Recommend me a turbo!
01-25-2011 | 01:49 AM
#1
Recommend me a turbo! Hey guys,
I'm getting ready to start my turbo build (finally) and am picking up my hotside (truck mani kit) on thursday. I'll be running a 38mm wastegate and I have a T4 flange.
Other specs are as follows:
Stock bottom end
TEA stg 2.5 5.3 heads (may swap out for 317s)
TSP 228r cam
LS6 intake
6spd tranny (when it ***** out, I'll be putting in a TH400)
Dual walbros and 60lb injectors
MWC 9" (3.90s right now, will be swapping for 3.25s or 3.08s)
Anything I'm forgetting?
I was thinking a TC76 but I'm not sure what A/R I should run or other specifics. Help me out
I'm getting ready to start my turbo build (finally) and am picking up my hotside (truck mani kit) on thursday. I'll be running a 38mm wastegate and I have a T4 flange.
Other specs are as follows:
Stock bottom end
TEA stg 2.5 5.3 heads (may swap out for 317s)
TSP 228r cam
LS6 intake
6spd tranny (when it ***** out, I'll be putting in a TH400)
Dual walbros and 60lb injectors
MWC 9" (3.90s right now, will be swapping for 3.25s or 3.08s)
Anything I'm forgetting?
I was thinking a TC76 but I'm not sure what A/R I should run or other specifics. Help me out
01-25-2011 | 01:54 AM
#2
A 76mm would be fine as far as a backside i would go with a .96 as any smaller will most likely choke up top!
I would deff. swap to 317 heads if i were you i'd swap out that cam as well for a LS6 cam but thats just me goodluck!
I would deff. swap to 317 heads if i were you i'd swap out that cam as well for a LS6 cam but thats just me goodluck!
01-25-2011 | 01:57 AM
#3
I think I'm gonna leave the cam alone, I know it's not the BEST, but it won't be bad. Might as well do a 317 swap, they're better for boost and I can sell my heads for a decent price.
01-25-2011 | 02:04 AM
#5
01-25-2011 | 02:43 PM
#7
For what he is doing, untouched manifolds will make plenty of power.
I would be more concerned about the small wastegate on a stock bottom end. The 38mm may only be able to control the boost down to 8-11lbs.
TC76 with a .96 A/R would be a good choice, along with any 76-78mm T4 turbo with a .96 exhaust housing.
You still need to spec out your cold side with a bov as well. Plus you still need to either tune it with the maf, or SD.
I would be more concerned about the small wastegate on a stock bottom end. The 38mm may only be able to control the boost down to 8-11lbs.
TC76 with a .96 A/R would be a good choice, along with any 76-78mm T4 turbo with a .96 exhaust housing.
You still need to spec out your cold side with a bov as well. Plus you still need to either tune it with the maf, or SD.
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01-25-2011 | 04:55 PM
#9
For what he is doing, untouched manifolds will make plenty of power.
I would be more concerned about the small wastegate on a stock bottom end. The 38mm may only be able to control the boost down to 8-11lbs.
TC76 with a .96 A/R would be a good choice, along with any 76-78mm T4 turbo with a .96 exhaust housing.
You still need to spec out your cold side with a bov as well. Plus you still need to either tune it with the maf, or SD.
I would be more concerned about the small wastegate on a stock bottom end. The 38mm may only be able to control the boost down to 8-11lbs.
TC76 with a .96 A/R would be a good choice, along with any 76-78mm T4 turbo with a .96 exhaust housing.
You still need to spec out your cold side with a bov as well. Plus you still need to either tune it with the maf, or SD.
01-25-2011 | 07:01 PM
#10
****, if i could do it over again, (i guess i could) for this street machine, i wouldve went with a 2" cross over myself.
TC unit is small and easy to package. Im with phil on free mods as well
TC unit is small and easy to package. Im with phil on free mods as well
01-25-2011 | 07:17 PM
#13
Sure it will work but a free mod is a free mod. It doesn't cost anything to touch up the headers assuming you have a die grinder which almost everyone should have if they are doing their install. Truck manifolds combined with a 2" crossover would be a nice combination for a street car. You dont really need a 2.5" crossover at that power level.
I've noticed you comment on crossover size a couple of times. Would a 2.5" hurt performance somehow? Just curious, I have 2 cars running tc76's.
01-25-2011 | 07:59 PM
#15
Turbos are all about velocity. We run a 2.5" crossover on my setup and make over 2000hp. The pipe size was determined with a calculator, for a 346" making 15# of boost targeting 600-650hp, 2" would work fantastic. With turbos its all about velocity, you could probably drop down to a 2" crossover and quite possibly increase your turbine A/R and still spool faster.
01-25-2011 | 08:05 PM
#16
Your tube size determines airflow velocity, the larger the tube the more airflow required to reach your turbine drive pressure and the longer the air has to cool down. A properly sized system works wonders. If I build a basic 346" shooting for less than 700hp, it would have 1.5" header tubes and 2" crossover.
You got 2 motors, 346" and 427", everyone still seems to think you need to run 1 3/4" and 2.5" on a 346 but thats what alot of people run on the big motors.
Whats a standard AFR 205 exhaust port, 1.44 x 1.60?
01-25-2011 | 09:03 PM
#18
Do dual 2" with a quality merge and a single 2.75" going to the turbo, it will be more than enough to make 800hp if not more. The airflow numbers show room for growth...At a 346" with 30# of boost(1100hp) and 92% ve is when you probably need to step up the tube size.
01-26-2011 | 11:14 AM
#19
Quoted from another thread...
hey phil, you nailed it again...! I finished the new 2" cold side and it made a BIG difference....power, spool and even with drivability on tip in. Just to recap what i've done the past month, i fabbed an entirely new hot and cold side twin rear mount system and relocated the turbo's up and in for better ground clearence/straighter shot. I had a twin STS system before the changes and it worked well for what it was (683rwhp at 14 pounds). I changed the hot side from dual 2.5" all the way to the turbo's to dual 2.25" and then stepped down to 2" just before the turbo's. I also installed larger housings at the same time, went to t3 .82's from .63's. The hot side change made for quicker spool with less backpressure (with larger exh housings). Then I changed the cold side from dual 1.75" to dual 2" and also shortened the cold side piping at least four feet per side. With the new system, it transformed the car!! I played a bit on the way to work this morning and it is stupid fast now (relative term)! It comes in quicker and much harder versus the STS system. I will try to take some pics tonight to show my new system. This weekend I'll do a backpressure test and update with results. p.s.... i moved my hp goal up to 900+rwhp!! I think i'm there now under higher boost (22 - 24 pounds or so). Boost is so addictive......Thanks for all of the help!
01-26-2011 | 05:02 PM
#20
good info... so 2 inch on the crossover
and keep the cold side small too? or 3 in about the norm for cold side?
i plan to do a shorty style on driver with cross over to the pass with a log to the turbo..
and keep the cold side small too? or 3 in about the norm for cold side?
i plan to do a shorty style on driver with cross over to the pass with a log to the turbo..