Merovign

I'm looking for a cheap(ish) ECU upgrade, along the lines of an S-AFC, for controlling fuel delivery on an NA with a lot of engine/airflow upgrades and an upgraded stock ECU. I basically need to compensate for the fact that even the upgraded ECU really only anticipates a K&N and headers, with which it does well (10hp or so ECU only).

I know a lot of people are going to start shouting Wolf! AEM! Haltech! etc, but I've been down that route (Wolf3D), and I can't afford to go that route again for what little I gained last time (and yes it was professionally tuned - fat lot of good that did me).

The Greddy e-manage is out because only a shop can tune it, and I may not do all of my mods at once, i.e. I may upgrade my AFM or port the upper manifold at a later date...

So assuming one is a very cautious boy, has a good A/F meter handy, and possibly a knock sensor linked to ignition retard, which of the less expensive (a'pexi/HKS/???) ECUs would be a good choice? Looking for less than $450, not counting the A/F meter.

I know I'm not going to be faster than an FD, that;s not my goal. Just a good, quick NA with a decent torque curve that runs well, doesn't require a lot of tuning all the darned time, and will be running well a few years down the road...

Thanks,

Chad

kabooski

never mind
I have info on a full stand alone computer
fuel and ig
for a little over $600 including the extra 1 bar
and TPS and shipping


but you want to spend less then 450 so a S-afc
is the best you can do

Merovign

Which model do you have? Are you a dealer or selling used?

The problem with most standalones (except AEM) is that they do fuel, ignition, and nothing else, rendering a lot of the car's other controlled functions useless (warning lights, etc). I'm not the only person that will ever drive the car.

In addition, as I found out with the Wolf, there are things the factory ECU can compensate for that the standalones (at least some) can't! For example, while I don't intend to drive around in a car with a stuck apex seal, the factory ECU can make that idle, the Wolf couldn't keep and idle and died at idle no matter what you did.

On top of that, I want to stay within a stone's throw of emissions-legal (i.e. swap out the header and in a manifold and I'm legal - I'll be running cats with the header), so I am retaining the harness, sensors, and so on from the stock setup.
Of course, I'm trusting that the average smog tech doesn't know the difference between a S5 NA AFM and a S5 turbo AFM... as long as the exhaust is clean.

My intent is to be able to drive past a "smog detector" and not have anyone know that I'm not stock - the only problem there that the most common way to control detonation in a rotary is to throw more fuel into the fire (which works, but doesn't do wonders for your emissions).

Even running moderately rich, dual cats should do the trick.

Why do I care about emissions? First, I don't like to gag walking behind my own car. Second, I don't want to get busted. Third, like I said, I'm not the only person who's going to drive this car. I don't want to saddle someone else with a load of compromises if I don't have to.

FPrep2ndGenRX7

Have you considered the SDS EM-3? It only controls fuel but you would need to install a distributor(81-85 12A). A friend of mine is running that setup with a supercharger and is making over 220HP to the rear tires. The engine is a stock TII engine but the SDS controls it nicely.

www.sdsefi.com

It cost more than you want to spend but you would never need another upgrade. A used one can be had for $450.

Merovign

I'll probably stay away from used parts on something like this, particularly since it usually affects (negates) the warranty.

I looked at the site, and again I want to augment, not replace, the factory ECU's program. The factory ECU is very good at certain things, one of which is compensating for varying conditions. I mentioned my problems with the Wolf before. This is not going to be a system that will be re-programmed every time I change altitude or brand of fuel (I may also install a knock sensor).

I don't expect to get every possible ounce of power out of the engine, just nice healthy increases.

I also intend to have the car do a few things that many highly customized cars aren't asked to do - like post good numbers on smog tests, not smell bad, not deafen people, not leak, not have radically hacked up wiring or irreversible changes that make it untransferable. Well, a heavily ported manifold is irreversible but basically undetectable and, if done intelligently, doesn't hurt the driveability.

You get the idea. Not necessarily fire-and-forget, but pretty close. I've even considered a custom JET ECU, I have to find out what their "custom" versions cost (the basic ones are $400).

jmseven

I have the same goals for my vert....

Your in Sac also huh.....I'm going to follow this post.

waynespeed

"In addition, as I found out with the Wolf, there are things the factory ECU can compensate for that the standalones (at least some) can't! For example, while I don't intend to drive around in a car with a stuck apex seal, the factory ECU can make that idle, the Wolf couldn't keep and idle and died at idle no matter what you did."

Just out of curiousity, did you have the AUX out controlling your IAC?

I find that a lot guys upgrade their ECU but leave out the extra goodies like:
idle control and the radiator fan control features.

Merovign

JMseven - keep an eye out, as I progress on this project I have several pretty cool ideas that aren't normally found on 7's - I need to see if they work before I start shooting off my mouth too much... besides, I might want to sell the stuff!

I should have left more stock stuff in control, but as I discovered, the fellow who did the install, while a genius, had a sort of "slash and burn" mentality - I found all sorts of connections (injectors, coils) snipped at the harness (new harness anyone?) and not even taped off.

I would/will/am needing to do a rebuild anyway, with an apparently hopelessly stuck apex seal. (He says looking across the room at rotor housings, manifolds, and various stuff).

This is not going to be an ultimate buildup, but my rough plan is to keep roughly stock (or better) torque below 4000 rpm, but get rid of some restrictions when the 6pi/VDI kicks in. I really honestly don't know if I'm going to end up with 180hp @ 6800rpm or 243hp @ 8000rpm yet... too many things in between now and then. As far as I've been able to tell, the latter figure is possible with a streetable NA, but I don't know if I can afford that kind of testing/tuning (change dyno change dyno change...).

I can tell you two things so far. The 13B is a hell of a design with a lot of untapped potential, with regards to both power and reliability/durability, and that Mazda's screws are too soft! (I just stripped out three screw heads while disassembling a throttle body for porting/polishing - need to buy extractor bits tomorrow.)

So far I think the AFC will do well, especially in the streetability set-and-forget department. I wonder if I could use the V-AFC's VTEC controller to control VDI and 6pi?