Holden V6 CONVERSION

[NeilsTransit]

In my previous post I should have said from 3rd to 4th gears was a slowish but ongoing increase in engine revs as opposed to not much change in Revs from 3rd to 4th. Good idea DodgeRover I will jack the vehicle up and do as you say as then I will know for sure.

[NeilsTransit]

If that's the ratio in 4th then it's definitely not the diff you think, try jacking it up and turning a rear wheel and count how many turns the prop makes.
Lock up just means it acts like a manual box when the clutch is up rather than slipping slightly

I finally got around to doing the above and for 1 revolution of the wheel the prop turns twice and a bit so what does that mean? I have changed the original 14" wheels for 15" wheels so that would make the prop revs more like just twice

So with the auto lock up mode is that always1/1 or can it be 0.75/1 for example and how do I know if I'm in lock up mode?

[NeilsTransit]

[DodgeRover]

Well if that was with one wheel in the air then I make that 1:4.twice a bit? So it's a puzzle why it's pulling so many revs

[tdg61]

G'day Neils transit. I too am from Oz, and considering fitting an ecotec into my 99 VG. I was concerned with diff ratio as this would make it abhorrently thirsty. I have consulted with a guy in Brisbane who owns A9 diff conversions, about doing a conversion but short of making a 9 inch setup, which would be expensive, he's yet to get back to me. I did hear of a guy who ran big tyres on the back to compensate, but not sure if this is ideal. Can you tell me if the ecotec is worth the trouble

[DodgeRover]

Neil just did some more reading if the ECU doesn't receive the correct signal from the temperature sender then the box won't go into lockup mode which apparently happens between 80 and 100 kph in the commodore? Could also be the kick down cable is out of adjustment?

[NeilsTransit]

G'day Neils transit. I too am from Oz, and considering fitting an ecotec into my 99 VG. I was concerned with diff ratio as this would make it abhorrently thirsty. I have consulted with a guy in Brisbane who owns A9 diff conversions, about doing a conversion but short of making a 9 inch setup, which would be expensive, he's yet to get back to me. I did hear of a guy who ran big tyres on the back to compensate, but not sure if this is ideal. Can you tell me if the ecotec is worth the trouble

Hi tdg61, I am assuming you have a Transit engine in your vehicle atm. If you are going to do this conversion then yes an Ecotec V6 is the way to go and from the research that I have done a VS V6 seems to be the favourite for me because there's lots of them around and cheap to buy, easy to get parts and out in the countryside every other person has a Holden V6 and they are not to complicated with all the electronics stuff but people have put in later models. I have a VN with 125kws of power however the VS has 147kws so that's handy as the Transit is bigger than the Commodore.
I have a SWB tranny which came with 14" and I've changed them for 15' but can go no bigger as the wheel arch gets in the way. If you have a LWB then they come with 15" or even16" wheels depending whether it's a diesel or petrol but I'm not an expert on LWB Trannys that so maybe somebody else is a better person to ask, maybe Minormat.I get a bit more speed with the 15" for the same RPM so at 80ks the speedo would read about 77ks so on long run it adds up but it cost me $400 for adapters plus I had to get 5 new 15" tires plus 15" rims so all up just over $900
The diff issue is a problem but I'm seriously considering getting a taller diff actually welded into the transit axle as this saves all the hassling around with brakes, shockers, suspension and maybe tail shaft adjusting but it isn't cheap.I've heard figures like $2500/$3000 stated but I will look into this in more detail. The Holden diff is 3.08/1 and the Transit diff in mine is 4.56/1 so as you can see there's big difference. People have suggested changing the whole back axle but I don't know enough about doner axles from other vehicles to do that and anyway if the axle is out of the vehicle you don't know what it is like. Yoy can buy conversion kits from Castlemaine Rod Shop or V6C Conversions but I don't know which is better. Both these places are in Victoria, I don't know anything about where to go in other states

[NeilsTransit]

Neil just did some more reading if the ECU doesn't receive the correct signal from the temperature sender then the box won't go into lockup mode which apparently happens between 80 and 100 kph in the commodore? Could also be the kick down cable is out of adjustment?

I've actually just replaced the coolant temp sensor and the sender for another problem (The thermo fan isn't coming on) and also realized that I had set up the kickdown cable incorrectly so in the end I had to resort to the manual as I heard somewhere that if all else fails then read the instructions . So you might be on to something there with the lockup mode not happening as I've been hawk eyeing the rpm and seen no visual sign of a slight decrease in RPM at any speed and I've driven the Transit very occasionally at 100ks.
ATM I'm waiting for a new Thermostat housing as the old one is has welded itself onto the block as I don't think it's ever been changed and the engine is 25years old and this is a Series 1 VN which means the stat housing is at the back of the engine . My hand has been inching towards a large hammer but until the replacement arrives from South Australia (I'm in Victoria) then I'll hold off with the brute force. Anyways thanks for your help thus far, it is much appreciated.

[tdg61]

Thanks Neil for that great info. I actually have 2 transits, both long ones. One is high roof TD 2.5 with a buggered pump that I use as a mobile shed and spare parts bin. The other is 2 litre petrol which is the one I'm doing up as a traveller and tow vehicle for my race car. I have a VT model ecotec that logic dictates would be ideal for the van. It's fuel consumption with the standard 5.14 diff in it that scares me. Any diff conversion is going to cost money. If I come with something I'll let you know

[sos recovery]

where are you getting your tacho signal from ?

[NeilsTransit]

I spoke to a Transmission guy and he said often with these V6 conversions that the installers don't wire in the Lockup mode to behave automatically as it adds hundreds of dollars to the installation cost but he can do it manually at a modest price so I'm thinking my lockup mode is not connected at all. I'm not sure how the tacho is connected to the power train atm but I will find out

[NeilsTransit]

where are you getting your tacho signal from ?

Apparently the tachometer reading is coming from the DFI module according to the electronic gurus on the Holden Commodore Forum so how do I check the tachometer for accuracy and change it if necessary?