Generic turbo questions

[-Nemesis-]

Sorry guys, this isn't for my 1UZ but who else can I trust?!

My new Toyota is a turbo 1FZ-FE 4.5L I6, these are only NA normally obviously. The tune the 4WD has is very conservative and I plan to change that. I've been going over intake restrictions at the moment and have sorted from the Atmo to the filter box.

Whilst I've been digging around though I found a few issues I can't seem to agree with.

A: The intake pipe from the air box TO the turbo inlet is a rough cast alloy item (from the people who make the turbo kit), but it has an internal diameter of less than 2.5", closer to 2.25". Surely, when it comes to the task of feeding the turbo air before the compressor, 2.5" is a major restrictor on a 4.5L turbo? The only thing that makes this awkward is the turbo flange inlet looks to be onl 2.5".

Would I get benefits from upping this to 3 or 3.5" pipe (about 1.5foot long) and stepping it down at the turbo flange?


B: The pipe that runs from the turbo to the W2A intercooler looks even smaller, possibly 2.25". I understand this is compressed air so is this too small?

C: The dump pipe and exhaust is only 2.5" also, I assume 3-3.5" dump and exhaust is better suited.

For the moment I have no idea what turbo it is at is stamped AXT Turbo which is the selling company. Is there a way to tell what it is?

 

[XR8tt]

For short path 2 1/2 is fine as the air speed is very high then 3" before intercooler..

Dump pipe should be atleast 3" and even 4" off the turbine then reduced to 3" .. This actually helps spool..

I guess they DON'T want to make too much power as a 4.5 engine will..
It's best to post pics so we know what your talking about..
These motors are very tuff / strong .. We have one in South Australia in an old Toyota Crown Coupe...
Whats the specs on turbo etc ???

 

[-Nemesis-]

I have no idea what the turbo is, it has AXT stamped on it.

Here's the intake that fed it, the silver cast pipe actually fits inside regular 3" pipe

I just knocked this up

 

[-Nemesis-]

One other question on the exhaust side, if you you look at this pic of the dump pipe, how would you fit a 4" dump on there when it looks like the bolts on the flange are barely 4" apart? Soz, never had a turbo before!

 

[XR8tt]

Yes this turbo looks awfull small for engine size ??
IMO don't fit a turbo to power levels..
Fit a turbo for engine size...
It's way smaller that the Gt35/40 XR6T turbo on a 4.0..
It looks like it's internal gated ?? The 3 or 4" dump pipe can be welded to turbine flange closer to turbine and removing the 90* exhaust flow from wastegate ..
What size are the wheels where you can measure ?? On the exducer ??
http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech102.html

Under 61mm is small on anything over 4.0..
1.06 A.R on T3 turbine..

 

[-Nemesis-]

It is definitely set up to help towing etc not outright power, I'd rather find a happy medium. It does come on boost quickly, but by time you start reaching high revs the boost level drops off.

Making a calcutated guess, I would say the exducer is under 60mm pretty easily.


I guess setting up a better turbo is big $?

 

[XR8tt]

Plug the exhaust manifold between head and turbine with a metal [copper, steel etc] tube and temp fit a pressure gauge to it.. The 02 senser plug can be used ??Then check back pressure against boost pressure.. The back pressure should NOT go over double boost..The turbine size is what determins sizing..
Too much back pressure in upper rpm leads to detonation..
In this low rpm engine you should be fine...
Keep in mind this turbo is fitted to Isuzu, and 3ltr diesel engines...

 

[JBrady]

For short path 2 1/2 is fine as the air speed is very high then 3" before intercooler..

Not sure what you are referring to here. IMO the compressor inlet should have the least possible restriction. Are you saying 2.5 from the compressor? If so I agree and even smaller depending on peak power target.

Dump pipe should be atleast 3" and even 4" off the turbine then reduced to 3" .. This actually helps spool..

Definitely.

 

[XR8tt]

Not sure what you are referring to here. IMO the compressor inlet should have the least possible restriction. Are you saying 2.5 from the compressor? If so I agree and even smaller depending on peak power target.




Definitely.

Yes on the compressed side...On aircleaner / intake it depends on length.. For a short span the size of outlet is fine...

 

[-Nemesis-]

Would There be a benefit it knocking up a 3.5-4" Dump pipe stepped down to the 2.5" (mandrel) exhaust? Mainly as I can't afford a full system just yet.

 

[-Nemesis-]

Some bad typos there soz, can't edit posts here for some reason.

 

[XR8tt]

Would There be a benefit it knocking up a 3.5-4" Dump pipe stepped down to the 2.5" (mandrel) exhaust? Mainly as I can't afford a full system just yet.

Yes The exhaust flow is circular coming out of turbine..