The Ported Eatons putting out 17-19 lbs of Boost
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From: Selden NY
The Ported Eatons putting out 17-19 lbs of Boost
Finally got to take it for a ride today,
Been raining since I swapped to the 2.7 upper pulley @$%$%@$@$%(@$
With the 9-1/2" lower / 2.7 upper, 81 Degrees and the (3) H's out
INSTANT 17 lbs of Boost, and it clearly climbs a couple more.
A little stap on the pedal at any speed, will give you an instant 15-17lbs.
It feels strong, responsive, and pulls hard.
I can tell you for a fact that at 130 MPH it was showing a clear 19 lbs of Boost.
Would have loved to stay into it a few seconds more, but right about there it was
I noticed my exit passing me by and I had to make a little hi speed adjustment, hehehehe....
(as soon as Sal allows me in, I will dyno it) How bout tonight Sal ??? : o )
Been raining since I swapped to the 2.7 upper pulley @$%$%@$@$%(@$
With the 9-1/2" lower / 2.7 upper, 81 Degrees and the (3) H's out
INSTANT 17 lbs of Boost, and it clearly climbs a couple more.
A little stap on the pedal at any speed, will give you an instant 15-17lbs.
It feels strong, responsive, and pulls hard.
I can tell you for a fact that at 130 MPH it was showing a clear 19 lbs of Boost.
Would have loved to stay into it a few seconds more, but right about there it was
I noticed my exit passing me by and I had to make a little hi speed adjustment, hehehehe....
(as soon as Sal allows me in, I will dyno it) How bout tonight Sal ??? : o )
Did you get the new valve springs installed too??
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From: Selden NY
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From: DETROIT, (formerly Eaton County, Michigan)
Rob,
Your heads aren't ported. Isn't "boost" a measure of pressure resulting from the resistance of air flowing through the motor? If so, 19psi, isn't necessarily a good thing.
Lets open a can of worms!
Look at JJ. He's running 10's with what 15#'s of boost?
Either
1. He is running a small pulley and isn't making that much power
2. he is running a lot of air through the engine without restrictions (resulting in a lower "boost" number)
I'm guessing #2, becuase he's in the 10's.
I'm guessing even if Suavy runs his BIG pulley, He won't see as much boost as he did before, becuase his heads are hollowed out and the cam allows more air to flow with less restriction. (only reason I'm using him as an example is his MASSIVE pulley) But I betcha he'll be putting out more power.
Summary:
high boost isn't necessarily a good thing! It shows that there is a considerable amount of backpressure.
If you port your heads, you'll make less boost (less backpressure) yet more power! YOU KNOW WHAT YOU HAVE TO DO!
Your heads aren't ported. Isn't "boost" a measure of pressure resulting from the resistance of air flowing through the motor? If so, 19psi, isn't necessarily a good thing.
Lets open a can of worms!
Look at JJ. He's running 10's with what 15#'s of boost?
Either
1. He is running a small pulley and isn't making that much power
2. he is running a lot of air through the engine without restrictions (resulting in a lower "boost" number)
I'm guessing #2, becuase he's in the 10's.
I'm guessing even if Suavy runs his BIG pulley, He won't see as much boost as he did before, becuase his heads are hollowed out and the cam allows more air to flow with less restriction. (only reason I'm using him as an example is his MASSIVE pulley) But I betcha he'll be putting out more power.
Summary:
high boost isn't necessarily a good thing! It shows that there is a considerable amount of backpressure.
If you port your heads, you'll make less boost (less backpressure) yet more power! YOU KNOW WHAT YOU HAVE TO DO!
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From: Downriver, Michigan
Sounds dang dead-on. You take that blower and put it on a motor with ported heads, you get a lower boost number. Kind of like pouring too much tranny fluid into a funnel to refill the case and having it over flow because the funnel and tranny dip stick tube need porting. 
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Originally Posted by Don's Bolt
here it is
OK Don, that's a two point something inches. The smallest pulley that the snout will allow is a 2.7. A 2.6 can be used with some shaving of the snout.
In percentages a 2.7 is equivalent to a 2.3 lb pulley and a 2.6 to a 3.5lb. If someone ever figures out how to make a 2.0, the ratios would be completely insane. The equivalent would be a 13lb pulley.
TB
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From: Burlington, Ma
Originally Posted by TrackBeast
OK Don, that's a two point something inches. The smallest pulley that the snout will allow is a 2.7. A 2.6 can be used with some shaving of the snout.
In percentages a 2.7 is equivalent to a 2.3 lb pulley and a 2.6 to a 3.5lb. If someone ever figures out how to make a 2.0, the ratios would be completely insane. The equivalent would be a 13lb pulley.
TB
In percentages a 2.7 is equivalent to a 2.3 lb pulley and a 2.6 to a 3.5lb. If someone ever figures out how to make a 2.0, the ratios would be completely insane. The equivalent would be a 13lb pulley.
TB
It really had to be machined down, not just some shaving.
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From: Selden NY
As she said to Don WOW, that is small 
IM you are 100% correct my friend, all that boost can work against you. But got dam we were surprised to see how good the IAT temps were, even after 3 dyno's on a hot sticky night. And WOW does it have massive low end power and it carried it all the way up to 130 MPH the other day on the parkway, and was still pulling like a frigging raped ape.
Another good example is with the same Pulleys on the Mag + Eaton the Diff was 21-23 lbs on the Mag, vs 17-19 on the Eaton. Even with 3-5 less lbs of boost the Eaton didn't lose power. (my guess is in cool weather I will see more boost yet on the Eaton too)
I think I am just about boosted out though, when I removed the Mag I found that my Rotor coating is now gone, yet I went 13,000 miles with 15lbs of boost on the Eaton without ever losing 1 spec. All it took was 1K with the extra Mag Boost to take the coating off)
This winter we will most likely be doing some more work, let me see what I can work out.....
IM you are 100% correct my friend, all that boost can work against you. But got dam we were surprised to see how good the IAT temps were, even after 3 dyno's on a hot sticky night. And WOW does it have massive low end power and it carried it all the way up to 130 MPH the other day on the parkway, and was still pulling like a frigging raped ape.
Another good example is with the same Pulleys on the Mag + Eaton the Diff was 21-23 lbs on the Mag, vs 17-19 on the Eaton. Even with 3-5 less lbs of boost the Eaton didn't lose power. (my guess is in cool weather I will see more boost yet on the Eaton too)
I think I am just about boosted out though, when I removed the Mag I found that my Rotor coating is now gone, yet I went 13,000 miles with 15lbs of boost on the Eaton without ever losing 1 spec. All it took was 1K with the extra Mag Boost to take the coating off)
This winter we will most likely be doing some more work, let me see what I can work out.....
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[QUOTE=Rob_02Lightning]As she said to Don WOW, that is small
She sure is small Don. Usually 2" won't do much damage but this may be the exception...
The diameter of the snout is about 2 1/4" so comparing this to my 2.7, this must be close to 2.5". When I plug that in my spread sheet, that alone is equivalent to a 5lb pulley. The pulley diameter is measured by the top of the inside grooves. Where did you get that Don?
I know how to grind down the snout but how the hell to you machine it down like that?
TB
She sure is small Don. Usually 2" won't do much damage but this may be the exception...
The diameter of the snout is about 2 1/4" so comparing this to my 2.7, this must be close to 2.5". When I plug that in my spread sheet, that alone is equivalent to a 5lb pulley. The pulley diameter is measured by the top of the inside grooves. Where did you get that Don?
I know how to grind down the snout but how the hell to you machine it down like that?
TB