Towing w/ a radix
10-17-2007, 09:37 PM
#52
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Turbo guys don't require the engine to produce that extra 50 hp and use waste energy instead, that's not to say it's totally free energy because to overcome the added restrictions in the exhaust some guess around 10 hp is needed. I believe that is why Turbo guys have better fuel efficiency when towing and why most serious haulers are Turbo charged.
Wait a minute... Typically turbo engines run about a 1:1 ratio of intake manifold pressure vs. exhaust back pressure. For example: If you're running 10psi of boost it would require around 9-10psi of exhaust back pressure to spin the compressor fast enough to generate that 10psi of boost. Some systems are more efficient, some are less efficient as there are many factors involved (placement of turbo, size, turbine efficiency, etc).
Let me play devil's advocate here: If we took a naturally aspirated engine with a free flowing exhaust and raised exhaust back pressure to 10psi, do you think you are only going to lose 10hp?
If this was true then why would you need to buy an aftermarket exhaust?
10-18-2007, 01:34 PM
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10-18-2007, 03:04 PM
#56
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If torque drops at a specific RPM level, HP will also drop at that specific RPM level.
If backpressure is increased at a given RPM, torque will decrease as the level of work required to pump gases out of the cylinder will have increased.
If backpressure is increased at a given RPM, torque will decrease as the level of work required to pump gases out of the cylinder will have increased.
10-18-2007, 05:20 PM
#57
Horsepower and torque arent related??!?!?!?!? wow...
umm.. im not going to waste my breath (typing) a relevant response..... I'll just leave you with this..
HP = Torque * RPM /5252
how are they not related?
umm.. im not going to waste my breath (typing) a relevant response..... I'll just leave you with this..
HP = Torque * RPM /5252
how are they not related?
10-19-2007, 04:16 AM
#58
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From what I understand. Exhaust pressure, velocity, and heat are all good from a turbo's point of view. (If the fella had one).
From an engine stand point, backpressure Bad.
Right?
10-19-2007, 11:51 AM
#59
As backpressure or airflow increases between the engine and turbo, so does boost. More boost, more torque. As long as it isn't out of the turbo's efficiency range. Also backpressure normally creates a high velocity which helps us turbo guys build more boost, and more torque.
From what I understand. Exhaust pressure, velocity, and heat are all good from a turbo's point of view. (If the fella had one).
From an engine stand point, backpressure Bad.
Right?
From what I understand. Exhaust pressure, velocity, and heat are all good from a turbo's point of view. (If the fella had one).
From an engine stand point, backpressure Bad.
Right?
a turbo requires heat, exhaust pressure and velocity to work.. but guess what.. it takes energy away from your engine to do all of that
10-20-2007, 10:30 AM
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At 100% efficiency a turbocharger providing 101 kPa (14.7 lbf/in²) of boost would effectively double the amount of air entering the engine because the total pressure is twice atmospheric pressure. However, there are some parasitic losses due to heat, friction from bearings, aerodynamic drag from the compressor wheel, and exhaust backpressure from the turbine. Turbochargers are typically 70-85% efficient, at peak efficiency, due to having to heat the air during the compression.
The thermal efficiency, or fraction of the fuel/air energy that is converted to output power, is less with a mechanically driven supercharger than with a turbocharger, because turbochargers are using energy from the exhaust gases that would normally be wasted. For this reason, both the economy and the power of a turbocharged engine are usually better than with superchargers. The main advantage of an engine with a mechanically driven supercharger is better throttle response, as well as the ability to reach full boost pressure instantaneously. With the latest Turbo Charging technology, throttle response on turbocharged cars is nearly as good as with mechanical powered superchargers, but the existing lag time is still considered a major drawback.
I'm done, Turbos are better, get over it... 
It all comes down to what a person wants there power. Both are WAY Better than stock for towing. I just think turbos have a slight advantage in the towing department.....
