the image that are by no means even, which you would normally see in a computer generated image.

The Beav

i've got two thoughts so far

1 - not all dyno's give the same numbers, dunno the reason why, but different dyno's give off slightly different numbers

2 - on a dyno you cannot develop your full potential power that you can while one the road, because your intake has to work harder to get air (since it's not being shoved through it like it when your car is moving), but also you are drawing in substancally less cool air (and thus less dense), usually warm to hot air depending on the layout of the air surrounding the dyno, if you want a more real world results get some large fans to help the inatke get cooler air

also it'd help if you rotated the pic like this

Lensman

As has been suggested, someone who can needs to contact Mazda directly to clear this up. We need to know if the car is designed to produce low power for a while until run in or whether this is some other issue. If it's going to STAY like this then something is seriously amiss right?!

ZoomZoomH

iTrader: (1)

well it's definitely not stuck ports, as you can see clearly when each intake ports open at a certain rpm in the chart.

neit_jnf

I thought that if the DSC was completely off it wouldn't come back on unless you turned the ignition off and restarted the car. Maybe it wasn't completely disabled.

Lensman

This is so.

1stRX8

The car has a thousand miles on it. I have been a rotary enthusiast for 20 years and have NEVER even heard anyone suggest that the engine would continue to build power after a thousand miles. I don't even remotely believe that.

I will certainly go back on the dyno a month from now to see the results. If it makes more power I will apologize.

While I do believe that not all dynos are created equal - I seriously doubt they would vary by 25+ HP. The shop that I went to does high-end work that is subject to scrutiny by other high-end shops. If the numbers don't come close to other dyno's they would not be working on $500,000 german race cars for long.

The RX-8 hardly depends on Ram-Air for horse power. We had the hood open with a few high-velocity fans pointed at the nose. A third gear pull takes at most 9 seconds or so. Not exactly enough to overheat the engine or have any real effect on the life of the engine. After five pulls in about 45 minutes - the run-to-run comparo was VERY similar. The ports open at exactly the same point every time. The HP is very consistent.

I could put a few thousand miles on it, take it out of the car, and put the engine on an engine dyno and expect to see just over 220HP. Even lowering the temp 30deg. wouldn't make 27 more HP and the Dyno computation takes pressure, temp, and humidity into account.

The pulls were made with DSC on and off - it made no noticable difference. Once the system detects a gross error it apparently shuts off and the light (car with squiggily lines) stays lit constantly. If the disable switch does not disable it fully then the dyno results are inconclusive. That would also mean ther is no easy way to check up on Mazda claims of power.

This was never meant to be a conclusive test. I would hope that a few others will take a dyno run and see what they get. I plan on contacting Mazda to simply ask why I might see this result on a dyno. I look forward to hearing some answers.

I want my 247HP!

1stRX8

Mileage: 1010 miles

Fuel: 93 octane although I bet that would make only a slight difference.

Break-in: I drove it on a 600 mile road trip. Fairly easy driving. A couple of bursts here and there. Generally following the rules, however I do believe that the break-in specified in the manual is exceptionally cautious.

What in the world is a post-break-in tune up? changing the oil? Checking the tire pressure?

eccles

Simply pressing the button disables the DSC (and traction control?) until and unless the ABS is engaged, apparently. Pressing and holding the DSC button for several seconds disables it completely until the ignition is turned off and back on again. When in this mode, the DSC OFF and Traction Control ("slippery when wet" lookalike) lights both remain on constantly.

tribal azn2

actually engines do get more power as u put more miles on it, to a certain extent. one of those car magazine did an article on it, they had a is300 from when they first tested it and then they tested it again at like 20000 miles and the car gained like 20% more power and a few tenths quicker. several people at is300.net can also confirm power increases

r0tor

iTrader: (1)

Next time hook up a voltmeter to the Throttle Position Sensor so you can see if the throttle is open 100%... with an electronically controlled throttle and DSP/TCS you never know whats going on unless you monitor the TPS

1stRX8

The dyno shop is at most 300ft from my office. I will take there and do a pull every few thousand miles. I certainly hope the power increases, but my hopes are low.

MikeW

Please dyno in fifth gear (1:1)
You should get 210-220 hp depending on rear tire pressure, and state of engine break in

yawpower

Take a look at the air fuel ratio. It gets progressively richer as the motor goes past 5,000 rpm. This keeps internal parts nice and cool, and keeps the stresses down on the bearings and gears.

The motor is pig rich by the time it reaches 8,000 rpm.

Who knows what the timing curve looks like.

Mazda is simply running the engine in safe mode while all the internal parts are getting to know each other.

This is a wise move for any performance car. Just imagine what the lot jockey, salesman, and test drivers will do to a performance car before it even clocks 20 miles!

Don't worry, just keep driving.

Paul Yaw
Yaw Power Products

1stRX8

Please tell me why this will make a difference, other than making the pull last longer and being harder on the car. I pulled it in third gear.