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Old 01-17-2009, 10:35 AM
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Originally Posted by paulmasoner
anyway, i say go for it... run a straight pipe however you decide to set it up and see how long you can take it before you decide it was a bad idea you said you just want the sound... you ever heard a rotary uncorked? and ppl think ricer fart cans sound bad and loud....
There is not a piston engine made that can match the ear splitting scream of an uncorked rotary. When sound regulations first came into motorsports, it was due to racing rotaries.
Old 01-17-2009, 02:59 PM
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...and that is why we drive the most awesome cars, ever.
Old 01-18-2009, 01:57 AM
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Maybe, try 2.5 inch pipes to keep the noise quieter.
Old 01-18-2009, 11:44 AM
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this thread is the perfect barometer to what kind of people are on this forum. It seems like anything cool here gets trashed. I want to know why if i ran it to the side its dumb but if i put it through the rotary accent its cool?
Old 01-18-2009, 11:48 AM
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Originally Posted by 04RX8man
ok ppl.....now less backpressure will not DIRECTLY reduce power....however with less backpressure the motor will run more rich....we all know(or should know) that a 14.7:1 AFR is PERFECT now with smaller or no backpressure the motor will run rich....say10:1 or 9:1 something like that so without being able to adjust AFR (we are talking about a stock motor no AP or tuning device)

Now yes a slightly rich mixture like 12:1 will cause BETTER PERFORMANCE however running extremely rich will not increase performance....And we have no way of knowing how rich it is running without having an AFR gauge to keep an eye on it..

The motor will run rich which will of course burn more fuel. when the plugs ignite the entire Mixture is not burned up because of too much fuel so there is lots of fuel being dumped into the exhaust system..... Therefore SOME less backpressure YES will net more power because of a slightly rich mixture however Zero backpresure will burn more fuel and make an EXTREMELY rich mixture and will not NET ANY extra power...

Like i said running straigt from manifold is almost zero backpressure and an extremely rich mixture having straight pipes with a small resonator or Y pipe Xpipe and running out the back of the car will give enough backpressure to lower the AFR to a SLIGHTLY rich mixture and net more power....




I have a MM AP. Rotaries run better pig rich
Old 01-18-2009, 12:16 PM
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Also causes more carbon buildup and exhaust heat..
Old 01-18-2009, 01:04 PM
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Originally Posted by 04RX8man
ok ppl.....now less backpressure will not DIRECTLY reduce power....however with less backpressure the motor will run more rich....we all know(or should know) that a 14.7:1 AFR is PERFECT now with smaller or no backpressure the motor will run rich....say10:1 or 9:1 something like that so without being able to adjust AFR (we are talking about a stock motor no AP or tuning device)

Now yes a slightly rich mixture like 12:1 will cause BETTER PERFORMANCE however running extremely rich will not increase performance....And we have no way of knowing how rich it is running without having an AFR gauge to keep an eye on it..

The motor will run rich which will of course burn more fuel. when the plugs ignite the entire Mixture is not burned up because of too much fuel so there is lots of fuel being dumped into the exhaust system..... Therefore SOME less backpressure YES will net more power because of a slightly rich mixture however Zero backpresure will burn more fuel and make an EXTREMELY rich mixture and will not NET ANY extra power...

Like i said running straigt from manifold is almost zero backpressure and an extremely rich mixture having straight pipes with a small resonator or Y pipe Xpipe and running out the back of the car will give enough backpressure to lower the AFR to a SLIGHTLY rich mixture and net more power....
there is so much fail in this post. you clearly dont fully understand how the PCM uses fuel trims...

Originally Posted by alnielsen
There is not a piston engine made that can match the ear splitting scream of an uncorked rotary. When sound regulations first came into motorsports, it was due to racing rotaries.
thats what i was getting at

Originally Posted by lamarvannoy
this thread is the perfect barometer to what kind of people are on this forum. It seems like anything cool here gets trashed. I want to know why if i ran it to the side its dumb but if i put it through the rotary accent its cool?
if YOU think its cool, go for it. Your original question got answered, everything beyond that is our opinions. Take them or leave them

i think its dumb either way


Originally Posted by tubingchamp
Also causes more carbon buildup and exhaust heat..
afaik carbon buildup is mostly an effect of burning oil in the combustion chamber and has very little to do with AFR. also my understanding that given otherwise equal parameters, generally leaner = higher egt

Last edited by paulmasoner; 01-18-2009 at 01:06 PM.
Old 01-18-2009, 03:34 PM
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^thanks but i understand how cars in general work and how the PCM works....but yall can do what u want i'm not going to fight and stroke ur Epeen!

OP it's ur car if u like it do what u want to it....ppl don't like my chrome wheels but i do and that's y i got them!
Old 01-18-2009, 11:11 PM
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Originally Posted by 04RX8man
almost positive u will get a nice ticket for that one....also running straight from headers to side will have almost NO backpressure so any performance ur trying to gain it will not happen performance will just go down!!!! t

that is SO FLIPPING wrong i'm embarrassed for you.
Old 01-18-2009, 11:15 PM
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Originally Posted by 04RX8man
ok ppl.....now less backpressure will not DIRECTLY reduce power....however with less backpressure the motor will run more rich....we all know(or should know) that a 14.7:1 AFR is PERFECT now with smaller or no backpressure the motor will run rich....say10:1 or 9:1 something like that so without being able to adjust AFR .... BLAHBLAH BLAHBLAH BLAH BLAH
man you are so deep in that hole if you dig any deeper magma is going to shoot out. just stop already.


there are more smilies and i WILL use them
Old 01-18-2009, 11:16 PM
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Originally Posted by lamarvannoy
this thread is the perfect barometer to what kind of people are on this forum. It seems like anything cool here gets trashed. I want to know why if i ran it to the side its dumb but if i put it through the rotary accent its cool?
because of the noise level as someone posted earlier.
Old 01-18-2009, 11:17 PM
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Originally Posted by lamarvannoy
Rotaries run better pig rich
that is close to being as wrong as 04rx8man. you cant be serious?
Old 01-18-2009, 11:18 PM
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Old 01-18-2009, 11:19 PM
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damn zoom laying the smack all over the thread
Old 01-18-2009, 11:27 PM
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Originally Posted by 04RX8man
ok ppl.....now less backpressure will not DIRECTLY reduce power....however with less backpressure the motor will run more rich....we all know(or should know) that a 14.7:1 AFR is PERFECT now with smaller or no backpressure the motor will run rich....say10:1 or 9:1 something like that so without being able to adjust AFR (we are talking about a stock motor no AP or tuning device)

Now yes a slightly rich mixture like 12:1 will cause BETTER PERFORMANCE however running extremely rich will not increase performance....And we have no way of knowing how rich it is running without having an AFR gauge to keep an eye on it..

The motor will run rich which will of course burn more fuel. when the plugs ignite the entire Mixture is not burned up because of too much fuel so there is lots of fuel being dumped into the exhaust system..... Therefore SOME less backpressure YES will net more power because of a slightly rich mixture however Zero backpresure will burn more fuel and make an EXTREMELY rich mixture and will not NET ANY extra power...

Like i said running straigt from manifold is almost zero backpressure and an extremely rich mixture having straight pipes with a small resonator or Y pipe Xpipe and running out the back of the car will give enough backpressure to lower the AFR to a SLIGHTLY rich mixture and net more power....
um...
Originally Posted by lamarvannoy
I have a MM AP. Rotaries run better pig rich
..............huh...?
Old 01-19-2009, 12:36 AM
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What the hell is going on in here?

I take a break for 2 days and all hell breaks loose!.

https://www.rx8club.com/series-i-aftermarket-performance-modifications-23/so-you-wanna-tuner-100333/
Old 01-19-2009, 01:12 AM
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Wow, I'm late to the party on this thread. How I missed it I don't know.

Clearly there's a couple people in here that need to leave the tuning, and all information behind it, to those who have the complete understanding. I'd suggest not giving any tuning advice what so ever.

Thankfully the majority of the crowd around here are educated enough about tuning the RX8 to see through BS.
Old 01-19-2009, 10:12 AM
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ok via straight from my school book Automotive Service by: Tim Gilles

"The desireable air/fuel mixture is about 15:1 which is about 9,000 gallons of air to 1 gallon of fuel. a normal a/f mixture for High power is about 12 parts to 1. This is a 12:1 mixture and is called rich. Maximum power ocurs from 12:1 to 12.5:1 AFR (called rich). the ratio for maximum economy is 15:1 to 16:1 called lean"

"A rich mixture results when there is too much fuel for the amount of air. 9:1 would b a rich mixture. A slightly rich mixture (12:1) for instance) will improve power but WILL result in fuel economy and increased exhaust emissions."

So this is straigt out of a 1600 page automotive service book please show me where i'im wrong about the AFR being rich will make more power but "pig rich" will not make more power...If this is wrong let me know I"m just trying to learn and this is what i have been taught! thank u

Last edited by 04RX8man; 01-19-2009 at 10:19 AM.
Old 01-19-2009, 10:25 AM
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just a chart of fuel consumption with afr's and power performance with differnet AFR's
Attached Thumbnails Straight pipes-performance-chart.jpg  
Old 01-19-2009, 10:30 AM
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AZ

Originally Posted by 04RX8man
please show me where i'im wrong about the AFR being rich will make more power but "pig rich" will not make more power...If this is wrong let me know I"m just trying to learn and this is what i have been taught! thank u
READ! I posted what you need to know.
Old 01-19-2009, 10:51 AM
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ok i read it and a couple parts twice....so what i am saying about AFR is correct as u said that u want to b in the 11:1 to 12.5:1 area for best performance which is exactly what i was saying. Most in that thread is things I already knew but does not hurt to read up on them again and refresh myselft on the concept...

BTW MM nice write up
Old 01-19-2009, 10:57 AM
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Originally Posted by 04RX8man
ok i read it and a couple parts twice....so what i am saying about AFR is correct as u said that u want to b in the 11:1 to 12.5:1 area for best performance which is exactly what i was saying.
Uh, not. You aren't understanding what you are reading.

14.7:1 is stoichiometric.
13.3:1 or so is maximum power for an N/A app.

11.5:1 - 12.3:1 or so is for a BOOSTED application, though maximum torque will happen at the lean end of that range.

The flame front actually speeds up as the mix gets richer until the low 11's or so, then is slows down.
Old 01-19-2009, 12:32 PM
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Old 01-19-2009, 01:31 PM
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ok so for a BOOSTED setup say i was tuning i want to see about 12.3:1 for maximum torque...

However for NA i want to see around 13.3:1 CORRECT?

Still trying to learn I now understand (I think) I was thinking for a Boosted setup not NA but either way somewhat more rich will net more power....
Old 01-19-2009, 01:32 PM
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oh and however if i was seeing 11.5:1 on a boosted setup it would still b a safe range to b in as far as engine being sound and not running too rich or lean.....correct???


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