Help please. Is it possible to chip the stock RX-7 ecu?
 

I have been talking to a honda guy who is big into tuning cars. He was saying with the hondas that there is Uberdata which is a free standalone. He was also saying that he can "chip" the honda ECU just like this:

http://superhonda.com/tech/honda_ecu...installed1.jpg

I was wondering if you can do the same to the RX-7 ecu, or if there is anything simular?

His guess is that it would be a Read only memory chip that would allow you to control fuel, ignition and other perameters.

I'm sure it's possible, but I don't think anyone in the RX-7 aftermarket scene knows how. There used to be aftermarket ECUs that consisted of a stock ECU with an extra daughterboard that changes fuel and ignition, but the popular thing today is the Apex Power FC, which is a 16-bit system (the OEM ECU is 8-bit) that allows you to adjust (and monitor) a TON of parameters.

-s-

Spend the extra bit to get the right equipment to be able to tune to YOUR engine. Catch-All tuning is not recommended for the turbo rotary.

So if this isn't the best idea, how would the pettit ECU compare? I am not going to be looking for big hp numbers. Hopefully get up to 300, but that would be about max and I know that I won't be at that level for a while since my only future performance upgrades are intake, DP, cat back, intercooler and possibly a new rad.

I have searched the site and found out alot of info on the pettit ECU so I don't need any more answers on that. But if anyone esle has any more info on chipping the stock ECU please let me know.

Thanks alot,

Honestly.....do you really want to risk putting a chip in the stock ecu yourself? Call Pettit and see if they have the chips still....and if theyre willing to sell them to you. But for like $300 or $400 you can pick up a pettit ecu...thats already chipped and good to go. And if you cant afford that upgrade and are trying to cut some corners on saving a buck.....then you need to sell your car. Rx7's are not cheap to own or upgrade. Good luck


:buttslay:
Oh yeah....and i just happen to have a 93 Pettit Unlimited ECU going up for sale

lol. I'm not trying to cut any corners with costs and well prepared to pay for upkeep on this car. I was just thinking that if I can get a tuneable ecu that would be more precicly tunned to my car with whatever mods for cheaper then why not. I wouldn't be doing this myself, I would be getting help from a very experienced tuner with this. He has all the programs and knowledge and it probubly wouldn't be much cheaper by the time I pay for dyno time and for the guy to tune the chip.

Send me a pm with info on your pettit chip with a price shipped to Canada.

There is a very good reason that not many people use reprogrammed ECU's for these cars.


The 3rd Gen RX-7 was sold during the 1993-1995 model years. The technology inside the ECU was probably developed no later than 1991. Did you own a PC in the early 90's? They were VERY slow and expensive compared to what's available today. For instance, the original Pentium CPU ran at a 'blazing fast' 60 MHz when it was introduced in 1993. There is also a big difference between 8-bits compared to 16-bits. The increased number of bits allows much more precision across the board: the sensor readings will be more accurate, for starters. The 16-bit ECU will have a more precise knowledge of the boost level, throttle position, and engine speed and position. A good tuner will be able to take advantage of this.


I really recommend upgrading to a more modern ECU (Apex PFC, for instance)if you can afford to do so. Your 'very experienced tuner' should agree if he's got half a brain in his head.

-s-

yeah that makes alot of sence. The guy that was going to help me with the tune didn't know much about the rx-7 factory ecu's, so thats why I asked. He had a feeling that there was a reason that no one was chipping the ecu's instead of purchasing the apexi pfc's and this would explain that,

Thanks Scotty.

The Pettit ECU is just fine if you are looking to stay around the 300-330rwhp range and the stock fuel system (with ported engines and the boost turned up, they have made 360rwhp). People have been using them for years without issue and continue to use them.

The good thing about picking up a used Pettit ECU; if you decide to sell it later you can sell it for the same amount you bought it. In a used conditioned, they don't loose any value. However, you will save yourself some money getting a used one rather than getting a new one from Pettit.

I've run a Pettit ECU in my car since about 2001. I will continue to run it most likely for the duration I own the car.

I don't know anything about these but if you're really a DIY kind of person, you could do something with a megasquirt. Plenty of information out there and open-source tuning tools, etc. If you really don't know what you're doing when it comes to tuning though, this is definitely not the way to go.

http://www.bgsoflex.com/megasquirt.html

Power FC all the way. Just bought one and love it. Haven't even played with the tuning, the base map is perfect for now, and I can tune it in the future if I ever go single, or upgraded twins, etc.

There are lots of stock ECU's out there that have been "rechipped". Pettit and M2 are among the most popular. They are proven to work very well, but are not tunable. I have an M2 unit, and am very happy with it. I am currently around 300 rwph @13 psi.

Bummer, on a lot of GM units you can just reflash the stock one.

I have a fairly good working knowledge of Uberdata. In Honda ECUs there is an area where you can solder an EPROM to containing your desired fuel/ignition/etc. numbers. It works fabulously and there are a wide number of stock baseline maps you can use as well as some aftermarket ones. On my particular motor, for example, the H22A I had socketed my ECU and had three EPROMs burnt off, one for the stock map, another a "tuned" (to the best of my ability anyways) map, and then finally for shits and giggles a JUN program. It was great being able to switch programming in minutes, and there was laptop datalogging capabilities. Support was huge when I did this, I am not sure how far the knowledge base in the many years I have been gone.

The biggest advantage from Uberdata was that it was cheap. Socketing and chipping was something you could do for less than 50 dollars, baseline maps were free as is the software, the only thing that really costed money was an EPROM burner which you could share between many people.

I do not modify my cars anymore and for the most part have left my old tuning days behind me so I never thought about opening the FD ECU. I imagine it can be done, but it will require a person with a good electrical engineering background. Car computer units are a bit different than personal computers.

Miff,

That is already done with M2 and Pettit ECU's (as well as many of them overseas). There is a daughter board soldered into the stock ECU, where a new chip placed for the updated maps. The problem is that as far as I know, no one here in the US can actually do the programming. I believe all of it is done overseas.

Companies like Knightsports, RE and others do have several maps for several different configurations. Pettit was thinking of selling a rechipped ECU for larger injectors but decided not to.

There have been several people over the years to say "I've unlocked Hondas and Toyota ECU's, and I'm going to unlock this one"; or "they re-program all sort of cars so I should be able to do the RX-7"; yet, none of them have yet to do anything. There were a few guys about 2 years or so ago that said they were 'close' to producing something however nobody ever saw a darn thing.

Best to say, deal with what is already out there in terms of rechipped ECU's or go with a complete ECU replacement.

Mahjik's got it.

Chipped ECU's are rather common in Japan. Techtom is the king - they make the daughterboard and tuning software that many shops buy. A shop buys the Techtom setup, opens your ECU up and installs a daughterboard with a new ROM, tunes the car in on a dyno with the Techtom tuning software, burns the ROM, installs in your ECU, and off you go. Many shops in Japan do like Pettit and have pre-programmed ECUs - put this ECU in your car, you're good for these mods, and this much boost. I believe Pettit actually uses Techtom or some derivative.

But, I don't think it's easy to add the daughterboard in. The ROM in our ECU is a large package and surface mounted to the motherboard. I believe it has to be de-soldered (which is tricky with large surface mount components), have a socket soldered in, then the daughterboard is attached to the socket.

I would LOVE to see someone hack the FD ECU. But, I think it's quite a bit more complicated than people realize. Considering you can get chipped ECU's all day long for a VERY reasonable price, and even the PowerFC is SO reasonable and works SO well, that spoils a lot of the reason to invest the work necessary.

I am jealous of the newer stock ECU's out there that are easily re-programmable with a simple cable, do tons of datalogging with the OBD-II port, etc. But, as long as the PowerFC is available, there's a great alternative for us.

Dale

Mahjik and Dale pretty much covered it.

not only Pettit, M2, RE-Amemiya, Knightsports, local tuners such as XS engineering and other previous tuners all go through the same method before.

I remember when Rom-tune at XS engineering used to be $650 dynotuned + chip back in 96, 97.

But all that stopped pretty much after PFC came out. Although people use HKS F-con, but it was never as popular in the U.S. as PFC's now. Newer technology are almost always better for many reasons ..

IMO, if you have a stock RX-7 with light mods, go with a used reflashed Tuner ECU cheap (usually around 2-400 bucks) off a honest seller and enjoy your 12 second runs. Then save up for PFC, Haltech, Motech, Tech2, when you start doing major mods.

11 seconds:

https://www.rx7club.com/showpost.php...5&postcount=15

;)

I think I will take everyones advice and look for a used pettit ecu. But I might also take mystock ecu and do some testing with it to see if it is possible to chip it. I will have to see if my buddy is willing to work on this with me, cause if he isn't then I really don't have a hope in hell of figuring it all out. Thanks for all of the input.

Why fuck around with it when there's already a cheap fix on the market that works and is available???

Does anyone know, or have any experience with the HKS F-con? I have seen them for the FC3S and the 96+ FD3S's but am unable to find any info on them for the S6 FD's

Changing Chipped OEM ecu's
 

Old thread, but some may be interested in an update.

I currently have a spare ecu chipped by XSEngineering. I don't run it because it is pig-rich, likely done in an effort to minimize the 3K hesitation ( that the P-FC eliminates ).

This company will modify a chipped ecu, or perhaps chip an oem ecu. They have the required Techtom equipment.

http://www.technosquareinc.com/technosquareecu.htm

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Just called (Wednesday 1/25/2012 @ 5:06 p.m. EST) and they said they stopped the service for Mazda RX-7's over a year and a half ago:(!

bummer, I planned on some tuning, using controlled speed local dyno with O2 trace.