Thread: 4BD1T Turbo Sizing and Performance Prediction.

Originally Posted by Vern

Thanks Justin. Length is good. So that 77mm measurement is from one of the bolts where the Turbo bolts on to the end of the Turbo?
The 55 mm intake is quite small considering at the moment my vnt is 75mm.
Do you think the compressor outlet could be clocked so it will aim back up over the rocker cover?.
Cheers

Ah sorry, they're not bolt holes. They are the edge of the flange. Compressor housing to nearest bolt centre is more like 88mm.

OK so that from the end of the compressor housing (where the inlet hose goes on) to the flange bolt is about 88mm? Sorry to be a pain, I just need to be fairly accurate. Mine is currently about 110mm, so it may just fit. Alternator is my next worry as I just purchased a newy and it may be in the way

I'm also running the TD04- 19T, non intercooled at the moment, 20psi boost. the thing pulles like a train! Even managed to round up an XR6 Foul-coon around the outside going up Mount Victoria after a weekend camping at Lithgow.

Originally Posted by Vern

Thanks Justin. Length is good. So that 77mm measurement is from one of the bolts where the Turbo bolts on to the end of the Turbo?
The 55 mm intake is quite small considering at the moment my vnt is 75mm.
Do you think the compressor outlet could be clocked so it will aim back up over the rocker cover?.
Cheers

Mine points about 45 Deg back towards the rocker cover, to a 45 deg silicone elbow, and a 45mm pipe with recessed flat pressed into the underside to clear the rocker cover.
Incidentally, if you pull the heater matrix out, and turn it around so the pipes are near the guard, you get clearence to use a standard donaldson elbow on the compressor inlet.

Heater matrix, huh? Mine is in a soft dash range

Originally Posted by Vern

OK so that from the end of the compressor housing (where the inlet hose goes on) to the flange bolt is about 88mm? Sorry to be a pain, I just need to be fairly accurate. Mine is currently about 110mm, so it may just fit. Alternator is my next worry as I just purchased a newy and it may be in the way

No problem. Correct. If you don't measure to the end of the hose fitting that will be covered by the intake hose and only measured to the compressor housing, then it's shorter than 88mm. The inlet hose fitting sticks out a bit and is included in the 88mm to the nearest manifold flange bolt.

I forgot to mention before, but jackz has pretty much answered I think. With my compressor outlet facing down, the actuator bracket is on the wrong side. If you rotate the housing so it goes over the rocker cover, then the actuator bracket should line up I reckon.

jackz, are you using the wastegate actuator and bracket that came with it?

Originally Posted by Judo

I forgot to mention before, but jackz has pretty much answered I think. With my compressor outlet facing down, the actuator bracket is on the wrong side. If you rotate the housing so it goes over the rocker cover, then the actuator bracket should line up I reckon.

jackz, are you using the wastegate actuator and bracket that came with it?

Yes, with the 1.5Bar spring. from memory, I had to flip the bracket over to get the position right.

Originally Posted by Dougal

The Kinugawa actuators come with a lot of different springs. I ordered a wastegate with 5 of their highest pressure springs. Something like 2 bar down to 1.2 bar. Interestingly the springs don't get stiffer, just longer so there is more preload internally.

I've been running an ebay 22psi actuator for a long time now. It holds boost well around 20psi. It does need 22psi on a bench test but when driving turbine drive pressure is also helping to open the gate. I haven't fitted anything else as 20psi is essentially an EGT limit until I get that intercooler fitted. I can wind boost up to 24psi and EGT doesn't drop.

What's the highest sustained EGT you've noticed so far without an I/C, mine seems to top out at around 640 now, having given the fuel screw a bit more of a tweak.