pully question
pully question what pully setup do i need to see 8 psi with a D1? the car is a stock bottom end heads cam car. i know there are alot of things that affect psi, and im new to the game so any help would be great.
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Joined: Jun 2003
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I have a H/C stock bottom end -347 1998 Camaro
LS6 manifold
224/228 cam with 114 LSA with Yella Terra rockers
Patriot LQ9 heads.
Racetronix 42lb injecters
JetHot 1 3/4 LT's with a non catted y pipe.
Magnaflow catback
Vig 3200 TQ
Local built 4LE60
Moser 12 bolt 3.73
ATI D1SC 8 rib installed by EPP with 4.5 pulley (ATI says 6-7 lbs of boost).
ATI twin 3.5 inch intercoolers and pipe.
With Bob's (EPP) MAF tune on a Mustang dyno it did 487 rwhp with all of the above mods.
I recently made the following changes
EPP FMIC with custom aluminum piping.
Racetronix 60 lb injecters
Yank PY 3400 Extreme TQ along with a Peformabuilt level III 4LE60
ARH LT's with catted ARH y pipe.
Downsized pulley from 4.5 to 4.38
I switched to a conservative SD tune at 16 degrees timing.
Again on a Mustang dyno with the above additional changes we upped power to 565 rwhp. I didn't try to go any higher because of my stock bottom end.
So depending upon the mods to your car it appears Bob is correct in that each reduction in pulley size increases boost 1 - two lbs along with about a 50-75 rwhp increase.
Since I made more than a simple pulley change it's questionable if the pulley alone increased rwhp by 90 on my motor.
But I don't doubt that if I dropped to a 4.25 pulley I am sure the car would easily make over 600-625 rwhp but I would probably blow piston # 7 over time.
So ballpark to start - IMO get a 4.38 or 4.25 pulley and take your chances for longevity with a conservative tune sans meth assist if your motor has a stock bottom end.
This also assumes the motor is an LS1 and not LS2 or LS3. The stock LS2's and 3's appear to be a little more durable with less likelihood to grenade over 600 rwhp.
LS6 manifold
224/228 cam with 114 LSA with Yella Terra rockers
Patriot LQ9 heads.
Racetronix 42lb injecters
JetHot 1 3/4 LT's with a non catted y pipe.
Magnaflow catback
Vig 3200 TQ
Local built 4LE60
Moser 12 bolt 3.73
ATI D1SC 8 rib installed by EPP with 4.5 pulley (ATI says 6-7 lbs of boost).
ATI twin 3.5 inch intercoolers and pipe.
With Bob's (EPP) MAF tune on a Mustang dyno it did 487 rwhp with all of the above mods.
I recently made the following changes
EPP FMIC with custom aluminum piping.
Racetronix 60 lb injecters
Yank PY 3400 Extreme TQ along with a Peformabuilt level III 4LE60
ARH LT's with catted ARH y pipe.
Downsized pulley from 4.5 to 4.38
I switched to a conservative SD tune at 16 degrees timing.
Again on a Mustang dyno with the above additional changes we upped power to 565 rwhp. I didn't try to go any higher because of my stock bottom end.
So depending upon the mods to your car it appears Bob is correct in that each reduction in pulley size increases boost 1 - two lbs along with about a 50-75 rwhp increase.
Since I made more than a simple pulley change it's questionable if the pulley alone increased rwhp by 90 on my motor.
But I don't doubt that if I dropped to a 4.25 pulley I am sure the car would easily make over 600-625 rwhp but I would probably blow piston # 7 over time.
So ballpark to start - IMO get a 4.38 or 4.25 pulley and take your chances for longevity with a conservative tune sans meth assist if your motor has a stock bottom end.
This also assumes the motor is an LS1 and not LS2 or LS3. The stock LS2's and 3's appear to be a little more durable with less likelihood to grenade over 600 rwhp.
Are you buying a new or used kit?
How much boost the blower can produce depends on many variables.
* Cubic inch. The larger the engine the less boost it will make with a P-1SC.
* Headers and exhaust. A better flowing system will produce less boost, requires a smaller pulley to regain the loss in boost. Ultimately though, more power will be gained.
* Camshaft and heads. A camshaft with some overlap will leak out some boost through the valves. Better flowing heads react a lot like a better flowing exhaust system.
* Altitude. Elevation plays a big part in how much boost is produced. Those people living in the higher elevations have to spin the blower harder to see boost.
* Condition of engine. An engine with real good sealing rings will ultimately produce more boost than one with worn rings.
* Rpm. An engine that is spun up higher in the rpm range will normally produce more boost.
When we place an order for a ProCharger, all of the above items are taken into consideration to spec out the right blower pulley to get the amount of boost the customer wants to produce. Bob
How much boost the blower can produce depends on many variables.
* Cubic inch. The larger the engine the less boost it will make with a P-1SC.
* Headers and exhaust. A better flowing system will produce less boost, requires a smaller pulley to regain the loss in boost. Ultimately though, more power will be gained.
* Camshaft and heads. A camshaft with some overlap will leak out some boost through the valves. Better flowing heads react a lot like a better flowing exhaust system.
* Altitude. Elevation plays a big part in how much boost is produced. Those people living in the higher elevations have to spin the blower harder to see boost.
* Condition of engine. An engine with real good sealing rings will ultimately produce more boost than one with worn rings.
* Rpm. An engine that is spun up higher in the rpm range will normally produce more boost.
When we place an order for a ProCharger, all of the above items are taken into consideration to spec out the right blower pulley to get the amount of boost the customer wants to produce. Bob
