What boost PSI should I be seeing.
#41
Also remember that boost doesn't create power but fuel does. It the boost that keeps the EGT's in check.
HY35W turbo are limited to 30 PSI because of the 9cm2 housing.
HX35W turbo are limited to 35 PSI because of the 12cm2 housing.
Even at these extremes these 2 turbos you pushing the limits of efficiency.
But remember 99% of us are daily drivers so that's fine for short kick in the pants to pass another vehicle but for the 1% that are drag racing you'll need another turbo. difference being is daily driver rarely uses the upper band of the turbo where a drag race always uses the upper band of the turbo.
HY35W turbo are limited to 30 PSI because of the 9cm2 housing.
HX35W turbo are limited to 35 PSI because of the 12cm2 housing.
Even at these extremes these 2 turbos you pushing the limits of efficiency.
But remember 99% of us are daily drivers so that's fine for short kick in the pants to pass another vehicle but for the 1% that are drag racing you'll need another turbo. difference being is daily driver rarely uses the upper band of the turbo where a drag race always uses the upper band of the turbo.
#42
Also remember that boost doesn't create power but fuel does. It the boost that keeps the EGT's in check.
HY35W turbo are limited to 30 PSI because of the 9cm2 housing.
HX35W turbo are limited to 35 PSI because of the 12cm2 housing.
Even at these extremes these 2 turbos you pushing the limits of efficiency.
But remember 99% of us are daily drivers so that's fine for short kick in the pants to pass another vehicle but for the 1% that are drag racing you'll need another turbo. difference being is daily driver rarely uses the upper band of the turbo where a drag race always uses the upper band of the turbo.
HY35W turbo are limited to 30 PSI because of the 9cm2 housing.
HX35W turbo are limited to 35 PSI because of the 12cm2 housing.
Even at these extremes these 2 turbos you pushing the limits of efficiency.
But remember 99% of us are daily drivers so that's fine for short kick in the pants to pass another vehicle but for the 1% that are drag racing you'll need another turbo. difference being is daily driver rarely uses the upper band of the turbo where a drag race always uses the upper band of the turbo.
#43
Let's say I got back from Ontario, OR with my RV and my 02 Dodge towed like a dream over 6-7% grades and no issues with EGT's at all. As long as you drive like a truck driver and not a race car. You'll get excellent performance from the turbo. Like going over 6-7% grade drop from 5th gear to 4th gear and kick the RPM's up to 2,000-2,100 RPM which is roughly 55 MPH and I'm walking around full load semi's just slightly fast than they move. Still did awesome. EGT's max'ed out at 1,100*F and about 25-30 PSI of boost and even engine temp only got to 197*F at the most.
#44
no they are most efficient at about 3.5 Pressure ratio
at sea level 3.5PR* 14.7psi =51.5 - absolute pressure of 14.7= 36.8 PSI
Assuming at 4500ft 3.5PR* 12.5 = 43.7 - absolute pressure of 12.5= 31.3 PSI
If you go higher in boost you are less efficient, hotter, and more restrictive, and you normally have to restrict your exhaust by lessening flow from the wastegate increasing back pressure (which takes more power to overcome.
The turbine wheel is about 60mm or 2.4" opening at the wheel, and of that you have the wheel and a 7mm shaft which further restrict the opening even further to under 2".
One could increase boost by putting on a 2" exhaust but there is no reason to do that, but people make a decision to block off the waste gate and do just that.
#47
I read it, I appreciate all the tech info I am receiving. I originally started this thread to see If my Boost was to low, which apparently it is. Then it went to a lot of guys posting how much boost they have with a modded motor. Mine is stock, and apparently I have a major boost leak. I just haven't had a chance to make myself a pressure tester yet.
#48
no they are most efficient at about 3.5 Pressure ratio
at sea level 3.5PR* 14.7psi =51.5 - absolute pressure of 14.7= 36.8 PSI
Assuming at 4500ft 3.5PR* 12.5 = 43.7 - absolute pressure of 12.5= 31.3 PSI
If you go higher in boost you are less efficient, hotter, and more restrictive, and you normally have to restrict your exhaust by lessening flow from the wastegate increasing back pressure (which takes more power to overcome.
The turbine wheel is about 60mm or 2.4" opening at the wheel, and of that you have the wheel and a 7mm shaft which further restrict the opening even further to under 2".
One could increase boost by putting on a 2" exhaust but there is no reason to do that, but people make a decision to block off the waste gate and do just that.
at sea level 3.5PR* 14.7psi =51.5 - absolute pressure of 14.7= 36.8 PSI
Assuming at 4500ft 3.5PR* 12.5 = 43.7 - absolute pressure of 12.5= 31.3 PSI
If you go higher in boost you are less efficient, hotter, and more restrictive, and you normally have to restrict your exhaust by lessening flow from the wastegate increasing back pressure (which takes more power to overcome.
The turbine wheel is about 60mm or 2.4" opening at the wheel, and of that you have the wheel and a 7mm shaft which further restrict the opening even further to under 2".
One could increase boost by putting on a 2" exhaust but there is no reason to do that, but people make a decision to block off the waste gate and do just that.
Thread
Thread Starter
Forum
Replies
Last Post
offroad00
12 Valve 2nd Gen Dodge Cummins 94-98
24
10-23-2014 03:28 PM