What is EPROM

[mathewdylang]

This is probably a dumb question, but what is EPROM?

Do they actually set up a tune on your ECU or does it just update the ECU and get it ready for DSMLink?

I'm doing a 4g63 swap in my 3000GT and am starting with a factory T25 but plan to upgrade to a Holset HX35 which means I'll need bigger injectors and a tune. I really don't want to pay 550 dollars for DSMLink, plus 135 to EPROM an ECU, and buy a used ECU to actually send in.

Is it more cost effective to rewire things for an Evo 8 ECU since its flashable? I'm doing this build from the ground up so throwing the sensors on to run the Evo 8 ECU would be an easy thing to do while putting it all together. Any input would be great. Thanks guys.

BTW I did a search and it came up with 12 pages of links but the first 10 I tried had nothing to do with what I searched for.

 

[Archer Fabrications]

Erasable programable read only memory (EPROM)

It's just a flashable chip. You still need external software to tune (ecmlink) and an exmlink chip to replace your stock eprom chip. or for the 97-99 black box you can use evoscan

 

[mathewdylang]

I thought about a black box ecu but the threads ive read said evo ecus are far superior. I can just get the cable and software and tune the evo and 97-99 ecus off a laptop correct?

 

[Archer Fabrications]

Do some research. I use ECMLink. So I couldn't tell you about flashproms

 

[gieri002]

Yes, you can get a plastic (black) box ecu found in the 98-99 turbo eclipses and a tactrix cable (2.0 with reflash adapter)/ceddymods/evoscan/ecuflash and tune your car.

 

[mathewdylang]

Thanks guys. Looks like ill just get a programmable ecu.

 

[lasthope05]

I wanna hear more about this dsm powered 3000gt. Did you get it started yet?

 

[mathewdylang]

Im collecting all of the parts.i have the car, got it for 26 dollars. Building a 6bolt and puttng a t25 on to start then hopefully.upgrading to a hx35. It will be fwd as the transmissions from a 91-94 fwd mount exactly the same as a 91-93 sl 3000. Ive always liked the bodies of 3000s but i love the 4g63t and figured it'd be a fun swap.

An does anyone know where to get an evo ecu or 98-99 ecu less than 150-200 or is that a good price?

 

[gieri002]

That is a great price.

 

[99gst_racer]

Electronicly programable read only memory (EPROM)

Close.

The 'E' stands for "erasable".

Btw I did a search and it came up with 12 pages of links but the first 10 i tried had nothing to do with what i searched,

Next time that happens, try Google. Let me google that for you

 

[Archer Fabrications]

Fixed

 

[mathewdylang]

I knew what it stood for, i didnt know if it put a new tune on or if it just set it up to be tuned. Thanks for the feed back though.

 

[Broke4speed]

Im collecting all of the parts.i have the car, got it for 26 dollars. Building a 6bolt and puttng a t25 on to start then hopefully.upgrading to a hx35. It will be fwd as the transmissions from a 91-94 fwd mount exactly the same as a 91-93 sl 3000. Ive always liked the bodies of 3000s but i love the 4g63t and figured it'd be a fun swap.

An does anyone know where to get an evo ecu or 98-99 ecu less than 150-200 or is that a good price?

FWIW, the evo 8 rom can be flashed to an 01-03 3G eclipse MT ecu, or an 02-04 MT Lancer ECU. Much cheaper .

I use an 02 Lancer AT ecu (with a modded evo 8 rom) on my 1G (well 89 Colt GT Turbo) .

 

[GST with PSI]

Here's a history lesson I found interesting regarding EPROM ECUs:

Back in the late 80's and early 90's, automotive microprocessor chips were either mask programmed ROM (they make the transistors for the ones and zeros of the software at the same time as they are making the ones for the processor gates) or fuse based ROM. Once you had good software, including the EPA approved fuel and timing maps you could send the software bits to the microprocessor factory and they would start making MPU chips, and 8 to 12 weeks later you would see parts and if everything was good you could start making ECUs with them.

Since the production line couldn't something like wait 8-12 weeks for custom CPUs the factory would the same ECU design as the development teams used with a interface circuit that could run the software from an external chip (the EPROM) that they could program over and over or in bulk and ship cars. The downside was those ECUs were at least $10 more in just raw parts and may have been several hundred $ more each actual cost. If you making a couple hundred thousand cars that's some real money, so as soon as you can you switch to the cheaper masked programmed MPU part and stop shipping EPROM ECUs. So typically you would see the EPROM ECUs in the early production months and then from time to time as the Just in Time delivery process failed and they needed ECUs to keep the production line running.

It wasn't until 98 or so that the ECUs started getting flash memory (a type of EEPROM) inside the processors allowing the factory and their service arms to update the programming at the plant or in the field.

For cars like the GVR4 there wasn't enough volume to justify a custom masked programed part so all the cars received EPROM ECU's but DSM production levels were such than no year had only EPROM ECUs