classicauto

iTrader: (3)

Yep.

What are you tuning wth?

RX7freak08

what do you mean.

scrip7

iTrader: (6)

His engine isn't built yet.

RX7freak08

No one has answered this question or statement.

Evil Aviator

yes

Yes, that is the amount of cc/min per rotor required for the entire engine to produce the horsepower entered. Like any other estimate, the output is only as accurate as the input.

The hp you enter is for the engine, not the rotor. Therefore, for 260hp, your car would require 1050 cc/min per rotor, for a total of 2100 cc/min for both rotors. I assume that you calculated 1050 correctly for your particular engine, as the calculator would not come up with that value given the method I posted.

If you find the method I posted confusing, you can just enter "1" as the number of injectors and it will calculate the cc/min requirement for the entire engine.

So you are saying that you don't know any "real tuners" who are good enough to tune with a narrow band meter? I believe it. Good tuners are rare. Most customers just want a base tune anyway.

... and the best way to save your pennies is to NOT buy a wideband O2 meter or sensor and let your tuner use his own.

Yes, but they can't do any tuning until you buy a piggyback ECU, standalone EMS, or carb conversion kit.

RX7freak08

Ok what about my question.

whorider

I would say the 460's will be fine for an NA streetport. Mine is running rich with the stock 460's and a streetport. Mine gets even richer under heavy load. No need on an NA for anything more.

4WDrift

iTrader: (3)

RX7FREAK- Not entirely sure how you think you can tune with a narrow band.i believe you said that the range is about 14.1-15.1 and anything outside of that range is going to read rich or lean depending on the end of the spectrum its in. Well if you tune a turbo'd car to run an AFR of 14.0 (rich according to a narrow band) at wot and underfull boost the motor will pop not matter if its a rotary or a piston engine. the Temps will get too high and you will detonate.

Most tuners are looking for high 12's to low 13's for afrs AT wot. Given the motor and conditions of course.

Now i do understand what your saying further down about letting the tuner use his own. But for comfort sake and if you mod the car afterwards your more than likely going to need adjustments to your previous tune. Also a portable wideband like most dyno tuners use run around a point leaner than what you will find your wideband to read in your downpipe/header, FOR THE MOST PART

classicauto

iTrader: (3)

Essentially yes. You're engine would be lucky to approach 200whp, and 460's will support that in N/A form safely. So yes, the 460's are fine.

RX7freak08

4Wdrift. I understand what your saying I just thought would it be possible to tune my car with a narrowband. I found out that you cant but I want to make sure I'll have enough fuel for driving. So that is why asked if the 550cc and the 460cc would be fine. From what classicauto said the 460cc is fine.

Evil Aviator

It is possible to tune your car with a narrowband. Your car came from the factory with a narrowband O2 sensor that the stock computer uses to tune the engine on a daily basis. Obviously, most of the people on this forum don't know what they are talking about when it comes to tuning. It is also possible to tune your car with a wideband, or with no AFR meter at all. It depends on the person doing the tuning. It is important to understand that YOU should not attempt to tune your car on your own, regardless of the instrumentation you use, unless you receive good instruction on how to do it.

I was rather hoping that you would be able to determine that on your own.

RX7freak08

I'm trying to think. I was talking to scrip7 over the phone. We were talking about how the T2 S4/S5 has about 185 to 202 for both engines. I'm going to hopefully make 185 but that means that I should use 550cc primaries and secondaries. But even though it is a large street port. The Primariy ports are smaller than the T2 ports. So I think the injector chose is good. With a Port intake I think it might be about right.

classicauto

iTrader: (3)

turbo and N/A car's make power differently. More accurately, they make whatever power they make at vastly different AFR's.

You won't need the TII injectors, the car will run worse with them unless you've got a good standalone to tune them. Plugging in larger then stock injectors will make less power because the car will run rich. Now, you can tune them - but you'll need at the minimum an SAFC, at maximum a standalone - to make them work even close to properly.

RX7freak08

Ok well I really rather have the 550cc on right now to know that i'm going to running rich because i'm not sure if I'm going to detonating. I have alot of air going threw. I have cold air intake with modified throttle body, Ported s5 intake, With pineapple racing inserts and a Large Street Port. I just want to make sure I'm going to be ok.

4WDrift

iTrader: (3)

Your not a car guy are you? If you seriously think that the stock o2 sensor is ment to "tune" with your wrong. The engineers at mazda have carefully calculated injector sizes to match the mtor and timed the pulse width to match them. But they have to compensate for a margin of difference as not all motor are recreated equal within tolerance specs yes, and as motor age they tend to need retuned, and as atmospheric conditions change it needs a different tune. Thats why there is a "narrow band" o2 in the exhaust to compensate and let the motor know what is too far out of "spec" and obivously it can only do so much other wise you would be able to modify your car and the car would simply retune itself for every single mod you did upping the fuel to compensate for high Volumetric Effeciency. its only ment to keep things within a certain parameter. When you are on boost the only thing the engine is looking for is to make sure your not hitting boost cut, and its looking for a signal from the vaf and baro sensors and just dumping fuel according to a pre determined level. its not ment to do anything else.

Sorry long rant its just not possible to tune with a narrowband effectively! you tune your car without knowing your afr's and i will see how long to make it.

Roen

iTrader: (2)

you can tune with a narrowband and EGT gauge, several tuners on this forum have been doing so for ages.

You don't need a wideband to tune, if you're good enough.

scrip7

iTrader: (6)

This thread needs to die. So much misinformation, it's getting ridiculous. It isn't worth the risk of popping a motor by going lean under hard accel if you tried to effectively tune with a narrowband. They just don't have response rates or the tuning range of a wideband. Period. End of story. Fini.

Roen

iTrader: (2)

Of course not, you (not anyone in particular) shouldn't have any business tuning on a wideband either if you don't know how to tune in the first place.

Tuning isn't only done by AFR's, the best will tell you that. I personally hope to see how they do it someday.

Evil Aviator

Good God you are totally lost.

Kinda funny how people like us post the truth, but nobody ever believes it because of all the internet dipshits who pretend to be tuners.

What, you mean that a dipshit + wideband = a dipshit with a wideband? I thought that a dipshit + wideband = mega awesome tuner, or so say the wideband vendors! lol

It's done by trends.

cloudx189

iTrader: (3)

Just one question... could the stock ECU be able to read with a Wideband 02 Sensor? ALL I want to know...
Let a pro teach ya.

Roen

iTrader: (2)

yes and no, it can't read the 0 - 5v output, but since the stock ECU requires an O2 sensor, and some wideband O2's have a narrowband simulator, you can use that 0 - 1V output to avoid tripping any check engine lights.

But if you're thinking of directly plugging a wideband O2 sensor to the stock ECU, then no, you can't.

cloudx189

iTrader: (3)

Thanx Roen... that always bothered me. Now I need a bung at the collected end of my downpipe....

84stock

iTrader: (5)

I have tune v8's long ago being 45 now, so yeah we did tune back in the day with egt readings and plug readings. later came the narrowband. I upgraded to a wideband last year, and i gotta say it is an unbeatable tool for tuning. I have my car dialed in perfectly at cruise, light throttle and wide open throttle. It runs beautiful, and that's with a "carb". Imagine what you could do with a little education, a laptop and a standalone if you know what you are doing.

RX7freak08

Oh I never thought that you guys would still be interested in this thread. We can drop it basically. I wanted to know if I'm going to be running lean or rich. How I wanted to make sure I had enough fuel from my injectors.

Evil Aviator

The incorrectly-sized T2 secondaries will cause your engine to run rich beginning at about 3800rpm. In order to use those secondaries you will need a fuel computer or standalone EMS to keep the engine in tune.