This is something i just put together based on what I've learnt through the years of modding. If you want to know more, i suggest you do a search on this forum as everything has been covered in quite detail.

The purpose of this thread is to provide an individual a quick summary of what ECU's are out there and what they are exactly. Prices provided are a rough indication at the time of this post. It will obviously change from time, as more options become available. Best to ring around and get exact quotes.

Refer to the Workshop Thread for contact details of relevant workshops and tuners

There are 3 types of Engine Control Unit (ECU).

Piggybacks
A piggy back is exactly what the name implies. It uses the stock factory ECU to run the majority of the functions. The piggyback controls the air flow, ignition, boost. Stock ECU stays in the car and the air flow meter (AFM) is still in use

Types available:
- Unichip (Type A for MY93-00 WRX and Type B for MY01 onwards)
- Haltech (Interceptor)
- Utec (Delta)
- Chiptorque Xcede
- Greddy Emanage
- AVO SMT6

In the second hand market, these units will range from around $300 (unichip)up to $1000 (Utec). Some of these can be wired in or a plug and play harness purchased.


Reflash
The stock ECU gets a "reflash", basically depending on which brand of tune you get done, the factory settings are "adjusted" to suit your mods. Imagine your home computer ROM, being re-written over with new instructions, hence the term reflash. The stock AFM is still in use.

Types available:
- Verso, http://versoautomotive.com/ (supports all except MY97-00)
- ECUTek, www.ecutek.com.au/
- AVO
- Generic DIY (open ECU)

Price will range from Free (if you DIY) to up to over (or close to) $2k depending on what's done. Best to ring a workshop that specifically does one of this to get an exact price based on what mods you've got to support it.


Full Replacement ECU
As the name implies, this unit replaces your stock ECU and can allow the removal of your AFM (Apexi Power FC requires fitment of your stock AFM).
Achieving the perfect idle and cold start may take a while as the new ECU won't be able to achieve the factory conditions. But over a few tunes, this may be achievable.

Types available:
- Motec
- Autronic
- Link (old skool) and Link G3 (new age, supports AVCS,etc)
- PowerFC (requires AFM)
- HKS FCon (requires AFM)
- Haltech
- Hydra ("recently" released ECU (2004/5?), with similar specs to Autronics)
The 2 below are probably not ideal for a street driven car but worth mentioning if you've got a car from over east.
- Microtech
- Wolf 3D

Prices for this varies from a lot (e.g. Motec depending on the options enabled) right down to around $500 for the Link units.
For specificactions of each of the ECUs mentioned, best to use google and go direct to their website.
Give one of the workshops a call for exact quotes on price

Happy modding.