Seems like numbers from atleast 3 different dynos suggests the rx-8 is putting out 180 rwhp way short of the advertised 247 bhp. The rx-8 forum has the charts posted. Can anyone here who might work for mazda or a mazda dealer try and find out what the hell is going on??? This could turn into a total disaster for the rotary engine comeback.

 

OOWIES!!!!

 

.. oh dear, I hope this is a glitch, Mazda has said that sales of the RX-8 will determine the fate of a north american FE. I know in canada ALL rx-8's have been sold, which is scary considerinng there won't be a single part or enigne available for that car, in Canada, till after Xmas soonest.

Do you have a link to that dyno?

 

http://rx8forum.com/showthread.php?t...highlight=dyno

 

For charts, go to www.rx8forum.com tech and performance sections.

 

When I test drove a prototype RX-8 back in January I thought it had no power. Some people said it was because it was an early car and that something was probably wrong. My streetport GSL-SE felt so much stronger. Looking at those numbers it completely backs up what I said based on my driving impression. My GSL-SE runs mid to high 14's and weighs much less than the RX-8. Based on that chart my horsepower to weight ratio is better. To the people who didn't believe me: Maybe something really is wrong on those cars though or the drivetrain has ridiculous amounts of friction.

 

Look at the AFR ratio for the Dyno, i think its just the ecu detunning during break in.

 

manufacturers always quote flywheel hp and you are quoting rwhp. Still seems a bit low though unless there is 30% drivetrain loss. Are you sure it was the higher hp engine? There are 2 different ones.

 

hmmm....remember when Mazda overstated the hp on the miatas???

 

umm..read my post again, carefully. I said it made 180 RWHP and mazda has it rated for 247 BHP. You can't have 67HP drivetrain loss unless their clutches are really bad. Anyway, they are the high performance, 6-port cars not the lowly automatics.

 

If someone really wants to get to the bottom of this... Start a little P.R. problem for Mazda....

Write a letter/email to a major magazine CLEARLY stating the "problem" and provide the links to the proof. Hopefully the magazine will investigate and/or get the scoop from Mazda for you!

Brian

 

The 255 hp 3rd gens typically dyno around 215 or near this number. It would be hard to believe that a 250 hp engine would dyno only 170-180. That is a huge difference.

 

My feelings %100 !

I test drove the RX8 and the engine feels "soft" definatley no where near the power they claim ! (In Australia we get the 237bhp version) due to tighter emmissions standards. Either way it sucked ***.

RENISIS is a scam ! give me peripheral exhaust ports any day. Funny how in Japan some tuners are already making mods to bring back the peripheral exhaust obviously to regain the losses in power !

 

I'm laughing hard now... all these kids were drooling over the thought of 250hp N/As and "imagine how much power they can get with mods!"... not realizing that the nature of side exhaust ports and the way the engine was designed for them means that you can't bolt on 50hp with an exhaust like you could with peripheral exhaust... and now it appears that once again Mazda overstated things. I would like to hope that the problem is break-in tuning, or as someone else mentioned the tertiary ports not opening...

Be interesting to see what Yawpower gets on their dyno, given that all that is being dyno tested is the engine, not the engine + Mazda's tuning.

 

i think its the ecu break in detuneing

 

That seems reasonable given the a/f ratio. I doubt mazda would be willing to give up easy gains in fuel economy. However, even if this is true I don't think the mileage switch can account for the entire difference.

 

yeah, um, read MY post again carefully. I guess I should have added a after the 30% drivetrain loss part to clarify for those who might have thought that 30% was "normal".

 

I hope Mazda can get to the bottom of this soon!
The Miata was one problem they delt with before concerning horsepower numbers also.
Some of the early RX-8's were having problems with the ports not opening when they were tested by the mags.
Let's hope it's the same.
Believe it or not but as of late a lot of the manufacturers are having problems backing up horsepower claims.
The present Viper is showing up with 20 hp missing. The dealers are calling them back to remedy the problem which involves removing both heads and changing all the valves with the only difference than before being that they are putting them back in with a three angle valve job with the hope to gain the missing 20 hp.
When Ford first released the new Cobra they had the same problem also. Their remedy were to replace the intake manifold with a much better desinged one. I remeber one law suit against them where they rented our Dyno for an entire day trying to prove the owner wrong. The owner one that one
Have faith people. Let's hope it's something simple.

 

I thought most cars ran a running in map until you took the car back for its first oil change.

IIRC Mazda did this with the 3rd gen RX7's

 

I thought that the out-put was about 250 before all the drive-shaft, and tranny loses.?

which would put it at about 200rwhp?

 

I heard that there was an RX8 at vishnu tuning with only 1500 miles that only made 157rwhp.

boy the owner must have been pissed. I know I would be

 

What type of dyno's were those runs recorded on? if they are dyno dynamics then it would be right on que, on a dyno dynamics with 27% reading discrepency between flywheel and RW HP, 180rwhp = 248fwhp. which is what they are claiming

 

These were dynojet numbers.

 

i thought dynojet numbers were higher then mustang dyno numbers.

 

A member of the rx8 forum had their car dynoed at pettit and put down around 170rwhp. What kind of dyno does pettit have?