Where in the drivetrain is the RX-8 losing so much power?
06-12-2008 | 06:21 PM
#27
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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?
Anyone else have any thoughts on this?
06-12-2008 | 06:32 PM
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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.
They also have a different...diff...which could better transfer power to the wheels, but I don't know.
06-12-2008 | 10:30 PM
#32
06-12-2008 | 10:33 PM
#33
06-12-2008 | 11:53 PM
#34
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....
Guess they're experiencing the same vanishing hp phenom over there too....
06-13-2008 | 12:03 AM
#35
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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?
06-13-2008 | 12:09 AM
#36
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.
Last edited by kersh4w; 06-13-2008 at 12:13 AM.
06-13-2008 | 09:49 AM
#37
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.
Paul.
06-13-2008 | 10:52 AM
#38
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.
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.
06-13-2008 | 11:47 PM
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06-13-2008 | 11:53 PM
#45
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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.
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.
06-14-2008 | 09:08 AM
#46
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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.
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.
06-14-2008 | 01:35 PM
#47
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.
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.
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