3.25 pulley
Thread Starter
Drifting
Joined: Jun 2010
Posts: 1,944
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From: CT
3.25 pulley
Has anyone used a 3.25 pulley on an E-force ls2 without a cam? How much boost can I expect to see with 1.7/8" headers, xpipe w/cats and a 3.25 pulley?
Will a blower cam add boost or subtract it?
Will a blower cam add boost or subtract it?
Le Mans Master
Joined: Apr 2011
Posts: 7,821
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From: Montreal
St. Jude Donor '13
I am putting a 3.25 now to get the boost back and will try and get to the tuner next week. I can tell you the number after I get there.
Pro
Joined: Nov 2007
Posts: 605
Likes: 15
From: Rocky Mountains Colorado
I have the E-Force on my LS2 with the 3.25" pulley. Altitude does effect boost. My last data log taken at Bandimere Speedway (5,800') logged max kPa of 144 @ 6,300 rpm. The DA for this run was 8,400' (144 kPa X .1450377377) = 20.89 psi - 10.75 psi for a DA of 8,400' = 10.14 lbs of boost created at 6,300 rpm with a DA of 8,400'.
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
I have the E-Force on my LS2 with the 3.25" pulley. Altitude does effect boost. My last data log taken at Bandimere Speedway (5,800') logged max kPa of 144 @ 6,300 rpm. The DA for this run was 8,400' (144 kPa X .1450377377) = 20.89 psi - 10.75 psi for a DA of 8,400' = 10.14 lbs of boost created at 6,300 rpm with a DA of 8,400'.
Safety Car
Joined: Sep 2006
Posts: 4,075
Likes: 6
From: Wilmington NC
Motorhead47 had some info on pulley sizes and boost in this thread. See post #199.
http://forums.corvetteforum.com/c6-f...e-force-2.html
http://forums.corvetteforum.com/c6-f...e-force-2.html
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
Motorhead47 had some info on pulley sizes and boost in this thread. See post #199.
http://forums.corvetteforum.com/c6-f...e-force-2.html
http://forums.corvetteforum.com/c6-f...e-force-2.html
Thanks
That info is dead on what I had before adding headers. Right near 7.5 lbs with the 3.5 pulley. I'm guessing I will gain back the 2 I lost by going 3.25.
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Pro
Joined: Nov 2007
Posts: 605
Likes: 15
From: Rocky Mountains Colorado
realcanuk, My boost readings are based on a calculation and not actual boost read by a boost gauge. Edelbrock states that their 3.25" pulley creates 9.5 lbs of boost at sea level. My guess is you will create more than 8.5 lbs of boost with the 3.25" pulley. Remember, the boost I registered of 10.14 lbs was only for a fraction of a second at maximum/peak rpm.
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
I have a TVS2300 on my LS3 with mild blower cam, bolt ons, and 3.3" pulley. About 100' above sea level. Sees around 9psi. Also have a 6.0L equipped similarly with a 3.1" pulley. It sees 12psi. I'd bet a stock LS2 with headers and 3.25" pulley would see in excess of 10psi unless the intake was really restrictive. Good air cleaner/intake is pretty important with these blowers. I picked up an additional pound and a half of boost by putting a much bigger air filter on my 6.0L.
Le Mans Master
Joined: Apr 2011
Posts: 7,821
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From: Montreal
St. Jude Donor '13
realcanuk, My boost readings are based on a calculation and not actual boost read by a boost gauge. Edelbrock states that their 3.25" pulley creates 9.5 lbs of boost at sea level. My guess is you will create more than 8.5 lbs of boost with the 3.25" pulley. Remember, the boost I registered of 10.14 lbs was only for a fraction of a second at maximum/peak rpm.
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
I have a TVS2300 on my LS3 with mild blower cam, bolt ons, and 3.3" pulley. About 100' above sea level. Sees around 9psi. Also have a 6.0L equipped similarly with a 3.1" pulley. It sees 12psi. I'd bet a stock LS2 with headers and 3.25" pulley would see in excess of 10psi unless the intake was really restrictive. Good air cleaner/intake is pretty important with these blowers. I picked up an additional pound and a half of boost by putting a much bigger air filter on my 6.0L.
Pro
Joined: Nov 2007
Posts: 605
Likes: 15
From: Rocky Mountains Colorado
realcanuk, your 1 7/8" headers will make a difference in your ability to create boost. I have 1 3/4" Kooks long tubes. Are your boost readings taken with a boost gauge or a calculation using kPa. If a calculation, are you using density altitude (DA) or elevation above sea level (14.7 psi @ sea level).
Safety Car
Joined: Sep 2006
Posts: 4,075
Likes: 6
From: Wilmington NC
Keep us posted, I also have 1 7/8 headers and 3.5" pulley and my boost reads around 7 lbs max (I don't have a gauge that holds the max reading so this is by eye). It looks like I only lost about 1/2 lb with the headers. I'm interested in how much the 3.25 pulley actually adds to your boost.
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
realcanuk, your 1 7/8" headers will make a difference in your ability to create boost. I have 1 3/4" Kooks long tubes. Are your boost readings taken with a boost gauge or a calculation using kPa. If a calculation, are you using density altitude (DA) or elevation above sea level (14.7 psi @ sea level).
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
Thread Starter
Drifting
Joined: Jun 2010
Posts: 1,944
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From: CT
Keep us posted when you pulley down. I'm going straight for the 3.25 unless it'll put me over 10psi.
Is Edelbrocks intake restrictive as it sits in the kit? Are there other intakes for the E-force out there? will LS9 parts work on this setup?
Is Edelbrocks intake restrictive as it sits in the kit? Are there other intakes for the E-force out there? will LS9 parts work on this setup?
Le Mans Master
Joined: Apr 2011
Posts: 7,821
Likes: 412
From: Montreal
St. Jude Donor '13
If all goes well I will be on the dyno next monday and post up the results. I dont think the edelbrock intake is restrictive but I really dont know if there is a better option.
Burning Brakes
Joined: Feb 2010
Posts: 825
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From: Laplata Maryland
I'm curious I have 1 7/8 headers with 3.5in pulley on my LS3 EForce and on the Dyno I got 6.99 psi at max rpm. So has anyone changed to a 3.25 without changing out the fuel pump. So I figure you pickup top in HP of maybe 50-60 hp but how much medium range torque if any. And would you need to retune the car with adding just a couple psi?