So I had a little trouble with my dealer, I was going to get an 09 Cobalt SS but they came at me with different numbers than we originally talked about so...

I am going to build my engine and do a turbo swap.

I was looking through the threads and found some people say one thing about a turbo and some say different, so I am not too sure which way I want to go. My internals with be fully build and I am looking for around 400HP.

I did some selection software to get a base line turbo but not cetain on what to use. I need to get a Garrett because my father works for them and can get a hook up.

GT35R?
T3 50 trim?
A twin scroll turbo? (dont know a selection)

I know what and how a turbo works, I just dont know how to select one.

 

GT28 would be really all you need. You can string that out and make 400 whp. Also, a lot of people really like the mitsubishi s20g that hahn offers. I'm running on a 57 trim compressor .63 ar exhaust housing and it spools pretty quick, you might be better off getting a .53 a/r exhaust housing though for better spool time.

Just my opinion. Make your own educated decision.

 

I have been looking thru the GT28's and cant find a .53 a/r. I found .60 62 trim, .60 52 trim, and .42 55 trim.

 

Anyone else?

 

Personally, my goal is 400whp and I'm going with the Hahn kit. I agree with Sentry tho, you don't need bigger than the GT28. 400whp is very acheivable with our cars as long as you go with a custom toon, but don't get more turbo than you need.

 

3071r .

 

That is actually a good one, there is a lot more to get out of this on too. The Air flow/pressure ratio graph is graph for my set up.

A lot of the GT28's either go over the surge point or are a .60 a/r.

 

I have a new GT-2876r turbo for sale

 

I would jump on that if I didnt get a hook up through Garrett. But is that a .70 a/r, 48 trim? I was looking at that the other day, but I dont know if I want .70 a/r. Unless I was lookinga at a different one, or not remembering it correctly.

Thanks tho. If anything changes I will let you know.

 

Ok so I am thinking of this for the build, let me know if there is something that should not be or I can add, or just comments.

Before anyone says why do custom parts, my father knows a lot of people in the race industry that can help us, if needed, in making parts. We have fabricated a lot of parts for different vehicles (i.e. headers, intakes, brackets, etc.)

This build is going to be my father and I working together and making one hell of a car

9.5:1 Diamond Forged pistons
Total seal rings
Crower 4340 Rods (possibly eagle)
Windage Tray
Garrett GT3071R Turbo, 56 trim, .50 a/r
Custom 3" intake and 3" charge piping
600 HP Intercooler (24x12x3: 3" inlet and outlet)
Custom Intake manifold
ARP Head Studs
Comic Multi Layered Head Gasket
Custom Turbo Manifold
Injectors (dont know size I have 60#'s not sure if they will be enough)
Colder Plugs (necessary?)
Psychotuned (still have to talk to him)
Custom 3", high flow catted, turbo back exhaust (not sure on brand, might add a few resonators, haha)
Cams (dont know on size yet, talking to someone on grind)
Ported head
SS valves
Springs (what #? 78?)

 

Will 60# injectors be enough for this build?

 

For the 400 hp goal, my math came to 62.5 lb/hr at 80% Duty Cycle. You still have some room to bump up the flow, by increasing the fuel pressure to get the target of 62.5lb/hr. But overall you should be alright, no need for the bigger injectors.

Which ported/polished head are you going with? Do you have the flow chart for it? If so I can help you get some numbers for a cam made for that head to optimize air flow.

 

my Gt30 gets to full spool at 4100rpm. Just a heads up.

 

We have a guy here in AZ that will do the heads for me. I have to talk to him more about it.

Do you have the T3 or T4 housing? And do you like it? Pro's? Con's?

 

how things have changed

 

my calculation requires 80# injectors for 400 crank horsepower.

 

Haha you know it.

I did end up getting 80#'s. Also did a GT3076R turbo. Got a good deal on it.

New List:

Custom grind cams
78# Supertech Springs
Mid ported head
80# Injectors
Diamond w/ total seal
Pauter forged Rods
Cometic Head Gasket
ARP head studs
GT3076R
600 HP intercooler
Vulcan tubular header
Tial 38mm wastegate
Universal boost tubing
Custom in fender intake
Stock M62 pulley
Tuned by me

Probably missing things.

 

good choice on the 80lbs u will need them

 

A is just about perfect for this motor and 400whp. The 35R is a bit out of it's efficiency range there and a gt28 is way out on the other side.

 

or an m62 and smaller turbo

 

New List:

Custom grind cams
78# Supertech Springs
Mid ported head
80# Injectors
Diamond w/ total seal
Pauter forged Rods
Cometic Head Gasket
ARP head studs
GT3076R
600 HP intercooler
Vulcan tubular header
Tial 38mm wastegate
Universal boost tubing
Custom in fender intake
Stock M62 pulley
Tuned by me

Darton sleeves

^Forgot that^

Yah I didnt want to deal with running out of fuel. So I just bought them since I had to take them out to pull the motor.

I just did want to wait for the 35R to spool. Since I sleeved it I would not have cared if it was higher than 400.

Plus with the GT30r if I go E85 then I will squeeze some little above 400 HP out of it on a mild tune.