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-   -   Where in the drivetrain is the RX-8 losing so much power? (https://www.rx8club.com/series-i-tech-garage-22/where-drivetrain-rx-8-losing-so-much-power-148231/)

fahrfegneugen 06-12-2008 06:05 PM

I doubt you can find any car that lives up the factory numbers.

Falken 06-12-2008 06:21 PM


Originally Posted by RatedX8 (Post 2506193)
Could the hp difference have something to do with why some engines lose compression or go kaput very early? Might there be a connection? I remember when I first picked up my car (brand new 07) and being new to rotaries, I had a number of different people tell me how a rotary should be broken in? Drive it like you stole, burn rubber out of the dealership, etc. So, I followed Racing Beats break in procedure. At 7000 miles, I can feel the engine is stronger than when new. Could a simple break in procedure be the reason why some engines die an early death or don't put out advertised hp numbers?

I really, really think this is an amazing line of discussion to pursue.

Anyone else have any thoughts on this?

LionZoo 06-12-2008 06:24 PM


Originally Posted by Brettus (Post 2506243)
what makes you think it will be any higher than the older models ?

Lubrication changes.

Brettus 06-12-2008 06:31 PM


Originally Posted by LionZoo (Post 2506275)
Lubrication changes.

for an extra 15 hp ? I don't think so ...

Racing beat got an extra 2hp by premixing at 80:1 so there is your benchmark .

Falken 06-12-2008 06:32 PM

I would think that would improve reliability more than anything, but hey, miniscule changes in ignition timing have netted people 10hp. You never know.

They also have a different...diff...which could better transfer power to the wheels, but I don't know.

delhi 06-12-2008 07:09 PM


Originally Posted by fahrfegneugen (Post 2506257)
I doubt you can find any car that lives up the factory numbers.

err... the Nissan GT-R defies that.

nycgps 06-12-2008 10:30 PM


Originally Posted by fahrfegneugen (Post 2506257)
I doubt you can find any car that lives up the factory numbers.

Dont say that buddy.

Nissan R35's true hp numbers are actually *higher* than what Nissan saids.

nycgps 06-12-2008 10:33 PM


Originally Posted by Brettus (Post 2506243)
what makes you think it will be any higher than the older models ?

I think because after all the *testing that we did for Mazda*, Its safe to say that Mazda should have a better clue on how to push more HP out of this little 1.3L sucker.

Eight 06-12-2008 11:53 PM

Couldnt find a dyno for the 250hp (Type S) but found a 5spd mt rx8 stock rated at 210hp factory, and the dyno result was 123kw which is at 173hp(?)
Guess they're experiencing the same vanishing hp phenom over there too....;)

rotarygod 06-13-2008 12:03 AM


Originally Posted by RatedX8 (Post 2506193)
Could the hp difference have something to do with why some engines lose compression or go kaput very early? Might there be a connection? I remember when I first picked up my car (brand new 07) and being new to rotaries, I had a number of different people tell me how a rotary should be broken in? Drive it like you stole, burn rubber out of the dealership, etc. So, I followed Racing Beats break in procedure. At 7000 miles, I can feel the engine is stronger than when new. Could a simple break in procedure be the reason why some engines die an early death or don't put out advertised hp numbers?

I think you're on to it. I've mentioned this before when we found out about the new oil metering system and I made the thread about the Renesis issues finally being resolved(?).

kersh4w 06-13-2008 12:09 AM


Originally Posted by Mazmart (Post 2506196)
I hear you. I would actually pay to see a chassis dyno on the newest RX8 (Literally). I'd be surprised if it doesn't exceed 190.

Who'll participate in this exercise? I'll put my money where my mouth is.

Paul.

exceed 190? almost every single rx8 puts down 185 or less. 190+ is a pipe dream that few have seen. only the people that have spent tons of money will be close to factory hp numbers. or the very lucky.

lets say the standard rx8 makes 180whp, and the cobb AP adds 15whp. thats 195whp. 232^.15=34.8. 232-35=197. that means you have to spend $700 extra to just get where the car should be in the first place? thats utter bs on mazda's part. not to mention, thats really tuning out the engine, you cant go much more than that. which is more bs, because i'd like to buy a car with the hp numbers i thought it had, and then tune for additional hp. not to make up lost hp.

the numbers i got drag racing 14.48, plus the weight of my car, 3000lbs, roughly equate to 185whp. the math works out in both drag racing and on the dynos to 215hp at the engine.

Mazmart 06-13-2008 09:49 AM

Pure speculation: I think they've been making increased power since 06 or 07, through internals and tuning. I've personally seen an 04 make about 220 on an engine dyno with stock everything including exhaust (I won't say who's dyno). My wild guess is that all the stir about the numbers stirred them to build and tune to the best they could within the EPA limits allowed for that car, resulting in 232 hp.

Paul.

nycgps 06-13-2008 10:52 AM

Im repeating myself, after all these years Mazda should (finally) be able to squeeze more HP out of their Renesis, Im sure they made quite a lot of changes to the engine itself, even it looks exactly the same.

For example, the rotor housing you can buy today is not the same version found in 2004 engine. So yes Mazda made some changes to it. What update? who knows.

Mazmart 06-13-2008 12:29 PM

Most people don't know that the apex seals have gone through 10 part# revisions since their introduction.

Paul.

robrecht 06-13-2008 12:58 PM


Originally Posted by Mazmart (Post 2507343)
Most people don't know that the apex seals have gone through 10 part# revisions since their introduction.

Paul.

Wow. Very interesting.

Brettus 06-13-2008 06:13 PM

if they added a secret ingredient that nets another 20 hp - i'd be interested :)

Razz1 06-13-2008 08:14 PM

^ It's called ceramic.

The content is very small. don't ask me how I know.

mysql 06-13-2008 08:18 PM

how do you know?

Delmeister 06-13-2008 11:47 PM


Originally Posted by Falken (Post 2505455)
Where in the drivetrain is the RX-8 losing so much power?

The RX-8 stock in top condition puts out 232hp at the crank, no? Yet only 175 or so ever make it to the wheels. Thats a 25% power loss.

What part/parts is/are eating so much power?


Originally Posted by Falken (Post 2505486)
Fine. 20% loss.

Where is it?

Heaven forbid you get an answer to your question.

Falken 06-13-2008 11:53 PM


Originally Posted by Delmeister (Post 2508160)
Heaven forbid you get an answer to your question.

Its all good as long as I'm learning something, and this is an interesting topic line nonetheless.

Although I wouldn't mind knowing.

Can anyone tell me the equivalent overall car weight losses from the rotational parts per pound? Like 1lb off the flywheel is equal to Xlbs off the weight of the car.

Falken 06-14-2008 09:08 AM


Originally Posted by Charles R. Hill (Post 2508292)
The location of heat is the place(s) where you will find the greatest losses/highest inefficiencies in the engine and drivetrain.

The nearest analogy I could conjur up to answer your second question is dependent on being a 3,000 lb. vehicle. I have read that each pound removed from rotating mass at the flywheel is about 2.5-2.7 h.p. gained at the wheels. General math indicates that each 5 h.p. gained at the wheels will cut .1s off your 1/4 mile times(very rough estimates, though) and that each 100 lbs. reduced will do the same. Thus, each 1 lb. removed from rotating mass is roughly equivalent to removing 50 lbs. from the car.

Exactly what I was looking for.

Mazmart 06-14-2008 01:35 PM

As part of my job I look at Mazda's part numbers EVERY day. The supercessions (Revisions) to the numbers represent various things not the least of which are'actual' changes. Sometimes it's a supplier, sometimes it's an improvement in the part; it all depends.

It's not typical for a part number to supercede 10 times as with the renesis apex seals. I would guess material composition to be some of it rather than design. By the way, the seal springs haven't changed up to the 09 motor.

Paul.

faboo 06-14-2008 05:24 PM


Originally Posted by fahrfegneugen (Post 2506257)
I doubt you can find any car that lives up the factory numbers.

03+ mustang cobras

390 claimed.......about 420 actual:Eyecrazy:

learn from ur parent company Mazda:uhh: :icon_no2: :eyetwitch


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