Whats the max MPH the RX-8 Can output
12-21-2005 | 12:33 PM
#26
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Originally Posted by 4 years to Supercharge
Yup but it would be tough to get past emissions.
I've seen a 3 rotor running, mind you it was not completely tuned it was quite apparent that it would not pass emissions in most states.
I've seen a 3 rotor running, mind you it was not completely tuned it was quite apparent that it would not pass emissions in most states.
Maybe they've already been working on it & it's jus not ready yet? Now maybe it's harder to convert a rotary engine from port fuel injection over to D.I. than it is a piston engine, but if they can basically "slap on" a D.I. head onto their 2.3l 4banger piston engine, how much harder could it be to do the same to a rotary? Jus wonderin.
Oh & this is my 1st post on this forum so thanx in advance to all who welcome me & choose not to flame the newb!!
12-21-2005 | 12:36 PM
#27
n00b
Joined: Jun 2005
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From: Bay Area, CA
Originally Posted by Aspire705
Now I've been wondering about this for a lil while & maybe it's been answered already, but why doesn't Mazda just add the 3rd rotor and make the engine direct gas injection (or whatever phrase u choose to describe that tech) to lower emissions back to acceptable levels?
Maybe they've already been working on it & it's jus not ready yet? Now maybe it's harder to convert a rotary engine from port fuel injection over to D.I. than it is a piston engine, but if they can basically "slap on" a D.I. head onto their 2.3l 4banger piston engine, how much harder could it be to do the same to a rotary? Jus wonderin.
Oh & this is my 1st post on this forum so thanx in advance to all who welcome me & choose not to flame the newb!!
Maybe they've already been working on it & it's jus not ready yet? Now maybe it's harder to convert a rotary engine from port fuel injection over to D.I. than it is a piston engine, but if they can basically "slap on" a D.I. head onto their 2.3l 4banger piston engine, how much harder could it be to do the same to a rotary? Jus wonderin.
Oh & this is my 1st post on this forum so thanx in advance to all who welcome me & choose not to flame the newb!!
Putting a 3 rotor engine into our cars would not help keep things down cost wise.
12-21-2005 | 12:50 PM
#29
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Originally Posted by cleoent
Part of the reason the FD was the last rx7 in the states is that it priced itself out of our market.
Putting a 3 rotor engine into our cars would not help keep things down cost wise.
Putting a 3 rotor engine into our cars would not help keep things down cost wise.
But why would production costs increase so much when they already use a 3 rotor engine for their racing endeavors?
12-21-2005 | 12:54 PM
#30
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I'd bet the # of buyers Mazda would get from a 350hp/240lb.tq 2.0l rotary RX8 would more than make up for the increased costs of producing such an engine.
I for 1 would buy an RX8 w/ that kinda power over anything else costing up to 35k. Wouldn't you guys?
I for 1 would buy an RX8 w/ that kinda power over anything else costing up to 35k. Wouldn't you guys?
Last edited by Aspire705; 12-21-2005 at 01:09 PM.
12-21-2005 | 01:01 PM
#31
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p.s. Sorry for the threadjack Melchior, I just get kinda passionate about cars when I see room for improvement & wanna get to the bottom of things.
If any of the mods would like to move/separate this thread from its original topic, plz feel free 2 do so. Sorry bout that peepz. Thanx much.
If any of the mods would like to move/separate this thread from its original topic, plz feel free 2 do so. Sorry bout that peepz. Thanx much.
12-21-2005 | 01:16 PM
#32
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So is that the final say on the subject guys? Are cost & emissions the limiting factors keeping us from having a 3+ rotor engine in our cars?
C'mon...I kno some1 has something to add to this discussion. Or is it that this question's been beat 2 death already & no1 has the energy to waste on flaming the new guy & telling me to "search" or "read the stickies/faqs"? lol If that's the case, I guess I should be thankful to you all cuz I've seen many a newb almost get flamed right off the board. lol
In any case, if this topic has already been concluded, thanx for humoring me this long.
C'mon...I kno some1 has something to add to this discussion. Or is it that this question's been beat 2 death already & no1 has the energy to waste on flaming the new guy & telling me to "search" or "read the stickies/faqs"? lol If that's the case, I guess I should be thankful to you all cuz I've seen many a newb almost get flamed right off the board. lol
In any case, if this topic has already been concluded, thanx for humoring me this long.
Last edited by Aspire705; 12-21-2005 at 01:26 PM.
12-21-2005 | 01:17 PM
#33
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From: California
Originally Posted by dmp
Oh - and the weight of the car doesn't matter to the car's top speed. My car with 238hp and 4000lbs would have the same top speed as another rx8 with 238hp and 3000lbs.
Visit http://auto.howstuffworks.com/tire4.htm for a full explanation.
Cheers,
1.3L
12-21-2005 | 03:13 PM
#35
RX8 and a Truk....
Joined: Nov 2004
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From: OKC
Originally Posted by 1.3L
Not true. There is a thing called "Coefficient of Rolling Friction" that can't be repealed. All other things being equal, it takes more power to push the heavier car in your example to the same top speed as the lighter car.
Visit http://auto.howstuffworks.com/tire4.htm for a full explanation.
Cheers,
1.3L
Visit http://auto.howstuffworks.com/tire4.htm for a full explanation.
Cheers,
1.3L
You're mistaken. Friction is not weight. In the case of a car, increased weight could lead to more Friction. For the sake of reality and for the sake of this thread, his car having 1 person in it or 4 people would make NO recognizable difference in his car's top speed.
12-21-2005 | 03:18 PM
#36
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Not that I'm challenging ur logic or nething, but just so I understand. Even tho increased weight negatively affects acceleration, you're saying that it wouldn't likewise reduce a car's top speed?
Am I reading that right? Could u briefly explain that? Thanks!
Am I reading that right? Could u briefly explain that? Thanks!
12-21-2005 | 03:23 PM
#37
RX8 and a Truk....
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From: OKC
Originally Posted by Aspire705
Not that I'm challenging your logic or anyhing, but just so I understand. Even though increased weight negatively affects acceleration, you're saying that it wouldn't likewise reduce a car's top speed?
Am I reading that right? Could you briefly explain that? Thanks!
Am I reading that right? Could you briefly explain that? Thanks!
Right. Weight affects how long the car takes to reach it's top speed - not it's ultimate top speed.
12-21-2005 | 03:31 PM
#38
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lol Oh I see you have a problem with me writing shorthand internet language huh? Ok, no biggie. Just remember not to ever get caught doing the same. 
You sure about that? I'm no physicist, but it seems logical that more weight does limit a given vehicle's top speed.
Maybe you're right then. Thanx 4 the input.
You sure about that? I'm no physicist, but it seems logical that more weight does limit a given vehicle's top speed.
Maybe you're right then. Thanx 4 the input.
12-21-2005 | 03:36 PM
#39
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From: California
Originally Posted by dmp
You're mistaken. Friction is not weight. In the case of a car, increased weight could lead to more Friction. For the sake of reality and for the sake of this thread, his car having 1 person in it or 4 people would make NO recognizable difference in his car's top speed.
1.3L
12-21-2005 | 03:41 PM
#40
RX8 and a Truk....
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From: OKC
Originally Posted by 1.3L
I guess you didn't bother to read the link I provided. Oh well, have a nice day.
1.3L
1.3L
Of course I read the link - I'm saying that the info in the link doesn't matter.
The guy stated 'Assuming the car weighs 2800lbs, what's it top speed with 238hp?'
I'm saying, the car's weight will have no effect on his top speed. INCREASED FRICTION, however, is another story. If his RX8 weighs 2800lbs, 3000lbs, or 3800lbs is immaterial.
12-21-2005 | 03:51 PM
#41
Oil Injection
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From: Orlando, FL
1.3L : very interesting read. I honestly did not some of that info...thanks!
I knew that weight in the car increased the rolling resistance against the road, but not at such a large rate based on speed/weight. Wow.
I knew that weight in the car increased the rolling resistance against the road, but not at such a large rate based on speed/weight. Wow.
12-21-2005 | 04:01 PM
#42
RX8 and a Truk....
Joined: Nov 2004
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From: OKC
Originally Posted by KYLiquid
1.3L : very interesting read. I honestly did not some of that info...thanks!
I knew that weight in the car increased the rolling resistance against the road, but not at such a large rate based on speed/weight. Wow.
I knew that weight in the car increased the rolling resistance against the road, but not at such a large rate based on speed/weight. Wow.
But it won't increase the rolling resistance to a point where you'd know the difference...today's sidewalls and **** aren't yesterdays.
Where's a good physics geek when you need one?? lol :D
12-21-2005 | 04:36 PM
#45
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From: California
Originally Posted by dmp
I'm saying, the car's weight will have no effect on his top speed. INCREASED FRICTION, however, is another story. If his RX8 weighs 2800lbs, 3000lbs, or 3800lbs is immaterial.
1.3L
12-21-2005 | 04:42 PM
#46
RX8 and a Truk....
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From: OKC
Originally Posted by 1.3L
Everyone please remove your hat and bow towards dmp, for he is the first person in the world to repeal the law of physics!
1.3L
1.3L
Try this: Drive to the Salt Flats. Do a Top speed run. Now, go ahead and fill your car with bricks and run again. Your car will just take longer to get to the same speed you reached on the first one. If you don't, it's not the weight...it's Aerodynamic drag, or broken axles, or something.
Don't shoot the messenger because you don't agree with what I'm saying. I'm right. Seriously.
Last edited by dmp; 12-21-2005 at 04:59 PM.
12-21-2005 | 04:46 PM
#47
RX8 and a Truk....
Joined: Nov 2004
Posts: 4,658
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From: OKC
NSX-specific, but accurate:
http://www.nsxprime.com/FAQ/Miscella...queHPSpeed.htm
http://www.nsxprime.com/FAQ/Miscella...queHPSpeed.htm
Many factors affect top speed. Weight (except very indirectly) is not one of them. Think about WHY there's a top-speed limit at all (i.e. How come you can't just put a really tall 5th gear in a car and accelerate all the way up to 600 MPH or beyond?)
The reason is friction, of which there are three main sources: Aerodynamic drag, losses through the transmission, and tire friction. The loss from each of these sources increases geometrically with increased speed. Eventually, you reach a point where all the engine's power is being used to overcome these losses, so none is left over for acceleration.
Weight affects none of these drag sources except tire friction, and even then, its effect is almost COMPLETELY overwhelmed by aerodynamic losses. If you loaded up an NSX with a couple tons of lead, it'd only drop the top speed by maybe 10 MPH or so.
The reason is friction, of which there are three main sources: Aerodynamic drag, losses through the transmission, and tire friction. The loss from each of these sources increases geometrically with increased speed. Eventually, you reach a point where all the engine's power is being used to overcome these losses, so none is left over for acceleration.
Weight affects none of these drag sources except tire friction, and even then, its effect is almost COMPLETELY overwhelmed by aerodynamic losses. If you loaded up an NSX with a couple tons of lead, it'd only drop the top speed by maybe 10 MPH or so.
12-21-2005 | 05:15 PM
#49
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From: California
Originally Posted by dmp
I'm sorry you had to resort to scarcasm - doent mean I'm wrong. Just means you don't understand it. (shrug)
Try this: Drive to the Salt Flats. Do a Top speed run. Now, go ahead and fill your car with bricks and run again. Your car will just take longer to get to the same speed you reached on the first one. If you don't, it's not the weight...it's Aerodynamic drag, or broken axles, or something.
Don't shoot the messenger because you don't agree with what I'm saying. I'm right. Seriously.
Try this: Drive to the Salt Flats. Do a Top speed run. Now, go ahead and fill your car with bricks and run again. Your car will just take longer to get to the same speed you reached on the first one. If you don't, it's not the weight...it's Aerodynamic drag, or broken axles, or something.
Don't shoot the messenger because you don't agree with what I'm saying. I'm right. Seriously.
1.3L
