EGT and Boost Gauge on diesel turbo

craig_nav · 02-03-2010, 10:46 AM

Hi all, I have been thinking for a while now, of putting a EGT (exhaust gas temp) gauge in the nav.. Other nav owners say its a good idea but the price of a decent gauge is a bit steep.. On the other hand i would like to install a boost gauge so i know what sort of pressure its pumping out,Their pretty cheap but im having trouble tracking down a T peice to tap into the boost sensor pipe... Some have said the nav make around 15 psi...

Jarh73 · 02-03-2010, 10:52 AM

Craig a boost gauge really doesn't tell you a lot on its own.

Other than you might be over boosting.

The boost gauge should be complemented with an EGT gauge at all times.

The EGT gauge tells you far more in terms of the load the engine is under.

If your engine is still stock standard and no chip its not absolutely necessary however it is a very good method of telling you when its time to change down a gear or two.

What sort of Navara do you have? What year?

Cheers

Justin

craig_nav · 02-03-2010, 11:04 AM

Oh ok, Its a ST-R 3.0L 05 model

Jarh73 · 02-03-2010, 11:13 AM

Graig I "think" you should be able to put a plastic T piece into the rubber hose that actuates the waste gate on the turbo.

There should be a gold coloured cylinder on the turbo with a hose coming off it. That hose will measure turbo boost as it controls the wastegate.

Bit like this: http://www.courtenaysport.co.uk/imag...tuator_new.jpg

So far as i know the Navaras don't have a varible geometry turbo like the Patrols so it should be very easy to put in a boost gauge.

Cheers

Justin

craig_nav · 02-03-2010, 11:15 AM

Cheers, i shall have a little look

phs · 02-03-2010, 04:25 PM

You can tap into any rubber engine vacume line and get a reading with a plastic push on tee, the easyer location to get too the better, try and keep the plastic tee away from hot places like the turbo and exhaust.

as said befor an EGT is a good idea too.

advantages of a boost guage are been able to see when and how you ride makes boost, what psi its running (being carful it does'nt spike or over boost) seen if it holds boost well or runns off, and been able to tell if you acuator bars come off, Haha (iv had this happen befor). wasnt so funny, or if there is a leak in the system some where.

quite surprizing when i got my first boost guage, i was making 14psi at 2400RPM and at 5500rpm i was back at 10Psi thats how bad it was running off...
mind you my fix was getting a much bigger turbo, last time i drove it, it was makeing 14psi @ 4000RPM and still holding well at 6500Rpm.

it was also good to see if it spikes and at what psi the over boost kicks in as once it was doing it all the time

craig_nav · 02-03-2010, 04:33 PM

Yeah thats the main reason i'd like to install one. I've herd so many claims of over boosting its not funny.. But how would i stop the over boosting? Put a boost regulator on or something?

phs · 02-03-2010, 04:45 PM

^ find out whats causing it.

a fail safe would be an over boost valve, i think they have banned them cause of EPA.
but none the less there not a solution they are a back up.

waste gates and acuators not functioning correctly can cause over boosting.

as far as i know the nissan patrols 3lt.TD had wastegate issue that is causeing the turbo 's too spull up too much and after a while BANG!!!!

Jarh73 · 02-03-2010, 04:46 PM

Craig you won't get over boosting with a non variable geometry turbo VGT.

The 3.0L Patrols get it but that's a function of the VGT turbo, the navara does not have a VGT.

You can't really have boost spikes. You can have an overboost but that would mean the waste gate actuator was not working and that is very rare.

Cheers

Justin

craig_nav · 02-03-2010, 08:55 PM

So if i did put a boost gauge on the nav, The gauge has vacume and boost... The diesels dont produce vacume so what would the gauge say?