[Porky's Patrol]

I am looking at a Tubo upgrade for the TD42 in a 2004 Series IV GU and found a series of Garret Ballbearing Turbos on offer the 2860, 2871, 2876, 3071 & 3076.

I am running 285 70 17 which is about 10mil larger diameter than standard and have found over all the vehicle is far too high a ratio needs more power across the whole rev range so I will be looking at upgrading the intercooler as well with 3in mandrel bend exhaust.

Which turbo? I have heard the larger the turbo the longer it takes to spool up. Ideally I would like the Turbo to be spooled up at 1700rpm but delivering maximum torque.

Is bigger better?

Now ideally if I could convince the handbrake and had the money perhaps the $35,000 to put in the 6.5 supercharged Chev Diesel putting out 820Nm. Gotta have those dreams!!!

 

[EagleBay]

Give united fuel injection a call, they have done countless hours testing different turbos. I have done a heap of research but there is so much conflicting information out there that you really need to talk to someone with experience in setting something up that is suited to you

 

[goldfinder]

Hey Porky's Patrol I would be interested in your final decision and why. Looking at a possible upgrade myself. Keep us informed.

 

[truckster]

am running 285 70 17 which is about 10mil larger diameter than standard and have found over all the vehicle is far too high a ratio needs more power across the whole rev range so I will be changing diff ratios.

Good idea.

 

[patroladdict]

Unless your looking at changing the IP, airbox and going a big front mount intercooler, I'd forget the GT30's

 

[Porky's Patrol]

If I was running larger tyres than a diff change would be perfect. Tyre size I am basicly standard so if I alter the diffs the performance on the highway would be compromised running too high a revs and less economy.

I had an old 88 Patrol naturally aspirated, had heaps of grunt and good economy. The 4.2 now is woeful. Basically Nissan have chocked the **** out of it, the intercoolers on them heat up the air instead of cooling it as it is supposed too and the turbo is basically a hair dryer that should not be on any motor over 2.5 litres.

But all that said I am not all that clued up on diff ratios, what is in it as standard and what would it be best to change too? How much is that likely to affect highway speeds and the revs at that speed?

Appreciate the assistance, but all this does make you question why you would need to change ratios in what is essentially a standard vehicle? Over all I love the vehicle just some things seem to be manufactured wrong.

 

[zoom0001]

Best way is to work out the tyre size first.

If you go 31 to 33 that is an increase of ~6.5% meaning you will need to increase your current 3.9 ratio by about the same amount to keep things the same.

3.9 + 6.5% = 4.15, or a 4.11 diff. Personally if you are going to run 33's and don't look like going back to 31's go a 4.375 ratio. The 3.9's in a late model patrol are just to tall to start with, especially once you start accessorising.

 

[Snail Pace]

Well to work out your diff ratio's have a look under the bonnet. Left hand side of the fire wall on the ID tag. It should say trans axel and most likely say 2 letters then 4.11 if so i would recommend the next step up. Which would be the 4.3 which are found in the 3L patrols old and new petrol and diesel. They dont rev to hard while on the high way but gives you that extra grunt. 4.6 is just that bit to high unless u run 35's.

Hope that makes some sort of sense.

Cheers
Shane

 

[Porky's Patrol]

Thank you all,
standard the vehicle has 275 70 17, I run the 285s because I could not get any 275s when I first got the vehicle. So tyre size is no real difference, I was talking with a mate who was saying they are 3.9s so from what I am reading I need to go to 4.11.

From this info if I make the adjustment to the diffs and put on a proper straight through exhaust 3 in with dump and an intercooler, that actually cools the air, it should be a good rig.