Questions before undertaking LS1 GU conversion

[str8up]

I'm looking at buying a Gu Patrol and doing a ls1 and commodore auto gearbox conversion. I haven’t bought anything yet not even the car, I’m still trying to suss out everything before I start going ahead with it. I also plan to cut and shut the wagon into an extra cab further down the track but that shouldn’t matter for now.

I was planning on using

* “Marks 4wd Adapters” Engine mounting kit consisting of:
Left and right chassis bracket, rebuildable engine mount rubbers, re-machined alternator and air-conditioning brackets, Alternator Interface Bracket, all required nuts, bolts and washers.

* “Marks 4wd Adapters” Modified Cast Aluminium Truck Sump, and Modified Pickup to Suit.

* “Marks 4wd Adapters” 4L60E TO 4.2 GQ/ GU T/CASE
Adaptor housing (length 155 mm.), changeover main output shaft, coupler shaft, seal, all required bolts, and instructions - 4L60-E to replace 5-speed and automatic transmissions.

* Either a commodore radiator or maybe one of them dessert cooler ones and probably commodore electric thermo fans or maybe AU falcon thermo fans, not sure what really works well and fits.

Once everything is together I was going to take it to Power Torque at Brendale, Queensland and get the computer issues sorted and give it a nice tune for some power. I heard these guys are pretty reputable for tuning ls1’s.




I’ve got a few questions…

1. What car would be ideal to buy in the first place? I guessing a 3L TD auto? As its cheap. Does it have the same driveline as the 4.2?

2. I noticed on the Marks 4wd Adapters website that the only transfer case adapter they make is to go to the 4.2 transfer case why not the 3.0L TD transfer case?

3. Is the auto gearbox behind the ls1 commodores a 4L60E, 4L60E 6 bolt or a 4L80E?

4. Will the tail shaft need to be modified?

5. Should I go custom made headers and exhaust? Or should I buy the Marks 4wd Adapters extractors?

6. Will I need to change any of the wiring loom? I was thinking it should all be fine since its commodore engine and gearbox.

7. Should I buy the Marks 4wd Adapters speed sensor interface? I was thinking it mite be half simple getting a signal from the gearbox and splicing and dicing it into the dash cluster. Maybe use one of them jaycar speedo corrector things to compensate for different size tyres too?

8. What fuel pump and regulator should I use?

9. Are the truck sumps easy to pickup else where cheaper? Marks charges $800 and do they actually need any modifying?

10. How hard will all this be to comply as legal in Qld? Will I need to upgrade anything else? Eg. Brakes?

10. Will all this work?

11. Have I forgot about anything?

Sorry to ask a million questions but any help would be much appreciated and hopefully help out others too.

Cheers,

Trent

[bogged]

I'd buy a 4.5 petrol or 2.8 diesel.
both cheap as piss these days...

[msjc38]

I drove a ls1 in a gq it was quite dissapointing. There wasnt enough power & torque down low but over 3000rpm was great. Also had a computor edit. A differant cam can also help. Get the ls1 stroked or use an ls2. I drove a ve with a 6lt & it had a lot better power curvemore suited to a patrol

[TheBigBoy]

str8up - Call Steve (killahilux) from killacustoms. He does all the engine conversions and wirring, computer edits, the lot. Drive in, drive out and on the sunny sunny coast. Highly recomended 0404811498

msjc38 - You are joking right?? Maybe it was a import crate ls1. They dont produce as much as the aussie gen3's (dont ask me why but they dont).

Mine produces 900lb/1220nm of torque at 1900rpm and 105hp. Takes off like a rocket and throws you back into your seat. And doesnt stop slowing down until 190kph. Is all stock as a rock behind the patrol 5 speed.

Admittedly Ive heard the 6 litre has a bit more down low. But geeezzz

[TOJO2NISSAN]

I have a GU patrol without a motor that im thinking of selling. was a 3ltr and it blew up. well if ur interested gimme a call 0405707908

cheers brendan

[matto]

[quote=

Mine produces 900lb/1220nm of torque at 1900rpm and 105hp. Takes off like a rocket and throws you back into your seat. And doesnt stop slowing down until 190kph. Is all stock as a rock behind the patrol 5 speed.

Admittedly Ive heard the 6 litre has a bit more down low. But geeezzz[/quote]

the holden tech man says vt 220kw@ 5000rpm
446Nm@4400rpm
vy 225-245kw@5000rpm
446-465Nm@4400-4000rpm
yours is seriously worked dude.

If you can get custom headers for around the same price i would try that as my marks headers are a tight fit.

get your sump from ebay and save $400

ask marks 4x4 if they can email you there installation guide .

[Hoppy11]

I would think that the 4L65E is behind the V8's and supercharged V6's
Hoppy

[TheBigBoy]

matto - Thats at the fly mate... after running through the gearing thats what i get in the rear wheels. Why what did you end up with on yours?? ive got 310bhp and 1450nm

And they are called block hugger headers for a reason. I got mine custom made ($1800 for full exhaust) and they are no different than marks. There are a very tight fit. Go the marks ones, simple cheaper and easier.

[muz84]

What car?
probably better to go with the 4.5 petrol because all fuel lines are correct and in place, (unless your going big power and you would upgrade anyway). Dont know much about the auto gearbox side of things. but you can pick up a cheap TI (4.5 auto) full of all the bling bits and possibly save on buying a gearbox aswell. Personally i'm a manual man, which is why i did the conversion on my 4.5 TI.

Fuel pumps
if stock 5.7. then standard 4.5 fuel pump is not enough. Use the standard intank pump to fill a surge tank and the use a Bosch 044 fuel pump to feed the hungry beast.

Pressure regulator
us any of the well know brands, cnt go wrong

Thermo fans
Mark's also provides a replacement water pump pulley for the 5.7 and it adapts a engine driven fan, i think off of a v6 tf rodeo.

Exhaust
Unless you are trying to get every bit of power out of the motor (or want bling, stailess), just go with the cheapest and most free flowing option

Sump
dont know about this yet. Have been speaking to a bloke who says his sump has plenty of clearance as standard, (he has 5" lift)
Can pick the sump and pick up off ebay for $400

Compliance
It's not how it's modified it's who you know

Yes it will all work

You have forgotten about heaps of things, as did i when asking the same questions. I cant think of any thing off the top of my head right now. But you will learn the hard way just like the rest of us when doing the conversion.
This is not a cheap excersise, trust me i know, especislly if you start getting carried away like i did. And its still not on the road yet

[killalux]

I'm looking at buying a Gu Patrol and doing a ls1 and commodore auto gearbox conversion. I haven’t bought anything yet not even the car, I’m still trying to suss out everything before I start going ahead with it. I also plan to cut and shut the wagon into an extra cab further down the track but that shouldn’t matter for now.

I was planning on using

* “Marks 4wd Adapters” Engine mounting kit consisting of:
Left and right chassis bracket, rebuildable engine mount rubbers, re-machined alternator and air-conditioning brackets, Alternator Interface Bracket, all required nuts, bolts and washers.

* “Marks 4wd Adapters” Modified Cast Aluminium Truck Sump, and Modified Pickup to Suit.

* “Marks 4wd Adapters” 4L60E TO 4.2 GQ/ GU T/CASE
Adaptor housing (length 155 mm.), changeover main output shaft, coupler shaft, seal, all required bolts, and instructions - 4L60-E to replace 5-speed and automatic transmissions.

* Either a commodore radiator or maybe one of them dessert cooler ones and probably commodore electric thermo fans or maybe AU falcon thermo fans, not sure what really works well and fits.

Once everything is together I was going to take it to Power Torque at Brendale, Queensland and get the computer issues sorted and give it a nice tune for some power. I heard these guys are pretty reputable for tuning ls1’s.

""Heard to many bad stories from them, speak to andrew at alan blair auto's in noosa, he did a good job on mine.""




I’ve got a few questions…

1. What car would be ideal to buy in the first place? I guessing a 3L TD auto? As its cheap. Does it have the same driveline as the 4.2?

"Yes same drivertain AFAIK, maybe by the 2.8D or 4.5P they would be cheapest"

2. I noticed on the Marks 4wd Adapters website that the only transfer case adapter they make is to go to the 4.2 transfer case why not the 3.0L TD transfer case? "?? give them a call"

3. Is the auto gearbox behind the ls1 commodores a 4L60E, 4L60E 6 bolt or a 4L80E? "6 bolt 4l60e"

4. Will the tail shaft need to be modified? "No"

5. Should I go custom made headers and exhaust? Or should I buy the Marks 4wd Adapters extractors?

"Marks headers do the job just fine, would possibly get them heat coated cause they get very hot through the floor"

6. Will I need to change any of the wiring loom? I was thinking it should all be fine since its commodore engine and gearbox.

"Yes you will, i do a changeover harness that has all the relays and fuses added in and just have to connect about 9 wires into the car, or depends where you are i can sort the whole lot"

7. Should I buy the Marks 4wd Adapters speed sensor interface? I was thinking it mite be half simple getting a signal from the gearbox and splicing and dicing it into the dash cluster. Maybe use one of them jaycar speedo corrector things to compensate for different size tyres too?

"Don't bother, just get it tuned without the speed sensor, the sensor on the t-case will still run the speedo"

8. What fuel pump and regulator should I use?

"Bosch external pump, Holden have a reg / filter built into one unit that is used on later gen 4's, about $120 from memory. Go that way"

9. Are the truck sumps easy to pickup else where cheaper? Marks charges $800 and do they actually need any modifying?

"Ebay for around $400, would only need mod if you have no suspension lift to cl;ear the tierod i think. all the ones i have seen use the truck or camaro sump no worries (camaro one is shallower)"

10. How hard will all this be to comply as legal in Qld? Will I need to upgrade anything else? Eg. Brakes?

"Piss easy, simple mod plate. Just have to have cat converters in the exhaust"

10. Will all this work?

"Yes it will, if you drive hard look at gettin the gearbox upgraded to 4l65e spec, cost about $900"

11. Have I forgot about anything? Don't think so

Sorry to ask a million questions but any help would be much appreciated and hopefully help out others too.

Cheers,

Trent

See my answere above in the quote

[TheBigBoy]

MUZ84 - Still not on the road mate? the easter goal has been and gone. Im still keen as to see how your turns out. And yes, mine in a REAR DROP SUMP and pick ups I got from eagle parts. They are a us import place. Sump new $500 and pick ups I think where $110. No problem with jumping my truck or full suspension tuck with a 5" lift.

ps. That air box needs to be changed asap.... Ask killahilux about the ones he's shown me.

[chunderlicious]

the standard airbox restricts even a standard ls1. talk to the guys at brisbane airfilters... they have an awsome donaldson one with 4 inch in and outlets

[matto]

thebigboy- hey mate i havent got mine tested i will have to to see what i get, what size tyres and gear and dif ratio was it tested in?

When i went looking around for a custom headers no one could do it except for one guy who wanted $700 a day and he would need it for 2 weeks. i ended up having to wait 5 months for marks to make one.

[TheBigBoy]

WOW - 5 months or $7000. ha ha hard decission. What computer are you running? What engine do you have? What box? What truck is it in?

Mine is a VY engine that i got rebuilt (220kw). I chose this 1 because it still had a cable throttle body. Dyno results are in 4th gear behind the patrol 5 speed in a td42 st ute. 4th gear with the standard tyres on and 4.1 gears.
ps. Ive since got 310 bhp and about 50more nm but I didnt upload a pic.




The easy way if your lazy to get your rwhp to fly kw.
4WD cars - add 10bhp to the wheel figure and divide the result by 0.84
To get estimated bhp figures just do it in reverse.

290hp = 357hp. Convert that to kw = 266kw at the fly Most of that 44kw gain is from my aftermarket computer and exhaust. Apart from that the next best thing is the clutch. With the stock tyres on I can spin it up on a wet highway at 90kph in a straight line. Wich is why muzza84's truck makes me smile and I will twin turbo a 6 litre with some work aswell for my next truck.

[grinch2]

i didnt think chapmans had the gear to tune the ls1?

[killalux]

Big boy's LS1 uses an EMS computer

[TheBigBoy]

Yeah, EMS6680, unfortunately mine was 1 of the first gen 3 conversion. I rang every comp guy and commodore guy in aus. By that stage even mark's hadnt done 1, so I was on my own. They told me it was illegal to unlock the computer and noone would do it for me+noone had the edit software. I had a entire wrecked ute at my disposal. Which is a pitty because I wanted to keep the ignition modual and coded key for security aswell. :(. Im not sure what the difference is between our computers. Killahilux is right about the commodore comp starting better than the aftermarket 1. I wish I had your number back then mate...

Do you get the same figures from the commodore computer?

[killalux]

the commodore computer has the sam amount of tuning possibilities as the EMS.
In my truck i got 239HP at the wheels with stock motor, 35's, standard exhaust manifolds, and pod filter that sits to close to the exhaust. And its an auto. Also that is tuned for economy.

Also have heard from many people that chapmans dyno reads high by around 40HP

[TheBigBoy]

Yeah, 1madengineer told me. Thats nice work out of an auto... Sounds pretty similar. Oh I spoke with marks today about replacing my clutch. They recommend the 12" heavy duty button clutch with 26 tooth clutch plate and 26 tooth output shaft splines (instead of the old chev 11"). They have had a fair few come back. There is problems with them bending the gen 3, ls2 fly wheels. And have a custom 2 peace fly wheel made up for $450 (I think) around that.

Just so you know...

Actually thats awsome work considering standard exhaust manifolds... Im pretty sure my fuel line running with in 60mm of my exhaust and my high temp fuel pump isnt doing me any favours. (it doesnt get vapour lock, but im sure im killing horses)

[matto]

hey bigboy
yeah mine runs a standard ecu that has has a mafless tune and all security taken off, it was an ebay tune.
mine is a 1999 vt ss ute motor running in a gq 4.2 gearbox into 4.6 diffs spinning 37 maxxis. when i had 33" tyres it felt like i was digging bituman up taking off, 37's feel good.
i done a test 0-100 in 13 seconds and that was on a slight rise i would be interested to see what time yours does.

seeing as there is so many v8 patrols getting around these days we all should have a get together it could be a big turnout.

[TheBigBoy]

You really need to get it dyno tuned hey. Better tune = Better running (cold start aswell) better eco and more clean power. Air box and fuel pump may be letting you down bigtime. Mine does 0 - 100 in 7 flat with the original patrol tyres on and original tune (260 bhp) and also when the engine was tight and new. The reason there isnt much gain from new to the second tune (above) is because I added a few more mufflers to keep it silent . That killed it a little bit.

I run 33's for the road now, but ive since upped my power and torque aswell (310bhp). So with the compensation it shouldnt be too far off that. Was your time with 33's or 37's? There is absolutely no reason why yours shouldnt be up with mine. Especially running 4.6 diff gears.

[str8up]

Cheers for all the help boys there's a fair bit of useful info there and some nice power figures too. I'm going to try and do as much of it as I can, hopefully save a bit of dosh.

So no one is running the commodore auto? I'm wondering how it sits? I wanna keep it if possible I've heard its a bloody strong box.

[matto]

the only concern i would have with the commodore box would be that the cross member may need to be moved and a custom transfercase like an atlas (3k i think) and custom drive shafts and you might have to beat the shiv out of the floor.

[killalux]

Cheers for all the help boys there's a fair bit of useful info there and some nice power figures too. I'm going to try and do as much of it as I can, hopefully save a bit of dosh.

So no one is running the commodore auto? I'm wondering how it sits? I wanna keep it if possible I've heard its a bloody strong box.

I am running the commodore auto in my 80 series and my brother has one in his GQ. There is adapters available to bolt up to the transfer case. The GQ adapter involves striping the box to change the output shaft though, This is a good excuse to upgrade clutches and bands, which is about $500 on top of changing the shaft.

I am happy with mine, can recomend it. Best thing is with the software you can fully tune shift points, shift firmness. shift speeds, etc.

[str8up]

How did the GQ go with the 4L60E if that's what its called? Did he have to get a new tailshaft made/ modify the old one? How did it sit? Do you just modify the existing cross member a bit? and does anything to the body of the car have to be done?

Cheers

[grinch2]

How did the GQ go with the 4L60E if that's what its called? Did he have to get a new tailshaft made/ modify the old one? How did it sit? Do you just modify the existing cross member a bit? and does anything to the body of the car have to be done?

Cheers

bolts in with std shafts and cross member only thing you need to sort is the shifter

[bigbluemav]

I drove a ls1 in a gq it was quite dissapointing. There wasnt enough power & torque down low but over 3000rpm was great. Also had a computor edit. A differant cam can also help. Get the ls1 stroked or use an ls2. I drove a ve with a 6lt & it had a lot better power curvemore suited to a patrol

In commodores (I've owned a VX SS and currently own a VZ SS with an L76 6.0 litre) I've found the same thing!

After not driving a V8 since an XAGT coupe that I sold in 1988, I found the LS1 very disappointing low in the rev range, but it ponied up higher in the rev range and rev WAY more than a cleveland! The L76 (L98 in the VE) have WAY more low and mid range and I'd reckon would be WAY more suitable for 4wd applications.

Unless you can get the LS1 for WAY cheaper, go the L76/L98. They are also a cheaper option than the LS2, I'd think.