RockLobster

iTrader: (7)

Being that i have only been roadracing for a year I am by all means still a beginer.

I have both an S5 Turbo and an S5 N/A. My personal preference for the track is my N/A. The reason for this is by no means that it is a superior roadracing car. I have no doubt my Turbo can destroy my N/As lap times in the right hands. But while I am learning how to drive I need a car that has a simple and predictable powerband and also one that can handle more 7-9k RPM abuse than my turbo. My turbo is my street car that I make sure I am not embarased by hondas in.

So I see where you are coming from but only as a begining racer.

And when i say learning how to drive i mean racing, not everyday driving. I have been driving for 12 years.

I know nothing about AutoX. Im sure its fun but have no desire to playaround in a parking lot when I can roadrace on a real track.

RX7goZoomZoomBoom

Ed thank you for your imput I will look at what mazda says are the appropriate values voltage wise to and from the ecu. It should be very to simulate a single constant voltage to make the ecu happy. Up untill now I have lost faith but you have given me some motivation. This will not only be great for those who want to convert the s5 ecus but for the people who already have s5 ecus and failed OMPs instead of having to spend the 800 dollars from mazda or take a chance on a used omp I can make a simulator for the ecu so it functions and will work with premix.

SS124A

this is rediculous, Bean,
you said you tuned your S-afc based on AFR's from the wide-band during your dyno runs. why couldn't you do the same thing with a stand-alone?

A friend of mine, I don't think you have met yet is running a microtech LT8 on his N/A FC with really good results. i haven't had a chance to fine-tune it for him, but then again, i don't think it is far off anyway.

I would reccomend this set-up to you, for a budget,

But onto the real issue,
I have a complete S5 ECU set-up with OMP.
Lets set it up, and measure what the OMP does based on RPM, andThrottle postion then build the simulator you want.

we can screw with the signal until it throws a code. then back off a little, talk to me aboot it later

I think i have seen them somewhere before, maybe on a japanese website

Evil Aviator

Yeah, pros like Jim Downing, Roger Mandeville, Pete Halsmer, Amos Johnson, etc., are best known for driving turbocharged cars, while street squirrels and wanna-be drifters always go for the simpler NA models that are better suited for a novice.

SS124A

I cannot wait to meet Jim at Rotary Revolution this year!
u

NZConvertible

I assume you mean very easy? You are correct that it would be easy to simulate a single constant voltage, but this will not make the ECU happy, quite the opposite in fact.

The OMP stepper motor has a position sensor, that tells the ECU how far open it is. The ECU uses load, rpm and engine temp inputs to calculate how much oil needs to be injected, and then instructs the stepper motor to open the required amount. The ECU watches the position sensor to see if the stepper motor has obeyed, and if it doesn't like what it sees limp mode is activated. The ECU must actually see the OMP working correctly, and it would take a very sophisticated simulator to do that. Leaving the OMP plugged in electrically, and hence operating normally in an electrical sense, is far easier and gauranteed to work.

SS124A

remember that Electric OMP is pretty heavy, especially compared to a small circuit board.

edmcguirk

It should actually be quite simple. The OMP does not respond to RPM or throttle. The ECU does that calculation. The ECU sends UP and DOWN signals to the stepper motor and then a seperate sensor measures how far the stepper moved. That seperate sensor is most likely just a pot on a 5 volt feed.

The ECU probably has an outer limit like "if the correct feedback isn't reached within 50 UP or DOWN signals -> throw a code and limp". The whole reason you need feedback on a stepper motor is because you are not sure how many UP or DOWN signals will get you to where you want to be.

The cool thing is that you don't need to know what the ECU wants. It tells you UP or DOWN every time you guess.

If you build a circuit that just raises the feedback voltage on every UP signal and decreases the feedback voltage on every DOWN signal, it should fool the ECU. All you need to know is max feedback voltage (probably 5 volts) and min voltage (probably 0 volts) and how fast to get there (not too fast , not too slow).

This is simple stuff for an electronics person. I don't have the experience but anybody could easily look up standard circuits for this type of function in a few hours. It's basically a low pass or averaging filter.

ed

RX7goZoomZoomBoom

Fuzzle
I am going to have to break out the FSm for s5 the last time I looked it did not say what the voltage values were nor did it say the color of the wires so it was kinda fucked to work with.

edmcguirk

I don't have an S5 FSM, I'm just going by common electronic conventions.

Most chips run on 5 volt logic especially voltage sensors. Most position sensors are simple potentiometers running one lead at 5 volts, one lead at ground, and one lead on the wiper that will vary linearly from 0 to 5 volts.

Most stepper motors run on UP and DOWN signals. Voltage on one lead causes it to turn one way and voltage on the other causes it to turn the other.

There should be between 3 and 5 wires running to the OMP (depending on if it needs ground wires) Hopefully the manual will have all that but you could make pretty good guesses with only a voltmeter.

ed

NZConvertible

You are certainly not the first person to post a rough electronic theory explaining how easy this should be to do. However if it really is this simple, why is it that 16 years after the S5 was introduced, nobody has released a product that does this? Remember every Mazda rotary made since then (FD RX-7, JC Cosmo and RX-8) has an electronic OMP. Even in Japan, the land where one stock ECU and ten piggybacks is considered normal, there is nothing that can do this AFAIK. It's been talked about often on this forum, and someone usually says they know an easy way to do it, but it never happens. If someone actually does it (as opposed to just talking about it) then I will be truly impressed. But I'm not holding my breath...

coldfire

iTrader: (1)

wow. i'm currently taking computer engineering and i am pretty sure you pseudo-engineers aren't hitting the mark on this one. please go and try to simulate this device instead of ghetto engineering things in your heads

anyways, in reply to some of the stuff...

- do you not realize that a lot of things other than the ECU changed with the S5? on the NA it was the combination of mainly the new induction system, VDI, higher compression, higher flowing exhaust, that led to an increase in power. the updated maps in the ECU were designed to account for the different characteristics of this engine

- the major changes in the S5 ECU were based on things that were not related to power output but rather driveability and input/output monitoring. as mentioned this includes things such as the new TPS, sensors, solenoids, OMP, etc.
and it doesn't take a computer engineer to realize that you would need that extra speed from the ECU processor due to all these updated electronics.

- how much power are you really making? if the MAF is becoming a restriction, that is impressive because you are putting down more HP than a TII on a stockport NA

- i DO have an S4 mechanical OMP with an S5 ECU (my car is an S5). i did not know at first how it was working, but Aaron Cake managed to find the OMP tied up near the firewall. it was pretty much stripped down to the main body containing the stepper motor. this is your best bet. it's not that big at all, and it should be good enough for someone like you.
i may one day take it apart and examine its inards.

- if you want to do this right you need to get the S5 harness and intake manifold also and do an entire swap. on top of this you also need to get a new CPU (not ECU, it's the one that controls lights, etc.). on top of this you must deal with the OMP, 6pi, VDI, solenoids, vacuum line routing, injectors...i could go on. still feeling like it is such a great "upgrade"?


no doubt that the S5 ECU is a better design...but you don't have an S5, do you?

Evil Aviator

I'm going to up the ante on that one... In 1988 a modified 10AE managed a record-setting 191mph at Bonneville with an estimated 350bhp with the original AFM mounted in the air path. While the AFM is more of a restriction than a MAP sensor, it is not as bad as most people think.
http://www.geocities.com/evilaviator/bonneville

totallimmortal

Honestly if you need more than the stock ECU than you really should go with some type of standalone. I assume you are goin to try to make and s5 ECU work on an s4? all the wiring required wouldn't seem worth it especially since as many people have mentioned the S5 ECU is superior in driveablitly type things and for all this work i wouldn't be suprised if you did not see a gain. Also what is your exact setup cause the 213 number you mentions is about all i'd expect from and stock FC ECU. For that kind of power you really should run a standalone to avoid some potentialy devastating damage to your engine and i'm sure you'll see a better power gain with a stanalone than with a S5 ECU

RX7goZoomZoomBoom

Hey, good input for sure.

But, First I never said it was on a stock port infact I mentioned that when I built the engine I used a combination of turbo and NA parts along with some inducion engineering. The VDI is great for building torque and increasing drivability at lower rpms. The fact however stands that with S5 internals (I.E high comp rotors) the s4 intake manifold flows better and makes more power over all. Also I never said the the stop AFM was becoming a restriction (I,m not really sure how much no having one would help) but I did say that the S5 type 6 flap looks more restrictive then the type 5 or garage door style. I will defend my self a little more later bu I have to go o work right know so untill then.

RETed

Wow, you do like making claims that have no proof to back them up...


-Ted

RX7goZoomZoomBoom

Well, it’s not very nice to come back with a rebuttal that you have no grounds for.
I know that the s4 manifold makes more power because I have personally tested the two against each other on both s4 and s5 internals. The S5 intake manifold is great for maximizing drivability and increasing your all around torque band through the use of the dynamic chamber. But for High rpm applications I can say for sure that the S4 manifold makes more power over all than the S5 at peak. I would like to put the dyno charts up fir everyone to see but I am still working on getting the proper program to convert the charts to a Jpeg.

Mk, thanks, yea

rx7raca

Does he need proof? Or can you prove him wrong? I agree with him about the manifolds. The s5 just looks like it has trouble flowing. Plus with the VDI in the middle of it causing restriction.

One question I do have, is what is the cheapest standalone besides mircotech? I mean thats not even too cheap at little over 700.

Also to give some advice. Make sure that you arent spending to much money on just making the ecu think the OMP is there, when you could have spent the money on a stand alone. Sometimes is better to just upgrade then make due with. Think about it.

RX7goZoomZoomBoom

I don't know what the cheapest stand alone out there is I like the e6k because it is really easy to interphase with and it has the ability to control up to 6 injectors.

As spending more money to convert to s5 its not about money its about race class to go stand alone would put me into a different class and I would not be able to compete.

thank you for backing me up it looks like no one wants to step up to the plate to back up there claims.

NZConvertible

The funny thing about your post is that you're right, but you have no idea why. Claiming you can tell a manifold has "trouble flowing" by looking at it is just silly. If you could do that you could make a killing contracting your services to the engineers who design intake manifolds for car makers. Imagine the time and money you'd save them. It's not the shape of the S5 manifold that is more restrictive at high flows, but the internal size of the runners. And you don't seem to know anything about how the VDI system works if you claim it's "causing restriction". Air does not flow through the VDI valve, it's only a path for pressure waves.

It pays to check your facts before getting cocky with people who know a lot more than you do.

RETed

I'd like to see the dyno sheets for proof.
Any computer can do a "Prt Sc" or SHIFT-"Prt Sc" to capture any image on your monitor.
All computers have MS Paint, so you can just "Paste" the image in there.
You can then "Save As" a jpeg file.
You can do this with almost any paint program - i.e. Photoshop, Paint Shop Pro, etc.

I'D LIKE TO HEAR HOW HIGH COMP ROTORS CAN AFFECT (I.E. INCREASE OR DECREASE) FLOW THROUGH THE INTAKE MANIFOLD?


-Ted

SS124A

I kind of take offence with this, but with out getting into a pissing match,... just not the point here.. trying to move forward etc..

I have tried talking thru parameters so i can actually sit down and get an idea of what circuits would be required to simulate this. Moreover, I plan to do the same as you, and determine what values the stepper motor reports back to the ECU to determine my the values of components needed in the "simulator"

As a pseudo engineer, I think i can come up with some as simple as this.

Please,
everyone, let be nice, and shift this thread into a dialogue to solve problems, and optimize. Not yell and be-little each other, as other people have said, we are in the same army.

I see alot of folks in this thread I have alot of respect for. I know with (y)our heads together we can get thru this.

coldfire

iTrader: (1)

i wasn't trying to specfically target or put you down, sorry if it seemed that way. it's just that a lot of things being said in this thread is nothing new, and i'm kind of sick of seeing things being blatantly thrown around.
i don't claim to know everything either. i haven't got the degree YET

but i can respect that you are trying figure out things in an analytical and methodical matter. and i didn't mean to sound too pompus with the pseudo-engineer comment. we all have a little garage engineer in all of us, me included. just having a bad day at school that day...

RX7goZoomZoomBoom

Damm, why do threads always get mean at the end.
The High comp. rotors are lighter thats how they are effected by flow DUH.
They spin faster need more air.

I'm sorry for being GAy about it but its really simple.
YAAAAAY YAAAAY

totallimmortal

just because they spin faster doesn't mean they flow more air it juust means they may climb in rpms fast and wouldn't require of make more flow. If anything i'd think that they may draw slightly less air than low comp rotors since they would have less volume. Also series determins rotor wieght not compression s5 rotors are light and both na and turbo modles have higher compression, and i;d like to see a flowbench of both manifolds as well as dyno sheets fro the same car with each manifold to end this discrepancy for ever