2.5 D4D (2KD) Performance Upgrades

[Heinsebal]

First time posting here but not really “new” to the Toyota world.

I’m planning on upgrading my Hilux again. It’s a 2015 2.5 D4D single-cab, with around 175,000km. I mostly just use it for work but I love driving it and surprising other cars with it. It’s quite nippy after the upgrades and I just absolutely love giving other unsuspecting cars a run for their money.
To clarify; I know this isn’t a sports car, I know it’s not fast and so does everyone else. But that’s the whole point of this, the surprise factor. The fact that you thought your slammed, straight piped TSI Jetta stood a chance. If you’re going to comment and say I should buy a sports car or trade this Hilux for a 3.0, then you’re missing the whole point. Also, I know many cars are faster than my bakkie, it’s not about the speed, it’s about the acceleration and the torque, traffic light to traffic light. If I get the launch just right, then I’m gone. I know reliability is affected but I’ve been driving years +-90,000km with the current upgrades and there has been no noticeable changes. The engine is as healthy as the day I got it, no oil consumption, no excessive smoke, no leaks, no sluggishness, nothing. So I can’t help but feel the engine is eager for more power. Though I do service it at 7k intervals instead of 10k and 15k like some people.

While I have some time off, I’m planning on doing more work on the bakkie. Here’s what I already did:
Swapped stock turbo for same unit but with larger compressor wheel
Blocked off the EGR
Installed a more free-flowing exhaust system
K&N air filter
Installed front mount intercooler (small one and not very efficient)
And had a minor tune done

Here’s a list of what I plan on doing/installing:
A larger turbo
Upgrading the oil feed/return lines
A larger intercooler
A small engine oil cooler
Boost controller
Boost gauge
EGT sensor and gauge
Probably a turbo speed sensor and gauge
Oil catch can
Custom tubular exhaust manifold
Custom downpipe
Upgraded clutch or stock clutch (not sure yet)
Have it dyno tuned (will post the numbers)

Injection pump and injectors I will do, but not now. At a later stage maybe.

I know a fair bit about cars and I know how turbos work but I have no idea how to determine which turbo is best suited for which application. My thinking is that I already have some lag low down but when the turbo boosts you can really feel that the limiting factor there is the turbine and housing size on the hot side of the turbo. The cold side can do more work but the hot side just isn't up for it. But increasing the size on the hot side will just increase lag. Meaning there is a fine line between late boost and no boost at all. Ideally I would like a turbo that has about 40-60% flow increase on the cold side and about 10-20% flow increase on the hot side over a stock turbo. Or is that ratio out of bounds/unrealistic? How big can I go on the hot side before it won’t boost at all? Has anyone experimented with different turbos/housings/impellers/turbines?

Because basically my goal is to have an efficient, but powerful engine. Currently I have flow rate and resonance issues, so I need a setup/system that doesn’t choke itself but doesn’t flood the engine either. My tuner is quite good and he said though my engine can do more work, there are other limiting factors, he said my piping, intercooler, turbo housing, that 90 degree downpipe bend, air box, fueling, etc, are all restrictive. Making everything work harder, in turn increasing temperatures. If the engine runs more efficient I wouldn’t have to push it as hard.

So what turbo would be best suited for this type of build? It doesn’t have to be an exact bolt on because I am building a custom manifold and downpipe anyway. Many people talk of CT9, CT12A, CT12B, CT16, TD04, etc. But no one has numbers for me, I’ve never even seen these turbos in person and have no idea what the differences are. Google doesn’t give much and as mentioned, even if I do find a flow chart, I have no idea what’s going on there.

[Thabogrobler]

Hallo Heinrich,

Welkom op die forum!

As ek in jou skoene was sou die volgende(en goedkoopste) upgrade daai simpel 90 grade bend net na die turbo verander na iets groter en met 'n groter radius buig. Op die oomblik briek daai buig die hele enjin. Self standaard bakkies trek stukke beter as jy net daai buig verander.

Dit help nie jou boost 17 bar maar die exhaust gas kan nie vinnig genoeg uit die enjin uitkom nie.

Gesels met Johan by Turbonique in Witbank oor die turbo - hy verstaan die somme.

Cirrus Coolers in Pretoria het kwaliteit intercoolers. Motorcade in die Kaap het glo ook netjiese coolers. En dan 'n dyno tune waar egt's gemeet word.

Ek hou van 'n Unichip, niks van mapping/sagteware/ecu flash, ens.

Ek sou eerste die bend/downpipe gedoen het, dan die intercooler en dan eers kyk na die turbo. Al die ander goed wat jy gelys het klink vir my na baie moeite vir min wins.

Soek ook vir Dwayne Voogt van Powerlabsa op(hy is ook op die forum). Ek dink nie daar is 'n 2.5 in SA wat beter as syne loop nie.

In Thailand loop die 2.5's gereeld met 350 perde MAAR hul toesande is nie dieselfde as ons s'n nie.

Sterkte en lekker speel!

[Tristin]

Evening sir
I would sort out all the restrictions on the engine before installing a new turbo.The price of a new turbo and installion and tuning doesn't make sense, if you still haven't done the small stuff to get the true potential of the current turbo or the turbo been the limiting factor. All these small things make a hugh difference in the end.
I've been tinkering with my kzte and have found all the small upgrades i have given it , has added up drastically improving it.

[pieta.swanepoel]

On my 2013 2.5 I fitted a Cirrus front mounted intercooler, a 68mm stainless exhaust (not free-flow because it is to noisy), a UniChip and had it tuned by KSD in Cape Town. Settings for the UniChip was very conservative. Basically brought the 2.5 up to 3.0 specs.
It made an really big difference. At least now I could overtake a truck on the open road.

Oh, and make sure your brakes work properly :)

[Heinsebal]

Thanks to everyone for the replies. Really detailed, really welcoming and great info.
Will definitely start working on de-restricting the engine first. Getting rid of that bend and do some fiddling with the intake.