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2010/2011 RX-7 Motortrend article

 
Old Jul 18, 2007 | 04:23 PM
  #151  
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sound like a plan

back on topic, do you think the 2.0l is a 3 rotor? The rumor i heard is that it is a 2 rotor, but I also heard about a year ago that mazda was getting ready to make 20b 3 rotor engines as a limited production engine for race teams and as a crate motor
Old Jul 18, 2007 | 04:28 PM
  #152  
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Originally Posted by rotary crazy
sound like a plan

back on topic, do you think the 2.0l is a 3 rotor? The rumor i heard is that it is a 2 rotor, but I also heard about a year ago that mazda was getting ready to make 20b 3 rotor engines as a limited production engine for race teams and as a crate motor
they have been making the 20b as a race engine, but almost no one buys them - they take them out of cosmo cars because it's far cheaper.

someone would have to look it up for an exact number, but i seem to recall somewhere around 20k as the price tag.
Old Jul 18, 2007 | 04:35 PM
  #153  
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nope, as I understant it they where making escentric shaft , but they stop making them, you could buy a remanufacture engine but that is another thing. Also production of the center housing has being stop.
Old Jul 18, 2007 | 04:51 PM
  #154  
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whatever the story is, I just hope Mazda sticks to the badge and brings out a massively attractive rotary. The all-new GT-R and EVO seem to yield no place for a friendly rotary like the renesis. They need to go turbo-wild again.

Just my 2 cents
Old Jul 18, 2007 | 04:54 PM
  #155  
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what will be the power to weight ratio of the new GTR?
Old Jul 18, 2007 | 05:55 PM
  #156  
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This thread is such a tease! We are at LEAST months to a year away from any offical information on the internals of the new rotary I don't know if I can handle it!
Old Jul 18, 2007 | 06:05 PM
  #157  
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Originally Posted by Opethdtr
2L with DI would be a huge leap of advancement for the engine. I would sell my kidneys in a heartbeat.
13B rotary engines have already been partially DI since '86.

DI tech is hardly new for rotary engines.
Old Jul 18, 2007 | 06:32 PM
  #158  
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I was under the impresion that DI was spraying the fuel directly to the combustion chamber and at a much higher psi than normal injection systems
Old Jul 18, 2007 | 06:45 PM
  #159  
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Originally Posted by rotary crazy
I was under the impresion that DI was spraying the fuel directly to the combustion chamber and at a much higher psi than normal injection systems
I was also under that same mpression concerning direct injection.

Last edited by Opethdtr; Jul 18, 2007 at 06:50 PM.
Old Jul 18, 2007 | 07:16 PM
  #160  
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The style of injecting into the center flat housing for the primaries is referred to as semi-direct injection.

Paul.
Old Jul 18, 2007 | 09:52 PM
  #161  
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Originally Posted by mac11
oh i took that to mean like ...version 1.5/2.0...the current renesis being version 1.0

I guess thats just me being around computers too much.
actualy that is how i meant it i wasnt talking displacment but version. sorry for any confusion. there was talk back during the engine failure/recall that they might put some "renesis version 1.5" in the pipeline for replacements. basically current renesis with improv vements they had found over the last few years. but those didnt materialise. so my post was saying they have been continuing their work on the next gen renesis but i dont know if its the version 1.5 or if its evolved enough to be version 2.0
Old Jul 18, 2007 | 09:58 PM
  #162  
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Originally Posted by Mazmart
The style of injecting into the center flat housing for the primaries is referred to as semi-direct injection.

Paul.

hey ive seen that- somewhere.....

oh yeah carlos lopez was showing us a housing tapped in the right place and explaining some of the pros/cons ,tuning issues etc. thats a good man right there. wife is a very nice lady as well. i was very happy to meet them last year.
Old Jul 19, 2007 | 07:19 AM
  #163  
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Originally Posted by zoom44
hey ive seen that- somewhere.....

oh yeah carlos lopez was showing us a housing tapped in the right place and explaining some of the pros/cons ,tuning issues etc. thats a good man right there. wife is a very nice lady as well. i was very happy to meet them last year.
I hope Carlos and wife make it to sevenstock this year, really good folks, I was under the impresion that for a rotary to be direct injected the injector would have to be in the rotor housing?

Im some what disapointed, the though of a 2.0l rotary engine made my mouth water, but I allways thought the 1.3l and 1.5l to be more realistic

1.3l=Kabura type vehicle
1.5l=rx-8 second gen
Old Jul 19, 2007 | 07:42 AM
  #164  
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Originally Posted by zoom44
hey ive seen that- somewhere.....

oh yeah carlos lopez was showing us a housing tapped in the right place and explaining some of the pros/cons ,tuning issues etc. thats a good man right there. wife is a very nice lady as well. i was very happy to meet them last year.
I meant that the stock design is semi-direct for the primaries.

Paul.
Old Jul 19, 2007 | 09:31 AM
  #165  
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sorry it was late and i mis read what Mazmart typed
Old Jul 19, 2007 | 09:49 AM
  #166  
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Originally Posted by zoom44
sorry it was late and i mis read what Mazmart typed
Damn youse Zoom!!!! Getting my hopes up on the 2.0 part....
Old Jul 19, 2007 | 11:10 AM
  #167  
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there is more than one way to do direct injection. You could fire the fuel from the top down, near the trailing plug, this has been done before on certain rotary race cars.

What is harder but should yield better economy results, is firing the fuel right between the plugs when the conpression is the greatest, hence the need for high pressure fuel injectors. I would guess Mazda will go this route, since they have teh R&D and the PCM ability to control that with the precision necessary.

You can get around the high pressure injector issue by using a subchamber setup, but I don't know how much better/worse economy is vs. the menthod mentioned above.

the issues raised with DI 12 years ago when it was tried using the sub chamber method were emissions related, not performance, or even really cost. lean burns raise NOx, which until recently, was hard to scrub out with cats.
Old Jul 20, 2007 | 12:48 PM
  #168  
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how about something like this? instead of 2 aux ports 4? and the exhaust ports in the center housing be about the same size as the ones on the side housins
Attached Images
File Type: bmp
Copia de renesis 15 b.bmp (182.3 KB, 147 views)

Last edited by rotary crazy; Jul 20, 2007 at 12:51 PM.
Old Jul 22, 2007 | 10:07 PM
  #169  
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Originally Posted by mac11
I've seen nothing that said the final drive was different. but you can go play around with that calculator all you want. changing the final drive size doesn't change the E.T. or the trap speed just the RPM at which those are achieved.

And that is deff. a bhp not whp rated calculator.
Definately not BHP ratings. Stock FD specs:



If it was BHP ratings, how would it possibly know the whp? Drive train loss is different on all cars. Auto vs manual, different trannys and differentials will make for different ammounts of drivetrain loss as well.

Also, different JDM FDs had different rear diffs. I believe Type RZ and Spirit R FDs had shorter 5th gears and shorter diffs.
Attached Thumbnails 2010/2011 RX-7 Motortrend article-untitled.jpg  
Old Jul 23, 2007 | 08:41 AM
  #170  
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you hit 108MPH in 3rd gear? maybe another shift is in order? and you are telling me the car weights under 2800lbs with a driver in it?


Try that calculation again.

Looks reasonably accurate to me....

FD


RX-8

Last edited by mac11; Jul 23, 2007 at 08:59 AM.
Old Jul 23, 2007 | 10:53 AM
  #171  
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Originally Posted by mac11
you hit 108MPH in 3rd gear? maybe another shift is in order? and you are telling me the car weights under 2800lbs with a driver in it?


Try that calculation again.

Looks reasonably accurate to me....
2780 is the dry weight of an FD and yes, an FD can break 110 in 3rd gear.

maybe a bit more accurate. how did you get the 27" tire height though? 16" rims with 225/50/R16s on them shouldn't be anywhere near 27" high...

Even still, RX-8s don't run 14.09, they run closer to 14.5 and FDs don't run 13.24s, they run closer to 13.5s.

You've still got way too much power. It's a whp calc and if you need me to, I can ask the guy who owns RP.


Alright, also where did 220hp come from for the 8? I thought they had 232?
Old Jul 23, 2007 | 12:36 PM
  #172  
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Originally Posted by velociti
Nah, I meant Cayman. Look, don't get me wrong, the Cayman would be my choice for a litany of reasons, but for outright speed, the Z is not that much slower, or that much worse of a handler. It's a matter of diminishing returns the more you spend. So if not 90%, than call it 80%. My point is, arguably, for twice the price of a Z the Cayman doesn't offer twice the outright performance. Better package, more refined, almost perfect handling as far as I've read and higher quality all around...surely, but not twice tthe performance. All I meant by it...
You are so far off base on this comment. I think you need to go out and drive both of these cars, then come back and let us know if you can stand behind this statement. It sounds like you are comparing these cars on paper, and have no idea what you are talking about.
Old Jul 23, 2007 | 12:56 PM
  #173  
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Originally Posted by SLWASFK
2780 is the dry weight of an FD
How are you going to make a 1/4 mile pass with no fuel and no driver?

Originally Posted by SLWASFK
maybe a bit more accurate. how did you get the 27" tire height though? 16" rims with 225/50/R16s on them shouldn't be anywhere near 27" high...
go look up the actual tire height of a 255/55/16" tire. its 27. where did you come up with 19.xx is a better question??

Originally Posted by SLWASFK
Even still, RX-8s don't run 14.09, they run closer to 14.5 and FDs don't run 13.24s, they run closer to 13.5s.
You are telling me that the calculator is low by ~1/4 second on the FD when BHP is put in yet its supposed to be using wheel HP?

go to the calculator and use WHP(~220) and tell me what kind of E.T. it gives you.


Originally Posted by SLWASFK
You've still got way too much power. It's a whp calc and if you need me to, I can ask the guy who owns RP.
If you put in ~190-200 - what the RX8 generally shows in WHP on a dyno - you get a number that is way to slow. I also used several other cars that I am very familiar with as test beds and they all worked out as this being a BHP calculator.


Originally Posted by SLWASFK
Alright, also where did 220hp come from for the 8? I thought they had 232?
There is always debate on the specifics of the number and the calculator seems to be geared for a bit more drivetrain loss than the RX8 has shown to have so i used a conservative number.

You also have to take into account that this is a calculator. its not magic. it doesn't say what the E.T WILL be. It says what you could run with great traction etc etc. On a real life run you have a bit of inconsistency with driver, tires, etc, etc. using your numbers to be within a 1/4 second is pretty good in my eyes.
Old Jul 23, 2007 | 02:57 PM
  #174  
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Originally Posted by mac11
How are you going to make a 1/4 mile pass with no fuel and no driver?
I'm sorry, 2780 is curb weight with full fluids and all. I forgot the driver, let's say the driver weighs 200lbs.

Originally Posted by mac11
You are telling me that the calculator is low by ~1/4 second on the FD when BHP is put in yet its supposed to be using wheel HP?

go to the calculator and use WHP(~220) and tell me what kind of E.T. it gives you.
It shows a 13.65, right around where a stock FD would run with modern tires.



Originally Posted by mac11
You also have to take into account that this is a calculator. its not magic. it doesn't say what the E.T WILL be. It says what you could run with great traction etc etc. On a real life run you have a bit of inconsistency with driver, tires, etc, etc. using your numbers to be within a 1/4 second is pretty good in my eyes.
BINGO we have a winner. So why was it brought up in the first place?
Attached Thumbnails 2010/2011 RX-7 Motortrend article-untitled.jpg  
Old Jul 23, 2007 | 03:08 PM
  #175  
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Originally Posted by SLWASFK
I'm sorry, 2780 is curb weight with full fluids and all. I forgot the driver, let's say the driver weighs 200lbs.


It shows a 13.65, right around where a stock FD would run with modern tires.




BINGO we have a winner. So why was it brought up in the first place?
you mentioned the magical 700hp FD and how they ran some mystic time that was shown to be possible on the advertised 280hp.

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