i know the asp blower pulley is good for about 2 lbs of boost but how much does the lower pulley produce?

 

I had the upper ASP pulley on my 99 and i saw no gain or rise in boost after install,but when i put the PSP lower pulley on my new 01 i saw between 2-3 real pounds of boost and alot of lowend power also!

Silver 01
1/4 13.14
MPH 106.67
Throttle body
PSP lower pulley

Matt

 

dare i ask how you put a smaller pulley on the blower with out increasing the boost?

 

Gang:

Am I the only one not being able to make sense out of this? Installing either a smaller upper pulley (and that's spelled P-U-L-L-E-Y for all of you) or a larger lower serves to change your "gearing" for the blower to a taller ratio, thereby increasing blower RPM at a given crank RPM. Assuming similar "gearing" (not sure how it all works out, but it has to be close between the aftermarket uppers and lowers), the blower RPM at a given crank RPM should be the same for either pulley swap. There should/can be no performance advantage between the two. The advantages come from convenience (installation difficulty), cost, weight reduction, and the like.

The only thing I can figure is possible belt slippage issues with a smaller upper pulley (smaller "contact patch" with the belt), which would be less with the stock, larger upper and the aftermarket lower. This is the only possible explanation for a performance advantage, assuming similar "gear ratios" between the two pulley swap options.

Also, the same well-documented "blower redline" issues faced with the aftermarket uppers will still be an issue with the larger lowers, assuming similar "gear ratio".

Any thoughts?

[This message has been edited by Silver-Y2K-SVT (edited 05-24-2001).]

 

well, my first thought silver, is that you are pompous and condescending. thats spelled,, pompous

 

silver - I may not explain this well but lets give a try.

These numbers are not real numbers, just to prove a point.

lets say stock configuration:
the engine spins @ 2000 rpms, spinning the blower at 10,000 which creates 4lbs of boost.

now lets say you change the stock upper pulley to a smaller one, or the lower pulley to a larger one:
the engine spins @ 2,000 rpms, which in turn now spins the blower at 12,000 rpms. Since the blower will be spinning more @ the same engine rpm, more boost will be created, thus more power.

Is that what you were asking?

 

I got 2 lbs more with Sal's PSP lower pulley. From 10-12 lbs on a Spa Tech Digital Guage.

12.95/104
ALL PSP

 

okay, the explanations are correct. now, let's kick it up a notch! the question i've asked many times and never got an answer (even from eaton) is- if we are making more boost, quicker,(i have the -.250 upper) at what rpm point will the blower start spinning without producing added boost? is there a peak rpm output? is it a heat factor or a physics factor or a nobody knows factor? ( how's my spelling so far boys?) it wasn't too long ago that people were saying nono to the pulley change. now people are running an upper AND lower at the same time! anybody out there have hard numbers on this or is it still all conjecture?

 

thank you calightnin.

 

Gang:

No, indeed, the question was how a lower pulley swap can give a real performance increase, while an upper swap won't. I think this was the implication of 'Roller's post. I believe I've seen this posted elsewhere, and it makes no sense.

'Al:

Don't start with me...

 

Maybe it's because his upper pulley wasn't that much smaller??? You can only go so small up top or you will lose surface area. I've heard the most you usually see with the upper is about 1 to 1.5lbs. People see double from the lower. Makes sense to me.

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99 Lightning, JL Ram Air, Daiblo Chip(JL Programmed)and 90mm MAF,JL Power Cooler, Level 10 shift kit,PSP Lower pulley, Single Blade T/B, Bassani exhaust, . 12.42 at 109.6..Full trim and stock convertor, MT Street ET's.

 

I jotted this info from one of the L sites re. blower limits. A member spoke with an Eaton engineer. There is a max allowable blower speed of 14000 rpm, tolerance limitted, (ie dimensional changes occur with respect to the blade to housing tolerances which could result in contact). @ 5600 rpm engine speed, the rotors are @ 14022 rpm, which I gathered was an increase in stock red line typical in aftermarket chips. If blower speed is further increased using pulley gearing, clearly the max safe rotor rpm has been exceeded.

 

puss.
j/k

 

Unless some one has a blower dyno or works for eaton will we ever know the answer to has fast is too fast. I am sure this is propritary info that Eaton will not release. You would need to connect your blower to a flow meter with temp sensors to determine at what point the extra boost presure is creating too much heat.

I have been running the lower pulley for several thousand miles of daily driving and strip with no problem.

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2000 Silver Lightning 13.16 (so far)
PSP 4-way
PSP Filter Kit
PSP Lower Pulley
Level 10 Shift kit
F-250 Trans pan
MagnaFlow 12468
Snug-Lid

I feel a 12.xx coming on.

Team PSP West