[Mk2] [Turbo] Rev2 to Rev3 Engine Managment Harness Conversion

[Wobbs]

Hi Guy's & Girls
Would anybody happen to know if theres instructions / right up's on how to modify Rev2 engine managment harness to a Rev3?

Any help would be appreciated!

Cheers!

[^Trickster^]

Ill try to give you some brief information as im sat on the couch and im being lazy!

There are quite a few "walkthrough guides" on this topic. I have done it myself with basic diagrams of both ecu pin outputs, you can also remove the lid off each ecu and note down the pin outs as they are all marked on the pcb which is handy.

If you have done some kind of electronics work before its pretty easy to do, its a case of simply cutting the wires and moving them around to suit the new ecu as neccesary, some match up, some dont, i think you can actually get the pin itself out of the connector with a tool, but 3 years ago i didnt know this!

You need to add a few wires too, i added 3 into the harness for the lambda sensor, and 2 to the manifold temp sensor.

Its not all that difficult you just have to get in there and do it!

Some other people will hopefully chime in with diagrams for you, i dont know where mine are!

Graeme

[steve b]

Question should be why?

If its to install arev3+ Apexi Power FC fair enough.

If its to run a rev3 ECU,... pointless the heads are different the maps won't work properly, car won't run properly.

[^Trickster^]

I would disagree with that statement.

It gets rid of the air flow meter and also the maps are better on the rev 3 ecu, reguardless of the heads slight differences, id rather have a rev 3 setup than a rev 2.

You can run the 550cc injectors and its far better for slightly bigger turbo setups.

Rev 2 mechincal wise setups run fine on the rev 3 electronics setup, ive seen it many times.

Graeme

[Wobbs]

Hi Guy's
Any information would be appreciated!
Im fitting a Apexi FC + Commander + Boost Controler. Ive just rebuilt my engine and have got to the stage of carrying out the managment system conversion. I am an automotive electrican so things shouldent be that difficault, I was looking for some pointers from people who have carrid out this conversion already GT Chris has been a graet help in providing me with some spread sheets that show the pins on the ECU that need swaping around to obtaine the correct pin location on a REV3. When I connect the new IAT, should I use the orignal wires that connect to the old intake temp sensor which was mounted in the old AFM?. For the MAT sensor, dose this need a +5v feed, were did you pick up your +5v for this sensor?
I understand that the Apexi boost controler uses the TVSV multi plug, is there any wireing changes required in fitting this valve or is it direct replacement?
Any tip's that you guy's could provide would be a great help.

Regards,

[^Trickster^]

You can just use the 2 wires that feed the stock air temp sensor in the afm to do your air temp sensor yes, originally i did not have a sensor so i used the one in the afm until i did get one.

As far is im aware the apexi boost controller plugs straight into the commander, and does not require you to connect into the tvsv, first ive heard of that anyway, I have heard that the apexi boost controller is not too good so i went with a HKS EVC 5.

If you have a pin out diagram for each ecu its pretty straight forward, I have just had my engine out to do some mods and while it was out i removed about 50% of the wiring in the engine loom and completely re did it, removing the diagnostic plug and everything as I dont need it on the power fc.

If your an automotive electrician you wont have a problem, I am an electrician and I do alot of specialist control systems which obviously made life easier, should be a breeze for you.

Graeme

[Wobbs]

Cheers Graeme!
With referance to the MAT sensor, did you cut open the harness and splice into the +5v line, or did you pick it up on the ECU?

[^Trickster^]

You do mean the temp sensor that goes in the manifold dont you? so we are both on the same wavelength? lol

If so, theres a pinout called Tham on the rev 3 ecu, its that plus a ground wire E1 or E2 i cant remember exactly, its only a 2 wire sensor, I ran a new pair back to the ecu.

Graeme

[Wobbs]

Graeme,
Would you happen to have or know were I can get a Rev3 engine wireing harness diagram? I have a Rev2 diagram for comparison. Anything will do, sketches etc....

[steve b]

I would disagree with that statement.

It gets rid of the air flow meter and also the maps are better on the rev 3 ecu, reguardless of the heads slight differences, id rather have a rev 3 setup than a rev 2.

You can run the 550cc injectors and its far better for slightly bigger turbo setups.

Rev 2 mechincal wise setups run fine on the rev 3 electronics setup, ive seen it many times.

Graeme

Funny, theres been loads of posts on here over the years along the lines of "did a rev3 conversion, now it doesn't run properly", usually stumbling when hard on the throttle, which is probably due to the higher compression ratio of the rev2.

[^Trickster^]

I pretty much doubt the slightly higher compression ratio of the rev 2 engine would make a difference and cause the car to stumble.

Plenty of people rebuild engines on the stock engine management system with various compression ratios with no problems.

People change the VE in all manners, inlet pipework, exhaust, manifolds, different turbo chargers and even cams which is a big change to engine VE and the stock engine management system copes fine, so why would the mild differences between rev 2 and 3 make a difference.

I think alot of the problems is simply lack of knowledge in modifying the engine, I have had running problems in the past when trying new things etc, I just never give up, ive seen people with running problems who end up giving up on the car and getting rid of it only for the next person to fix it and not have a problem.

Graeme

[^Trickster^]

Graeme,
Would you happen to have or know were I can get a Rev3 engine wireing harness diagram? I have a Rev2 diagram for comparison. Anything will do, sketches etc....

PM me your email address and your msn if you like and ill help you out as much as I can, ill try to dig out the drawings for you today.

Graeme

[steve b]

So the decreased VE of the rev 2 head counteracts the increased CR, so ignition timing requirements actually stay the same?

Its just people have trouble running cars on 95ron as it is, don't most say they don't even get the best running on 97 ron super, needing 99ron or V-power (so that means the ignition timing must be agressive as it is) how are they going to cope with a higher compression when the ECU is mapped for a lower CR, increased CR requires less ignition advance unless other mitigating factors push requirements forward again?

[^Trickster^]

Well at the end of the day you can throw any amount of differences at it that you want, one thing wont neccesarily couneract another. Ecu maps are designed for stock engines, so as soon as you change something you might aswell say the engine needs a remap to get the best from the changes, but as it is we stick with the stock ecu and let it cope the best it can with the difference.

Changing cams for instance give you worse idle because the engine VE is so drastically changed and the ecu simply is not programmed to idle as well as it could, but it still runs and makes more power, you just have to take the rough with the smooth with stock ECU setups.

On the note on ignition timing, which is everything when it comes to making power, if you wanted to get picky about it then everyone should be using the exact same base timing, which would mean using a degree wheel to find true TDC and setting your base timing from that and not the stock position, everyone should be running japanese grade fuel as the maps are aggressive because they have much higher octane fuel which allows more ignition timing to be ran.

The chance of someone running the exact mechanical setup, the same fuel and the same atmospheric factors that the original ecu was mapped under is pretty slim, thats why ecus are programmed with correction factors, for when your running different fuels, different CRs, different humidity and temperatures.

I have ran alot of different setups with different turbos and ecus and never had any kind of noticable running problems unless they are problems I put there and expect to see because of the limitations of the stock system (poor idling etc)

I would never run 95ron or any premium kind of unleaded in a japanese car anyway, your are asking for problems by doing that I think, people know the ecu is mapped for a higher octane so you need to get as close to that as is possible, especially when throwing more boost and ultimately more ignition timing at it.

But I would stand by and say id rather have a rev 3 setup on any engine over a rev 2 setup anyday.

Graeme