Thread: Turbo Isuzu Questions

Originally Posted by Dougal

It sounds like you're not getting much, if any, boost.

dougle sound correct.

while wating for your boost and EGT
do this

Originally Posted by isuzurover

Remove the metal side cover on the filter housing (the filter will still work). If the noise stays the same, you have a leak between the turbo and the inlet manifold.

If that’s no better then take off the hose from the air filter to the turbo, and take it for a short run NB no air protection for the turbo.

If that is no better then
Check you valve clearances, ( apparently they never need adjusting so they never get checked)
Timing you could be way retarded, not uncommon on a NA because it made no difference ( or not noticeable)

Or you have a massive boost leakage some where

Or you tail pipe is all blocked up.

I think I know what you mean by drumming. My NA did the same, a little at 90-100 klms then vibrations at 100-105 klm she smoothed out after that but the drumming came back. I moved the timing forward a bit 2 deg and that took things down a bit.

Pics of my turbo install. Still need install a 3in exhaust (incl. flex joint).

Cheers for to all for advice through my fitment

and more...

Looks good. That dump pipe looks a whole lot more professional than mine.
Have you got your EGT and boost gauges hooked up yet? I cant see any temp probe and not sure if the hose from the inlet pipe goes off to boost gauge.

What PSI wastegate actuator do you have on it?
If its a low pressure one, it might not have enough spring to hold the wastegate shut once you start feeding it some fuel. Maybe this could cause some of your funny noise? Maybe just wire it in the closed position since you've got the boost pressure hose disconnected anyway.

Steve

Very neat setup.

Cheers guys!!!

Oh yeah I forgot to mention an EGT probe as being on my 'bucket' list. I was originally going to fit the EGT at the exhaust manifold (i.e. pre turbo) however that would require me to take the turbo off- again - not keen!!! So for ease of installation I've opted to install the EGT post turbo on the dump pipe and close to the turbo outlet. I'll just have to keep in mind that EGTs out of the cyclinder are ~100 degrees higher than those measured at the probe.

With regards to the waste gate actuator, I really don't know what type of actuator I'm using and what boost it operates at. What I do know is that with some tweaking of the fuel I can pull ~13psi. As I haven't installed the egt at this stage I've limited boosted to ~10psi. I've teed the boost gauge into the actuator feed line near to the driver side aircleaner end.

I d/c the boost pressure line to the actuator as a last minute thing just to see if there was any difference - none detected to 13psi (max boost provided).

Now for the funny noise saga...After I read what others had to say. It was a matter of process of elimination. Removing the aircleaner I found that the intake pipe was d/c at the silicone joiner- obviously didn't nip the clamps up enough.

Once I sealed up all of the leaks...well oh my!!!

Real keen to see what difference a 3in pipe makes versus the existing (1 3/4in) to performance.

Any thoughts on timing and valve clearances w.r.t turbo charging?

Cheers

Personally, I reckon you've done such a good job of it so far it would be a shame to take the lazy road and put the EGT gauge post turbo.
You're only guessing at how much temp the turbo is dropping. You estimate ~100deg, but what if its actually 200 and you decide on 600deg as your max EGT. Means your pre-turbo temp is 800deg

Its only 7 bolts, and a couple of hose clamps...

Steve

Originally Posted by 110Landy86

I'll just have to keep in mind that EGTs out of the cyclinder are ~100 degrees higher than those measured at the probe.

EGTs pre turbo are closer to 200oC (+/-50oC) higher than post turbo. Peak cylinder temps are higher again.