F6A head swap on a F8B

[demondada]

hey guys.. i have an F8B hatch that i want to turbo charge and im wanting to swap a F6A head on it in order for it to become an EFi as well.
I just want to knw simply if its [i]possible[/i] or not and what all needs to be done if it is.

Thanks in advance

[Brayden]

Yes it is possible. You need a custom timing belt, F6A head gasket, and an aftermarket ECU to run it.

[demondada]

hey man,thanks for the info,
i have a few more questions though:

1. Is there a change in the compression ration with the swap?
2. Why would i need an after market ecu? i have the genuince F6A ecu and wiring
3. Are there any sensors in the block of the F6A? If so then my F8B does'nt have any provision for any sensors.
4. Can i get a wiring diagram for a F6A from sumwhere??

thanks

[Brayden]

1. Compression ratio change would depend on what thickness head gasket you use.
2. The F6A ECU fuel/timing map would not compensate for the additional 140cc, causing the engine to run lean and hot.
3. The only sensor in the block should be the oil pressure sender unit. Although the F8B has no provisions for oil feed/return lines, so you'll need to sort that out.
4. I haven't seen one.

[demondada]

Thanks again dude. Tell me what if i use a piggy back ecu on it? like an FASC? will it sort out the fuelling issues?

[Brayden]

In theory you could use a piggyback (SAF-C, etc), but the reality is you still have the factory fuel and boost cuts to deal with.

When I did the turbo/EFI conversion on my F8B I just went straight for a standalone aftermarket ECU.

[demondada]

i understand. But the problem is brayden that where i live, u cant possibly get after market ecu's :p thats why im a little tied down.

wont the O2 sensor help to regulate the fueling somewhat?

[dodgemnz]

I had a cappuccino Factory shop manual with all the info ... i sold that with my car to a friend and im trying to track down her son at the moment to borrow the book back. If i can get it back i maybe able to scan the data for you.
Because the system is MAP controlled it will not fuel properly, it might be fine at cruise with the O2 sensor but under boost and acceleration it may well stumble or run to lean for best acceleration.
Mike

[demondada]

i was planning on boring the head of the F6A to match the F8B and to polish the ports as well... willl this help? And is the combustion chamber of the F6A head similar to that of the F8B'a head??

[ceej]

The problem will still be the same. The fuel/ignition map on the standard F6A ECU is designed for the F6A 660cc engine. You are planning on running it with an 800cc engine which would require different maps to control the amount of fuel/air etc. This is because the F8B is approximately 140cc larger, and as such will run lean if the F6A map is used on it.

Don't polish the ports, it isn't good for fuel atomization, definitely port, but don't polish!

And no the O2 sensor won't help. O2 sensors are just for fine trimming of fuel loads when in open-loop mode (cruising etc.). This helps with emissions and to ensure that the engine has a stable AFR. It doesn't add fuel to compensate for the wrong ECU mated to the wrong engine. If this were the case, you could just about put any ECU into any car and with an O2 sensor you would never have a problem!

Where abouts do you live to make getting an after market ECU such a problem? Surly you can have a company send you one, they all have online stores!

[demondada]

what if i get bigger injectors? i.e of the F8C that came in the Daewoo Matiz...

[Brayden]

You could fit larger injectors and use an aftermarket FPR to raise fuel pressure, but it would then run really rich when off boost.

As ceej pointed out, most ECU manufacturers sell anywhere in the world. MicroTech, Adaptronic, Haltec, etc. In fact Adaptronic have a base map for an F6A which could be adjusted to suit an F8B twin cam.