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Discussion Starter #1
Hello,
I supposedly have a G-force ECU in my 94' Supra TT 6mt (according to the previous owner) and would like to get some fuel map/timing adjustments made if possible. Does anyone know who or where to get this done nowadays since G-Force is long gone? Any help would be great.

Also, is there any easy way to actually confirm I have a G-Force ECU? I only ask because some of the other mods the previous owner claimed were installed on the car have not all actually been true. (stuff you can't readily see)
 

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I don't believe there is anyone reprogramming them anymore. Technosquare used to, but the guy that did it is long gone. I'm not even sure they are around anymore. If you search "G-Force", you will find a lot of the same discussion. Hellbringer and Wreckless on here have the most insight about these as far as I've seen. Some of them had homemade labels describing the mods, some had sharpie marker notes on the outside of the ECU, some just had stickers on the chips inside. Tough to tell without some pictures of what you have.
 

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I have one, no markings, IIRC. They mainly had modified limiters - raised rev limiter, and either totally deleted speed limiters and fuel cut, or raised them to a very high level.

The easiest way to check is do a pull and see if you can top 7k RPM! A typical G-Force rev limit is 8k RPM, that's what I have. I have heard of them being 7500-7800, which is sort of useless.

Al
 

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Discussion Starter #4 (Edited)
I have one, no markings, IIRC. They mainly had modified limiters - raised rev limiter, and either totally deleted speed limiters and fuel cut, or raised them to a very high level.

The easiest way to check is do a pull and see if you can top 7k RPM! A typical G-Force rev limit is 8k RPM, that's what I have. I have heard of them being 7500-7800, which is sort of useless.

Al
I don't think one can base if they have a G-Force ECU just on the redline. That would be great if it were that easy. If the ECU was "tuned" for a BPU car, having a raised rev limiter wouldn't even make sense/help. Sounds like the only real way to determine if it is a G-Force ECU is to open it up and see if there are any labeled chips inside. I don't have any fuel cut due to boost, so I will have to take a look. Right now my car is in storage for the winter, so I will have to pull my ECU in spring and open it up. I do have dyno charts from the original owner that seem to show them working on the fuel curve, so maybe it is really a G-Force since you can't obviously tune that on a normal ECU. I would assume if I see a FCD installed, then it is a good chance the ECU is stock since no one would likely install that also then...

In the meantime, I tried emailing/messaging Technosquare to see if they can still modify my ECU if needed. Not holding my breath that they will get back to me though...
 

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I don't think one can base if they have a G-Force ECU just on the redline. That would be great if it were that easy.
Oh, you most certainly can! How else would the rev limit get raised from 6800 on a stock ECU, other than the ECU being modified?

And it may not make sense with BPU, but maybe they had future mods planned?

You don't work on the fuel curve on a dyno on a stock ECU without some sort of piggyback, like VPC/GCC or SAFC. Any fuel mods done to the G-force would be preset.

Al
 

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Discussion Starter #7
Oh, you most certainly can! How else would the rev limit get raised from 6800 on a stock ECU, other than the ECU being modified?

And it may not make sense with BPU, but maybe they had future mods planned?

You don't work on the fuel curve on a dyno on a stock ECU without some sort of piggyback, like VPC/GCC or SAFC. Any fuel mods done to the G-force would be preset.

Al
What I meant was, yes if the rev limiter is raised it is obviously either modified by speedforsale or a G-Force ECU, but what I was getting at is this particular owner may not have raised the rev limiter, so your theory of "if the rev limiter is above stock it is a G-Force" doesn't apply. It could still be a G-Force ECU, but with a stock rev limit.

As for the fuel curve, for all I know they were trying different chips or had G-Force make them a different map, who knows. I just know that the air fuel ratio was definitely changing from run to run.

Sounds like the only REAL way to know is to either look for writing on it like ajgibson528 posted, or to open it up and look for the chips like I have seen when I searched through old posts.
 

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My ECU was marked G-Force but I will have to test out the RPM theory above. Also, isn't G-Force outside of Atlanta, GA?

IMG_3941 by Adam Gibson, on Flickr
Unless the principals in that GA company are named Tadashi or Shawn Wang, it's just a coincidence....would be my guess...


Ken.
 

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Sadly, I do not know of anyone or any business anywhere in the world that can edit or change the tunes in these ECU's anymore.

Easy to tell if it's tuned, though - the tell tale sign of tuning on these ECU's is an aluminum spacer plate or a bulged aluminum ECU cover.

Because of the architecture of those ECUs, there's no way to simply tune them on 100% stock hardware like most modern ECUs. So a daughterboard aka riser board had to be added to accommodate an EPROM socket. Fuel and Ignition timing were done on separate chips, so one riser board each was required.
Most tuned ECU's done in this method only tuned fuel as that's where most of the gains were, and also the speed limiter and rev limiter. If there are two riser boards, both timing and fuel were tuned.

Unfortunately this was all done with hex editing on EPROMs and the technology is ancient by modern standards and I have no idea who even has the equipment to read those EPROMs let alone make sense of the raw data in any kind of meaningful way. Back in the day, though, tuning was available for up to 1000cc injectors (rare, most were set up for stock injectors - I'd estimate less than one in 20 were tuned for larger injectors and those were the common 550cc, 650cc, 720cc, and 800cc injectors of the day) and I've seen rev limiters as high as 9500rpm - brave, especially in those days!

I've gone into great detail in this thread, in post #4:

My pictures in post #4 are still hosted, 7 years later!

I hope that helps.
 

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Discussion Starter #10
Sadly, I do not know of anyone or any business anywhere in the world that can edit or change the tunes in these ECU's anymore.

Easy to tell if it's tuned, though - the tell tale sign of tuning on these ECU's is an aluminum spacer plate or a bulged aluminum ECU cover.

Because of the architecture of those ECUs, there's no way to simply tune them on 100% stock hardware like most modern ECUs. So a daughterboard aka riser board had to be added to accommodate an EPROM socket. Fuel and Ignition timing were done on separate chips, so one riser board each was required.
Most tuned ECU's done in this method only tuned fuel as that's where most of the gains were, and also the speed limiter and rev limiter. If there are two riser boards, both timing and fuel were tuned.

Unfortunately this was all done with hex editing on EPROMs and the technology is ancient by modern standards and I have no idea who even has the equipment to read those EPROMs let alone make sense of the raw data in any kind of meaningful way. Back in the day, though, tuning was available for up to 1000cc injectors (rare, most were set up for stock injectors - I'd estimate less than one in 20 were tuned for larger injectors and those were the common 550cc, 650cc, 720cc, and 800cc injectors of the day) and I've seen rev limiters as high as 9500rpm - brave, especially in those days!

I've gone into great detail in this thread, in post #4:

My pictures in post #4 are still hosted, 7 years later!

I hope that helps.

Thanks Wreckless! That helps a lot actually. Once I get my car out of winter storage, I will have to lift up the passenger carpeting and see what I have going on under there. I will likely be doing a baseline dyno (dynoed a few years ago, but have fixed/changed a lot since then) and take a look at my AF ratios. If all is well, great, otherwise I may do an OBDII swap to richen out the mix if needed.
 

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Discussion Starter #12
I would love to get a standalone, but I don't have the funds to go that route especially since I am always teetering on the edge of whether I want to keep or sell my car since I don't drive it that much... Hoping my current ECU does what I need/want it to do.
 
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