Divided Turbine Housing (T4) vs Undivided (T3)

[definitiveno]

Assuming you had either A/R option for your application (in my case gt35r with .63 t3 or t4 housing) which is better? I keep reading that T4 is more efficient with some scavenging effect created by the divided housing, this supposedly means quicker spool. I have an automatic car so response is important for daily driving. I am currently having a manifold built by straight line with a T3 flange and I am considering with some input from you guys weather or not I should change the manifold to T4. The change won't affect cost of the turbo or manifold that I can see right now.


Instead of creating another thread about Compressor housings I'd like to hear your takes on surge ported housings also. I am leaning towards a surge ported S housing unless there are others I should consider, but, my builder feels that without SP's the turbo will be much more efficient. My argument is that the car is a pump gas car only, no plans of race gas, ever. So not sure if that effects me but I will usually be in the lower end of the compressors pressure range and I think that would help keep me safe.

Compression is 9:1, I'm thinking I will be limited to 18-24psi with 92 here. If there is any information about my application left out I will try and help fill in the blanks. Thanks guys.....

[definitiveno]

Hmmm, I'm noticing some companies offer divided t3 housings too, where do those fall in the mix?

[zross1]

I have a gt35r with a .82 a/r t3 undivided turbine housing ported S cover. It's the best combo IMO for the 35r on a pump street car. I build power all the way to 9K with that TH. The divided TH is debatable on if it's any better then the non divided. I would definetly get a ported S cover because it will surge if you don't.

[prostreetdsmx1]

i recommend a T3 setup. what manifold are you planning on running?

[definitiveno]

Straightline specialties..... they offer mitsu, T3 and T4 flanges according to a rep.


http://store.straightlinespecialties...roducts_id=241

[nanokpsi]

According to some information that I have read, and hearsay from the folks at PTE, a .68 t4 will flow a little more and spool a little better than a .82 t3 (both undivided). Other than that i'm sure your not going to get any great information out of this. The reason being is that most people aren't trying to run a divided housing for small turbos on pump gas. They typically run the undidveded manifolds until turbo slection dictates the use of a divided mani a la gt4088r, gt42r, etc.
Theoretically, the divided housings will spool better by eliminating exhaust gas reversion. However, longer runner mani's (most divided) will increase spool time in exchange for better flow. For the most part you are talking about marginal differences in spool as well, so depending on your goal, the choice may be totally irrellevant.

[GVR4592]

Originally Posted by nanokpsi

According to some information that I have read, and hearsay from the folks at PTE, a .68 t4 will flow a little more and spool a little better than a .82 t3 (both undivided). Other than that i'm sure your not going to get any great information out of this. The reason being is that most people aren't trying to run a divided housing for small turbos on pump gas. They typically run the undidveded manifolds until turbo slection dictates the use of a divided mani a la gt4088r, gt42r, etc.
Theoretically, the divided housings will spool better by eliminating exhaust gas reversion. However, longer runner mani's (most divided) will increase spool time in exchange for better flow. For the most part you are talking about marginal differences in spool as well, so depending on your goal, the choice may be totally irrellevant.

One of the guys from AMS said something pretty similar to that. I don't remember the exact details but I think they swapped a .82 T3 with a .68 T4 on a GT35R and picked up quite a bit of power and had a similar spool.

[definitiveno]

Any recollection how the T4 .68 spooled on a 2 liter? I am wondering if the turbine will be a big restriction for me though, my plan/goal is not to make a ton of power but rather have an extremely broad power band. If can make 400 at around 5-6 grand and hold it as long as possible this is what I am after.

This is more of what I am trying to accomplish with my car.

In theory the smallest turbine housing I can get away with that can pass 400-450hp worth of exhaust (to 9-9.5 thousand rpm) without being a restriction is what I am looking for. I don't know how much it helps but I hoped the 44m tial would help route some of the load around the turbine. My goals are modest for power but pretty demanding in for the power band, hence the build.

I am using a tubular manifold exhaust/intake, cnc ported heads, fp3 cams and high flow IC and throttle body to try and help engine efficiency through the top end. Down to the last few nick nacs of sorting out the turbo.

[definitiveno]

Noticing that the t4 divided manifolds require and extravagant O2 housing and extra wastegate I think I am going to continue my search with just the undivided setup's. Unless some one can make a case that can prove the extra cost a value for my goals it's definately undivided for now..

[4wd-Eclipse]

Originally Posted by definitiveno

Noticing that the t4 divided manifolds require and extravagant O2 housing and extra wastegate I think I am going to continue my search with just the undivided setup's. Unless some one can make a case that can prove the extra cost a value for my goals it's definately undivided for now..

DNP divided T4 mani coming with ONE Tial 44 wastegate outlet flange ... this what I'm planning to get with T4 GT35R and Tiil 44 WG in few months.

[nanokpsi]

Originally Posted by definitiveno

Any recollection how the T4 .68 spooled on a 2 liter? I am wondering if the turbine will be a big restriction for me though, my plan/goal is not to make a ton of power but rather have an extremely broad power band. If can make 400 at around 5-6 grand and hold it as long as possible this is what I am after.

This is more of what I am trying to accomplish with my car.

In theory the smallest turbine housing I can get away with that can pass 400-450hp worth of exhaust (to 9-9.5 thousand rpm) without being a restriction is what I am looking for. I don't know how much it helps but I hoped the 44m tial would help route some of the load around the turbine. My goals are modest for power but pretty demanding in for the power band, hence the build.

I am using a tubular manifold exhaust/intake, cnc ported heads, fp3 cams and high flow IC and throttle body to try and help engine efficiency through the top end. Down to the last few nick nacs of sorting out the turbo.

What turbo are you looking at running? I run the .68 t4 but I run it with some big, heavy wheels. Its a t67/P trim combo that spools around 5500 on a 2.0 (23-24psi). Obviuosly, smaller wheels are going to cut that down a good margin as a gt35r in that housing spools similar to a 35r in a .82 t3 (5000). Just for refrence, my car made peak whp at 7100rpm on a stock 2g block/head/tb with HKS 264/272s and a 2g magnus. The .68 is a big housing for a small motor.
With you power goals and undivided .63 t3 or .58 t4 would be fine.

[JOEY A]

GT35 Non BB bolton is a laggy as hell


My buddy has it with a AMS Intake manifold,cams blah blah etc

He has the .83 hot side and hes getting sick of the lag

[GVR4592]

Originally Posted by JOEY A

GT35 Non BB bolton is a laggy as hell


My buddy has it with a AMS Intake manifold,cams blah blah etc

He has the .83 hot side and hes getting sick of the lag

It's a bolt on with a .83 hotside?

[fwdeclipse]

Originally Posted by definitiveno

Any recollection how the T4 .68 spooled on a 2 liter? I am wondering if the turbine will be a big restriction for me though, my plan/goal is not to make a ton of power but rather have an extremely broad power band. If can make 400 at around 5-6 grand and hold it as long as possible this is what I am after.

This is more of what I am trying to accomplish with my car.

In theory the smallest turbine housing I can get away with that can pass 400-450hp worth of exhaust (to 9-9.5 thousand rpm) without being a restriction is what I am looking for. I don't know how much it helps but I hoped the 44m tial would help route some of the load around the turbine. My goals are modest for power but pretty demanding in for the power band, hence the build.

I am using a tubular manifold exhaust/intake, cnc ported heads, fp3 cams and high flow IC and throttle body to try and help engine efficiency through the top end. Down to the last few nick nacs of sorting out the turbo.

Im running a .68ar t4 with my 60 trim and in third gear I see 25psi by 5k with a stock head and intake manifold.

[definitiveno]

Originally Posted by nanokpsi

What turbo are you looking at running? I run the .68 t4 but I run it with some big, heavy wheels. Its a t67/P trim combo that spools around 5500 on a 2.0 (23-24psi). Obviously, smaller wheels are going to cut that down a good margin as a gt35r in that housing spools similar to a 35r in a .82 t3 (5000). Just for reference, my car made peak whp at 7100rpm on a stock 2g block/head/tb with HKS 264/272s and a 2g magnus. The .68 is a big housing for a small motor.
With you power goals and undivided .63 t3 or .58 t4 would be fine.

The turbo's I am most strongly looking at now are the T4 GT35r .58 A/R, T3 gt35r .63 A/R, T3 gt3040r .80 A/R, and every once in a while I look at the holsets and borg warners but I don't know enough about them or their options. Looks like you will have allot of power in the top end if you upgrade the head and cams. I'm not too sure how much the tb matters but I wanted to make every airway in my system is as smooth as possible personally.

When I look at the fp3052 and the fp3065 I think it too should be capable of supporting my goals but since I am going garrett or T3 it's no use for me. I like the .70 a/r option it has.


I wonder, can any one help me figure out how many LBS/MIN my car will be flowing in exhaust? I just looked at garretts website and noticed the turbine graphs are also rated in LBS/MIN. Maybe figuring out how many LBS/MIN the car is flowing in exhaust will help me figure out how exactly what turbine and A/R I will need to meet my goals.

2 liter
9500 rpm
450hp

Not sure what else is needed.

Lets do this one too if it's not too much trouble.

2 liter
9000 rpm
400 hp

I don't have any idea what efficiency the engine will operate at with all the upgrades, hopefully pretty well in the upper end.

[nanokpsi]

Out of you choices I think the .58 (undivided) gt35r would be the best. It should also come with 3" v-band discharge which is very nice for down pipe removal.

As for my set up, the new motor will start this week It shouldn't have a problem making over 500whp on pump and close to 700whp on c16.

If you are talking about 450whp on pump your going to need 50lb/min of airflow. I was around 48lb/min on pump on my dyno.

[Reese92tsi]

Originally Posted by fwdeclipse

Im running a .68ar t4 with my 60 trim and in third gear I see 25psi by 5k with a stock head and intake manifold.

I'm glad you finally got it up to 25psi

[DSMunknown]

I'm not sure why another thread was started when there is an indepth thread already on this issue, but we'll see how well this goes:




Not Divided Mod

[nanokpsi]

Originally Posted by DSMunknown

I'm not sure why another thread was started when there is an indepth thread already on this issue, but we'll see how well this goes:




Not Divided Mod

Have you read any of this thread? I just ask becasue the link you posted has nothing to do with it. The poster in this thread is talking about divided turbine housing inlets, where the link you posted is in refrence to removing the divider between the internal wg passage and the turbine outlet on mitsu turbine housings.

[Steve93Talon]

Originally Posted by DSMunknown

I'm not sure why another thread was started when there is an indepth thread already on this issue, but we'll see how well this goes:




Not Divided Mod

Umm... That thread is about divided turbine housing outlets on Mitsu type turbine housings. This thread is about divided inlets like this: