why use a lower crank pulley?

[Almo]

http://www.svtperformance.com/forums/showthread.php?p=6324831#post6324831

Should be able to pull my car with the 6 pound lower (stock upper) to compare sometime next week.

 

[CobraBob]

Can't wait.

 

[96stanggt]

OK.. Because of my setup I only see 13# max... If I through a 2lb on there I will see around 15#. But because my boost is lower, is the blower rpm down too? I will still make the same power with less boost/heat ect... Obviously more efficient because of this but how do the blower RPMs compare to this?

Blower rpm and boost are two different things. Your blower is still spinning at the same speed regardless, your motor is just breathing well enough to only produce 13lbs of boost.

 

[Sniperdog]

:bated breath: :thumbsup:

 

[jm@ReischePerf]

Increasing the boost past a certain level without porting the supercharger is exactly the reason why the hp won't change drastically. You need a blower that is more efficient with higher levels of boost.

This is why you port. Superchargers/turbos have an efficiency range. If you just keeping upping the boost passed this range you are creating more heat without increasing flow further in the powerband. You'll make the power a little quicker, inc. torque, but you'll be more prone to heatsoak, timing etc etc.

Exactly and I think this is why the torque myth got started. Most don't put on a lower until they've pretty much maxed the Eaton out with an upper anyway.

What I don't understand is why everyone keeps talking about tq. Why not include hp?

Torque is a function of hp, so it's really the same thing. Torque X rpm = hp, so higher torque numbers just mean higher hp levels lower in the powerband.

So, if boost is boost, these combos will not make the same numbers...

You're right they won't, but it will be perfect to disprove the theory

Even with boost down a bit on the 6 pound lower (stock upper) it will still show the difference in TQ at peak and throughout the curve compared to the 2.75 upper (stock lower).

Nope, I'll bet anything the 2.75 makes more torque and power throughout the entire band.

 

[Sfcjerryharris]

i know this has probably been asked before, but i can't seem to find the answer.

Why use a 4# lower / 2.93 upper combo over just a 2.76 upper? does the lower pulley affect your torque numbers? if so how much?

i have a 2.76 upper, ported steig V blower, CAI, and she got 496 rwhp, 486 rwtq, what else can i do

 

[Sfcjerryharris]

2.93/4lb no port 508tq

so what shouuld i run on my 03 terp, i have 2.76 upper, stock lower, steig stag V ported eaton, got 496rwhp and 486rwtq, what more do i need to do

 

[03cobra#694]

i have a 2.76 upper, ported steig V blower, CAI, and she got 496 rwhp, 486 rwtq, what else can i do

so what shouuld i run on my 03 terp, i have 2.76 upper, stock lower, steig stag V ported eaton, got 496rwhp and 486rwtq, what more do i need to do

Start a new thread. This shit is 10 years old! Consider yourself lucky.