Turbo backpressure? What turbo backpressure?
04-22-2012, 01:14 AM
#1
Elite Member
Thread Starter
Join Date: Jul 2005
Posts: 6,420
Total Cats: 84
Turbo backpressure? What turbo backpressure?
I logged turbine inlet pressure and generated the plot below.
X axis is RPM
Y axis is TIP-MAP (kPa)
color is boost
The darn GT2560 operates in crossover (MAP > TIP) in most conditions below 4200 RPM, by over 1 psi. The sucker makes 5 psi of boost by like 2200 RPM BTW.
At 15 psi of boost, TIP-MAP is 5 psi at 5700 RPM and 10 psi at 6800, 12.5 psi at 7400.
BTW at 15 psi of boost, my intercooler has 1 psi of pressure drop at 5000 RPM and 2 psi at 7400.
My exhaust has 4.5 psi backpressure at peak power and probably 2 psi in the midrange (I will log this next)
X axis is RPM
Y axis is TIP-MAP (kPa)
color is boost
The darn GT2560 operates in crossover (MAP > TIP) in most conditions below 4200 RPM, by over 1 psi. The sucker makes 5 psi of boost by like 2200 RPM BTW.
At 15 psi of boost, TIP-MAP is 5 psi at 5700 RPM and 10 psi at 6800, 12.5 psi at 7400.
BTW at 15 psi of boost, my intercooler has 1 psi of pressure drop at 5000 RPM and 2 psi at 7400.
My exhaust has 4.5 psi backpressure at peak power and probably 2 psi in the midrange (I will log this next)
Reply
0
0
04-22-2012, 10:37 AM
#3
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,338
Total Cats: 573
what are your EGTs that correlate to that scatter plot?
Enthalpy drives the turbo and includes heat, pressure, and dynamic energy effects. with a hot, high volume flow rate exhaust, you'll spin that turbine.
I'm sure with VVT and some spark retard you can get more time in crossover.
Enthalpy drives the turbo and includes heat, pressure, and dynamic energy effects. with a hot, high volume flow rate exhaust, you'll spin that turbine.
I'm sure with VVT and some spark retard you can get more time in crossover.
Reply
0
0
04-22-2012, 12:20 PM
#5
Elite Member
iTrader: (1)
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 406
Very interesting.
Ive always heard that with a good turbo setup with a free flowing exhaust, that the pressure in the IM should be a bit higher than in the turbo manifold, I just never knew by how much.
Any idea what typical NA backpressure values would be?
Ive always heard that with a good turbo setup with a free flowing exhaust, that the pressure in the IM should be a bit higher than in the turbo manifold, I just never knew by how much.
Any idea what typical NA backpressure values would be?
Reply
0
0
04-22-2012, 04:56 PM
#11
I'm Miserable!
Join Date: Jun 2009
Location: albany, ga
Posts: 1,866
Total Cats: 0
looks like a shielded thermocouple.
http://www.omega.com/pptst/JTIN.html
exposed junction, k type, innconel
http://www.omega.com/pptst/JTIN.html
exposed junction, k type, innconel
Reply
0
0
U know how I know you're gay?
Thread
Thread Starter
Forum
Replies
Last Post
