Rotary Math
#26
They might not offer the turbo I have anymore. I acquired it 5 years ago.
Personally, I think the Garrett GT2871R is the perfect choice for a street-drive, stock-motor RX-8.
https://www.rx8club.com/showpost.php...6&postcount=11
You are gonna need some BIG injectors all around to see 40+ pounds of air!!!
Really big intercooler too.
Personally, I think the Garrett GT2871R is the perfect choice for a street-drive, stock-motor RX-8.
https://www.rx8club.com/showpost.php...6&postcount=11
You are gonna need some BIG injectors all around to see 40+ pounds of air!!!
Really big intercooler too.
Last edited by MazdaManiac; 01-11-2007 at 03:51 PM.
#27
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Originally Posted by MazdaManiac
They might not offer the turbo I have anymore. I acquired it 5 years ago.
Personally, I think the Garrett GT2871R is the perfect choice for a street-drive, stock-motor RX-8.
https://www.rx8club.com/showpost.php...6&postcount=11
Personally, I think the Garrett GT2871R is the perfect choice for a street-drive, stock-motor RX-8.
https://www.rx8club.com/showpost.php...6&postcount=11
Then you look around and many with GT35 and 60-1 options aren't seeing full spool until like 4500rpms or later.
http://www.turbobygarrett.com/turbob..._700382_12.htm
edit: roughly calc'd about 670cfm capacity intercooler (just throwing 14.4275cfm to lbs/min)...haven't got into the injectors yet...I'm waiting to see Cobb's flash capabilities and if they will match to certain injectors before making such decisions...
Last edited by Red Devil; 01-11-2007 at 04:09 PM.
#29
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Originally Posted by MazdaManiac
That is a good turbo - if you intend to run 14 PSI with a 100% efficient intercooler.
Did that GT28 pull all the way to redline? I hadn't looked that small yet on the Garrett line. But glancing at it, it looks like it would run out of steam below it or the efficiency would really fall.
#31
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Originally Posted by MazdaManiac
At a Pr of 2, the GT28 would run out of steam at 9200 RPM, but you run out of fuel way before that.
#32
Originally Posted by MazdaManiac
CFM does not equal VFR!
You have turned the math upside down.
Those formulas compute the flow of the engine, not the power adder. They just point out the requirements for the power adder.
At what Pr does that fan move 130CFM? Probably 1.0 (which is Pa)! As soon as you raise the pressure ratio for the fan, its flow will drop to almost zero.
Do you have a flow map for the fan? I doubt it.
Turbonetics is a decent company, but I was unaware that they made a kit for the RX-8.
I had one of their T3/T4 hybrids on my '8 for a while and it was perfect.
You have turned the math upside down.
Those formulas compute the flow of the engine, not the power adder. They just point out the requirements for the power adder.
At what Pr does that fan move 130CFM? Probably 1.0 (which is Pa)! As soon as you raise the pressure ratio for the fan, its flow will drop to almost zero.
Do you have a flow map for the fan? I doubt it.
Turbonetics is a decent company, but I was unaware that they made a kit for the RX-8.
I had one of their T3/T4 hybrids on my '8 for a while and it was perfect.
Bro Maniac do u have a calculation for RX8 4AT???
Last edited by theboy; 01-11-2007 at 06:24 PM.
#33
i am not good at this but can someone tell me whether this means:
SUPPORTED MASS FLOW RATE
MFRs = (IFR) x (AFR)
MFRs = (3.33) x (12)
MFRs = 39.96 lb/m
i can only add another 12lb/m to the car on a turbo.
SUPPORTED MASS FLOW RATE
MFRs = (IFR) x (AFR)
MFRs = (3.33) x (12)
MFRs = 39.96 lb/m
i can only add another 12lb/m to the car on a turbo.
#34
Rotary , eh?
iTrader: (1)
Originally Posted by MazdaManiac
You are gonna need some BIG injectors all around to see 40+ pounds of air!!!
Really big intercooler too.
Really big intercooler too.
What is it that I am missing here? The way i have calculated things you would need 40+lbs to maintain 12psi to redline. I don't see how else you would maintain 12psi without moving that much air.
Last edited by mac11; 01-29-2007 at 02:59 PM.
#35
Originally Posted by theboy
Bro if i use 1.0 pa to calculate the mass flow rate. then i will get 1.8lb/m is that correct? i have deleted my previous post so no one will be confuse.
Originally Posted by theboy
Bro Maniac do u have a calculation for RX8 4AT???
Why don't you download the Rotary Math spreadsheet and plug in whatever numbers you like?
I don't think you are getting how the math works.
If you want to get an idea of the flow rate of a given system, just multiply the Pr (Pressure Ratio) times the base mass flow rate.
In your example, you want to use a boat fan. It has a pressure ratio of 1 (meaning it generates no pressure at all at the rated flow).
Use the first two formulas to get the stock flow rate (26.96 pounds per minute) and multiply it by your projected Pr (one) and you get..
26.96 pounds per minute.
You need to know what the actual flow rating is for your fan. I bet you a six-pack of your favorite that at 130 CFM it generates no appreciable pressure.
Furthermore, it would have to generate at least the existing flow rate just to not be a pressure loss (i.e. 369.75 CFM).
So, your boat fan with actually cause a power loss because it will flow less than the engine will try to draw in on its own!
#37
MM - ya da man! Many thanks for great source of information.
I would have to spend several years to get all this information put together the way you did it. Special thanks for the excel files!!!
Unfortunately at the moment I can not rear page 2 of this post (slight problem with database) but I hope it will become available later.
Thank You
Ted
I would have to spend several years to get all this information put together the way you did it. Special thanks for the excel files!!!
Unfortunately at the moment I can not rear page 2 of this post (slight problem with database) but I hope it will become available later.
Thank You
Ted
#38
Registered
Thanks very much for this valuable info. Very handy for specifying fuel delivery system matched to a blower. Impressive work you do, MazMan.
I like your work on the MX-3.
I like your work on the MX-3.
#39
so if i wana go fast i get a turbo with 9 psi ? is that what ya'll are trying to say?
Q: don't the turbocharged rotary engine lack mixture intake at higher rpms because the turbo can not keep up with the engine and thus it blocks the flow?.... or is that a myth?
Q: don't the turbocharged rotary engine lack mixture intake at higher rpms because the turbo can not keep up with the engine and thus it blocks the flow?.... or is that a myth?
#40
Originally Posted by spraycola
so if i wana go fast i get a turbo with 9 psi ? is that what ya'll are trying to say?
Originally Posted by spraycola
Q: don't the turbocharged rotary engine lack mixture intake at higher rpms because the turbo can not keep up with the engine and thus it blocks the flow?.... or is that a myth?
Why did you post this "Q" here, anyway? Did you even read the "mission statement" for this thread?
#42
Finally Boosted!!!!!!!
In the Injector Math spreadsheet, are the vacuum injector pulse width numbers for all three sets of injectors comparable to duration that is seen in the OEM tune?
#45
^^ If it were only truly you...
Then again, how did you join in April of '03 and not post until now?
Please someone tell me this isn't really Yamamoto-san before I start crying like a little girl at an Elvis concert...
Then again, how did you join in April of '03 and not post until now?
Please someone tell me this isn't really Yamamoto-san before I start crying like a little girl at an Elvis concert...
Last edited by MazdaManiac; 03-26-2007 at 12:54 AM.