Hey guys this is my first post on this site. I'm not new to this website I read it like the bible :P

My question is that what changed between the 6g74 & 6g75 to get direct port ignition and coil packs, and the advanced\retard features of it to make use of good fuel. Can that system be fitted to a 3rd gen TH, what would be involved.

Also on a side note what is the black box bolted to the top of the RH drivers engine mount.

The 6G75 in the 380 has a completely different engine management system - Bosch CANBUS ECU with hot-wire MAF - compared to the 3rd gen 6G74. You'd have to retrofit a CANBUS loom into the non-CANBUS 3rd gen to make it work, as well as changing the intake system to use the HW MAF. Unless you have a 5 speed auto, there is also no practical option to drive the automatic gearbox in the 380 setup. IMO if you're that desperate to get COP ignition it will be much cheaper and more effective to just trade your car for a 380...

If you do a manual conversion, you could use an after-market full replacement ECU but it will still be pretty expensive...

Despite the attraction COP seems to have, a good transistor assisted dizzy works very nearly as well unless you're revving well in excess of 7000rpm. Both types of ignition suffer hard to diagnose issues when parts start failing...

Your TH ECU (the engine part anyway) is reflashable - see the thread linked in my signature for more info - and the ignition advance can be easily adjusted within the engine's tolerance limits. I'm close to releasing an update to the ECU definitions which brings the H series ECUs nearly to parity with the J/L/W series ECUs in tuning capability.

the 6g74 & 6g75 to get direct port ignition and coil packs, and the advanced\retard features of it to make use of good fuel.


The ECU controls the advance/retard of the ignition system.
In everyday use, you would not be able to detect any difference in how an engine runs comparing a single coil + distributor against a COP setup.

As in the above post - sell the third gen, buy a 380 - best option.

As far as I knew about the 3rd gen ecu it didn't have knock sensors or the ability to advanced or retard based on fuel type or driving style other than its basic learning capacity.

As for ecu systems I haven't done too much research as very few options available to magna's. And cannot decide between skr tune, piggyback or full replacement.

I cannot tell what has been done to the engine as I bought it from a scrap yard but it is at LEAST full record motor and box. But it goes faster than it should. Deffinatly needs a tune and dyno run but what to get tuned stock, piggy or full?

Thanks Loki,
I'll have to upload some me pics of the car.

What is a good transistor assisted dizzy, haven't heard of it before?

What is a good transistor assisted dizzy, haven't heard of it before?

You already have one.

Thankyou for that. Now I'll put my other foot in my mouth :P

Thankyou for that. Now I'll put my other foot in my mouth :P

Feel free. lol

No, let me elucidate!

Old system:
12 V, points cut current, transient voltage is dumped into coil, ---> high voltage for spark .

Not so old system:
12 V, points cut current, transient voltage is dumped into transistor circuit, raises voltage to 400V, dumped into coil, ---> high voltage for spark .

Newer, but still old:
ECU reads signals from crank and cam angle sensors, electronics --> 400V to coil, etc.

Current COP:
Same, but the ECU is smart enough to know from cam and crank angle sensors which coil should be fired.

Current system is more accurate and reliable than the older systems (hopefully), and if one coil goes out the car will still run. Needless to say, if something does go wrong it is harder to troubleshoot (reading ECU error codes helps) and more expensive to repair.

As far as I knew about the 3rd gen ecu it didn't have knock sensors or the ability to advanced or retard based on fuel type or driving style other than its basic learning capacity.
It is true that the 3rd gens don't have knock sensors, but that isn't a limitation of the ECU as such - the USDM Diamante's made in Australia (from which the Veradas were derived) did have knock sensors and used the same ECUs but with different ROM contents. The difference between the high and low octane ignition maps in the Diamantes isn't as much as many people expect though. That also applies to the difference between the stock tune and an appropriately done 98RON tune for the 6G74 as well... much to many people's chagrin.

Sadly the Diamante ECUs (or the ROMs) can't be fitted to 3rd gens as there are other loom compatibility issues than just the missing knock sensor.

The reality with the 3rd gen is that there are much better things to spend performance $ on than tuning - specifically the exhaust system followed by cams, though these days a 6G75 transplant (using the stock ECU and dizzy) might be considered better value than cams (which are part of the 6G75 package anyway). Then get the tune done to optimise the 6G75's performance.

Thank you to everyone for there information and clarification on questions and topics im sure have been spoken about before.

The biggest problem i am having is that the motor is not stock and without pulling the motor apart i cannot tell what has been done to it. Every person i take for a drive in the car and open it up a wee bit they tell me that it is not stock as well. I have a full high flow exhaust except the extractors, as i am waiting for a decent set of 2nd hand ones to go online. and the intake is custom but will be getting more attention. If you could read my profile you will see what i have done to the car.

In conclusion i dont want to buy cams and find that i have 6g75 cams in there, the bloke that did the reco could have transplanted 6g75 parts for all i know. one of the joys of buying your car for $150 you dont get the recipts :P

Loki :D