Reply With QuoteCorrect me if I am wrong,
Waste gates go on the exhaust side
blow off valves go on the intake side
should I be using both for proper performance
Hipshot
The Turbonetics Super-T series would be good for all out competition but, depending on the A/R of the turbines I doubt they would be good at all for anything else assuming you are going a duel setup on a 572. Make sure you check the trim; if the A/R is greater than .81 you may want to reconsider. Also for low gas flow rates on the compressor side (modest boating around) you would probably be really close to the stall area of the compressor (very bad). I have a pair of turbonnetics 62-1's (quite a bit smaller than the Super-T's) with a .81 A/R (P/N 10996) on a 472 Hemi and they stay spooled nicely right off idle. Also, the wastegates start stepping in at 4800 RPM at WOT when set for 18 PSIG so there is plenty of room on top should I decide to go there. The Super-T's have a big compressor so it takes a lot to get it turning.
Again, it's all what you are building the engine for. I recomend you visit the Turbonetics web site (Turbonetics (http://turboneticsinc.com)); they have all of their compressor maps, and a sizing sheet there. Lastly, call them - good knowledgeable people.
Correct me if I am wrong,
Waste gates go on the exhaust side
blow off valves go on the intake side
should I be using both for proper performance
unchained,
You saw this stealth at Phoenix. I was there Friday and was talking to Tom Papp about my buddies Cheyene. My buddy lives in Surprise. We took the Cheyene to Parker. I know there is more in this thing. Tom Papp is working on the ride plate and intake for it now. Here is a pic of the 420 lb stealth Gen III. That thing is sweet. I got back to CT. and it was 27 degrees and we had snow Thanksgiving eve.
http://www.tjsperformance.com/images/tpstealth.jpg
T.J.
www.tjsperformance.com
I took another look at twin turbos on a 572 and came up with 56 lb/min a pressure ratio of 2.68 at 5500 RPM and 36 lb/min at a pressure ratio of 1.22 at 3000 RPM (reasonable extream pleasure boating factors inputted) and definately you are off the curve for the Super-T series and marginaly on the curve for the large T series Turbonetics turbos. A single Super-T would be great for weekend boating. See the below calc results then compare to the maps that Turbonetics post.
Secondly, at the upper RPM areas you will need 89 LB/HR injectors if using 8 which will probably result in idle pulse width problems and very rich idle issues. You will probably need to step up to a 12 or 16 injector setup with smaller flow rate injectors.
Engine Air Flow / Compressor Sizing Calculations at 5500
Air Properties
Molecular weight 29.00
Z 1.00
k-1/k 0.288
Engine Data
engine rpm 5500 revs/min
displacement 572.0 cu inch
volumetric efficiency 75%
number of turbos 2
compressor efficiency 65%
Ambient Conditions
local baro pressure 29.92 in Hg 14.70 psia
ambient temp 85 deg F
Conditions at Compressor Inlet
Vacuum drawn at inlet 2.0 in Hg
Inlet Pressure 13.71 psia
Inlet density 0.068 lb/ft3
Conditions at Compressor Outlet
outlet pres 22.0 psig
outlet temp 359.6 deg F
P2/P1 2.68
outlet density 0.121 lb/ft3
Conditions at Intercooler Outlet
manifold pres 19.0 psig
manifold temp 110.0 deg F
manifold density 0.160 lb/ft3
IC pressure drop 3.0 psi
Results, mass and volume flows
compressor air flow 72.8 lb/min, ideal
compressor air flow 54.6 lb/min, actual
compressor air flow 412.6 gm/sec, actual
total engine air flow 825.2 gm/sec, actual
compressor air flow 802.0 ACFM, actual inlet
compressor air flow 450.8 ACFM, actual outlet
Data for use with Turbonetics curves
pressure correction 0.983
temperature correction 1.000
corrected suction flow 55.5 lb/min
Pressure ratio 2.68
Fuel Injector Sizing Calculations
No. of injectors 8
Desired duty cycle 80%
A/F ratio 11.5 :1
fuel specific gravity 0.735
fuel required 9.49 lb/min
fuel required 92.9 gal/hr
Injector size req'd 89.0 lb/hr
engine hp potential 813.6 hp @ BSFC=0.7
engine hp potential 949.2 hp @ BSFC=0.6
engine hp potential 1139.0 hp @ BSFC=0.5
Turbine Performance / Exhaust Pressure Calculations
Compressor Head and Horsepower req'd
polytropic factor 0.4431 (n-1)/n
head req'd 35,799 ft
horsepower req'd 91.1 hp required to drive compressor
Exhaust Properties
EGT 1600 deg F
exhaust MW 28.36
(k-1)/k 0.222
Exhaust flow 59.32 lb/min
% bypassed to WG 30.0% of total to wastegate
Flow thru turbine 41.53 lb/min
Turbine Power Recovery
isentropic efficiency 80%
mechanical efficiency 99%
hp delivered 91.1 hp
Pres. ratio req'd 2.46 inlet/outlet pressure
post turbine EGT 1302 deg F
Exhaust Pressures
TOP 5.0 psig, turbine outlet pressure
TIP 33.7 psig, turbine inlet pressure / exhaust backpressur
TIP/boost 1.53
Pipe Velocity Calculations
Compressor Inlet Pipe 3.0 inch inside diameter
Inlet Pipe Velocity 272.3 ft/sec
Compressor Outlet Pipe 3.0 inch inside diameter
Outlet Pipe Velocity 153.1 ft/sec
IC Outlet Pipe 2.5 inch inside diameter
Up Pipe Velocity 333.8 ft/sec
__________________________________________________ ____________
Engine Air Flow / Compressor Sizing Calculations 3000 RPM
Air Properties
Molecular weight 29.00
Z 1.00
k-1/k 0.288
Engine Data
engine rpm 3000 revs/min
displacement 572.0 cu inch
volumetric efficiency 90%
number of turbos 2
compressor efficiency 65%
Ambient Conditions
local baro pressure 29.92 in Hg 14.70 psia
ambient temp 85 deg F
Conditions at Compressor Inlet
Vacuum drawn at inlet 2.0 in Hg
Inlet Pressure 13.71 psia
Inlet density 0.068 lb/ft3
Conditions at Compressor Outlet
outlet pres 2.0 psig
outlet temp 133.9 deg F
P2/P1 1.22
outlet density 0.076 lb/ft3
Conditions at Intercooler Outlet
manifold pres 19.0 psig
manifold temp 110.0 deg F
manifold density 0.160 lb/ft3
IC pressure drop -17.0 psi
Results, mass and volume flow
compressor air flow 39.7 lb/min, ideal
compressor air flow 35.7 lb/min, actual
compressor air flow 270.1 gm/sec, actual
total engine air flow 540.1 gm/sec, actual
compressor air flow 524.9 ACFM, actual inlet
compressor air flow 469.8 ACFM, actual outlet
Data for use with Turbonetics curves
pressure correction 0.983
temperature correction 1.000
corrected suction flow 36.3 lb/min
Pressure ratio 1.22
Fuel Injector Sizing Calculations
Fuel Injectors
No. of injectors 8
Desired duty cycle 80%
A/F ratio 11.5 :1
fuel specific gravity 0.735
fuel required 6.21 lb/min
fuel required 60.8 gal/hr
Injector size req'd 58.2 lb/hr
engine hp potential 532.5 hp @ BSFC=0.7
engine hp potential 621.3 hp @ BSFC=0.6
engine hp potential 745.5 hp @ BSFC=0.5
Turbine Performance / Exhaust Pressure Calculations
Compressor Head and Horsepower req'd
polytropic factor 0.4431 (n-1)/n
head req'd 5,965 ft
horsepower req'd 9.9 hp required to drive compressor
Exhaust Properties
EGT 1600 deg F
exhaust MW 28.36
(k-1)/k 0.222
Exhaust flow 38.83 lb/min
% bypassed to WG 30.0% of total to wastegate
Flow thru turbine 27.18 lb/min
Turbine Power Recovery
isentropic efficiency 80%
mechanical efficiency 99%
hp delivered 9.9 hp
Pres. ratio req'd 1.15 inlet/outlet pressure
post turbine EGT 1550 deg F
Exhaust Pressures
TOP 5.0 psig, turbine outlet pressure
TIP 7.9 psig, turbine inlet pressure / exhaust backpressur
TIP/boost 3.96
Pipe Velocity Calculations
Compressor Inlet Pipe 3.0 inch inside diameter
Inlet Pipe Velocity 178.2 ft/sec
Compressor Outlet Pipe 3.0 inch inside diameter
Outlet Pipe Velocity 159.5 ft/sec
IC Outlet Pipe 2.5 inch inside diameter
Up Pipe Velocity 218.5 ft/sec
I have a 572 efi twin turbo motor ready to go in a boat. I am thinking on selling it. Built by gt performance. Sitting in a crate at his shop. has not been run except on the dyno. pm if your interested.
Thank you ttmott. That is just the kind of information I am looking for.
Not sure why a 572 pushing 25 lbs of boost could only turn a pump to 5500 rpm? Seems like a poor use of that sized engine. Super-T on a 572 turning an AA impeller to 6000+ rpm at 25 psi, compressor wise would be fine. The issue is squeezing a 572 through Q trim turbines. Not the optimal combination for large engines although spool up would be fast. Probably need 4 waste gates to hold pressure. The right sized GT or older TV, TA series turbos can flow much higher exhaust volumes so the overall system efficiency is better. Look for compressors that can support 75+ lb/min at 2.0 pressure ratio. If you want to pull the big pressure numbers you'll have to make sure you o-ring the heads and receiver groove the block. Big bore short stroke would not be my first choice for configuration if you want to run reasonable fuel. The larger the bore the further the flame propegation requires higher octane demand at high effective compression ratios. I turned an AA impeller to 6400 rpm with a 514 running 12 psi. I know unchained turns higher with his 540. 95 lb/hr injectors work fine all the way down to small blocks. My little 528 idles at 800 rpm nicely. Unchained is running 160 lb/hr injectors and it idles fine for a jet boat. The only system I'd double up injectors on is a constant flow (mechanical injection). I've tired running big single set injectors and they're pretty much digital. Forget about trying to run part throttle. For the best results with mechanical injection run 2:1 unvented to vented.
I live in Temple. About 30 miles south of Lawton..
Damn ... sorry to hear that bro ... that's in the middle of nowhere ... I have family in Lawton, Duncan & Marlow ... and it's just a little too "dwon home" for me ... good thing your close to Wichita Falls ...
I live in Temple. About 30 miles south of Lawton.
Do they still have that drag strip out there?
Heavyhitter
Didn't know he was turning a pump; even more of a reason to concentrate on bottom end power.
I used 5500 only to establish a scenario to compare to a compressor map. At 6500 (which is high for a rec. boat) and 25 psig boost each compressor should be flowing about 76 lb/min corrected (intercooler pressure loss not considered). 25 psig boost sets the pressure ratio to 2.89 (P1/P2); can't be 2.00. So if you look at the below map and if he is running two Super-T turbos he will be on the left of the surge line if at 25 psig and a more desired 5000 RPM, the turbos are a bit too big for a 572 not too small. Secondly, the Super-T series has a large AR's allowing more exhaust gas flow but spool up time on the turbine suffers greatly.
A far better situation is to establish a turbo such as a Turbonetics T-62 or Garrett GT 42 and set maximum boost (25 psig for argument) at just less than 5000 RPM and have the waste gates control from say 4000 rpm and up. This way the turbine will spool at lower engine RPM's making the engine far more responsive.
http://www.***boat.com/image_center/...20/1030T76.gif
I made the mistake on an early project and bought large compressors hoping to grow the engine into the large turbos over time as the cash outlay for turbos is big. The whole combination suffered until way up into RPMville when the turbos started to spin and breathe. Never could make good bottom end and midrange power. Lessons learned and passed on.
Tom
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