DriftingSeven

What would be the better option, I really dont want to have a stand-alone (haltech, etc.) or S-AFC. I have heard that most people are happy with the ECU from MD Racing but most people on the form seem to have a FCD. What would be the smart choice in the long run, further Upgrades...Reliability...Safety. Also would it work with larger 2nd injectors and boost controller? Let me know, Thanks!

FPrep2ndGenRX7

If you plan on continuing with upgrades after the MD Racing chip I would suggest a stand alone unit. To get the most from your upgrade you will need the ability to retune and the MD Racing will not let you change anything. The stand alone unit will allow you to adjust the fuel delivery and ignition as needed nto to mention the stand aolne units(depending on what you buy) eliminates the AFM and will also come with a new wiring harness.

Bambam7

For the money- Don't get a chip... The S-AFC is a much better option, for cheaper (you can get them used). Though it doesn't control timing.
They can actually kill your TII engine... they advance the timing a LOT (especially in the midrange) and lean out the mixture in midrange too... can lead to problems. Requires a thirst for premium fuel too.

The FCD is a simple solution to the fuel cut... and is good for mildy modded cars, but if you really crank up the boost you willl lean out and smoke your engine.
With larger injectors, you can just slap them in and you will reduce leanout, but normally, you would still need and S-AFC to tune them properly.


Best option in my opinion (without spending 1200 on a standalone) is to get a FCD and an S-AFC. Total, maybe 400 bucks tops, probably much less. (I got my AFC for 200 used...)
FCD's are pretty cheap aren't they?

tmak26b

Bambam, whats your take on the MD Race chip for the NA

Bambam7

Well, the dyno results speak for themselves.... but you can do the exact same thing by getting an S-AFC, and advancing the timing a bit- it's a lot cheaper than a chip. (Find a used S-AFC, there's many out there)
The S-AFC is a lot more dynamic too.
The chips are EXPENSIVE!!
Plus, you have to run 91 octane min. (becuase the timing is avanced like crazy)
Plus, if ever want to do any more add ons, bigger injectors, you still have to get the S-AFC anyways. You could never put a turbo on either.
I think dyno tuning a fuel computer will yield better results than a generic chip- because it's car specific.

tmak26b

Bambam, correct me if I am wrong. but once you put the chip in. Isnt everything set up for you automatically? In case you want to go back to stock, you can just plug hte stock computer back in and everything will run normal? I hate the idea of the S-AFC because you have to tune everything yourself. Its impossible to do it without the wide band o2 sensor dyno

Do you think it is safe to run that chip for long? Also do you really increase gas milage? THanks

Gimpdiggity

I'm not sure on this, but doesn't the MD chip advance timing alot in the lower end of the RPM band, and then slowly retard that advance as the RPMs go up?? That way, you get the best power curve. That, in my mind, would be better than just advancing timing and putting in the S-AFC...


Jeff

go_speed_go

I ran the MD ECU in my vert for the last 3 years I owned it. I never got much better gas mileage, but I always drove over 75 on the highway (top down) and my commute to work was 4.5 miles in mostly stop and go traffic.

You will have to run premium fuel, or you'll get knock at higher RPMs.

The spark is advanced 15 degrees at idle and backed off to a 5 degree advance by redline. This provides for a significant amount of torque in the lower revs.

I never got to dyno the car, but unlike some mods, you could easily feel the difference in power - especially after the VDI kicked in.

When you get your ECU back, it will have a socket where the stock rom used to be with an upgraded ROM plugged into it. To switch back to the stock maps, you open the ECU and swap the chips.

Two other threads with more info:
https://www.rx7club.com/forum/showth...threadid=39478

https://www.rx7club.com/forum/showth...threadid=27657

tmak26b

I am going to get another ECU to put a chip in. Car can go back to stock as soon as I plug the original ECU back in right?

So from what it seems like, this mod is worth it. Do you recommand it?

go_speed_go

Yes, if you have a spare ECU, then you can just swap them instead of opening up one and swapping the chip.

I'd highly recommend this mod to anyone who already has an intake and exhaust.

t_mak@mail.plymouth.edu

I currently has a bonez high flow cat, RB cat back and a cut intake box cover. I will do that after i get my wheels and my front spoiler.. I dynoed at 143rwhp with my current setup, think i can get 160 with the chip? I will definitely go to dyno, do 1 run on there first with the stock chip, then 2nd on the modded one