TD42 Turbo Tuning

[hath]

Hi all,

I have a quick question for you all in the know.
I have just fitted my turbo setup to my td42, it is a log style manifold with a TH05h turbo off a WRX impreza, full 3" exhaust and the air filter is from a toyota surf. I got it all running and set the boost to 10 psi and gave the fuel screw about a turn in as a starting point, now here is my concern.......
It goes like a rocket but after about a minute at full throtle the EGT hits 500c easily so i backed the fuel off, now it has a lot less power but I can still get the EGT to 500c in about the same time???? any ideas/comments? thanks, Jamie.

[Lynx]

Wheres Your EGT Probe Located??

Cheers Daniel

[hath]

about 60mm past the turbo

[darinz]

You need more boost. More boost will get more complete burn and so lower egt for same hp.
10psi is a virtual waste of time. Anything up to 16psi will have virtually no effect on engine life and up to 20psi is pretty safe anyway.

500 is really safe. We work on about 550 for normal use and in comps anything under 650 was not a worry. At 700 the engine has life of less than 1 minute before things start melting.

That being said, if you don't know this already and don't know you afm then you should put the truck into a professionals hands to be safe.

[DieselBoy]

I don't usually bother posting this sort of stuff on the forum these days, so feel lucky

Probe needs to be before the Turb.

Darin is sort of correct with his view of adding more boost, in a diesel, to much fuel makes them run hot. Less fuel means they run cooler.

Opposite to a petrol engine

BUT, don't forget that more boost and more fuel makes a bigger explosion and a bigger explosion generates more heat.


Now a couple of things that you may not know:

The fuel screw you adjusted is not a "mixture" screw as such. All it does is change the amount of fuel metered out of the injectors in relation to the position of the accelerator pedal.

What you have effectively done is increase the over all amount of fuel supplied through out the accelerator movement.

You will find it will over fuel off idle untill the turbo spools up, then it might be roughly right some where midd rev range, then it will lean out as the rev's and boost get up there.

Back the fuel off and it might be ok at the bottom of the rev range but leen right out through the mid and top of the rev range.

Turn the fuel up to far and it will over fuel everywhere inthe rev range apart from right at the very top.

This is because the injector pump is a purely mechanical stand alone pump. It cannot "sense" the changes in engine load and boost and therefore provide the correct fuel requirements.

As a result you will not be able set your fueling correctly for the Turb by playing with that screw no matter how hard you try.

You need to fit a boost compensator diaphram to the injector pump to allow it to "sense" the dynamic change's in fuel requirements in relation to boost and engine load.

The compensator assembly from a TD27t injector pump found in Terrano's, Mistral's and Navara's will work.

Once you have that fitted, you will be able to set the amount of fuel correctly in order to get the proper performance gains from the turb and get the EGT under control.

Hope that helps a bit.

[shroom]

so in that case - I will buy this for my turbo conversion? Can someone please confirm (without buying it) that its what I would require to mod the fuel pump?

http://www.trademe.co.nz/Browse/Listing.aspx?id=263098814&permanent=0

[FORGE1]

sorry dont mean to sound dumb but what does EGT mean?

Thanks

[shroom]

sorry dont mean to sound dumb but what does EGT mean?

Thanks

exhaust gas temporature

[shroom]

The compensator assembly from a TD27t injector pump found in Terrano's, Mistral's and Navara's will work.

Does anyone have any specifics on how to attach the boost compensators to the td42 pump before I rip into it?

[Fakey]

The compensator assembly from a TD27t injector pump found in Terrano's, Mistral's and Navara's will work.

Does anyone have any specifics on how to attach the boost compensators to the td42 pump before I rip into it?

Anyone got any pics of this on a patrol/safari?

[shroom]

not sure, but i posted up some info about the fuel pumps and how they work with the addons...so you may be able to figure it out.

best to take it to a diesel mech imo..

[Fakey]

not sure, but i posted up some info about the fuel pumps and how they work with the addons...so you may be able to figure it out.

best to take it to a diesel mech imo..

I am a diesel mechanic Im just not very familiar with the nissan set ups so was just interested to see if anyone had pics of the pump modded with the boost compensator so I can see whats involved:wink: