rxse7en

Any chance for PDA datalogging for the 7?

Brian

zjbarra

iTrader: (2)

NZ, I think what worries people (including me) is that if you cut the fuel at say, right when a new rotor face opens to the intake port, you get the fuel that is in the intake manifold forced in but no more making it a lean mixture which might still ignite and if not, that still would mean that there are different phases where it would. I might be wrong in the way I'm looking at it, but that's what has always worried me about the idea.

Blowtus

hailers... my t2 goes full lean (ie, something over 14.7) as soon as the throttle is lifted enough to shut off one injector. Find it interesting that you're experiencing a rich condition when the injectors should be shutting off, due to the tps signal... the tps is functional and set on these cars I assume?

turbo2ltr

iTrader: (1)

It is something we'd definitely like to do. Because of the lack of a diagnostic port the way it comes from the factory, it would be something offered with the Stage 2 upgrade. (Stage 2 is a daughterboard, not just a chip)

Regards,
Mike Montalvo
digital tuning, inc.
www.pocketlogger.com

NZConvertible

You need to stop thinking of the fuel as flowing continuously, and think of each cycle as a discrete event. At the beginning of each eccentric shaft rotation, the ECU looks at all the sensors, determines how much fuel is required and when the spark should be fired, and then performs those actions as the rotors pass the appropriate point in the cycle. It repeats this cycle for every revolution. If the ECU sees that boost is over the programmed setpoint, it simply doesn't inject any fuel for that cycle. It doesn't get part way through a cycle and then decide to cut fuel.

J-Rat

iTrader: (2)

Yeah, but electronic rev limiters make COOL flames!!!!...

zjbarra

iTrader: (2)

ok, so you're saying it will have decided if it's cutting fuel by the opening of the next rotor face and doesn't just say, we hit max boost, cut the fuel in the middle of cycles. That makes sense, good stuff.

NZConvertible

Only if they cut ignition.

J-Rat

iTrader: (2)

Well, thats what I meant, apparently I wasnt clear on that.

HAILERS

***Blowtus**** no, if I let off the throttle in a normal way the aft goes as lean as the meter will show (25.5) as the primary injectors shut off. I'm talking about an almost impercievable letting off. One other fellow with a wideband said he sees the same thing. I can see it with a wideband or a regular 02 sensor and a multimeter. And, yes, I can set a tps correctly.

Blowtus

ah right. My misunderstanding
never noticed it on my .1sec refresh rate lcd screen, I'll keep an eye out now...

Snrub

iTrader: (1)

Hendrik's up to 1.6psi contribution of the boost sensor makes sense for what I'm seeing. I have a broken/perhaps never worked homemade FCD. What happeneds is that it outputs a constat voltage equivilant to ~8.4psi.

Fuel consumption is way up for just driving around. I can see from the stock boost gauge that it rises with only the slightest throttle, but becomes accurate after a while. The car won't go into closed loop, but this is not enough to account for it. Highway millage has been reduced more than city millage (even for open loop). This makes sense to me too.

This would also explain what people like RETed have said about the boost sensor not having any influence on fuel delivery. In the cases they're probably interested it wouldn't.

anobii

Im gonna bring this one back a little bit, it's got some really good info on fuel injection. I am a bit confused, however, about the injector sizeing. Ok stock an s5 t2 runs 550cc primaries and secondaries, Is it just me but is this not ungodly huge for the displacement af a 13b? 2200cc/min from four injectors feeding 1.3 litres. Why is that not enough fuel? Notice the max cc/min capability is almost double the displacement. I'm not pretending I know very much about fuel injection, and i'm really asking to learn. For referance purposes, just because this is what i have experianced in the past, I had an 86 pontiac trans am, that came with a 305ci (5.0l) V8 and Tpi. I replaced this engine with a 400ci (6.6l) V8 and retained the stock injection setup. The stock injectors were 19lb/hr (or 210-220cc?) with the 6.6l on these injectors it ran unbelievably rich at idle and leaned out at 4000rpm due to 100% maxed duty cycle. Ok after messing up a few injectors I called summit, they said 29lb/hr will be perfect. Installed the new injectors and they flowed more than enough fuel than I'd ever need for this thing. The point is with 29lb/hr (or i guess around 320-330cc/min) injectors it was plenty of fuel for a 6. fricken 6 liter. To compare thats 320cc or so to .825 liters (one piston) for the V8 and 1100cc to .650 liters (one rotor). What gives, what makes the rotory so differant? Why does it need so much more fuel to run? I'm just trying to figure this out, when people talk about useing 1600cc/min injectors it blows me away. With that, 1 injector would flow enough fuel flow to run a V8. What am i missing here, help me out.

-E

BlackRx7

rotary flows much more air in one stroke that a piston engine of the same size, sometimes even more than a piston engine almost 2 times its displacement

This is due to the 3 faces of the rotor, one rotation of the eccentric shaft is equal to 3 rotations for a crankshaft on a piston motor.

Since it flows much more air in one rotation than a piston engine, it also requires much more fuel. As well as more power potenial per crank than a piston engine.

What ever happened to Henrick? is he still makeing those chips?

anobii

Okay, now im not trying to be dificult ( i promise).

One rotation of the eccentric shaft of a single rotor would equal 6 rotations of the crank of a single pistoned engine, as a four stroke only fires every other time.

Do does the injector(s) pulse once per revolution, or 3 times per revolution? This is important to me figureing this out , because if it pulsed 3 times per rotation it would only need to be able to spray enough fuel to one face of the rotor at a time. If this is the case then it should only require 1 330 cc/min injector per rotor and would be good up to 250 HP per rotor, based on the formula:

HP x brake specific fuel consumption / # of cylinders x duty cycle, or in this case 250x.60 = 150
---------- ----- = 31.25lb/hr
6x.80 = 4.8

# of cylinders was 6 because a 6 cylinder fires 3 times per revolution.

Okay, now to simply end my question all you would have to say is the injector squirts once and continuously through 1 full revolution.

This still dosent explain why 2200cc/min is stock when 1900cc/min is enough fuel flow to support 500hp based on the formula above replaceing # of cylinders with 12 (because a 12 cylinder fires 6 times per revolution, just like a rotory) and multiplying by 6. Can anyone explain that one?

I am really sorry to be so long winded, but I cant stop thinking about this. Im one of those who likes to know why, and not just how. It's taken me a while to come up with this so be gentle thanks

-E

drago86

When you make one for the NA remove the rev limiter(if it has one see below), also it'd be nice if you could make something like a MAF to AFM translator so we could all use cheap/ non restrictive GM hot wire setups. Also is there any truth to the whole the s4 ecu isnt fast enough to do calcs above 8000 rpm,.. or is it just a rev limiter?

drago86

making a daugther board with a data out port would be a good idea too, so we could data log stuff,.. and if you could make it so we could change stuff through this port (probably impossible unless you installed a little rom burner) it would be like having a standalone for half the cost.

Henrik

I have the daughter board in proto on my car now. It gives me full datalogging capabilities and also sets the stage for sending tuning updates to the ECU (added a little extra memory for this). What features would it need for you to shell out 3-400 (1/2 a standalone)?

Use of MAF is on the list as well, just need time... (damn day job!)

Next stage will be a mod that has some timing retard and moves the secondary staging point lower.

-Henrik

usmcjsy

iTrader: (1)

I am patiently waiting on the 1.5 upgrade here

gsracer

the ability to use larger injectors (4 x 720, 720/850, 550/720, etc...) similar to the e-manage. Just plug in the injector size on the e-manage and it compensates.

maf
being able to control secondary activation point
being able to adjust timing retard/degree of boost (similar to a dizzy set up)


You'd have my money, and I think many other t2 owners who have extensive bolt on's but need an intermediate zone between a safc and a stand alone.

drago86

3-400 is kinda steep, not sure you could get NA guys to shell out that much (look at the low number of NA's on stand alones) I'd target the price of a mega squirt if i were you 150-250$, of course the more features the more id pay. Datalogging is nice, setting the rev limiter where you want it, the MAF translation would add alot of value, as the main reason NA people go stand alone is usually to ditch the AFM. Built in SAFC type tunning would be nice and make it even more value, maybe something for ignition timming set up like the afc is for fuel, but this isnt criticle, just nice to have. It'd also be easier if you did it in instalments like the rtek7 for the T2's, like 75 bux now for rev limiter removed and i dunno slightly better fuel and ingnition maps,.. then latter like 75-100 more a few months latter for MAf translation and datalogging, then 100 bux more for ignition/ timming control. Or maybe have it modular somehow, so if you only need the rev limiter cut basic chip, you buy that +like 20 bux to install a place for a daughter board to plug in. Then later when you can afford it you can buy a daughter board for it that does what you need at the time/mod level your at. I just think you'll have trouble getting large lumps of cash from most NA owners unless you do it in small steps. It's awesome to have someone developing stuff like this for our cars though. So ultimatly for an NA ecu best case would be ajustable rev limiter, ajustible timming, ajustable fuel delevery, MAF(use something commonly avaliable liek the GM ones) to replace AFM, and data logging (only useful if it allready has ajustable timming/fuel or you have an SAFC)

Also maybe have some kinda plug in module you can purchase latter that would let you use a wideband on the stock ecu, have an output to display it on a guage and data log it, and maybe some way to mess with closed loop for better gas mileage,.. that just an idea though,..

RETed

Rotary BSFC is typically over 0.60.
At high RPM's, BSFC can surpass 0.90, while a boosted piston motor would be hard pressed to hit 0.80.
What does this all mean?
The rotary sucks in terms of efficiency.
Rotary engine output can be down as much as 20% versus a piston motor.

Comment on the thread...

This is not linked to recent thread about the Rtek 1.5 chip upgrade.

I haven't seen this thread until now...

I commend Henrik on cracking the code!
You can only modify the ECU so much before you hit all kinds of limitations (namely the AFM).
The price is very attractive, but at a certain level a stand-alone EMS is going to give you another level of flexibility that you cannot attain doing a "ROM tune".


-Ted

NZConvertible

Nope, not even close. You need to stop thinking of a 2-rotor as being similar to a 6-cyl just because there are six rotor faces. The rotors spin at one-third of e-shaft speed, so each rotor is fired once per e-shaft revolution. This means a 2-rotor has the same number of power pulses per rev as a 4-cyl.

I recommend you check out the animations at Rotary Engine Illustrated, as it's a lot easier to understand if you watch it happening.

The injectors fire once per e-shaft rotation.

Agent_D

iTrader: (2)

to disable the AWS on my car, i removed that wire from the bottom of the radiator as per advice on this forum, that was as simple as that was for me at least, i dont remember who told me, but it worked when i did it. i would love to see one of these chips for the N/A, would lowering the 2ndary injector point on the n/a relieve us of the hesitation that we experience at 3800?? im not sure, the MD Racing ECU that they used to sell had a rev limiti of 9000 on S4's so im assuming the N/A ecu can handle over 8000 rpm, unless it was an added code. has anyone done data logging on the N/A to see if RP's numbers of 59-63% duty cycle on n/a injectors is true?? other than removing the rev limiter, adding a fuel cut and removing AWS for n/a im not sure there is much else that could be added to improve the n/a anymore, but i could be wrong

drago86

Using a MAf insted of an AFM would help tons, and it sound slike Henrik is allready on it. I agree that for now removing the revlimiter and getting rid of AWS would be nice, but i think theres lots more that could be done in the long run, like integrating all the piggyback ecu's we all use function into the ecu.