Turbo Isuzu Questions

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Originally Posted by 110Landy86

Steve you know you're right!! Its probably a solid hours work to do it properly. Whats your take on the positioning of the egt w.r.t to the manifold?

As you are probably aware the manifold has a factory tapped 'plug' at the front end which simply requires drilling. I was thinking of installing it there however as its only picks up one cyclinder it might be a bit bias. The other alternative is to drill and install at the centre of the manifold immediately before turbo. This would require drill and tap.

Whats your take?

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Either way you will need to drill and tap, as the thread in the pre-drilled hole will be M8, rather than a suitable pipe thread.

I drilled and tapped the boss on #1 to 1/4 BSP and fitted my probe there. When I pull things apart in the future I will drill and tap the manifold just before the turbo like Offender90 has done (he has posted pics on here somewhere).

The boss on #1 works fine and my EGTs seem almost identical to similar setups, however it won't be able to let you know if you have a dribbly/overfuelling injector on 2-4.

I've got the T3-T2 adaptor plates between the manifold and the turbo so I just drilled and tapped the top edge of one of those. Think the boss for my probe was 1/8NPT so there was plenty of thickness to tap into.
The other easy place would be the small flat section in the top of the manifold just before the turbo flange.

Using an Auberins gauge, and one of their exposed tip thermocouples its VERY responsive. Jumps from 350-600deg in a couple of seconds if I floor it at 100k's.

Steve

Mine is a vdo egt guage and the probe is 1/8th NPT but lucky bsp is very close so I just run a npt tap through some bsp fittings save machining up bit :) 13psi max??? :o I would expect a gt28 to produce alot more boost than that... if there is black smoke on takeoff that is expected until boost is around 5psi (for me that is which is reached within a blink of an eye) I took my boost pressure straight from the intake manifold on its own seperate line just to make sure I was reading what is going into the engine.
Nice tig welding on those stainless pipes who done them?

I am having fuel issues at the moment I suspect a broken spring that attaches to the control rod on the inside of the pump :( $10 to replace is the good thing :)

My GT28 produces up to about 21 psi, no intercooler, wastegate disconnected.

I'm running the hybrid t25/28 which I'm told is good for ~20psi. I've purposely limited boost to 13psi (what I think is reasonable) until an egt gauge is fitted.

I had the 3in mandrel exhaust fitted a few days ago. Woohoo!!! Firstly the landy is noticeably quieter while coasting and gentle acceleration (a good thing!!). Totally different under heavy throttle...epic turbo whine and throaty. Very impressed!

With the 3in exhaust fitted max boost levels increased from ~12-13psi to ~16psi without altering fueling.

Now that the turbo fitment is complete I was thinking of having the engine professionally tuned. I was quoted ~$500 by a local garage for dyno tune. I asked the guy what the tune involved and if the fuel screw was adjusted during tuning to which he replied 'I don't touch the fuel screw...the mechanical fuel pump has many other adjustments'. Can anyone elaborate on this?

Thanks

Quote:

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Originally Posted by 110Landy86

Now that the turbo fitment is complete I was thinking of having the engine professionally tuned. I was quoted ~$500 by a local garage for dyno tune. I asked the guy what the tune involved and if the fuel screw was adjusted during tuning to which he replied 'I don't touch the fuel screw...the mechanical fuel pump has many other adjustments'. Can anyone elaborate on this?

Thanks

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:angel:

Save your money. Fit an EGT and tune it yourself using a nearby hill.

Did I say FIT AN EGT???

???

FIT AN EGT!!!

Agree with Ben, EGT is really important. My EGTs went down after disconnecting wastegate. I would recommend Archies Motors at Rocklea for getting the motor running smooth. They specialize in Isuzu trucks.

Quote:

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Originally Posted by 110Landy86

Now that the turbo fitment is complete I was thinking of having the engine professionally tuned. I was quoted ~$500 by a local garage for dyno tune. I asked the guy what the tune involved and if the fuel screw was adjusted during tuning to which he replied 'I don't touch the fuel screw...the mechanical fuel pump has many other adjustments'. Can anyone elaborate on this?

Thanks

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Run the other way.

Minimising boost creates higher egts if the fueling was turned up its not the boost you should be worried about its the egts that will kill it....i would like to see what that dyno tuner does without touching fuel screw ;) fair enough not touching fuel screw on a tdi motor and still getting good results but there a different storey altogether...

Yeah exactly what I thought. Don't think the guy was to keen on the job! Thinking I'll take others advice, and tune it myself once I've fit the egt gauge.

While I'm on the subject and need to have timing and/or valves adjusted???

Thanks