Thread: Budget 4BD1 turbo install

Originally Posted by Dougal

The manufacturers figures I've seen for turbine inlet temp were from 750-900C. We're more likely to cook the engine before the turbo.

True, but you cant buy a rebuild kit in Ebay eather.

Originally Posted by The Mutt

Anywhere on the manifold, or as close to the Turbo as possible.

Glenn

That depends.
If you know one cylinder runs hotter than the rest, then put it there. Otherwise entry to the turbo makes the best sense. I've seen probes put into the neck of the turbo scroll. Good idea if you can make it fit.

I run my current one in the neck just before the turbo entry. But my next one the probe will go in by #3 as there's no easy location closer to the middle.

Originally Posted by clean32

True, but you cant buy a rebuild kit in Ebay eather.

Heaps of Isuzu rebuild kits on US Ebay, plenty of turbo rebuild kits too.
I'm running an ebay T25 rebuild kit atm. Because I was silly enough to use austrialian made hose clamps on my turbo oil feed.

Update...

Finally have the EGT and Boost guage hooked up.

Factory (nissan) wastegate setting was 7psi. I tweaked the bracket when I modified it. It gets to about 10.5psi at the inlet manifold.

Fuel screw is currently at 1.5 turns. Max EGT so far is 640oC (accelerating hard up a hill in 3rd), but I need to find a decent hill to test it properly (not an easy task in Perth).

sits on 270-300 on a flat road at 70 in 4th.

The EGT responds very rapidly - so obviously the probe is in a suitable location! I ended up getting one from Auber instruments. Very happy with it.
auberins.com, Temperature control solutions for home and industry

Boost guage is a VDO 0-30 psi. One annoying thing is it makes a ticking/rattling sound internally when off boost. I think it might be a diesel rattle that is transferred along the tube - anyone else have this???

So what rpm do you need to hit 10psi?

Originally Posted by Dougal

So what rpm do you need to hit 10psi?

Don't have a tacho, but it climbs VERY quickly. Maybe 1100? Above about 2500-2800 the boost starts to drop off to about 6/7 psi at the governor.

Originally Posted by isuzurover

... Boost guage is a VDO 0-30 psi. One annoying thing is it makes a ticking/rattling sound internally when off boost. I think it might be a diesel rattle that is transferred along the tube - anyone else have this???

I have a VDO 0-30 psi gauge in the disco that does the same.

Originally Posted by isuzurover

Don't have a tacho, but it climbs VERY quickly. Maybe 1100? Above about 2500-2800 the boost starts to drop off to about 6/7 psi at the governor.

I suspect you are lacking fuel to build more boost.

I have been thinking that the profile of the torque cam may be one of the main issues, but won't have a chance to trial that theory for a while.

At full load, the control rack follows the torque cam as engine speed builds.

Going by the diagrams in manual IDE2140, the control rack moves to reduce fuel above about 2200 rpm in the 4BD1 (above 1900 rpm in 4BD1-T). But the rack moves further with the torque cam that is fitted in the 4BD1 IP.

I think Dougal is correct, that this is done because of the drop in volumetric efficiency at those higher speeds, but uprated turbo's can more than make up for the VE (if there was more fuel).

Originally Posted by Dougal

Heaps of Isuzu rebuild kits on US Ebay, plenty of turbo rebuild kits too.
I'm running an ebay T25 rebuild kit atm. Because I was silly enough to use austrialian made hose clamps on my turbo oil feed.

TURBINE sheesh not turbo