Stainless steel exhaust housings, what do you hear about them?

13241 Views 70 Replies 25 Participants Last post by wildbilldevine, Feb 8, 2011

Scotts87LX

Discussion Starter · Jan 23, 2011

I've seen them around for a while for the smaller turbos (import size stuff), but never for anything much bigger than a GT42 or GT45. I have a pair of GT47-80's and the lighter weight and the better spooling with stainless really sounds great, but it appears no one makes them for bigger turbos? Why is that? It sounds like Bullseye is gearing up to make them for Borg Warner turbos, but where could a guy find them for Garrett turbos? and are they really that good?

1 - 20 of 71 Posts

SuperCooper

· #2 · Jan 23, 2011

I for one would like to see a real datalogger trace showing the magnitude of the difference in spool up because I'm having a hard time believing it, especially when using full-tilt headers with several feet of tubing radiating heat before it ever gets to the housing.

If I'm wrong, I'm wrong, but the only thing I've ever seen on this is ass-dyno "feel".

Scotts87LX

Discussion Starter · #3 · Jan 23, 2011

SuperCooper said:
I for one would like to see a real datalogger trace showing the magnitude of the difference in spool up because I'm having a hard time believing it, especially when using full-tilt headers with several feet of tubing radiating heat before it ever getos to the housing.

If I'm wrong, I'm wrong, but the only thing I've ever seen on this is ass-dyno "feel".

I'm thinking the same thing. What I'm really wondering is, would a stainless housing REALLY be any better than a good quality turbo blanket on an iron housing?

89notch

· #4 · Jan 23, 2011

If you're doing it to reduce under hood temps then you shouldn't be doing it. You want real world proof? Go to the track and talk to the people who have switched over.

Same turbo's on the same setup make more boos than before, reduces spool up time not to mention back pressure almost falling completely to zero. The weight reduction is a beneficial by-product.

This is on a BBC with twin pro-mod 88s. I guess those are small turbo's these days... :smt102

NASTYCAMARO

· #5 · Jan 23, 2011

I just got mine from TIAL. Give them a call I think you will be very impressed..

SuperCooper

· #6 · Jan 23, 2011 (Edited)

89notch said:
If you're doing it to reduce under hood temps then you shouldn't be doing it. You want real world proof? Go to the track and talk to the people who have switched over.

Same turbo's on the same setup make more boos than before, reduces spool up time not to mention back pressure almost falling completely to zero. The weight reduction is a beneficial by-product.

This is on a BBC with twin pro-mod 88s. I guess those are small turbo's these days... :smt102

You're saying that nothing else was changed?

How does backpressure fall to zero without an A/R change? If everything else is the same, backpressure should stay the same or go higher, should it not?

Or did they go from divided to undivided volute or something?

I'm not trying to call BS on you, just trying to make sense of what you're seeing.

SomeWhatStock

· #7 · Jan 23, 2011

89notch said:
Same turbo's on the same setup make more boos than before, reduces spool up time not to mention back pressure almost falling completely to zero. The weight reduction is a beneficial by-product.

so your saying that the air flows through the wheel faster and the wheel spins faster all because the difference in material?

i cant see that

SuperCooper

· #8 · Jan 23, 2011 (Edited)

Also, who is supplying the GT47 stainless housings?

...nevermind...PTE

89notch

· #9 · Jan 23, 2011

SuperCooper said:
You're saying that nothing else was changed?

How does backpressure fall to zero without an A/R change? If everything else is the same, backpressure should stay the same or go higher, should it not?

Or did they go from divided to undivided volute or something?

I'm not trying to call BS on you, just trying to make sense of what you're seeing.

Look at the overall housing design. Nothing of the engine combo was changed and the A/R was the same. Only thing that was changed was from the standard housings to the PTE housings.

SomeWhatStock said:
so your saying that the air flows through the wheel faster and the wheel spins faster all because the difference in material?

i cant see that

Where did you see me say that? The design is what makes the housing perform better, not the material.

mgannon1986

· #10 · Jan 24, 2011

does anybody know what the price is on one of those units thanks

SuperCooper

· #11 · Jan 24, 2011

89notch said:
Look at the overall housing design. Nothing of the engine combo was changed and the A/R was the same. Only thing that was changed was from the standard housings to the PTE housings.

Where did you see me say that? The design is what makes the housing perform better, not the material.

Agreed!

Scotts87LX

Discussion Starter · #12 · Jan 24, 2011

NASTYCAMARO said:
I just got mine from TIAL. Give them a call I think you will be very impressed..

What size turbo? GT47? That's what I need one (well ... actually two) for.

Scotts87LX

Discussion Starter · #13 · Jan 24, 2011

89notch said:
If you're doing it to reduce under hood temps then you shouldn't be doing it. You want real world proof? Go to the track and talk to the people who have switched over.

Same turbo's on the same setup make more boos than before, reduces spool up time not to mention back pressure almost falling completely to zero. The weight reduction is a beneficial by-product.

This is on a BBC with twin pro-mod 88s. I guess those are small turbo's these days... :smt102

REALLY?? I thought it was physically impossible for back pressure to fall below the amount of boost pressure being produce. I've always heard that "in a perfect world" boost vs back pressure would be 1:1. So you can make boost and have zero back pressure??? I don't follow. Is what your actually saying: back pressure drops to 1:1?

SuperCooper

· #14 · Jan 24, 2011

Promod 88 is based on GT55, right?

89notch

· #15 · Jan 24, 2011

Scotts87LX said:
What size turbo? GT47? That's what I need one (well ... actually two) for.

TiAL units are nice but the ones I have seen do not have mounting bosses cast into the units. Precision units do.

Sorry for the picture size.

Scotts87LX said:
REALLY?? I thought it was physically impossible for back pressure to fall below the amount of boost pressure being produce. I've always heard that "in a perfect world" boost vs back pressure would be 1:1. So you can make boost and have zero back pressure??? I don't follow. Is what your actually saying: back pressure drops to 1:1?

Yes as that would be zero.(I only count BP as the number above a 1:1 ratio, backwards brained)

SuperCooper said:
Promod 88 is based on GT55, right?

Yes.

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brianj5600

· #16 · Jan 24, 2011

Having a round entry would help by not changing from round to rectangle back to round. Staying round from the collector to the wheel would help and having no change in diameter until it is reduced as exhaust is fed to the wheel would be beneficial. If the transition changes the volume then energy is used. It would be nice to see how much better they actually are.

10secgoal

· #17 · Jan 24, 2011

Scotts87LX said:
REALLY?? I thought it was physically impossible for back pressure to fall below the amount of boost pressure being produce. I've always heard that "in a perfect world" boost vs back pressure would be 1:1. So you can make boost and have zero back pressure??? I don't follow. Is what your actually saying: back pressure drops to 1:1?

I don't see how just the change could do it either. But you can even get below 1:1. Buddy of mine runs .84:1. It's a mother to spool though lol.

crowerscks

· #18 · Jan 24, 2011

89notch said:
Yes as that would be zero.(I only count BP as the number above a 1:1 ratio, backwards brained)

So does that mean you have zero boost in the intake manifold at 1:1?

Scotts87LX

Discussion Starter · #19 · Jan 24, 2011

crowerscks said:
So does that mean you have zero boost in the intake manifold at 1:1?

No that means if you had 20psi in the manifold you would have 20psi in the exhaust.

SuperCooper

· #20 · Jan 24, 2011

10secgoal said:
I don't see how just the change could do it either. But you can even get below 1:1. Buddy of mine runs .84:1. It's a mother to spool though lol.

Some folks refer to this as "crossover", kinda like turbo nirvana, and yes it does happen. In general it seems like it occurs on engines with chargers that are a hair "too big" so they spool poorly but once you're up on it, hang on.

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