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No it really wasn’t the argument. There is no offering for a T3 bolt pattern housing. The housings offered by Borg Warner are all T3 ports with a T4 bolt pattern. It’s suggested that if need be you can port the existing T3 to match a T4 header. I was simply arguing that T3 header with a T4 flange welded to it, or a custom made T3 header would provide better spool than a standard T4 header.
This thread is about S200 series turbos, so the above post is correct. Unless you go with an aftermarket hot side they all are T3 ports with a T4 bolt pattern.
I have owned four s300 series turbos so I obviously know they come with T4 flange and ports.
This is a large tube T4 header, morrisman’s is not.
My header uses Schedule 10 1.5" 304L 1.5" pipe. It has about a 2.7mm wall so is about 42mm inside diameter. Some headers are smaller and use 1.25" pipe, haven't really seen anything larger than 1.5" on these but not to say that someone hasn't done it. Doesn't make sense to me to make the runners larger than the port area in any case
My header uses Schedule 10 1.5" 304L 1.5" pipe. It has about a 2.7mm wall so is about 42mm inside diameter. Some headers are smaller and use 1.25" pipe, haven't really seen anything larger than 1.5" on these but not to say that someone hasn't done it. Doesn't make sense to me to make the runners larger than the port area in any case
The general rule I have been told and have seen other post is to use Schedule 10 1.25" Pipe (1.44" ID) up to ~750whp and then above that use Schedule 10 1.5" Pipe (~1.66" ID). My old header was Sch10 1.5", but very short runners and the new header is Sch10 1.25" with longer runners.
I had seen something similar. the 1.5" pipe shaped to the exhaust port well as well as the T3 divided volute so it made a bit of sense in my mind to go that way. Spool and response is great, I cant actually see any reason to go smaller on this setup.
I would love to see a 1.25” manifold and compare the difference to morrisman’s setup. No doubt that the smaller pipe configuration before entering the turbo flange has its benefits.
Because the T3 volute becomes a restriction and is much harder to fabricate a manifold for, not to mention you lose exactly zero spool moving to a T4 volute with the right size turbine housing.
The HX35 turbine wheel is biased for spool, and flows like **** past 50lb/min. The HX is a decent turbo, but it doesn't hold a candle to the SXE. Ya'll can bench race dyno charts all you want.
“You loose exactly zero spool”
T4 volute good for +1000hp
T3 volute good for up too 600hp with increased spool compared to a T4 period. This article proves that port cross sectional area before the entry into the turbine housing has substantial results on spool with extremely small sacrifices on maximum power.
Happened to run across this thread recently while digging for turbo info (EvoM never disappoints with the turbo knowledge of many of its members) and wanted to chime in as some of the references and data is from the original 2010 "Mr Peepers" setup and some articles from the website.
Originally Posted by Strm Trpr
The HX ripped quick, but nosed over sooner.
I think the 12cm² T3 turbine housing created too much back pressure.
Torque falls off terribly for a 2.0L, almost looks like a 2.3L.
It would've been nice to see the boost plot from the HX35 run.
The 7 blade HX35 always fell to 28psi up top so it was extremely similar to the 2.3L Red setup boost curve.
The 12cm^2 housing tended to perform the best for us on the HX35, with larger (14cm^2 or 16cm^2, always forget but can check) housings having the same trap speed and only making the exhaust note louder and slowing response in our experiences. Stepping up to the HX40 bits changed things but also gets muddier for comparison's sake.
Originally Posted by 2winscroll
Not for 450~500 hp they aren't, Mr. Peepers manifold is a 1.625" tube header, and every T3 twinscroll header I have seen uses 1.625" tubing (1.5" I.D.). Most T4 twin scroll manifolds use 1.5" sch10 pipe which is 1.7" I.D.
This is my point, if you goals are under 600hp a T3 twin scroll manifold will be better for spool. A T4 twin scroll manifold can support over +1100hp and is not optimal for a 500~600hp build.
You have a very rough grasp of how gas velocity affects turbo spool. Educate yourself before inserting you foot into your mouth.
The original manifold was 1-1/4NPS pipe, and actually sch40 so 1.38" ID. There was a slight concern that our current sch10 version (less wall thickness and same OD, so larger ID) would spool slower, but a back to back stall test (the car is auto now) spooled quicker despite the small bump in runner ID. The original worked very well, but there were many areas that could be/have been improved and we tend to attribute the quicker spool of the new version to that, with more flow potential to boot from both the better overall design and slightly larger ID.
Originally Posted by RWD4G63
LOL, you're talking about stuff that I've known for years. Mr. Peepers setup is not new, and I helped recreate a similar setup on an Evo 8 about 3 years ago. It performed admirably.
I've been part of about 20 exhaust manifold builds, all of which I saw hit the dyno afterwards. You can easily fabricate a T4 manifold with 1.25" Sch10 or whatever size piping you could want. I never said big runners help spool. The facts here are that a T4 divided manifold is just fine for a street car, and will spool the turbo just the same as a T3 divided provided that you sized your turbine housing correctly (which is much more important btw). They make a .83 A/R housing for the SXE now, which is quite small actually. I've seen the 1.00 and 1.15 on the S200SX series and they spool pretty fast. A personal friend of mine had a Galant VR-4 with a 2.3 and S259 reach full boost at 3800rpm in third with a 1.15 divided T4 housing...
We agree with this, as T3 and T4 are denoting the flange footprint.
Each flange entry for the T4 is larger, sure, but that is really just a change in where the merge collector is cut. You only have a larger flow potential from the divided T4 flange- which again, can be the same exact merge as a divided T3 but just cut further up to make the opening/outlet larger. That merge section that was cut off is now just being done in the turbine housing and that cross sectional area is there no matter what when you merge two runners. Even 1-1/4" "small" runners, which match up very nicely when merged to a divided T4 inlet opening. It's more of what's happening in the volute and A/R itself than simply the size of the bolted interface- as long as that isn't to small to restrict overall flow or too large to be properly transitioned to or add unnecessary volume. Looking at the collector and turbine housing as a bolted assembly, they can be the same whether divided T3 or divided T4 as long as the angle of convergence is similar. Just a parting line at a different location.
That was the whole premise to why we tend to prefer small runner divided T4 over a divided T3 (which we are adamant about pairing with small runners due to the size of the footprint/openings anyway) where possible. The small divided T3 works very well for the (limited) turbo options within a certain power window, but leaves you with less options/upgrade path down the road and less power potential (albeit somewhat unknown how much less as it's not as common).As mentioned before by RWD4G63, there is likely good reason why even the B1 EFR turbos are offered in divided T4 instead of divided T3 and even now the G25 series. We personally want to push the flow potential of the divided T3 footprint to see where it is comfortable at with a well sorted setup, and know there are folks who have made 700+whp, but they are the outliers.
That is all assuming that things are apples to apples for the rest of the turbine housing, which isn't always the case as 240Z TwinTurbo stated below.
Originally Posted by 240Z TwinTurbo
I don't know about those specifically, but my point is that a/r is just a RATIO (area/radius) and does not define any physical dimensions of the turbine housing. Therefore, you can have a turbine housing with a larger ratio, but it flows less than a turbine housing with a smaller ratio. Typically a T4 will have a longer radius vs a T3 so in order for them both to have the same a/r, the T4 will have to have a larger flow area to maintain the ratio and will likely flow more.
When the flow of a T3 is sufficient for a given turbine wheel then using a T4 with equivalent a/r might actually decrease spool and give you little advantage on the topend. I think this was the argument earlier so I am only saying it is not that simple to say one is automatically better than another.
I've been told that how the exhaust hits the turbine wheel also affects flow and spool along with the turbine wheel design so there are many factors affecting final performance. I think a lot of what we do is learn from what other's have experienced and then choose accordingly.
Also wanted to mention that we really love reading your posts and builds, 240Z!
Cheers,
Matt and Samantha
Last edited by MorrisonFab; Oct 16, 2019 at 03:03 PM.
Also wanted to mention that we really love reading your posts and builds, 240Z!
Cheers,
Matt and Samantha
I was digging through this thread again looking for data when I saw your post. Thanks for the kind words and I have read most of your stuff as well, which is also very impressive. I am thinking to upgrade my GTR turbos (currently Xona Green's) to the S252 SXE (5261) instead of the GTX3071r (5455) using the stock turbofold's.
On the EVO side I love my current setup, but I already have something else I want to try just because. I doubt I will change anything anytime soon, but always fun just to do the work and see what happens. That consolidated manifold data was very interesting. Despite having lower drive pressure the standard top mount did not perform as well as the consolidated despite both being below 1:1...definitely interesting.
Happened to run across this thread recently while digging for turbo info (EvoM never disappoints with the turbo knowledge of many of its members) and wanted to chime in as some of the references and data is from the original 2010 "Mr Peepers" setup and some articles from the website.
The 7 blade HX35 always fell to 28psi up top so it was extremely similar to the 2.3L Red setup boost curve.
The 12cm^2 housing tended to perform the best for us on the HX35, with larger (14cm^2 or 16cm^2, always forget but can check) housings having the same trap speed and only making the exhaust note louder and slowing response in our experiences. Stepping up to the HX40 bits changed things but also gets muddier for comparison's sake.
The original manifold was 1-1/4NPS pipe, and actually sch40 so 1.38" ID. There was a slight concern that our current sch10 version (less wall thickness and same OD, so larger ID) would spool slower, but a back to back stall test (the car is auto now) spooled quicker despite the small bump in runner ID. The original worked very well, but there were many areas that could be/have been improved and we tend to attribute the quicker spool of the new version to that, with more flow potential to boot from both the better overall design and slightly larger ID.
We agree with this, as T3 and T4 are denoting the flange footprint.
Each flange entry for the T4 is larger, sure, but that is really just a change in where the merge collector is cut. You only have a larger flow potential from the divided T4 flange- which again, can be the same exact merge as a divided T3 but just cut further up to make the opening/outlet larger. That merge section that was cut off is now just being done in the turbine housing and that cross sectional area is there no matter what when you merge two runners. Even 1-1/4" "small" runners, which match up very nicely when merged to a divided T4 inlet opening. It's more of what's happening in the volute and A/R itself than simply the size of the bolted interface- as long as that isn't to small to restrict overall flow or too large to be properly transitioned to or add unnecessary volume. Looking at the collector and turbine housing as a bolted assembly, they can be the same whether divided T3 or divided T4 as long as the angle of convergence is similar. Just a parting line at a different location.
That was the whole premise to why we tend to prefer small runner divided T4 over a divided T3 (which we are adamant about pairing with small runners due to the size of the footprint/openings anyway) where possible. The small divided T3 works very well for the (limited) turbo options within a certain power window, but leaves you with less options/upgrade path down the road and less power potential (albeit somewhat unknown how much less as it's not as common).As mentioned before by RWD4G63, there is likely good reason why even the B1 EFR turbos are offered in divided T4 instead of divided T3 and even now the G25 series. We personally want to push the flow potential of the divided T3 footprint to see where it is comfortable at with a well sorted setup, and know there are folks who have made 700+whp, but they are the outliers.
That is all assuming that things are apples to apples for the rest of the turbine housing, which isn't always the case as 240Z TwinTurbo stated below.
Also wanted to mention that we really love reading your posts and builds, 240Z!
Cheers,
Matt and Samantha
Question,
In your opinion would your manifold spool a turbo faster with 1.5” sch 10 pipe as opposed to the 1.25” pipe that you have chosen to use for this particular manifold.
I noticed you offer headers both large and small runners, why is that?
You said it right here^^^^^^
A T4 manifold will spool exactly the same as a T3. Simply not true when using a standard manifold. Turbines housing is only part of the equation.
Im not talking about custom stuff, I’m saying most T4 manifolds are 1.7” I.D. and T3’s are 1.5” I.D. I said this about Mr. Peepers manifold having smaller runners and T3 flange. Don’t put words in my mouth.
I do believe you are one of the first to offer a T4 flanged 1.25” pipe manifold. It seems you know the value of exhaust velocity when it comes to boost threshold.
You said it right here^^^^^^
A T4 manifold will spool exactly the same as a T3. Simply not true when using a standard manifold. Turbines housing is only part of the equation.
Im not talking about custom stuff, I’m saying most T4 manifolds are 1.7” I.D. and T3’s are 1.5” I.D. I said this about Mr. Peepers manifold having smaller runners and T3 flange. Don’t put words in my mouth.
I do believe you are one of the first to offer a T4 flanged 1.25” pipe manifold. It seems you know the value of exhaust velocity when it comes to boost threshold.
It seems that in your post you are in agreement that the larger runners will spool faster than small runners, you have me confused.
On the EVO side I love my current setup, but I already have something else I want to try just because. I doubt I will change anything anytime soon, but always fun just to do the work and see what happens. That consolidated manifold data was very interesting. Despite having lower drive pressure the standard top mount did not perform as well as the consolidated despite both being below 1:1...definitely interesting.
The boost vs drive pressure gradient was especially interesting how it flipped around on each! It would be great to see more than just the drive pressure as its only a lumped average- and instead some pressure traces that show what is really going on in the background. Each test seems to only leave a wanting for more
Originally Posted by 2winscroll
Question,
In your opinion would your manifold spool a turbo faster with 1.5” sch 10 pipe as opposed to the 1.25” pipe that you have chosen to use for this particular manifold.
I noticed you offer headers both large and small runners, why is that?
Originally Posted by 2winscroll
I do believe you are one of the first to offer a T4 flanged 1.25” pipe manifold. It seems you know the value of exhaust velocity when it comes to boost threshold.
It seems that in your post you are in agreement that the larger runners will spool faster than small runners, you have me confused.
A "small" runner 1-1/4NPS manifold will almost certainly spool a turbo quicker (and augment the midrange) than a more common "large" runner 1-1/2NPS manifold. Our response was written entirely with runner size being equal between the two, and specifically about small runners, as it would certainly change the conversation and results.
We offer many of our manifolds as either large and small runner so it can be tailored to the rest of the setup. For example, we only offer our divided T3 DSM offering in small runner, as each of the inlets on a divided T3 flange is smaller than a single "large" runner and the flow potential of the divided T3 footprint is less than a small runner manifold to begin with. So offering it in large runner would only make it lazier than it needs to be without much, if any, benefit up top. This has been the trend with every large runner 1-1/2NPS divided T3 manifold we've seen. There is always a give and take, of course, as the increased velocity eventually comes at the cost of higher blowdown pressure and frictional losses, but the right combinations can really shine and we like to see that taken advantage of- especially when the primary size isn't the limiting factor to begin with. The power level where small runner shows an overall gain over large runner is much higher than people tend to expect, but what's "right" for each still comes down to many variables and ultimately what kind of powerband gets you the most excited.
Matching primary size to the rest of the setup isn't new, but has always seemed a bit uncomfortable going to something smaller than the exhaust port and making that transition requires some attention to get right in our opinion. Using the smaller 1-1/4NPS isn't as common but we aren't the first by any means to offer it, for a divided T4 or otherwise, but feel that our approach to stepping down from the exhaust port size to the runner itself is done very well. If you look at our small runner offerings, it's hard to tell any indication as it forms from the oval exhaust port size to the round smaller runner size seamlessly. Getting that wrong could risk negating the benefits all together and not give it a fair fight.
Using the smaller 1-1/4NPS isn't as common but we aren't the first by any means to offer it, for a divided T4 or otherwise, but feel that our approach to stepping down from the exhaust port size to the runner itself is done very well. If you look at our small runner offerings, it's hard to tell any indication as it forms from the oval exhaust port size to the round smaller runner size seamlessly. Getting that wrong could risk negating the benefits all together and not give it a fair fight.
I noticed on your website that you have the transition piping right off the flange and just before the smaller runner. I think this is better than what I did, which was to do the entire transition using the flange and in ~1/2" of distance. I think ideally someone could make a 1.00" thick flange that did the correct transition so one can have a more compact design and similar to what AMS does with their GTR flange. I provided the flange drawings in a separate post, which at least gives the 2D dimensions to create a 3D CAD file.
The boost vs drive pressure gradient was especially interesting how it flipped around on each! It would be great to see more than just the drive pressure as its only a lumped average- and instead some pressure traces that show what is really going on in the background. Each test seems to only leave a wanting for more
A "small" runner 1-1/4NPS manifold will almost certainly spool a turbo quicker (and augment the midrange) than a more common "large" runner 1-1/2NPS manifold. Our response was written entirely with runner size being equal between the two, and specifically about small runners, as it would certainly change the conversation and results.
We offer many of our manifolds as either large and small runner so it can be tailored to the rest of the setup. For example, we only offer our divided T3 DSM offering in small runner, as each of the inlets on a divided T3 flange is smaller than a single "large" runner and the flow potential of the divided T3 footprint is less than a small runner manifold to begin with. So offering it in large runner would only make it lazier than it needs to be without much, if any, benefit up top. This has been the trend with every large runner 1-1/2NPS divided T3 manifold we've seen. There is always a give and take, of course, as the increased velocity eventually comes at the cost of higher blowdown pressure and frictional losses, but the right combinations can really shine and we like to see that taken advantage of- especially when the primary size isn't the limiting factor to begin with. The power level where small runner shows an overall gain over large runner is much higher than people tend to expect, but what's "right" for each still comes down to many variables and ultimately what kind of powerband gets you the most excited.
Matching primary size to the rest of the setup isn't new, but has always seemed a bit uncomfortable going to something smaller than the exhaust port and making that transition requires some attention to get right in our opinion. Using the smaller 1-1/4NPS isn't as common but we aren't the first by any means to offer it, for a divided T4 or otherwise, but feel that our approach to stepping down from the exhaust port size to the runner itself is done very well. If you look at our small runner offerings, it's hard to tell any indication as it forms from the oval exhaust port size to the round smaller runner size seamlessly. Getting that wrong could risk negating the benefits all together and not give it a fair fight.
I have been rethinking the entire pipe size strategy since really looking into how much power one can make on the GTR using the stock turbofolds. What is interesting is the stock turbofold transitions from the port size to a smaller runner just like your small runner manifolds. When the second cylinder feeds into the primary tube it stays the same size and when the final runner enters the primary tube it only slightly enlarges. I need to try and measure the ID right before the turbine inlet, but it is extremely small. However, people are making 1400RWHP on the stock turbofold and the boost response is phenomenal due to it being short runner and small runner.
I noticed on your website that you have the transition piping right off the flange and just before the smaller runner. I think this is better than what I did, which was to do the entire transition using the flange and in ~1/2" of distance. I think ideally someone could make a 1.00" thick flange that did the correct transition so one can have a more compact design and similar to what AMS does with their GTR flange. I provided the flange drawings in a separate post, which at least gives the 2D dimensions to create a 3D CAD file.
Trying to do the transition from oval to round, and then to the smaller size on top of it in <0.5" is less than ideal, but then making the flange stick out further limits the design options, especially on an Evo when you need to make some sort of bend almost immediately.
Being able to do both oval to round and a diameter change through the formed runner itself, and even through a bend works out extremely well, and in some cases the bend can be initiated right off the port and sunk into the flange without having to compromise the CLR. It definitely requires more time and tooling to do so, but we love using oval port flanges and handling any transitions through a formed runner for those reasons.
Those are really slick though, and if there is to be a full transition within the flange and the space is there, that is how it should be done!
Originally Posted by 240Z TwinTurbo
I have been rethinking the entire pipe size strategy since really looking into how much power one can make on the GTR using the stock turbofolds. What is interesting is the stock turbofold transitions from the port size to a smaller runner just like your small runner manifolds. When the second cylinder feeds into the primary tube it stays the same size and when the final runner enters the primary tube it only slightly enlarges. I need to try and measure the ID right before the turbine inlet, but it is extremely small. However, people are making 1400RWHP on the stock turbofold and the boost response is phenomenal due to it being short runner and small runner.
If we aren't mistaken, the firing order for the V6 ends up with each bank being the "paired" runners that you would arrange in a divided setup. So only one exhaust pulse is occupying the manifold/turbofold bank at a time (and no other cylinders are in their overlap phase), allowing it to maintain the same diameter without the expected loss as if it were thought of as simply a mass flow. Basically a divided setup but with two turbos, and all other rules applying.
We didn't know that was how the GTR turbofolds were set up at all and definitely worth taking notes on when things are pushed!
Add in more cylinders/a different firing order and that goes out the window though. We seem to recall an OEM twin turbo V8 application where one cylinder on each bank bypassed the turbine altogether to avoid cross-talk issues.
Sorry for taking this off on a tangent!
Last edited by MorrisonFab; Oct 17, 2019 at 04:45 PM.
Jun 9, 2019, 07:23 PM
