questions about Modifying the d22 diesel

[StockAppy]

Hello all,

i own a 2004s2 d22 3l diesel,

i have purchased a 3inch exhaust incl dump,
currently having an intercooler kit made for it,
and plan on putting it on diesel gas injection,

Im no stranger to modifying turbo petrol cars however i have no experience with diesel.

My main question is, is there anyone in Adelaide that can tune it properly after these mods have been done?
does anyone else have experience with how much the internals can take power wise until heavier duty rods etc need to be put in? what is the weak part of the d22 engine?
should i be looking for new injectors or any other fuel system parts? fuel pump etc? im new to the diesel world and would love to hear from anyone with experience in doing this or in these areas. thankyou

 

[tweak'e]

theres not a lot of tuning done. you buy an add on chip that you can adjust power, check it on dyno if you wish but otherwise its just a matter of keeping EGT's down below piston melting temp.

first thing to do is to fit boost and EGT gauges.

one weak part is the turbo.
no need to change injections. fuel system is more than cable of pouring in enough diesel.

the main thing is keeping egt's from being to high. keep intake cool, enough boost for the fuel, fuel needs to be clean and good air supply (filter, snorkel).

 

[StockAppy]

No worries,
ill make sure i keep that in mind. thankyou.

do you think the gas injection with the diesel would keep things cool enough?

what is the rough standard exhaust gas temp on a d22 and what would be too much?

what sort of AF ratio is suitable for a diesel or for that matter a gas diesel mixture on a navara?

cheers

 

[Old.Tony]

Diesels combust fuel differently to petrols as well. There's no butterfly to adjust the amount of air - the diesel engine gulps as much as it can all the time, you get a different amount of power by squeezing in a different amount of fuel.

LP Gas injection is likely to raise the temperatures higher - the basic idea is that if you're getting more power, you're generating more heat. Diesel gas is quite a power booster, but too much has been known to melt pistons.

A safe upper limit would be around the 700C mark measured somewhere in the exhaust manifold. When I say "safe", I mean "bordering on crazy" but not quite there. Some of the metals inside the engine melt at 750C. The immediate effect of combustion won't be felt by the piston & cylinder, it will be pushed out where the combination of thermal energy will cause the temps to rise a little, so calling it 700C as an UPPER limit ought to be safe.

These engines aren't designed to be massive powerhouses like petrol V8s. With huge gobs of power I'd expect clutch troubles, CV issues and transfer chain noise too, if you start 4WDing with the thing lit up.

 

[tweak'e]

after you have fitted the IC i would chip it before you look at lpg injection. these engines suffer from lack of fuel in the low rpm. a chip will fix that and it will be a totally different ute to drive. also block egr and do butterfly mod.

there is a few that run LPG injection but i'm not sure on the cost. water/alcohol is a cheaper version.

A/F ration is not a big concern, whats more important is keeping EGT's down to a safe limit. diesels don't get any cooling from fuel like a petrol does. only thing cooling the pistons is the air going in. so an intercooler is a great start.

 

[StockAppy]

thanks for the replies guys some nice information there for me to apply. cheers for your time.

the navara is mainly used for towing horses interstate. and towing my paving / excavator equipment around during the week.

 

[Old.Tony]

Some of the diesels have piston crown cooling through an oil squirt mechanism too, which just goes to prove how close to the wire these things are already.

 

[tweak'e]

most have piston cooling. tho its the air that does most of the internal cooling.

for heavy duty towing, i wouldn't go pushing to much fuel in tho chipping is still a good idea but you may want to tune it down a notch.