I want to know if I can get rid of my computer on my 1986 RX-7. Im a noob, I know. But does it control anything that I would really need? I've ripped out everything I dont need, like the a/c system, and Im working on my emissions, and all that bullshit. DO I need my ecu? And before anyone says "search is your friend" I searched, and didnt find anything. So please help. And if you live near Lufkin, Texas and you know about RX-7s, come help, cause like I said, Im a noob.

 

unless you ripped out your injectors, and your CAS and your ignition system and replaced them with carburator and distributor. you NEED your ecu!

 

you need to keep the ecu, it controls all of your fueling and timing.

 

Are you in TX or WI? If you're in WI where at?

But anyway, 2nd gens are electronicly controlled fuel injection, the ECU is the computer that controls that. The other 'Computer' (CPU), is used for other basic functions of the car and should remain in place.

 

I would think you have trouble searching for a thread like this because I doubt anyone has ever asked this question before...

 

Really?

 

Only if you install the corresponding flux capacitor.



http://kalecoauto.com/index.php?main...products_id=28

 

lol @ flux compacitor. I just figured that some vehicles you can jump the computer out and run it in an open loop mode, that maybe since the rx-7 was an 86 you could just drop that ****. Any aftermarket computers? Im looking to set this thing up for the track. Still trying to figure out if Im dropping a turbo in. Thanks for answering my dumbass questions.



Oh, and I live in texas right now because I work here. When I live in Wisconsin I live in a small town called Rubicon. Its like an hour north west of milwaukee.

 

LOL


maybe you should just start here:

http://auto.howstuffworks.com/auto-basics-channel.htm

 

Not only sounds like you are a rotary n00b but a complete car n00b.

Yes, unless you are going to replace your fuel injection with a carb then you must have either the factory ECU or an aftermarket ECU. There are several options and your best bet is to search.

Before you go removing everything from the car to prepare for the "Track" it would be helpful to know what "Track" you plan to go to. Are you going to drag race, AutoX, Road Race, Hill Climb or some other kind of racing. If you plan to do competative racing the first thing you need to do is obtain their rulebook, find out what class an RX-7 competes in and build it to meet their requirements. If you don't then you are wasting your time.

If all you plan to do is non competative drag racing or open track days then do whatever you want. However if you are so concerned about the weight of the car that a 1lb ECU that controls your engine is a concern then I also recommend removing the drivers seat and steering wheel because neither of those will be required either.

 

Trust me. Don't go to a carb'd setup. I have a carb on my 13b N/A and its terrible. Terrible on power. Terrible on gas. Terrible on everything. I absolutely hate it.

Do yourself a favor and stick with the stock injectors/ecu setup.

As soon as I have the extra money around, im actually going to be converting back to the injected setup with a rtek.

 

Not really worried about the weight of the computer there chief. Im getting rid of all unnessessary wiring harnesses, ect. I was wondering if I could run my computer in an open loop mode, which if you werent only into RX-7s, you'd know is possible. Also, I was wondering if theres any aftermarket computers that do the things I need and none of the things I dont (emissions control, other stupid ****) Plus Im re-wiring the entire car, so any lights, gauges, blinkers/hazzards, ect will be all custom wired. So if any one has any recomendations about computers please let me know. If you are just straight bitchin cause your mom took away your keys, well, thats your thing.

 

thouht shall not tear it up and she will run.

 

Run a Haltech, or a microtech, or a megasquirt, or a *insert stand-alone here*, and please post a nice build thread and show everyone! we would love to see. I suggest a megasquirt, and using it just for fuel and spark. Then use a sweet aluminum dash setup with a whole bunch of mystery switch's for all the lights and blinkers. so everyone else would be so terribly intimidated they would never ask to borrow your car .

 

how does the ecu run in open loop if it is removed from the vehicle. I also have a volvo and it needs it's ecu too.....

am i misinformed?? how does efi work without the ecu?

 

What kind of racing do you intend to do and do you care about being properly classed? Everything you are talking about doing will knock you straight out of any reasonable class for SCCA or NASA. If you are Drag Racing for fun or running open track days for fast laps then it is completely different. I ask because I have seen many many cars show up to race with F&F mods and are smoked by a stock car with a good driver. Then they don't come back.

Also, not sure how you plan to run the system in an open loop without the computer? Wasn't that your question "Can I remove my computer?". Please provide me insight into how that is done in any other FI car.

 

I will admit, I phrased my question poorly. Im not building it to be an SCCA classified car. I dont really do drag racing, cause its kinda lame. Im thinking drift for fun, maybe hit up road america (I grew up on that track). You know, grocery getter with spunk. I want the thing to be light weight so it can corner. No FnF mods here. Im not putting 8 lcd screens, a playstation, and four 12 inch subs. Its gonna be stripped down and light weight. So now that I have the applications clarified, what should I do.

 

if you want to run an after market ecu for some reason maybe you should check the engine management part of the forum

Also what car can run in "open loop"?

Its an rx7 it should already corner pretty well.

 

Look at this site. http://www.bobbyjasan.com/project/projectcars.asp He has a couple of stripped RX-7's that are around 2000lbs. One is running a factory motor with stock ECU. Last time out to Hallett he ran solid 1:29's. The other car has an LS1 conversion and is scary (still autox only). I have driven both. Before he added the wing to the blue car and the stickier tires I ran 1:33's and he was running 1:31's.

If you still have good wiring harnesses then I would keep them intact and make sure you have good working motor before going to a standalone system. I have not tried any standalones but the reading I have done shows they don't make a ton more power than the factory on a NA car. On a streetable NA motor don't expect to do more than 200 crank hp.

The only person I know with personal expierence with a rotary and a stand alone is a 3 rotor in a modfied miata chassis (EM). It took him over 3 years running the car at local, divisional and national SOLO II competitions to sort out motor issues and calibration of the computer. I am not sure which standalone he uses.

Once you are to suspensions there are many options and many opinions. I have run Koni and Tokico on ST springs and now am running Stance Coilovers. The former setup was very streetable and good on the track. The Stance's to me are definately track only unless you have very smooth streets. The blue car is running Koni's with Ground Control springs and camber / caster plates and the LS1 is on Megan Racing coilovers. I was faster in my car in AutoX with the Stance than his blue car on koni's. He is kicking my **** at Hallet although he is 2-300lbs lighter than my car.

I completely agree about drag racing. Friends don't let friends live their lives a 1/4 mile at a time.

Hope some of this helps.

 

The RX-7s ECU already runs in open loop quite often. In fact, the only time it's in closed loop is during steady state cruise. All other times it ignores the oxygen sensor.

I think you're seriously mixed up on your terminology here. "Open loop" does not refer to removal of the ECU. "Open loop" refers to the ECU determining the fueling requirements of the engine through the various readings from it's sensors, and then applying that to the engine without any correction. If it was then looking at the O2 sensor to get an idea of the actual A/F ratio of the engine and then correcting it's injector time to achieve the A/F ratio it wants, it is then running in "closed loop".

Your terminology is wrong and is confusing a lot of people.

Sure. Just check out the "Engine Management" section of this forum. Popular ECUs are the Haltech, Microtech and the totally DIY (which I would not recommend in your case) Megasquirt.

Good luck with that. It sounds like you aren't qualified to do this work. All the gauges, lights and such are already on a separate harness (with one exception) and don't rely on the ECU for control.


You'll find that there are a lot of knowledgable people here who will try to help. Telling them off when your knowledge level is so low is a sure way to keep them out of your threads.

 

Well, my background of performance vehicles all have carbs (snowmobiles, motorcycles). So, this is my formal appology for being ignorant when it comes to cars and computers. I just wanna make my RX-7 fast and unique. And computers in vehicles just make things complicated in my mind, and I know that I really should do some reading. Im not doing all the work myself, especially the electrical end of it. I appreciate the help and reality checks this forum has given me. Ideally, I need a seasoned RX-7 guy to be my advisor to tell me what to do, cause man, it gets really confusing. Ingroundeffect, thanks for the link to that dudes website. Thats helping me out greatly. If anyone else has some good examples and complete setup data, send it my way, because I need to learn from example.

 

If you can find a manifold to mount a 1st gen Nikki carburetor on your 13b it would run great. Why not just keep your car the way it is? Why does everyone have to go hacking these cars all up?

 

The ecu is the brains of the car. Older cars didnt use them because they ran on a coil and carbs.

But sense you have injectors, sensors, ext. Some kind of comp. is needed.

 

LOL...wow.

 

Let this thread die.