So its getting cold outside and I am now starting my winter build project. I have picked two holsets, an hx40 and a hx52. Both are the T4 ish flange size.

Im looking for spool time and power outputs that are proven. From the research I have found I'm dealing with anywhere from 400hp to 600hp with one of these turbos. Now before we go any further I better make my set up and car clear.


THE PROJECT


13b miata swap in the works, already have the car so that won't be changing.

pretty much plan on doing a ground up build


THE ENGINE

Right now I have a s4 t2 engine but may change to a s5 or s4/5 hybrid setup

I have alot of fc t2 parts so I would like to stick with fc stuff

plan is to rebuild and street port the engine.

I'll be modifying my s5 t2 intake to mount to the fd's upper intake manifold/throttle body.

THE POWER AND SPOOL

Since this engine will be transplanted into a miata, I wont need alot of torque since the car only weighs 2100lbs. I already have a miata thats turbo and is putting out around 300hp, its fast but not stupid fast.

I'm thinking of a goal of 500hp with full boost around 4000rpms.

Help me choose the right turbo

HELP ME IDENTIFY THE EXHAUST HOUSING SIZE I HAVE ALSO

I have located a 16 on the hx52 and a 18 or 19 on the hx40 why would the 40 have a larger housing than the 52?

 

I would probably go with the HX40. The 19cm housing will be about perfect for a stock port motor and should be able to do close to your 500hp goal while still being quite responsive.

 

What about spool time? Does anyone know when a hx40 and hx52 will hit around 15psi on a street ported engine?

 

Also, on identifying the housing size. 16 stamped on the hx52s exhaust housing does this mean it's really a 16cm2 housing. Because the exhaust looks the same as the hx40 which I believe is a 19cm2 housing. How do you measure these turbos to verify the size

 

I used to always want to put a 13b in a miata myself. This should be a cool project! Look forward to reading about it.

Are you using the greddy cast manifold in the pic... from what I have been reading I would think that going with a manifold that keeps the exhaust pulses separated will help spool taking advantage of the divided housing on the holset...

 

This doesn't help you much at all, this is my H1E (same rough size as HX40 with 22cm^2? (26cm^2? I forget) housing.

This is a datalog of a pull through a couple of gears...for the most part power hits at 4500-5000....hard.



The graphs from right to left are 2nd gear with lots of wheelspin, 3rd and 4th gear, I think.


As for the 19....there's no numbers on the inside of the housing of that one? I don't think that's the housing size.


Just go with the HX40, should suit you nicely

 

now planning to go with a S5 turbo motor for sure, with a full bridgeport the hx52 should spool it fairly nice.

If I were to stay stock port or maybe small street port i would go with the hx40, but after reading about full bridgeports and spool times with them the 52 should work wonders.

 

The 52 is awesome and spools great, the power is there for the taking. You need to dowel your motor

 

Does anyone know if the housing needs to be notched when using the racing beat bridgeport template? I would prefer to try and stay away from the water jackets.

 

most likely I will have to keep the factory turbo now due to clearance reasons. The 52 is so damn big I would have to cut into the frame to fit or go with a custom manifold. I don't have a welder and my local speed shop said that it would be around $800-$1000 for them to make me a manifold. Kinda sucks, but I can't bring myself to spend that much on a manifold. So I guess I'll be going the BNR stage 4 route now. See If I can break the 400hp mark with a nice street ported t2 engine.

at least I can ebay these turbos and that should help fund this build a little.

 

I'm in the process of upgrading my bnr stage III to a holset hx40, would the hx40 not fit either or just the 52?

 

rx7 SE he is putting this in a Miata ... and he is using a log manifold. I am sure you could make an hx52 fit into a TII with a custom manifold... maybe even with that manifold? but not sure...

 

yup, you're right, much less room in a miata I assume.

 

With the greddy manifold the hx40 should clear a fc no problem, I'll have to Double check and make sure the hx52 would clear an Fc frame. If I remember correctly it does but comes fairly close to the passenger side brake line.

I'll measure everything out and let everyone know what kind of space is permitted.

 

I've been trying to order a Holset turbo, but cummins who I'm dealing with, need a part number, they would like an engine number but thats not going to happen!

Could anyone help me with a Holset part number for an HX40?

 

the HX40 will hit 15psi by about 3600RPMs on stock ports.

 

The HX40 won't get you 500 @ 15 psi though...I was hoping for 450 @ 20 psi with a small street port. Supposedly the HX52 has a billet wheel, or at least the newer ones do. Should help with response and it will get you to 500 @ somewhere between 15-20 psi.

 

Whats the word on this setup? I am running a HX40 and would love to know more about how the larger ones are working. Holset FTW

 

I decided to swap the rotary in because I didn't want to smell like gas when I would have the top down.

I am currently running a built bp 1.8 with a holset hx30 turbo. I'll keep the rotary alive in my Fc.

 

im looking for a 40 to run at drift events you decide to sell it.

 

How much air is it moving @ 15 psi? And at what efficiency?

 

There's another thread on here with a 52, getting around 23 psi at 3800 rpm. Sounds pretty raw to me.

 

Sounds bad ***! I know my car with an hx40 is set at 13.5 psi and I hit that at a little over 3k rpm on stock ports, that's also with a divided mani and straight through exhaust and a screamer pipe on the wastegate. Needless to say I love it!