What do you want for comparing supercharger ports? Equal levels of boost or equal pulleys (external)?
Eaton Supercharger Porting Comparison: Boost or Pulley
- Thread starter cobracide
- Start date
boost for boost.
I'm trying to understand the question?
PSI for PSI a car with a aftermarket lower will make more lowend torque than a upper only car, and the most likely reason is because the lighter aftermarket lower has less enertia.
I think that has something to do with the question you have presented.
PSI for PSI a car with a aftermarket lower will make more lowend torque than a upper only car, and the most likely reason is because the lighter aftermarket lower has less enertia.
I think that has something to do with the question you have presented.
There are a couple ways we can attempt to "equalize" different ported superchargers to acertain which one makes the most power.
1) Use the exact same pulleys on each supercharger and assume that the gearing for each is exactly the same. This would also then assume that the rotational speed of the supercharger is exactly the same for each. Would these assumptions be correct? I doubt it since the sieg. sb TM has been shown to probably have a front snout re-gear. This would invalidate this method of evaluation. Since we are unsure, let's move to option (2).
2) Match the boost levels on the superchargers.
You bring a valid point on the upper - lower comparison. A front nose re-gear would be equivalent to an upper only pulley. So, with that in mind - I suggest that we would keep the equivalent lower pulley on all superchargers and use the upper pulley for matching the boost levels. There is no doubt that it would be encouraged to use a 2 or 4 lb lower because most people with a port are using some sort of lower pulley. A full comparison would dyno all the superchargers at different boost levels. I know this is not really possible so there would have to a boost level chosen. I was thinking 15.5 lbs would fall right around the middle of where most people are with ported setups (15 - 16 lbs).
Does that make more sense?
1) Use the exact same pulleys on each supercharger and assume that the gearing for each is exactly the same. This would also then assume that the rotational speed of the supercharger is exactly the same for each. Would these assumptions be correct? I doubt it since the sieg. sb TM has been shown to probably have a front snout re-gear. This would invalidate this method of evaluation. Since we are unsure, let's move to option (2).
2) Match the boost levels on the superchargers.
You bring a valid point on the upper - lower comparison. A front nose re-gear would be equivalent to an upper only pulley. So, with that in mind - I suggest that we would keep the equivalent lower pulley on all superchargers and use the upper pulley for matching the boost levels. There is no doubt that it would be encouraged to use a 2 or 4 lb lower because most people with a port are using some sort of lower pulley. A full comparison would dyno all the superchargers at different boost levels. I know this is not really possible so there would have to a boost level chosen. I was thinking 15.5 lbs would fall right around the middle of where most people are with ported setups (15 - 16 lbs).
Does that make more sense?
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Who pointed that very interesting tidbit out to you?
+1 For boost for boost. This way would help me decide.
Just so you guys know, boost is not the best factor to judge performance by. You want to match rotor speed. Boost itself is a factor in the output performance of the blowers, taking it out of the equation gives unfair assistance to the weaker port.
op:op: I voted pulleys for rotor speed. I thought a good port sould lower boost and temps while increasing power? :shrug:
Just to clarify - equal pulleys is NOT equal impeller speed.
this is beating a dead horse. steg is never going to go boost for boost because their flux capacitor is located in the snout. why not do a snout swap. steig snout sb port, then pull the snout off and put a posi case on it. this way you dont have to worry about pulley ratio and you can see who really has the best port job. or just leave the sb out of the test and go stock snout port to stock snout port.
dynobobstieg
New Member
This what we have been saying. We are testing today on the Dyno Jet and the SXF 1000 blower Dyno.
Stiegemeier
StiegeSplash
636-949-2275
Thank you
You mean the SXF-1000 Supercharger Flow-Test machine, designed and built by John Favazza and Bob Stiegemeier? Are you matching impeller speed, boost or something else?
both posi and stiegemeier should be able to change gears.
posi can change his blower speed if he wants to, so same pulley can be used:shrug:
If both can port blower's both should be able to handle the gear change.
I think this would also be fair. just my .02 cents
posi can change his blower speed if he wants to, so same pulley can be used:shrug:
If both can port blower's both should be able to handle the gear change.
I think this would also be fair. just my .02 cents
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