Our HDJ79 ute was used as the basis for developing front mount intercooler - standard they have around 90rwkw and now have over 3 fold power increase. A lot has been done along the way to make the daily something we can take anywhere. The process is covered below.
First thing was to fit some of the essentials needed for later upgrades. The cab came off during the process for easy access.
- GTurbo Badboy turbo
- Gturbo tuned and supplied tuning module
- NPC 1300nm clutch
- Safari ARMax snorkel
- check and replace all wheel bearings, new disks and pads etc
- 3.9 ratio diff gears installed, instead of the 4.1 gears, which were driving me nuts with the high rpm. Later we had 3.54 ratio gears installed (see below).
We could then do the first revision of the intercooler which was 500mm long. It was in time for 2016 summer and on a few hot days in Perth we tested the engine cooling ability and air con function. While fully loaded and pulling hard up a long hill with brakes applied we got the intake temps to 250/260 and after the intercooler down to 70deg. Considering it was 30deg outside that was pretty good since a good size (fan cooled) top mount has been shown to drop the temp from 130 to 90deg under significantly less load in the some condition.
We had 187rwkw and strong torque ~600nm. On driving it felt quicker than a wagon fitted with +30 injectors. In a 50kph zone we could still accelerate up a steep hill in 5th gear so it was time to remove the 3.9 ratio gears and fit the 3.54 ratio gears with the solid spacers we had made for the VDJ79. Now rpm dropped to 2000rpm at 100kph, 3rd was now very versatile and we had longer legs in all gears. The gearing like this is a pleasure to drive daily and just feels so normal - we get lots of positive responses about the setup with surprise how little it changes the low speed, which is the main concern for most people. The front diff housing was removed to have a bracing kit welded on for extra strength.
On one of those days, towing a 4WD on a trailer out to the wheatbelt, it was so hot that cool drink cans in the tray were bulging and a few burst. The engine did not overheat and the air con cooled better than ever before - icy cold. We knew that we had an effective solution so we designed custom moulded end tanks that allowed us to have a taller and longer core to use the full grill opening.
The next step was a set of +30 injectors as this makes a step change to performance. This gave the ute 240rwkw and over 800nm torque. For both towing and normal driving it was excellent and couldn’t be stopped. On a drive to Kalgoorlie towing a empty car trailer for 600km and another 300km with a cruiser wagon on the back it gave 16L/100km. The factory modified airbox was starting to have an impact on power, but without any options I felt were satisfactory we kept the standard airbox.
Then we did a performance upgrade for a customer with turbo, intercooler and module. His car powered up as expected and he was very pleased. During the test drive I realised how bad 79 series brakes are so started testing some different brake upgrade options. We came up with a larger diameter booster in double diaphragm arrangement and the result was impressive with sport cars stopping capability. Later we got braided flexible lines fitted for a bit of satisfaction and are available on our website.
Next we swapped the +30 injectors for some +70 injectors and cracked the 300rwkw mark. As a precaution we gave the gearbox and transfer case some additives to improve longevity with the new power level. At this point we had to switch over to a pod filter to make the power as our modified factory airbox was holding us back by 20kw at the 260rwkw mark and was getting worse. The pod was too loud so this was the start of the development of the PDI airbox range made from cast alloy to ensure box rigidity and allow for use of the 200 series filter panel. The time from design and development to final sales is sometimes longer than can be imagined.
Now that we were running almost 40psi boost we developed the 76mm thick core. That still fits very nicely behind the factory grill and uses the same piping and brackets.
With the GTurbo badboy red able to make over 30psi by 1750rpm we had great power on the highway so maintaining and watching the speedo become tiresome so a cruise control system was required. In our case we shoehorned a factory cruise system out of a different model.
Another consideration was to be able to have adjustable power so we designed an infinitely variable adjuster for the DTE/DPU modules/chips that in our case means we can have anything from around 170rwkw to 311rwkw available. This is great for reducing aggressiveness for driving in heavy traffic or on wet roads. Our ute is fitted with a Torsen front diff and the front hubs left engaged during winter for maintaining traction when required.
The ute now accelerates and pulls up faster than most would think possible. These upgrades are all relatively straight forward and can be done on vehicles even with high km. Recently we heard of a ute going in with 89rwkw and leaving with the same mods as our ute and achieving 283rwkw. Torque had increased too, but had been limited due to clutch slippage of unknown clutch.
As for getting better, after driving the GTurbo test mule HDJ79 fitted with their hybrid VNT turbo design it is clear that while ours is quick, that one is next level again feeling like the ute has no weight at all.
