How Do you size Twins Correctly?

[Philly#1 Lex]

Just wondering. I understand How to read compressor Maps for single turbos and How to size them correctly for my SC400 1UZ. But I dont know how to size twins using compressor maps. Looking for 500-6oowhp from a 1UZ. I dont know what Turbo's to choose. They dont have to be Garrett GT Ball Bearing Turbos, Looking for a better priced option. Trying to keep it budget as I can with the 1st Setup. Thanks

 

[Lextreme II]

Tell us your budget and power range.

 

[Philly#1 Lex]

Trying to spend 800-1500 for turbos. I know I can just go after a Garrett GT40 non-ball bearing for about 800-900, But I wanted to see my twin options. Looked at turbonetics T60-1's but they are about 750 a piece for new ones on ebay. And are quite difficult to come across used. Looking for a used turbo for the first setup. And I would also like to find something with a T4 Turbine side. My power levels are between 450-600rwhp. I want my SC400 to run low 12's - mid 11's. I have already been planning on all my other pieces trying to get up and running for about 5000-7000. Selling my skyline for this project. So could someone help me pick turbos. Are there any T3/T4 hybrid options? Thanks in advance.

 

[Lextreme II]

If single I would choose GT35R. Its smaller then GT40 and it will also provide the HP you needed. If twin I would recommend GT28RS with .64 A/R. Each GT28RS is rated at 350 hp. Remember ball bearing turbos are physically larger and fitmanship might be a problem. The GT40 compressor is little too big from my personal experience. If i have money i would go with Twin GT28RS, but looks like i would have to go with Garrett T3/4 Hybrid with 60 Trim. The standard bearings are half of the price.

 

[Philly#1 Lex]

What about a Garrett T04B/ Vtrim. V-trim turbos support up to 450hp a piece. Very afforable as well. Come with T4 Turbine as well. My question is that the A/R ratio is 1.15 on exhaust side and .60 on the compressor side. How quick will my spool up be? A little bit of lag is ok for me. Also when I look at the compressor map I am confused. With a airflow chart my pal gave me and using lextreme VE numbers the 1UZ should be flowing at around 90% from the Factory. I plan on running 15psi. Theorectically the 1UZ should be flowing 36-45lbs of air between 4000-5000 (Torque Peak) and 45-54lbs of air between 5000-6000 (Horsepower Peak) with the 6300 stock redline. I then use these numbers to plot points on a compressor map to see if its a good turbo for my needs. Looking at the maps on the T04B/Vtrim for example. Seems like the 1UZ will go off the map at around HP Peak. And that Torches turbos when you go off the map correct? To the Left is Surging and the right is Torching Your turbo? Is it different since I plan on running a twin setup in this scenario? If this are good please let me know. And school me if I am wrong in my calculations. Thank You.

 

[vvega]

t70
goes right up the middle of the compressor map

v

 

[stevechumo]

What about a Garrett T04B/ Vtrim. V-trim turbos support up to 450hp a piece. Very afforable as well. Come with T4 Turbine as well. My question is that the A/R ratio is 1.15 on exhaust side and .60 on the compressor side. How quick will my spool up be? A little bit of lag is ok for me. Also when I look at the compressor map I am confused. With a airflow chart my pal gave me and using lextreme VE numbers the 1UZ should be flowing at around 90% from the Factory. I plan on running 15psi. Theorectically the 1UZ should be flowing 36-45lbs of air between 4000-5000 (Torque Peak) and 45-54lbs of air between 5000-6000 (Horsepower Peak) with the 6300 stock redline. I then use these numbers to plot points on a compressor map to see if its a good turbo for my needs. Looking at the maps on the T04B/Vtrim for example. Seems like the 1UZ will go off the map at around HP Peak. And that Torches turbos when you go off the map correct? To the Left is Surging and the right is Torching Your turbo? Is it different since I plan on running a twin setup in this scenario? If this are good please let me know. And school me if I am wrong in my calculations. Thank You.

Check for matching within 70% efficiency of the map. It's usually the island in the middle.

 

[autronic]

Philly#1 Lex:

With twin turbo on the 1UZFE engine, each turbo will be working against a 2.0 liter 4 cylinder engine.

The Garrett T04B V-trim will do the job on the compressor side. The T4 P-trim with A/R 1.15 is to big.
If you intend to use a P-trim a A/R .50 -.60 will be big enough.

2 Turbonetics T04E 50-trim compressors with T3 Stage 3 and A/R .63 exhaust would be my weapons
of choice.

 

[Philly#1 Lex]

Garrett T3/T04E Super 57 trim wheel .60 A/R Compressor & .63 A/R seem to be the best cheap option. 1UZ seems to hit right in the middle on the compressor map. Hard to find used though. Anyone reccommend any more budget turbos for a twin setup. Also How would you calculation how much est. power you would be making on this setup. Do you multiple the lbs of air on the bottom of the compressor map and then add it to you factory horsepower. Like for instance @ the 1UZ HP Peak of 5600 stock it makes 250hp* with theTurbo mentioned above it will be flowing somewhere around 28lbs per min * 10, So each turbo would be making around 280*2 = 560hp. Do you add 560hp to your stock 250 or down you calculate it differently? Thanks Guys.

 

[Philly#1 Lex]

P.S those calculation where made @ 15 psi

 

[autronic]

What the flowmap shows, in this case 28lbs per min, is what the turbo flows at that boost.
So the 28lbs per min multiplied with "10" gives roughly 280 hp.

The "Garrett T3/T04E Super 57 trim wheel .60 A/R Compressor & .63 A/R", sounds to be
from an ebay auction for a TurboXS turbo ?

 

[Philly#1 Lex]

http://www.turbocalculator.com/map-t04e.php?img=t04e-s57&turbo=Garrett%20T04E%20Super%2057%20Trim

not a xs power but a legit garrett. its also on turbbygarrett.com turbo list. look at the map.

 

[Lextreme II]

I looked at the Garrett T04B V-trim but i prefer T3 style turbine inlet for pact fitting. However, the V-Trim only have 1.00 A/R with external wastegate. For my application i would prefer Garrett T04B V-trim with .63 A/R with Internal wastegate.