High horsepower t3 turbos discussion

[Archer Fabrications]

I just wanted to open up a discussion on the controversy of high horsepower turbos in t3 hot sides in regards to reliability. I have heard some things here and there that the t3 hot sides are just not big enough to keep the back pressure down.

FP released the large t3 super 94 and super 99 And has usually had their other high horse power turbos t3 upon their release and only later had option for t4 or twin scroll t4.

PTE has been notorious for having smaller housings on their mid level hp turbos (scm series) but even the 6466 and 6766 also come in t3.

I was just curious to hear some peoples thoughts on why or why not having an 800-1200hp turbo in t3 is a good or bad thing.

I personally don't have any bias toward either or, but i happen to currently run t3 and most likely will for a while until i build another manifold. Which will then be TS t4

So lets hear your thoughts.

 

[bastarddsm]

T3 in this case only really describes the flange. A T3 flange has more surface area than most T4 volutes, so the "T3" part of the turbo is not causing any issues. I'd think it's save to assume that FP is having their own "T3" housings cast that has a volute large enough to handle the flow the massive compressors are capable of generating. It's essentially a T4 housing/Volute with a T3 flange. I would assume PTE on the other-hand is just taking a standard T3 housing for something like a 35R and boring it to fit larger wheels. So it has a small restrictive volute.

 

[Archer Fabrications]

I believe FP uses garrett turbine housings also.

When i say t3 I'm also referring to the selection of sizes you are open to. Which turn out to most of the time be smaller then Say a t4. I'm aware t3 is just the flange, but the housing the t3's are designed for dont seem to be up to the task according to some other members on here. I'll let them chime in.

 

[lasthope05]

FP's new .85 KT3 turbine housing has a larger throat/volute distance going around the majority of the housing compared to garretts housing. This allows more flow/less back pressure but still keeps the same spool characteristics.

Kevin Jewer with his super99 only saw a 1.2:1 drive ratio at 48psi. With FP's new turbine housing I dont really see a big need to switch to a t4 housing. Twin scroll on the other hand is an entirely different beast. T4 TS housings offer better transient response between shifts. Not to mention you get a much better spool to max flow ratio.


:::Edit:::

Here is a picture of a gt35r .82 housing I found on google.

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Now here is a picture of my 3794 with fp's new kt3 .85 housing. You can see it is a much larger housing.

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[Miasma]

I'm interested to see what everyone says regarding this topic. I haven't experimented to much with various turbos. For my current build I have a hx40 16cm2 t4 divided, but I have been debating which housing and manifold I am going to use for my 2.4 evo 8 build.

I've got to pull the trigger soon, so any extra info from others here will be great!

 

[Archer Fabrications]

It's good to known the kt3 design is new. I was planning to get the 3794 myself actually if the billet chra is re-released next year

 

[lasthope05]

It's good to known the kt3 design is new. I was planning to get the 3794 myself actually.

Theres a member on the link forums selling theirs, brand new, for $1600 right now. That's a hell of a deal.

 

[Beaubo]

There is a video online of Robert from FP explaining the new designs. It is a very informative video I will post it if I can track it down.

 

[biglady112]

Wow. I spent $125 on my turbo brand new and it made 800hp through an auto. Would never see me spend that kind of cash on ANY part.

 

[Michael@FP]

Our .85 housing has no problem supporting every bit of flow the Super 99 is capable of as evidence by the multiple 170+ trap speeds and 950-1000WHP dyno sheets people using the turbo have generated.

While the volute and nozzle area can be played with the inlet is the bottle neck in the setup. Being that it's T3 is has to conform to those measurements otherwise it won't bolt up to a t3 manifold. Some people need a T4 in order to have a good drive pressure but some people don't. Unless you're monitoring it, you won't really know.

- Michael

 

[Miasma]

Wow. I spent $125 on my turbo brand new and it made 800hp through an auto. Would never see me spend that kind of cash on ANY part.

What housing are you using for you hx52? Hows the spool and launch with it?

 

[JusMX141]

I'd love to know how a/r is calculated within a flange platform by various brands. I'm aware a T4 housing of the same a/r as a T3 will still be larger because the area is bigger, but it doesn't seem like there's a universal understanding of a/r between brands- like a PTE .63 a/r housing isn't exactly the same design as a Garrett .63 a/r housing, a BEP .70 a/r T3 housing is physically larger in every way than a Garrett .82 a/r housing...etc.

 

[boost97gst]

What housing are you using for you hx52? Hows the spool and launch with it?

Im interested as well. I know its a t4 but did revhard even make a divided mani is the question..... idk.

 

[black_gst]

I'd love to know how a/r is calculated within a flange platform by various brands. I'm aware a T4 housing of the same a/r as a T3 will still be larger because the area is bigger, but it doesn't seem like there's a universal understanding of a/r between brands- like a PTE .63 a/r housing isn't exactly the same design as a Garrett .63 a/r housing, a BEP .70 a/r T3 housing is physically larger in every way than a Garrett .82 a/r housing...etc.

This!

 

[bastarddsm]

the inlet is the bottle neck in the setup.

- Michael

I don't really believe that at all. Can you post a picture looking into the volute of a super housing?

 

[spin1r6]

I think what fp is saying by the inlet being the bottle neck is that you can only go so big obviously. The shape of the volute is important to performance so going any bigger than the .85 would be similar to putting a 2" exhaust flange on a 3" pipe, even tho the pipe is 3" its still passing thru the restricted 2" flange. So in this case going any bigger on the a/r wouldnt help because the t3 flange isnt big enough.

 

[LandSpeed-DSM]

You can get quite a lot of pressurized > 1200*F gas through the Open T3 flange (CSA ~4.1in^2). Open T4 is 44% bigger at the flange, ~5.9in^2.

The cross-section of the volute where it meets the nozzle (accounting for boundary/displacement thickness) is going to be the real limit.

Is there an expansion after the flange? Can you share the critical area, or at least where the centroid is taken?

 

[BoostforBreakfast]

I think there needs to be a new "measurement" that can be standardized by direct physical dimensions, kinda like the cm3 that most of the standard "diesel" performance companies use for their turbos.
we're in the 21st century.... something needs to be standardized so it can directly be compared...

 

[LandSpeed-DSM]

I think there needs to be a new "measurement" that can be standardized by direct physical dimensions, kinda like the cm3 that most of the standard "diesel" performance companies use for their turbos.
we're in the 21st century.... something needs to be standardized so it can directly be compared...

Well, it's nozzle area not volume so cm^2 is the unit. But that still doesn't tell you where they took that measurement.

Which is what makes converting to A/R from nozzle area inaccurate.

If you don't know where they took the area from, you can't find the centroid of the area which means you don't have the radius from the turbine shaft.

Even then if you had all that information.. you can really only accurately compare to other housings on the same compressor/turbine combo.