Can I swap to a Garett turbine housing?

[dwdsm]

Ok I'm going for more efficiency here so I was wondering if I could swap my Mitsu hotside with a garett. I have the SBR G-50 BB with the to4e compressor housing. SBR says it's a garett race 360 center section so I think it would be different then a 30R center section correct? While I'm at it I want to switch over to V-band if I can.

 

[JusMX141]

It's absolutely possible....you'll just have to double-check your turbine wheel's specs to that of the Garrett's to find which housing will fit your wheel properly.


Your car hauls ass, by the way.

 

[Burnett03]

Yes you can.. You need to figure out what exhaust wheel you have. I believe it's a Stage III which is a t31 76 trim. Aa buddy of mine has a brand new t31 76trim .68 garrett housing if you need one. You realize you need a new manifold and o2 housing now i assume right?

 

[dwdsm]

Yes you can.. You need to figure out what exhaust wheel you have. I believe it's a Stage III which is a t31 76 trim. Aa buddy of mine has a brand new t31 76trim .68 garrett housing if you need one. You realize you need a new manifold and o2 housing now i assume right?

yes I know.. I need a little more timing and I figure It's worth the flange, housing, and an O2.. See how much your buddy would want for it and if he has paypal to make it easy. I'll call garett to see if they have an all V-band hot side. here are the specs on the turbo from SBR.

Compressor Wheel Diameter 54mm
Compressor Wheel Inducer - 2.123
Compressor Wheel Exducer 3.000
Wheel Trim 50 Trim
Compressor Cover Inlet 3
Outlet Size 2
Bearing System Garrett Race 360 Center Section
Turbine Wheel Style - T31 (Stage III)
Turbine Wheel Inducer 2.559"
Turbine Wheel Exducer 2.229"
Turbine Wheel Trim - 76

I still wonder if it would be worth it but I'm happy with my car and just want to tweak it here and there.

 

[dwdsm]

It's absolutely possible....you'll just have to double-check your turbine wheel's specs to that of the Garrett's to find which housing will fit your wheel properly.


Your car hauls ass, by the way.

hey thanks! I drove like shit Wed at the track. was that you there? I can't find it here that's why I'm a little lost. TurboByGarrett.com - Turbochargers

 

[Burnett03]

I've done a lot of research on this already.. The housing he has will 100% fit and work.. It doesn't however have a vband flange, it's a 4bolt outlet.. His email is [email protected] Tell him Ryan sent you. He has paypal. You can weld on a vband to it.

 

[JusMX141]

I'm normally there every wednesday....my buddy runs a dark green '95 TSi AWD. Neither of my cars are done yet; although I'm finally caught up on work so it's time to pull the FWD back into the shop. It needs the least amount of work done, so I'd like to get it making passes down the track before the end of the year.

I believe all T31 wheels are the same spec, ball-bearing or not. If you scope out a couple different sites that offer Garrett-style turbos (PTE, Turbonetics, etc.) you'll find their wheels are the same spec as the one in your G50. Any T3 housing should fit as long as it's for the T31 wheel.

 

[dwdsm]

I e-mailed him. Thanks!
the only thing I don't know is what my current A/R is but I'll check when I get home.

 

[dwdsm]

Great info both of you thanks!

 

[1992awdlaser]

T31 Exhaust housing for StageIII (76 trim) turbine wheel: atpturbo.com

Convert it to v-band with this if you want. V-Band Adapter Module, Smaller 4 bolt (T31) 2.5" to 3" V-Band: atpturbo.com

 

[dwdsm]

Before I take the plunge, do you guys think this will help spool, and increase efficiency or am I wasting my time?

 

[1992awdlaser]

I doubt there will be any difference in spool at all. It will be capable of a little more power though. It will also make it so you have less chance of knocking since it isn't as restrictive.

 

[dwdsm]

I could use a little more timing and I figured a little more across the board would help spool slightly.

 

[Burnett03]

Bigger housings spool a bit slower but make more topend because they are less restrictive.

 

[delta448]

Be sure to post up the results you see after you do the switchover. I'm sure I'm not the only one who'd love to see what exactly the difference really amounts to.

 

[dwdsm]

Bigger housings spool a bit slower but make more topend because they are less restrictive.

If the a/r is the same wouldn't the housing flow the same? I figured the volute would be the only difference. A garrett volute is way more efficient then a mitsu half volute.

 

[JusMX141]

The a/r greatly effects how the turbo spools as well as it's flow characteristic.

Garrett has a good writeup to help describe a/r:

"Turbine A/R - Turbine performance is greatly affected by changing the A/R of the housing, as it is used to adjust the flow capacity of the turbine. Using a smaller A/R will increase the exhaust gas velocity into the turbine wheel. This provides increased turbine power at lower engine speeds, resulting in a quicker boost rise. However, a small A/R also causes the flow to enter the wheel more tangentially, which reduces the ultimate flow capacity of the turbine wheel. This will tend to increase exhaust backpressure and hence reduce the engine's ability to "breathe" effectively at high RPM, adversely affecting peak engine power.

Conversely, using a larger A/R will lower exhaust gas velocity, and delay boost rise. The flow in a larger A/R housing enters the wheel in a more radial fashion, increasing the wheel's effective flow capacity, resulting in lower backpressure and better power at higher engine speeds.

When deciding between A/R options, be realistic with the intended vehicle use and use the A/R to bias the performance toward the desired powerband characteristic.

Here's a simplistic look at comparing turbine housing geometry with different applications. By comparing different turbine housing A/R, it is often possible to determine the intended use of the system.

Imagine two 3.5L engines both using GT30R turbochargers. The only difference between the two engines is a different turbine housing A/R; otherwise the two engines are identical:
1. Engine #1 has turbine housing with an A/R of 0.63
2. Engine #2 has a turbine housing with an A/R of 1.06.

What can we infer about the intended use and the turbocharger matching for each engine?

Engine#1: This engine is using a smaller A/R turbine housing (0.63) thus biased more towards low-end torque and optimal boost response. Many would describe this as being more "fun" to drive on the street, as normal daily driving habits tend to favor transient response. However, at higher engine speeds, this smaller A/R housing will result in high backpressure, which can result in a loss of top end power. This type of engine performance is desirable for street applications where the low speed boost response and transient conditions are more important than top end power.

Engine #2: This engine is using a larger A/R turbine housing (1.06) and is biased towards peak horsepower, while sacrificing transient response and torque at very low engine speeds. The larger A/R turbine housing will continue to minimize backpressure at high rpm, to the benefit of engine peak power. On the other hand, this will also raise the engine speed at which the turbo can provide boost, increasing time to boost. The performance of Engine #2 is more desirable for racing applications than Engine #1 where the engine will be operating at high engine speeds most of the time."

I wouldn't choose a housing with too big of an a/r at the risk of adding too much lag....unless, of course, you used Nitrous or had a 2.4 stroker.

 

[Boosted98gsx]

you're going to see more of a benefit dumping some race gas in that thing and upping the boost to 28-30psi than changing the manifold / turbine housing of the turbo. You're on the frontside of it's boost / airflow graph.

 

[dwdsm]

you're going to see more of a benefit dumping some race gas in that thing and upping the boost to 28-30psi than changing the manifold / turbine housing of the turbo. You're on the frontside of it's boost / airflow graph.

Your right but I want to squeak out the best pump gas car I can. If I did anything I'd do meth injection.. I don't know I'll think about it would the little timing and possible higher air/fuel be worth the 185 bucks for the housing? I should of just went with the FP3052 in the first place and I wouldn't have this problem.

 

[dwdsm]

The a/r greatly effects how the turbo spools as well as it's flow characteristic.

Garrett has a good writeup to help describe a/r:

"Turbine A/R - Turbine performance is greatly affected by changing the A/R of the housing, as it is used to adjust the flow capacity of the turbine. Using a smaller A/R will increase the exhaust gas velocity into the turbine wheel. This provides increased turbine power at lower engine speeds, resulting in a quicker boost rise. However, a small A/R also causes the flow to enter the wheel more tangentially, which reduces the ultimate flow capacity of the turbine wheel. This will tend to increase exhaust backpressure and hence reduce the engine's ability to "breathe" effectively at high RPM, adversely affecting peak engine power.

Conversely, using a larger A/R will lower exhaust gas velocity, and delay boost rise. The flow in a larger A/R housing enters the wheel in a more radial fashion, increasing the wheel's effective flow capacity, resulting in lower backpressure and better power at higher engine speeds.

When deciding between A/R options, be realistic with the intended vehicle use and use the A/R to bias the performance toward the desired powerband characteristic.

Here's a simplistic look at comparing turbine housing geometry with different applications. By comparing different turbine housing A/R, it is often possible to determine the intended use of the system.

Imagine two 3.5L engines both using GT30R turbochargers. The only difference between the two engines is a different turbine housing A/R; otherwise the two engines are identical:
1. Engine #1 has turbine housing with an A/R of 0.63
2. Engine #2 has a turbine housing with an A/R of 1.06.

What can we infer about the intended use and the turbocharger matching for each engine?

Engine#1: This engine is using a smaller A/R turbine housing (0.63) thus biased more towards low-end torque and optimal boost response. Many would describe this as being more "fun" to drive on the street, as normal daily driving habits tend to favor transient response. However, at higher engine speeds, this smaller A/R housing will result in high backpressure, which can result in a loss of top end power. This type of engine performance is desirable for street applications where the low speed boost response and transient conditions are more important than top end power.

Engine #2: This engine is using a larger A/R turbine housing (1.06) and is biased towards peak horsepower, while sacrificing transient response and torque at very low engine speeds. The larger A/R turbine housing will continue to minimize backpressure at high rpm, to the benefit of engine peak power. On the other hand, this will also raise the engine speed at which the turbo can provide boost, increasing time to boost. The performance of Engine #2 is more desirable for racing applications than Engine #1 where the engine will be operating at high engine speeds most of the time."

I wouldn't choose a housing with too big of an a/r at the risk of adding too much lag....unless, of course, you used Nitrous or had a 2.4 stroker.

I understood this and that is why I wouldn't change the a/r only the housing make. The volute is the shape of the housing and the Mitsu flow is much more disrupted due to the shape it has. A garrett has a complete volute allowing for faster flow/more efficiency.

 

[daren_p]

Your right but I want to squeak out the best pump gas car I can. If I did anything I'd do meth injection.. I don't know I'll think about it would the little timing and possible higher air/fuel be worth the 185 bucks for the housing? I should of just went with the FP3052 in the first place and I wouldn't have this problem.

Hey Dave, I was just checking your dyno numbers & saw that our graphs look very similar (just went to the dyno tonight, will get the graph posted when I have a chance). I run the 3052 & at 24 psi I hit 408.5 whp & 351.5 ft/lbs (didn't do any tuning, just did 3 pulls to see what my street/pump tune was at). It looks like your running a SMIM & Comp 200 cams, so you should have an advantage over me there as I'm running an evoIII IM & FP1X cams (designed for mid range power). I would assume my better flowing turbine housing is helping me make up the difference vs your better flowing intake components. Your top end hp curve looks very similar to mine, so it seems as though replacing your current Mitsu style housing may help, with your "pump gas" goals (unless you have something else restricting your flow).

 

[dwdsm]

Hey Dave, I was just checking your dyno numbers & saw that our graphs look very similar (just went to the dyno tonight, will get the graph posted when I have a chance). I run the 3052 & at 24 psi I hit 408.5 whp & 351.5 ft/lbs (didn't do any tuning, just did 3 pulls to see what my street/pump tune was at). It looks like your running a SMIM & Comp 200 cams, so you should have an advantage over me there as I'm running an evoIII IM & FP1X cams (designed for mid range power). I would assume my better flowing turbine housing is helping me make up the difference vs your better flowing intake components. Your top end hp curve looks very similar to mine, so it seems as though replacing your current Mitsu style housing may help, with your "pump gas" goals (unless you have something else restricting your flow).

Thanks for your info. Those numbers are before the larger injectors, driveshaft, SMIM street mani, and 2 psi. I have No restrictions at all. I am huge about efficiency . Do you have link? If so how many lbs. per min are you flowing?

 

[daren_p]

Thanks for your info. Those numbers are before the larger injectors, driveshaft, SMIM street mani, and 2 psi. I have No restrictions at all. I am huge about efficiency . Do you have link? If so how many lbs. per min are you flowing?

If thats the case, it would be interesting to see what the SMIM has done to your top end curve. If your all about having no restrictions, then I think ditching the Mitsu style turbine housing, with the non symetrical volute is a good idea

For that dyno run I was just slightly under the 24 psi mark, but close enough. The first run was the only one I got a log of, which resulted in 407 whp & was flowing 44lb/min. With this boost level I usually see 44-45lb/min on the street. At the track with a couple more psi, I have seen 47-48lb/min. I still have some restrictions though, I'm running a CAT (though 3" HF), my cams are designed for mid range power, not top end & the rest of the head is stock 2g, as far as flow is concerned. What kind of flow are you seeing currently & at what boost level?

 

[dwdsm]

If thats the case, it would be interesting to see what the SMIM has done to your top end curve. If your all about having no restrictions, then I think ditching the Mitsu style turbine housing, with the non symetrical volute is a good idea

For that dyno run I was just slightly under the 24 psi mark, but close enough. The first run was the only one I got a log of, which resulted in 407 whp & was flowing 44lb/min. With this boost level I usually see 44-45lb/min on the street. At the track with a couple more psi, I have seen 47-48lb/min. I still have some restrictions though, I'm running a CAT (though 3" HF), my cams are designed for mid range power, not top end & the rest of the head is stock 2g, as far as flow is concerned. What kind of flow are you seeing currently & at what boost level?

Interesting... I flow 45lbs per min. currently. I flowed 42-43 (i can't recall) on the dyno. All on pump. Is your car fwd? that would also account for some power. My head is a stock 1G. I don't think the mani will effect the top end to much considering it's the street version. i'll try to get on the dyno by the end of the year and let you know.

 

[daren_p]

Yes, I am fwd. With switching to a SMIM (even a street version), with a well matched setup, I've seen some pretty nice airflow gains in the upper rpms when looking through DSMLink logs. I'm wondering, looks like your running an RSR exhaust? Have you ever checked the resonator internally? I thought my 3" Apexi N1 system was a great flowing system, till I had a custom 3" system made. I picked up 4-5 lb/min in top end airflow. The issue was the resonator on the N1 system necked down to probably 2" or abit less internally, which was obviously hurting airflow. DSMLink logs also showed 40-50 hp & ft/lbs increase at 7000 rpms, tested with the same boost, same conditions on the same stretch of road.