Turbo gurus, need your help!

[Timbo]

Just bought a second hand HT18 (4.2td factory turbo) unit off ebay, all genuine.

Wanting to replace the aftermarket turbo on my Patrol which is water & oil cooled.

The HT18 turbo I just bought is only oil cooled it seems. Can I just plug the water cooling system up and just use the oil feed & drain? Or do I actually need a turbo that has water cooling? I could plug the water feed and drain up easily enough but would that cause problems?

Also, why did they release 2 different types of turbos? One being water & oil cooled, the other being just oil cooled. Is one better than the other?

Cheers!

[MudRunnerTD]

Sorry Timbo but you just bought a Down Grade mate

Why are you replacing the Aftermarket Turbo? what brand is it?

[Timbo]

It's a Denco and it's too big. It reaches peak boost at like 3100rpm. I had it dyno'd not long ago to confirm my suspicions. The problem with it is, the car is a bit of a dog to drive under about 2200rpm because you're effectively driving with no turbo. It then starts to ramp up and at about 3100rpm, you're pretty much at full boost and ready to change gear. Full boost needs to come down at least several hundred RPM's for it to be usable for towing and enjoyable general daily driving. So, rather than pay upwards of $3,000 for a fitted garret turbo, I bought a HT18.

Only reason I bought the HT18 was to get low down boost. I know they can make decent enough power with some adjustments. Cheapest option I could see but might not turn out so cheap since now I have to try and source a factory turbo intake pipe and crossover pipe which are rare as hens teeth to get separately.

[Timbo]

Just spoke to Kevin at Eastern Turbos.. great guy, straight shooter.
Looks like a rebuild of the Denco is the cheapest and the best option. He'll make it into a ball bearing driven turbo, faster spool and can basically make it to do whatever I want. His own Landcrab spools at 1100rpm and pulls from there all the way past 3500rpm. Rough price will be $2,000. Best part is, it's all in the current turbo housing so everything goes back together easy.

[Ade]

Just bought a second hand HT18 (4.2td factory turbo) unit off ebay, all genuine.

Can I just plug the water cooling system up and just use the oil feed & drain?

Cheers!

BIG NO NO..mate. Oil are to lube the bearings and cool the turbo while coolant will only cool it.

Cheers,
Ade

[dirtaddict]

BIG NO NO..mate. Oil are to lube the bearings and cool the turbo while coolant will only cool it.

Cheers,
Ade

i think he means plug the water feed from the engine , i`m assuming the turbo has no water inlet if its only oil cooled . I would see where the fuel is at with the denco, get it tuned properly, unless its been moded and not the specific turbo for a td 42 the fuel will have ahuge impact on spool revs and driveability. my dts system was not very good at 12 psi and with the fuel where my mechanic tuned it , had nothing below 2000 then spooled up quickly , i put another 1/4 turn on it and its a different car , i can keep up with the traffic no problem without reving it past 2200 revs , its a little over fueld under heavy load as the egt`s will climb over 550 post t but nice to drive and getting a genuin 10.5 litres per 100 around town . 13 towing 1200 kg

[nissannewby]

Yeah mate this sounds like a tuning issue to me if the injector pump has a boost compensator this will give you the symptons your describing as it wont open to allow fuel until you have boost and you cant make decent boost until you have fuel. The turbo and fuel system run hand in hand getting yours rebuilt with what you mentioned will basically be a high flowed version of your current turbo. You can make the standard ones good but the aftermarket items although of the shelf are much better suited than that tiny little ht18. Keep the turbo and find a better tuner ask them to check the timing and basically tune the compensator out of it then go from there.

[Timbo]

Well the thing is, it was recently tuned by a very reputable tuner here in Melb. Diesel Tec is really well known for their work with Patrols. Doubt you'll find a much better tuner anywhere.

[nissannewby]

Yeah i can tell you now it wont be any better with the ht18 my standard turbo on my gu is the same is basically useless under 2200 rpm (because of fuel pump setup). As mudrunner said you would be going backwards to the ht18. See how it goes with the rebuild but unless it is tuned better through the compensator it wont be much better

[Timbo]

thanks for the info guys.