Here's my take on it...You orignially have a 6# pulley pushing 6# of extra boost and pushing alot more heat through the engine. You get your supercharger ported to become more efficient. You can now go down to a 4# pulley and have the same boost you did when you had a 6#, but since you are spinning it slower you are creating less heat. So with a ported 4# supercharger you have more efficient, cooler air than you did when you just had the 6#. A cooler more efficient engine is worth $450 in my book

 

I don't think we can gain 25-30hp when switching from 4lbs pulley to 6lbs pulley and stock eaton.

 

throwing in my 2 cents:

going to a smaller lower pulley you decrease your boost.
the Ported Eaton, Increases boost.

My 3# lower will push 5-6 lbs of boost with the ported eaton.

The ported eaton will Heat up but not as hot as before since there is MORE air flow at the same RPM as before when it was unported.

Further, the ported eaton makes more power at a lower engine RPM than a regular eaton with a larger pulley.

The smaller pulley won't over spin the eaton, which creates a substantial increase in heat.

all in all....
I can stick with my 3#, sell the 6# Which sat on the shelf since i bought it, and have the same if not more power than an unported eaton with a 6#, with less heat generated and without overspinning the Eaton.


If I had a built bottom end, I's slap a 6 or 8# lower with the ported eaton, and that would tied me over until the magnum powers blower arrived. But I have a stock bottom, so I'll stick with this for a few months.

 

No flame intended here, just asking.


Has this statement been proven? Not just by you but anyone with a ported Eaton.

If in fact this statement is true, then how much more power with 3#'er/ported vs. 6#'er /non-ported? Basically, those of you who have ported their Eatons, then placed a smaller pulley to maintain the same amount of boost pre-porting, how much more HP/TQ did you gain? or e.t. gain?

All of your points make sense and if there is a substantial increase in power (or quicker e.t.'s) with the smaller pulley/ported Eaton vs. bigger pulley/non-ported, then it's worth it to me. However, if the power remains the same, I can't see spending $500 just to have "less stress" placed on the internals.

 

NOPE, NO FACT.... just my non-engineering opinion.

I wish WYDOPNTHRT would chime in,
he's the engineer that could give a great explanation regarding vectors, velocity, and that other engineering LINGO...

I do know that WYDOPNTHRT swears by his 4# and has beaten many Michigan 6# in the 1/4 mile. the 6# gets him off the line, but he catches up and passes most of the ones I've seen by the finish line. Maybe he has a freak truck?

that would be a helluva comparison though..

Take a stock lightning, and put a chip and 6# on it and dyno it,
Same truck, take off 6# and put on 3# with ported eaton and very close chip settings and see the results.

 

The only concern about boost should be directed towards the amount of stress on the stock block, not necessarily power. The power comes from increased efficiency, not boost. I know of 2 examples of this:

1) I tested open air filters vs. stock modded box at the track a few years back. The open kit definitely shows more boost (1-2 lbs), but the stock box was always faster...more efficient.

2) I know a few Cobra guys with ported Eatons and most of them see the same boost as before porting or in some cases 1 lb less. They are making more power though and hopefully that will get translated to a better ET. Not saying that the Apten port on Cobras and Lightnings are the same in terms of boost increase/decrease...just stating a fact.

 

During one of the dyno days we meaused engine VE with a 6lb lower car and a 4lb lower ported eaton car. The 4lb lower ported eaton car made more HP on the dyno with the ported eaton than the 6lb lower car did with a stock eaton. On top of that the 4lb ported eaton car was moving less airflow according to the MAF voltage than the 6lb lower car, so it was more efficiently making more power. That was just one test though, but it was on the same day with two different trucks. We may do more testing if enough people are intrested. It was by no means a completley scientific test, but the cars were close enough in modifications to make the data pretty accurate.

Brian

 

Not to dispute, but many people here have seen drastic differences between Lightnings with the exact same mods. But then again, a chip tune in a Lightning makes a much larger difference than one in a Cobra. A tune alone in a Lightning can be +/- 7-10 hp!

 

I plan to hit the dyno this week. I wanted to get it done Saturday, but couldn't.

I have dynoes from before the Apten with my 4 and 6 lb lowe and then my 2lb upper. I still have the same tune. I will have dynoes with all 3 combos in the next 3 days using my Apten.

Yes...making the same boost with lower spin should result in more H.P. The heat my blower picked up from a 6lb lower and 2 upper is enough to fry an egg.

This should also result in more consistency when hot lapping in a bracket race situation.

All of this post is based on conjecture and pure speculation. The dynoes will support this or not. The track times will tell the real tale.


Less heat is a good thing.

Rocks

 

Keep us posted