Compressor housing discussion | Turbobricks - Turbobricks

I got into reading compressor maps and blah blah blah, but I'm yet to find something that explains the effects of differing compressor housing dimensions. As an example, how is 50 trim map going to be affected by moving that wheel from a .60 AR housing to a .70 AR housing?

BTW, I've seen a number of housings offered with anti-surge porting. Anyone have any experience with one of these. I have a .46 trim T04E in a .70 AR housing and would like to go to a .50 trim in the same housing size. Those anti-surge housings look kinda sexy. To me.. with more space in the housing.. you're opening up the way for a little more cfm and possibly less heat. I wouldn't see it hurting your response any and the plus side is you get to run a 4" intake system to the compressor housing.. When you have a small inlet turbo say 2.25" the ratio of the pressure going in to the pressure going out is gonna skyrocket.. take the same wheel in a larger a/r housing and a 4" inlet and the wheel doesn't have to do as much work and will probably transmit less heat into your intake tract... If you feel like for some odd reason you're gonna lose any response just stick with a smaller wheel.. Big wheels really take alog time to get their masses in gear.

It looks like you already have anti-surge.. unless the slit perpendicular to the rotational axis hasn't been machined.. which it looks like it has.

It hasn't. That's why I've been curious why it's designed as such. It does look similar to something like a GT housing.



I wondered if I could just have it machined, but that seems a waste if what I really want is to graduate to a 50 trim wheel.

Oh well.... I'm sure if you sent it to the right turbo shop they could do it for you.

The turbo on the right is similar to the one you have.. It's cast with pockets but hasn't been machined near the inducer.
The turbo on the left was just an as cast housing.. ATP machined it for an additional 70 clams or so.. took an extra day.

I'm sure if you sent it to the right turbo shop they could do it for you.

Yeah, that's worth some consideration. The big thing being the amount of downtime required. OTOH, I may be better off just buying another CHRA and 50 trim cold side setup. I could at least then fall back on the existing setup as a backup.

If you think it looks cool then whatever floats your boat.

It's too bad you are too busy defaulting to punk mode to really read the thread. If you look at the below things I said, you can see I was more curious then anything else here.

Another curiosity is the reasoning behind variations in inlet design.

...

Is what I have another anti-surge mechanism?

...

That's why I've been curious why it's designed as such. It does look similar to something like a GT housing.

...

I wondered if I could just have it machined, but that seems a waste if...

Notice a pattern there?

If you know something conclusive or definitive about the effects of compressor housing variations, we would appreciate and it love hearing.

He's allowed to act like a prick because he's a moderator..

There is a difference between being a prick and being right albeit somewhat abrasive.

If am in general allowed to be a "prick", it is because generally, I am right.


That inlet design is for reducing Blade Pass Frequency noise (turbo whine).

Porting compressor housing shrouds is also referred to as "Map Width Enhancement" because it does exactly that.

At low flow rates the port allows compressor inlet air to escape the compressor housing and recycle into the inlet if the engine's air demand is lower than the turbo inlet's air demand for a certain shaft speed.

At high flow rates the port allows additional air into the compressor and increases the choke point of the compresison- the point at where engine demand exceeds compressor demand for a given shaft speed.

The reason you often see noise reducing design like you turbo also incorporate ports is that ported shrouds are much louder than unported shrouds, so the 2 technologies are often used in tandem.

There are numerous SAE articles written on this subject FWIW.

Another useless post from another useless prick...

There is a difference between being a prick and being right albeit somewhat abrasive.

If am in general allowed to be a "prick", it is because generally, I am right.


That inlet design is for reducing Blade Pass Frequency noise (turbo whine).

Porting compressor housing shrouds is also referred to as "Map Width Enhancement" because it does exactly that.

At low flow rates the port allows compressor inlet air to escape the compressor housing and recycle into the inlet if the engine's air demand is lower than the turbo inlet's air demand for a certain shaft speed.

At high flow rates the port allows additional air into the compressor and increases the choke point of the compresison- the point at where engine demand exceeds compressor demand for a given shaft speed.

The reason you often see noise reducing design like you turbo also incorporate ports is that ported shrouds are much louder than unported shrouds, so the 2 technologies are often used in tandem.

There are numerous SAE articles written on this subject FWIW.

Another useless post from another useless prick...

Tell you what. Now that you've given some good information, why don't you just bug out of this thread from now on. No harm no foul.

Thanx for the info.

To me.. . Big wheels really take alog time to get their masses in gear.

Cousin, that is true but that larger diameter wheel is also, AT THE TIP, moving a lot more distance and thus--naturellement depending on the shape o th blade-- potentially scooping up a lotta air.
So even rotating at lower shaft rpm it could very well be moving lots more CFM.
Look at the udder extreme and those microscopic little Mistrbitchy turbos HAVE TO spool all the way up to 160k just to make some piddly 5-7 peee ess eyes.

Just a thought. Yeah.. thats where the newer "extended tip technology" comes into play.. and It's also why I picked the 60-1 compressor since it had a 3" exducer.. Giving it the ability to move larger portions of air with lower tip speeds than a wheel with a smaller exducer and same sized inducer. I'm a big fan of less stress.. to me a bigger wheel doesn't have to do as much work to get alot of CFM for a given shaft speed.