RX7goZoomZoomBoom

I have decided that the Series 5 fuel managment is slightly better than that of a series 4s.

A. the series 5 ecu holds fuel maps all the way to 9000
B. Dual range tps sensor allows for more acurate engine throttle assesment and fuel judgements by the ecu.
C. The processing speed of the ecu itself is faster
D. because it is an evolution to the S4 its program is more advanced and more consitant.
E. I beileve it will be easier to tune out with SAFC due to its almost linear consistancy.

Down side.
A. Mass Air flow looks like it might be more restrictive than garage door style.
B. S5 uses high impedance injectors that requir a ballast.
C. Different sensor connections

I Do not know if anyone has tried to do this yet but I feel it will yeild some nice results.

I have one problem I do not know how to deal with the Oil metering pump.
I would like to know how I could simulate that its there but use my mechanical or none at all and run a pre-mix.
So for anyone out there running s5 with no Electronic OMP tell me how you did it.


Thank you
Clinton

NZConvertible

All your points are technically correct (except that high-imp injectors don't require a ballast), but this would be a huge amount of work, result in very little real-world gains, and there is no way to deal with the electronic OMP (it must remained plugged into the harness).

Some things are nice to have, but not necessarily worth a bunch of effort to get. Spend your time and money more productively. If you're going to replace your entire EFI system it should be with a Haltech or similar.

RETed

Does that apply to turbos?

How did you determine that?


I don't understand what S-AFC adjustment have anything to do with it.
Both types AFM's spit out almost the same signal, so why would one have any advantage over the other?
I know that the S-AFC works perfectly well on either.


-Ted

SureShot

The MOP is the deal breaker.
If it's position sensor doesn't match where the ECU has positioned the stepper motor to, it goes into default (limp) mode.

wheelmanst

The MOP does not have to be attached to the engine, but it must be plugged in. The computer is happy when it is plugged in. So basically just plug the thing in and hang it somewhere out of the way in the engine bay...it does not have to stay on the motor. I will be running premix in my car soon and as far as I know it is just that simple...I have done a lot of research too.

RX7goZoomZoomBoom

There has to be a way to easily simulate a working OMP.
Also No that 9k redline does not apply to turbo cars those redline at 8k.
S-AFC works better on S5 cars for whatever reason there is no stutering when jumping from one correction to another. No its not allot of work for something small. The work is not that bad and It a really a big deal. Microtech and Haltech are both useless with out hours of dyno time unless you want to use other peoples maps.

I want to fool the ecu from knowing about the status of th omp.

RETed

Define easily...
It's a 4-stepper motor device with a feedback / position sensor.
I'd like to hear how you can do this "easily"!

A car out-of-tune can easily do this.
I've never has problems with S4's that have been maintained to have any stutering[sic] problems.

Wow, "useless" is such a strong word.
I can dyno tune a Haltech install in 1 to 2 hours on a DynoJet.
I can street tune a Haltech in 1 to 2 hours.
I don't call that "hours of dyno time"...


-Ted

Evil Aviator

As per the Mazda RX-7 brochures, the S4 has an 8-bit 16k ECU, while the propaganda for the 1989 models listed the ECU as "twice as fast" as the S4 ECU.

My personal opinion is that both systems are best thrown in the trash can, and replaced with a standalone EMS.

RX7goZoomZoomBoom

I know I should not have said useless, but a stand alone is alot of money and somethimes very difficult to hide. I am tryin to keep my costs down plus I have had lots of luck with the S-afc I should have started out by saying this on a mustang dyno I was able to put down a little over 200 wheel hp with my s4 ecu fc while stutering hardcore. with every correction the thing would wig on the rollers. Now i built my own engine and when I did I made it "special". My friends S5 car with a street port from atkins with all the same mods as me was able to put down 175 wheel horse power. Our fuel corrections were different but I did'nt expect for them to be the same. My opinion of his car was if he had my engine and his managment the car would be puting down 250 rwhp. I know how bold of a statment that really is but you could only understand if you were there. The S5 ecu was so smooth and it delt with the corrections so nicley with no hesitation. I am going to switch to S5 and I am going to run a pre mix like I always have I don't care. I can't run a stand alone simply would not work for my purpose I am sure it would be better but I think I can get damm close with out one.

If anyone has info that can help me than let me hear it.

vicious525E

dont you have to switch out the left side harness (engine and dash)? which would be the reason why im not using the s5 ecu with my s5 engine?

NZConvertible

No, it wouldn't. The differences between the S4 and S5 ECU's would have practically zero effect on peak power. To claim you'd have another 50hp (25%!) is just silly.

The areas where the S5 ECU is superior are emissions control, idle control, transient throttle response, self-diagnosis, boost control (Turbo), induction control (6PI/VDI on NA), OMP control and knock control (Turbo). Not peak power.

RETed

Your car has something serious wrong with, so stop blaming the "inferior" stock ECU.


-Ted

Jesse[SM]

why not just get the R-Tek-7 ECU upgrade?

SonicRaT

iTrader: (6)

I'm a bit confused here, are we talking N/A or turbo? I believe you're talking about N/a, and unless whatever 'special' was, was a p-port or something as severe, 250whp is absurd, 200 is even pushing it for a ported N/A.

RX7goZoomZoomBoom

okay guys, I like all the positive feedback imp getting here. The issue as I see it is that the stock s5 ecru in my experience is more responsive and a little easier base to tune of. When I look at my widebands log to see what all was going on with my FR's I make my adjustments to the safc and fire away. According to the wide bad the FR's are near perfect the EGT's are right were the need to be as well. The think I see happening is that at full throttle at around 6k and then again at 6700 and then again at 7200 and then again at around 7900 and then after 8k I am in hardcore richness so I don't really pull much more out of it. But I have been experimenting with leaning with safc and I have been able to sail fairly smooth to 9k still very rich but not as bad still pulling power out. Anyway the S5 due to wide range tps maybe and the differences in the stock maps pulls further in the rpm band (until it to decides to pig out rich) but the stutter that the S4 ecu it giving me does not happen to the s5 car. It is very possible that I am nearing the max capabilities of my ignition system but that is highly unlikely due the strength of the stick setup. The other thing is I am not here to hurt anybodies feelings but even in this horrible stuttering state the N/A 13B is still putting down a little over 200 (213.7 Highest run at 68 degrees 17% humidity) at the rear wheels. I suppose another 40hp is a little much to ask for but I think that with a smoother climb I will be able to gain at least 15 to 20. I am nearing peak for Stock ecu and near stock runners as horse power goes. I'm sorry I am not running a p-port setup its not really possible with my fuel management I mean it is but it really the S-afc does not have the resolution to tune something like that out. I build engines as a second job and I have had my fair share of horrible failures so I know what works and what does not as engine construction goes. I really only started this forum to see how I could fool the ecu into thinking it has a good and connected OMP other than that I really was just interested in seeing what everyone else had to say about the matter. I really appreciate RETed's info about how the OMP works. This may not seem like its worth the trouble to most but its really all about pushing out the last 5% as they say in racing.

Also if anybody wants to buy some wheels they are very nice 16" Koseis I use them for AutoX because of there offset. The ones that you would be getting are actualy brand new I had to order 5 sets to get them in the states other wise they would'nt even consider it. This was back in the day when I had money but I am trying to build something new now so they are for sale check out the link if you are interested.
http://cgi.ebay.com/ebaymotors/ws/eB...spagename=WDVW

RX7goZoomZoomBoom

Oh yea my car is not turbo I dont like the way power comes on in a turbo car it makes it very unpredictable on the track and at the limits of god. Anyway NA is better all round and while not the most powerful down a straight can signifigantly outway a turbo going into a corner.

YAAAY YAAAy YAAAAy YAAAY

SonicRaT

iTrader: (6)

Turbo's are only unpredictable if you've never driven it and/or don't know how to drive it. When you know where it spools/how fast/etc, it's VERY predictable, and as for weight, well, my turbo car weighs in at less than 2400lbs, so I don't think that'll matter all too much. I am curious as to how you got 213rwhp on a 'stock manifold' setup, even with a bridgeport and every other mod available I've yet to see an n/a pass 210rwhp.

RX7goZoomZoomBoom

why not just get the R-Tek-7 ECU upgrade?

Because I am NA non-turbo

RX7goZoomZoomBoom

. Regardless whether you are trained to the way a turbo spools and even if you have an acute sense of how long it will take before the power comes on. The power band of a turbo rx is very non linear comparatively speaking because it is in respect to other piston powered cars. But the way the power comes on make the car a little more raw at the very bitter edge. I can only explain with examples but for instance when you over estimate your vehicles frictional coefficient going into turn 1 and over a 120mph and you need to recalculate you entry angle and make adjustments with all brake gas and wheel you will find that even the most trained drivers feel that this is were a turbo car lacks finesse. Because of on off nature of this type of adjustment you will find that depending on the time off the throttle the boost will come on at different levels and at different times. The energy needed to make these kind of throttle adjustments in those situations leaves a driver with a lost sense of confidence and it is for this reason that the driver will likely loose his or her but more likely his pace the next run through. It is all a compromise This is only the way I feel and some people have different places were they display most of there strengths. I can not sacrifice the turns because that is were my strength lies

SonicRaT

iTrader: (6)

Understood, but, you also ignore that even in a road course acceleration counts for a lot, this is why I can never beat a turbo at road america or in autocross, due to their ability to maintain damn near the same speed in the corner, and even if they do experience lag or are forced to readjust thus forced out of their power band or to back off due to a spiked powerband, they more than make up for it exiting when they out accelerate me. Now, if the N/a was similary powered to most tII's on the road (that are around 13-14psi pushing 250rwhp), and still streetable, then I'd definatly jump the wagon and go that route for my course car, but it just doesn't work well. Granted, handicaps are great, but even still, our poor cars get so dicked on the handicaps it's crazy. SCCA gives a non-turbo rx7 a worse handicap than an AWD mitsu eclipse turbo, so it's hard to compete and do well even in that aspect.

RETed

Yeah, you can stick to the easier driving car.
Leave the turbo driving to the pros...


-Ted

RX7goZoomZoomBoom

You do make a good point about the SCCA's nice way of making older cars that are better than some newer car in everyway possible seem terrible because of there stupid class rules.
I look at the way scca classes things and it seems the only way to be competitive is to be the one of the top drivers in the autox world or just have allot of money and get a new car every two years. I was told this once by a great autox guy who had been doing it for a long time "Autox is 50% driver and 50% car" I looked at him and felt he was insane but as my skill level increased and I started becoming more smooth I was beating cars that I had no business being classed with me due to their obvious advantages (power braking gearing tires weight exc.)

RX7goZoomZoomBoom

Damm RETed, your friends NA 20b is disapointing me,
I would figure that car would make more HP,
The torque figures are real nice though, man I wish I had torque like that.
Im sure its a blast and mad props for leaving it NA with some creative port designs and some internal lightning that engine should be right up there with some turbo boys.

RETed

We made 232hp at the wheels in that thing.
It's basically an experiment.
Another 20B with stock turbos only made 240hp at the wheels.
We made 8hp less than the turbo 20B.
Ours is a bone stock 20B, and it has never been opened up.
Imaging if it was ported?
I call it an eye opener.
Our goals for it was about 230 - 250 at the wheels - it made that goal.
I would've loved to get a little more power on it, but the small intake filter was the limitation.
We pulled the air filter and AFR's on the wide-band showed at least a 1.0 AFR increase.
We could've retuned with no air filter, but why risk it?



-Ted

edmcguirk

I don't think this has ever been tested but here is a suggestion on fooling the ECU about the OMP.

Due to manufacturing tolerences, it is unlikely that the ECU has exact voltage/position tables for the OMP. More likely it has a max and min voltage and all it is looking for is a feedback change to go with it's output signal.

It should accept a circuit that simply raises or lowers the feedback voltage in response to UP and DOWN commands. It's really almost a low pass filter feeding the control signal back to the feedback signal. It should be an OP-AMP or two and a couple of resisters and capacitors. Unfortunately I don't have enough experience to design and build one.

Most people who have the S5 ECU also have the S5 OMP so they don't need it and there doesn't seem to be that many people who are swapping S4 and S5. There just hasn't been enough desire to test it out. (like me - I don't have an S5, I don't have desire)

ed