MazdaManiac

iTrader: (3)

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.

Red Devil

You really have no idea how amused I am now...I've discussed the GT3076R .82 AR with several vendors...all of which told me the GT30 was way too small. Looking at the compressor maps, it loooked like a damn good fit to me anywhere from 7-12psi, but the efficiency is about 5 points less than the GT35xxx series.

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...

MazdaManiac

iTrader: (3)

That is a good turbo - if you intend to run 14 PSI with a 100% efficient intercooler.

Red Devil

If you find that, without ice, etc..., please let me and everyone else know.

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.

MazdaManiac

iTrader: (3)

At a Pr of 2, the GT28 would run out of steam at 9200 RPM, but you run out of fuel way before that.

Red Devil

I'll have to take a look at that closer, then. 1 bar is definitely way higher than what I consider practical for this application. For that matter, I feel 1.82 is very optimistic - then again I'm not an expert. Thanks for the pointers.

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.

Bro Maniac do u have a calculation for RX8 4AT???

theboy

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.

mac11

iTrader: (1)

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.

MazdaManiac

iTrader: (3)

I'm pretty confused by that as it stands!

The calculation work the same for every engine. You need to know the Ve at different load points for it to be accurate, though. That is why I had people scrambling for MAF datalogs the other day - I was computing the actual Ve of the 6-port.

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!

theboy

Bingo! now i get what u mean!

Tudor

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

dynamho

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.

spraycola

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?

MazdaManiac

iTrader: (3)

No. Just push the right pedal a little longer. If you want to get there more quickly, then there are possibilites.


I don't know if I'd call that a "myth". I think I'd just call it a completely incoherent thought based on some weird mixture of meth and Jagermeister.


Why did you post this "Q" here, anyway? Did you even read the "mission statement" for this thread?

spraycola

bro, i dont even know what a mission statement is... are you russian?...

tdiddy

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?

MazdaManiac

iTrader: (3)

Not really. It is an approximation.
The OEM PCM does some really funky things that can't be calculated - you would have to data log them.
I'm working on a comprehensive set of datalogs that show the OEM PCM's tuning at various PRs.

KenichiYamamoto

Very nice compilation

MazdaManiac

iTrader: (3)

^^ 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...

swoope

iTrader: (5)

^^^^^

if your avatar were only truly you.

i feel your pain.

beers

zoom44

chickenwafer

rotarygod

LOL!!! Owned! I looked him up too! KenichiYamamoto aka chickenwafer is a prison guard in Phoenix, AZ!!!

MazdaManiac

iTrader: (3)

So, how did Dave spoof the "join by" date?

zoom44

he either actually signed it up back then or has accessed someone elses account