PEEJAY.....RIGHT ON! Put a fuel pressure gauge on you car with the turbo pump and then with the n/a pump. The rail pressure is going to be the same. At least on a 87 it is.

 

I didn't say spark controls fuel mixture(input value), I only mention that if I relentlessly throw buckets of gasoline at you and you don't have the chance to light it up in time, you get unburned gas(output value), right? Another example(maybe not be pp13's case), if I were to throw in extra wide gap plugs on there do you expect all that fuel to burn completely, I doubt it-and that's where you have a rich condition. So ignition(improper spark) can be a cause of rich condition as well as bad tps,etc.

 

I do believe that a 13:1 air:fuel ratio is just about what most cars look for. But, I am used to the piston crowd, so it may be different with a rotary.

 

They normally shoot for 12:1 on a turbo, and he's nearly getting down to 10:1 on an NA! I think he should try for about 13.5:1 or so.

 

do i get a star for guessing that you would make stock crank hp at the wheels? i was pretty damn close!!!!

 

You where pretty close. But who'd of thought i was running that rich? CJ

 

that ful curve look good you just need the turbo lol

 

i am very interested to see how you get it worked out... keep us posted.

 

hey cj
i was also wondering...how rich does your a/f gauge show that your running?is that thing anywhere close?

~david

 

Just in case you just glanced at PEEJAYS answer to this thread, and did not pay any heed to it.........The turbo fuel pump is not the reason you are running rich. The fuel regulators in both turbo and non turbo are the same and put out 37 to 40 psi at atmospheric pressure. Both regulators, turbo and na, if you put 10psi air pressure on the vac/boot line going to the regulator , will give you 50psi fuel rail pressure. But seeing as how the na does not give boost, it reads the 37-40 max pressure. So you see, it ain't the fuel pump.

 

I think someone else asked this a few pages up...
What is your stock A/F gauge reading?
When I take voltage from mine while driving, it sticks at about .79-.92 while under power, no amount of AFC adjutsment can change it (to the point where th car is bucking, or spewing gas!!)
Conclusion- USING THE STOCK O2 SENSOR FOR ANYTHING BUT A WILD ESTIMATE OF WHETHER THE ENGINE IS ACTUALLY RUNNING OR NOT IS POINTLESS! (And usually you can tell if it's running by, oh, I don't know...) I'm just outlining it's inaccuracy alright!!
Whew.

I definately notice power when I lean mine out- I have mine tuned about down about -8% through the midrange... it makes a VERY noticable difference- more than putting on an exhaust or anything! I haven't touched it over 5000 rpm's though becuase I don't have the wideband yet- and I'm playing it safe!

 

The gauge reads full 3 bars green. Thats as rich as it goes. CJ

 

I would have to disagree. The n/a regulator is set for the n/a fuel volume. The regulator bypasses a specific volume of fuel for a specific manifold pressure. If you increase the volume of fuel(TII pump), then the pressure will rise, from the regulator not being able to bypass the extra fuel. I know both the TII and n/a are set to 37-40 PSI like you said, but theyre not the same. Each is calibrated for its specific pump.

 

MAZDASPEED7 .....I prepared myself for the event someone would say it aint so. I have a 87na and a 87 turbo. I put them butt to butt and hooked a fuel pressure gauge b/t the filter and the fuel inlet on the n/a. I checked the pressure with the N/A pump in the 87na and then swapped the fuel pumps b/t the turbo and the n/a. Same pressure. Felt very foolish doing this knowing what the results would be. Same pressures. With and without a vacuum on the regulator. I'm very pleased withmyself that I took the time to do it yesterday instead of today. Daytona 200 and Monterrey Cart racing today. EDIT: Either pump read just a tad below 40 psi with the vac line off the regulator, simulating full throttle. EDIT: Before I forget, the voltage was 12 and a half volts. Ever notice how, even with a n/a regulator, if you simulate a boost pressure of 10 psi on the vac hose on the regulator, that the FUEL PRESSURE will go to 50psi?? That more or less convinces me that the regulators are one and the same item, whether turbo or na. I do understand the point you were making in your post though. It just does not seem to me to be the case.. Put a turbo pump in your na car and check the pressures before and after. I think you'll find the results the same .

 

Thanks for clearing that up some. I have one more question though. I had a TII pump and 550 cc secondaries on my car for a while. That setup made my car grossly rich at idle. I put the n/a pump and secondaries back on, and it went back to almost normal. Any ideas? BTW, Im just curious, the original n/a fuel system is back on my car, and staying on my car.

 

It might be that the capacities are very close, so you didn't see any significant rise in fuel rail pressure.

My experience - stock turbo fuel pump to Walbro 255lph fuel pump.&nbsp We're talking going from 183lph to 255lph, that's like a 40% increase in fuel capacity!&nbsp My SPI fuel pressure gauge showed a definite increase of 5psi of fuel rail pressure when I did this - pressure jumped from 35psi to over 40psi.



-Ted

 

A Walbro I would expect to overwhelm the regulator, but the turbo pump with 12v going to it in a na car does not.

 

Ok everyone.....my next session is next monday. The only thing that might changed it, is if i have to close my house loan on that day. But othewise i'm there.

I've done a couple things to my car since the last dyno run. The biggest thing is put the s-afc in it. This is the real reason i'm getting it dyno'd again. Just to get all the hp i possiably can from it. I've also wired open my 6 ports. yeah...yeah..yeah...i know. All i say to everyone is make them work....not wire them open. I wanted to find out just how much low end you loose when wired open vs. working 6 ports. Keep in mind i will not be tuning the s-afc lower than 4k rpms, because my a/f ratio was fine below it. So the numbers will be accurate.

I'm also going to wind the crap out if it. I'll probably take it to 8,800....or the down side of the power band.....wich ever comes first. I'm hoping that the down side of the power band comes first.

But anyways, i'm hoping for 180rwhp, up from 157rwhp.

Wish me luck guys.

CJ

 

I think you will be pretty damn close to that!

So you have the S-AFC installed now, and you are getting it tuned on the dyno? Sweet!

Let me know how it turns out, I'm really curious to see what the A/F chart looks like- what mixture your car gets the most power at!

Hey- how do you like the 6 port sleeves? Notice any difference?
Mazdaspeed7 made his, and says he really noticed a big increase in smoothness over anything else.
I just have to find the time...

 

I don't know if i'll be able to drive it until monday with the ports wired open. It feels so doggy down low. Un-wired, the motor reved realy nice, and quick. Now it feels doggy and slow under 3.5k. Not to mention, i can't see how you guys can lock your vdi into high position. O-well, to each his own. It would be better with a lightweight flywheel...but i realy can't afford one now.

On anouther note, Rob said don't worry about winding the crap out of it. He said the apex seals are "special ones" with a laugh. He went on to further say that "Don't worry about blowing up anything....I usually over build your stuff anyways." Whats he think? That i actually drive my cars hard or something??? I would never do such a thing!

CJ

 

what ever happened ?

 

nevermind, found it

https://www.rx7club.com/forum/showth...ghlight=intake

 

QUOTE-
Ever notice how, even with a n/a regulator, if you simulate a boost pressure of 10 psi on the vac hose on the regulator, that the FUEL PRESSURE will go to 50psi?? That more or less convinces me that the regulators are one and the same item, whether turbo or na.

Could that be because the NA and TII fuel pressure regulator is not rising rate via boost but rather has this vacuum fitting for high pressure position for hot start situations (no vacuum on regulator) where vapor lock has occured?

Hmm... Better check that manual under "hot start assist" and read up on "pressure regulator solenoid."

TII does not have RRFPR, but instead incorporates "air bleeds" into the injector sockets.