Outer Limits 4x4 Board

What is max boost on TD42 with intercooler and 3 inch exhaust.

Mannells GU have 12psi and Binskins GQ shorty have 24psi!!! and no problems.

mine runs 15psi and has done for about 7 years from what I can gather. No probs.

Nissans 4.2 motors are built to take a turbo and are really strong. I think if it is generally in good nick then figures of 10 -15psi would not be a prob with an intercooler.

Some say that this will affect the life etc but this is an impossible thing to gauge so is not right. I would be a lot more hesitant to put over 10psi thru a 1hz for example.

Just wind it up!!! 15psi is nice

vn15 wrote:What is max boost on TD42 with intercooler and 3 inch exhaust.

Mannells GU have 12psi and Binskins GQ shorty have 24psi!!! and no problems.

Yes... no problems. Binskins is a comp truck that I would hazzard a guess gets rebuilt after each OBC, or before it..

24psi is a hell of a lot of pressure on an engine.. Go for it, if yours blows up, we wont follow.

14psi is safe.

Be aware that some 4.2s were built with lighter pistons etc and should be treated conservatively. I think about 1994 to 97 and some GUs.

Bazzle

Trent Leens has 22psi boost and the only thing the motor has done to it is general servicing and injectors replaced all the time. But thats due to trying to force more fuel in there, not cos they are buggered.

I think with an intercooler upto 15psi should not be a problem as long as it has the fuel set right.

turps wrote:Trent Leens has 22psi boost and the only thing the motor has done to it is general servicing and injectors replaced all the time. But thats due to trying to force more fuel in there, not cos they are buggered.

I think with an intercooler upto 15psi should not be a problem as long as it has the fuel set right.

They actually upped it to 24 or so PSI, but the motor is down on compression.

Has he changed pistons to low-compression ones? How much power and torque is it in Trents GQ

bazzle wrote:Be aware that some 4.2s were built with lighter pistons etc and should be treated conservatively. I think about 1994 to 97 and some GUs.

Bazzle

that is correct.

Thus why i chose a 93 model engine to rebuild. as they've heavier pistons and can handle turbo boost better than the late models

TOM

vn15 wrote:How much power and torque is it in Trents GQ

Lots and lots and probably lots more than the average punter would need.

bogged wrote:

vn15 wrote:How much power and torque is it in Trents GQ

Lots and lots and probably lots more than the average punter would need.

It produces so much grunt, I dont think the fuel economy is very good. Also read somwhere before (might be the alpine challenge thread), that when ever he puts the foot down the world disapears, for his team mates.

Even still I like it. And with discussion here, I think it has been decided that the early (87-93) ones can be wound out to 15psi and the later (93+)ones you probably want to limit it to 12psi.

vn15 wrote:Has he changed pistons to low-compression ones? How much power and torque is it in Trents GQ

Nope, Pistons and stuff all stock but the motor is pretty rooted, that is why to comp is lower.

All that fuel washing the bores, diluting the oil

having my GQ 4.2 diesel tuned at 18psi after the front diff is fixed ...

will let u know how it goes

so if you can run 15psi with an intercooler, how high can you go without an intercooler? I currently run about 12psi, but wouldn't mind going a little higher.

Hoonz wrote:will let u know how it goes

*BANG*...

bundyrum4x4 wrote:so if you can run 15psi with an intercooler, how high can you go without an intercooler? I currently run about 12psi, but wouldn't mind going a little higher.

I've seen 20psi with no intercooler.... but to be safe 14/15 if you want any sort of lasting quality out of your donk

ehehe no ... i know of enough 4.2 patrols running alot more then 18

The main thing will all the above is to monitor EGT.

Bazzle

so if you can run 15psi with an intercooler, how high can you go without an intercooler? I currently run about 12psi, but wouldn't mind going a little higher

It really depends on the level of reliability you want from your vehicle, and its intended use. Pre August 1993 built engines with the heavier pistons seem to consistantly take 15 or so psi, while the later ones ought to be limited to 10-12psi....and can be driven all day every day with no problems. If you're wanting performance for competitions you can go in excess of 18-20psi, but knowing that its lifespan would be reduced somewhat.

Going to significantly higher boost then requires serious fuel pump mods to get the most from it.


Cheers
Mitch

On the wagon we had before which was a diesel we ran about 22 during comps, i would strongly suggest you get a booste guage if you dont already have one and more importantly a pyro so you can monitor the exhaust temperature. When our car finally died due to a head on we stripped the motor down and there was no sign of ware, so 18 psi shouldnt be a problem provided care is taken and everything is tuned properly.

yeh i have a boost guage ... pyro ... looking air fuel mix guage
should be able to tune it on the run then

only on 12psi atm ... till we've fixed the front diff ...
then its off to get dyno's .... im looking at a dual boost controler
$$$$ 12 for traveling and 18 for comps

Air /fuel mixture guage?? never seen a proper one for diesel, still need to run by the EGT gauge any way, just ensure you know what temp to look for either before of after turbo.

Bazzle

you can use a normal 02 sensor, but they ware out quick aprox 50hours use i think so you would only use it for tuning

remembering to go to 13+psi, Ive been advised you need a fuel aneroid thing.. No idea if thats how its spelt, but they are about $800, thats why Im stuck at 11psi..
I want 14psi!!! Maybe while wife is in USA later this mth...

aneroid plate is just for ur preboost fuel and when ur boost comes on it opens ur fuel right up

bogged wrote:remembering to go to 13+psi, Ive been advised you need a fuel aneroid thing.. No idea if thats how its spelt, but they are about $800, thats why Im stuck at 11psi..
I want 14psi!!! Maybe while wife is in USA later this mth...

a fuel aneroid is for altitude compensation,

What you are after is a compensator, they work the same way but do the opposite thing and aneroid reduces fuel as air thins while a boost compensator enriches fuel/air mixture as boost increases

stu

Fathillbilly wrote:a fuel aneroid is for altitude compensation,

What you are after is a compensator, they work the same way but do the opposite thing and aneroid reduces fuel as air thins while a boost compensator enriches fuel/air mixture as boost increases

So I guess one of them is the same cost roughly? Still want to try 14psi!

[quote="Hoonz"]yeh i have a boost guage ... pyro ... looking air fuel mix guage
Why would you need and air fuel mixture gauge on a diesel shags?

Camshaft1 wrote:

Hoonz wrote:yeh i have a boost guage ... pyro ... looking air fuel mix guage
Why would you need and air fuel mixture gauge on a diesel shags?

I reckon a good VDO Engine Temp Gauge would be of more use.
Thats the trio I have. Boost, EGT and Temp.