Aftermarket Ecu On Standard 8V

[Anthony 1,003]

You can mount the ECU wherever you like given that you'll need a loom making up for your particular application anyway.

 

On the 8v I did I mounted it in the standard position, but equally I've done looms for people before to mount the ECU in a 306 style battery box or inside the car on the passenger side (running the loom in under the expansion tank). The biggest issue mounting the ECU in the standard position is that depending on the exhaust manifold, you can get heat damage to the loom near the bulkhead where it runs close to the manifold - not too much of an issue with an 8v though compared to say a GTi-6.

 

With regards ECU choice, it would be worth considering who you want to do the mapping as some mappers will prefer one ECU over another. DTA ECU's are probably one of the most popular ECU's used by people on this forum, typically the S40.

[opticaltrigger 52]

Their 600 series ECU seems to have all the functionality needed , it does say TPS or MAP for load though so it will have to be one or the other . Their basic loom seems good value at £60 .Would the injectors still be batch fired , I assume sequential would be for more highly modified engines ?

 

The injectors would be batch fire unless you install a cam sensor too. That is assuming that the controller you mention suports fully sequential.

 

Lucas did a tremendous amount of very high quality research, many years ago, into the benifits of having sequential injection over batch fired and the findings seemed to show that there wasn't really anything special to be had from it.

However it has to be said, that research was done before the pressent digital age.

If a combination of fully sequential ignition and fuel injection was adopted, then with some serious maping of the injection and ignition angles it should be possible in theory to make some small gains over batch fired throughout the range. (Possibly..???) ..... The emisions would be improved undoubtedly though.

 

All the best

O.T.

[hoodygoodwood 71 3 Cars]

The more expensive Omex 710 ECU can sequentialy fire the injectors but it is over £1000 .I was just curious to see if anyone had tried sequential over batch and found large gains .An Omex 600 or DTA S40 seem to be the popular choice .

A friend has a spare 1.6 bottom end so I need to do some forum searches on 1.6 pistons into a 1.9 engine .

[petert 588]

Wouldn't it be multipoint? Not batch? Batch fires in pairs. The gains with sequential come in mid range torque, not total hp. At full noise, regardless of the injection type, the injectors are open almost all the time. It's not easy to add a cam (or home) sensor to an 8V.

Edited April 15, 2015 by petert

[hoodygoodwood 71 3 Cars]

The engine I have at the back of my garage for this build has not been run properly for many years , I will get it apart in the next few weeks to make sure the block is sound . There seem to be a lot of corrosion problems coming through the crankcase at liner 'O' ring seal level .

The Piper website shows a 30 BHP gain for its BP285 cam profile which seems a bit optimistic and their price for 8 new tappets is scary , do FAI or similar still do them , I will have to check when I am getting my new liners , rings etc for my Miami project .

[welshpug 1,661]

30bhp from the 285 is probably attainable, only if compression ratio and air&fuel demands are met, I believe that gain stated is for carbs or itb's.

[hoodygoodwood 71 3 Cars]

I have bought a Cosworth air temp sensor from Ebay and received a used 106 GTI MAP sensor this week ( for 99p ) which I might fit to the inlet manifold as well just in case I ever want to try that option . Will probably put both at the other end of the plenum near the core plug .

I should have an early GTI inlet manifold and TB winging its way to me shortly , provided by DCC on here .Will be dowelling it to the head then matching the ports so there are no steps in the airflow .

Made a start stripping down the engine which I will be using for this build , all the headbolts came out ok which was a result after breaking one in my Miami block 2 weeks ago and will hope to have it in bits soon .

[hoodygoodwood 71 3 Cars]

Won a 1.6 short engine on Ebay today , will be using its pistons in this new engine .

[hoodygoodwood 71 3 Cars]

Have just been looking at jimmi's underbonnet set up in Ireland and he has an 8v on Emerald which has retained the dizzy and coil on inner wing using the hall effect as the ignition trigger . I had assumed that for proper spark control and mappability I would have to use a coil pack and appropriate leads , half the reason for trying the aftermarket ECU was to keep the std underbonnet look so I would keep the dizzy if possible .I suppose The vacuum advance would be disconnected and the mechanical advance locked solid then could I use either the 'hall effect' or a GTI6 flywheel and pickup for the ignition signal .

So what I am asking is would it compromise the engine to retain the dizzy to distribute the spark if I had a fully mapped ignition curve from the Omex ECU .

Thanks

[jackherer 543]

As Miles said on page 1, you need to use a VW Golf Mk2 16v distributor for its hall effect sensor, the 205 one isn't suitable. It used to be a common way of doing it back in the day before cheap wasted spark coilpacks were easily available.

[Matteo 17 1 Cars]

I have a similar setup on my 205: http://forum.205gtidrivers.com/index.php?app=garage&do=view&id=94

As I wanted to keep an original look in the engine bay, I use a dizzy from a Motronic 205 and a custom made flywheel with pulse ring to trigger the ignition. The Mectronik MKE1 ECU has the ignition curve.

I even retained the AFM (with the flap stuck open) and as there is no external trigger wheel, sensor and bracket, actually nothing is visible.

A Mectronik MKL1 wide band lambda controller works with CAN connection with the MKE1 and the map is always adjusted in real time.

[petert 588]

If you know what you're doing, you can lock up the Jetronic dizzy and make it fire approx. 50 deg BTDC. You also need to adjust the rotor phasing at same time however. It takes a little patience and nohow, but it keeps it all original in appearance.

[hoodygoodwood 71 3 Cars]

From an engineering point of view what would provide the best trigger signal for the spark to the new ECU , a 'hall effect' dizzy or a GTI6 flywheel and pickup . I would imagine the far larger diameter of the flywheel would make it the more accurate choice , as well as not having any cambelt tension/replacement or vernier cam pulley issues .

An appropriate flywheel is also cheap to find .

If the flywheel and pick up was providing the trigger signal would a std dizzy (with fixed vacuum and mech advance) be ok to solely distribute the spark via a standard rotor arm , cap and leads and coil .

Collected my 1.6 GTI short engine last night - pistons look good .

[Anthony 1,003]

I'd personally use a Motronic flywheel and pickup everytime, especially given that the engine is out of the car.

 

No issue with retaining the dizzy setup for spark distribution, although unless you really want the original look I can't see why you would over and above a wasted spark coil setup given that any vaguely modern ECU will have two ignition drivers (or more).

[petert 588]

Flywheel is absolutely the most accurate solution, but as I said earlier, early BE1 gearboxes don't have the hole for the sensor. You just need to work out what's best for you.

[Tom Fenton 1,542]

Personally I would junk the dizzy and use the crank sensor and flywheel. You can get a late thermostat housing which allows you to bolt on the appropriate coil pack for an OE quality install, no s*itty home made brackets. Buy ign leads from such as 1.9 ZX Volcane and you have direct fit leads from coil to plug. No rotor arm or distributor cap to wear out.

[hoodygoodwood 71 3 Cars]

I have a spare BE3 box from a Goodwood , all cleaned and painted , new yellow arm bushes etc been waiting on a shelf for this project for over a year so no probs with the flywheel pickup location .

[Miles 331 1 Cars]

Later BE1 box's do have the hole in the UK, only upto and around 1986 did they not have one

[309jazzpanda 41]

The more expensive Omex 710 ECU can sequentialy fire the injectors but it is over £1000 .I was just curious to see if anyone had tried sequential over batch and found large gains .An Omex 600 or DTA S40 seem to be the popular choice .

A friend has a spare 1.6 bottom end so I need to do some forum searches on 1.6 pistons into a 1.9 engine .

I am in the process of doing the same thing,1600 pistons 3 angle valve seats 285 cam with a 4 branch, with a 4.4 cwp should be a nice little road rally set up.On a different note we do look after a sprint 205 with this set up on standard management, its VERY lumpy on idle but pulls like a train.

Edited April 28, 2015 by 309jazzpanda

[Reebmit 51 4 Cars]

The engine I have at the back of my garage for this build has not been run properly for many years , I will get it apart in the next few weeks to make sure the block is sound . There seem to be a lot of corrosion problems coming through the crankcase at liner 'O' ring seal level .The Piper website shows a 30 BHP gain for its BP285 cam profile which seems a bit optimistic and their price for 8 new tappets is scary , do FAI or similar still do them , I will have to check when I am getting my new liners , rings etc for my Miami project .

Running BP285 in one of mine with big valve head and 45's, nice cam, feels very strong, especially considering its 8 valve.

[hoodygoodwood 71 3 Cars]

The Piper 285 cam was one of the must haves from the start , plus the Magnex stainless manifold and system which I already have .

My Magnetti Marelli air temp sensor ( Cosworth ) came in the post this week .

While having the Omex ECU wired in would be the ideal time to get an immobiliser fitted .

[309jazzpanda 41]

Just a thought if you are going for an ones why not bump it up to a 300 cam? Is this for the turbo trophy replica you wants to build?

[Tom Fenton 1,542]

Don't fall into the trap of "if more cam is good then massive cam is better".

I have been there and done it and regretted it, a big duration cam can really make the engine an utter pig if everything else isn't well matched.

On a XU 8v I think the limiting factor will be the standard inlet and specifically the big pulses from a big cam making it run awfully low down.

On throttle bodies with a suitable CR then OK.

[hoodygoodwood 71 3 Cars]

I think the 285 is a good compromise with power gains through the range , a wilder cam would start to push the power band into higher rpm and this will be a road engine so I want to keep its driveability .

Yes its for my 309 turbo Cup replica ( see my forum pic )The gearbox is from a Goodwood and has been in my garage for 2 years , the engine is from a ph1 309 GTI and the base car is a 309 1.3 XL which is currently in my mates yard in Oxford .

[309jazzpanda 41]

Why not put the 2.0 litre turbo in for that more original look. Ah I didn't realise it was just a road engine I wouldn't have suggested a 300 for that you are right, I thought you were using it for track use. Yes I know what a turbo ccup car is that used to be my forum pic pic as well ha ha. If you search the 309 owners forum there is a guy who purchased a genuine cup car, it's a few years ago may be before you joined up but I'm sure it got saved when the forum moved and not deleted some good close up pics from what I remember