JUNKyardHOE

so I have been reading up and from the sites I have found and threads I have looked through, and I am led to believe that the 2004 RX8 has 247 hp... however from more searching I have found a few stock dyno sheets that state 178 rwhp... is the transmission in the rx8 really that inefficient that you would lose almost 70 hp through the drivetrain????

please tell me I am mistaken... because that is terrible for a manual transmission

RX8Soldier

iTrader: (24)

ENGINE hp is anywhere from 232-238 (depending on what magazine you're reading)
Yes, 178WHP sounds about right for a 6 port 6 speed. Usually between 170-190, without mods or tune

JUNKyardHOE

even if you assume that the hp is supposed to get 232 and you end up with 190 you are still losing almost 20% of the power to the drive train which is on par with an automatic


now don't get me wrong I still absolutely love this car... since even after the drop in power through the drivetrain my new 8 has more power than my old car (celica) had at the crank

StreetGT

^ I used to have a 7th gen celi...

and yeah, there is a rather significant loss I'm afraid.
going to the rear wheels takes a toll.

bse50

You also have more ethanol in the gas than other countries. That plays a role as well.
The average dyno plots i see here are around 190\198hp if the engine is fresh and the car in good working order.

Beodude

iTrader: (3)

It's a number. Who cares? Just go out and drive your car. What the RX-8 can does belies it's numbers. They are meaningless.

M3D1C

I'm pretty sure the drive train loss isn't 20%... it more like 12%-16%

which 232*15%=34.8
34.8=hp loss
=232 - 34.8 = 197.2whp AVERAGE

now thats an example drivetrain loss isn't a flat % all around it
is different but around the same...Feel free to add input too

*if my math is wrong, please feel free to correct*

JUNKyardHOE

your math is correct... and from what bse said with a max at 198 that sounds a little better

alnielsen

iTrader: (4)

How about a little history lesson.
Mazda originally listed the HP at 247. That was the rating for the Japanese spec car. Mazda later had to downward list the HP for the American spec car to 238 due to the engine tune for pollution standards. This was later revised again to 232 due to a change in the US government standards for measuring HP.
Some have speculated that that measurement is still too high.

bse50

Holy truth, plus not all rolling roads are created the same.

MR_Fisher

alnielsen is correct. However, "rolling roads" (aka: a dynamometer) have nothing to do with this number. Mazda - or ANY manufacturer for that matter - does not use them to measure power output. All engines are measured on an engine dyno in a lab. Outside of a car. This is the most accurate way to measure the torque output of an engine, then calculate the horsepower figure from that number.

bse50

You're right on the spot but this thread started with the results from a dyno so i thought i'd add that as well to the user's complaint

The truth about drivetrain losses is that they vary. Break a transmission and you'll get 0 power to the rear wheels!

MR_Fisher

The only convenient method for us to use, however, is a "rolling road". We just have to put up with the inconsistencies they are prone to. If you want a big number to quote people when you are bragging about your car, use Mazda's Brake Horsepower (bhp) number of 232. If you want to compare what a modification has done to your car's power output easily, use the Rear Wheel Horsepower (rwhp) number provided by a local shop's dyno.

If you want to have fun with your car, drive it and you'll forget about every number except the ones that matter - how fast you're goin', what gear you're in, and when to shift.

Renesis555

iTrader: (8)

haha wow, I also came from a Celica!(2000). Like Beodude said, it's just a number. The fun and experience from driving the 8 is what counts. <3 my 8.

REDRX3RX8

Are you fishing or do you own one?

I mean, I track my 07 6spd auto with only 212 rated engine bhp, and if I dynoed it'd probably be only 170 hp if I'ma lucky.

So fockying what!

I track with the big boys at 90 mph slowing to 60 for the corners, and the only cars that can lap me are the GTR's.

I run with 500hp cobra Stang's all day and they can only pass me if they knukle down and drive right.
\
If you want a supercar, don't be cheap; get out the $100k bill, and calm down.

JUNKyardHOE

definitely not fishing... and some pictures are in my sig

basically the purpose of this thread was to determine whether my research was correct or not and it appears that it was not and the trans is just as efficient as I was hoping... and like I said I love to drive this car and it is great in the corners

and for the record numbers are what I do... I am a mechanical engineering student so I can't help it so this research wasn't for bragging rights either, if I wanted big numbers then I would have bought a v8

champi0n

iTrader: (1)

I have a 1st generation N/A dodge neon that can do the quarter mile in under 13 seconds with full interior (actually minus spare tire and jack) and still take me to work every day. It's got about ~188hp and ~175tq at the wheels. The thing is an absolute monster when you floor it!

It absolutely DESTROYS my rx8 in the 1/4 and will embarrass you to shame when you get beat by a neon.

Drop a few corners on the track and the rx8 eats it up no problem. Doesn't even break a sweat.

So looking at numbers, my neon is a better faster car. While in reality... its not.

JUNKyardHOE

oh trust me when I say I understand that better than most... I always loved the celica forums because it's not the fastest car in the straights but you put it on a windy road and it will eat it up, and there were always people coming on the forum talking about how slow it is compared to their 60's camero or whatever they had and then they of course had to bash on how slow the celica is... when the reality is if you put the cars side by side on an autox course my celica would have put it to complete and udder shame... so 1.8L vs. 6.5L don't mean **** on a road course... or I guess in my new case 1.3L vs. 6.5L don't mean ****

Snrub

Mazda initially advertised the output as 247hp. They then revised it down to 238hp. Later they adopted the SAE standard method of measuring HP and it was revised down again to 232hp. 232hp is the more accurate number for the earlier cars, as it is for the newer cars. Many suspect 232hp is still a bit on the high side.

RIWWP

iTrader: (2)

:lol LOVE IT!

I don't think enough people pay attention to weight, in it's various forms, and what it costs in terms of power.

^v they are remarkably ... similar.

8upbad

iTrader: (3)

Beodude is right, the #'s for this car mean next to nothing. The 8 will go 148mph STOCK, the 50/50 balance helps you take turns going much faster and the 9500 RPM limit (also stock) is just epic. I've owned a lot of cars and this one is uniquely amazing.

M3D1C

I pushed mine 158 stock... although it might have been a slight downhill, and after I got that high, I just slowed down.. isn't the fuel cut off supposed to kick in?