GTO procharger owners
05-04-2006, 12:11 AM
#1
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GTO procharger owners I posted this on LS1GTO as well, please excuse the duplicate....not sure we get everybody at both sites....
Since planning my 408 build I have known the little P1SC-1 was marginal at best. However I started playing with the max impeller speed equations and quickly realised that I am a long way from the max. Case in point the P1SC-1 enjoys a 65000 rpm limit. These kits shipped with a 3.85 Pulley even @ 6500 rpm the impeller is only spinning @ 48454 RPM.....I can get close to max speed with around a 2.9" blower pulley. The problem is ATI states anything much lower than a 3.25 is going to have belt slip issues. EPP confirms this and does not recommend anything lower than the 3.25.
The problem stems from the ATI crank pulley only being 7" in diameter. I have spoken with ASP they quoted me a custom pulley for around $250.00 if we come up with 30 sets the price point may come down to around $175.00
You guys with the D1SC-1 have a similar issue as your impeller limit is 62000 you still have to run a pretty small blower pulley to achieve this.
As my engine bay is completely empty right now I cant even check for clearance issues. I would like to see an 8" or 8.25" Anyone who's car is intact let me know if there is room for an additional .5 or .75 all around the ATI lower pulley.
if any of you are interested in this let me know, I doubt we can come up with 30 but I would like to go to ASP with more than just a couple.
Those of you who think maxing out the impeller will get you more boost than you want....the advantage is the boost comes on at a lower engine RPM. A restrictor plate can be utilized to maximize the torque at an earlier rpm yet keep boost levels at an acceptable level......
Just some things to think about.....
Since planning my 408 build I have known the little P1SC-1 was marginal at best. However I started playing with the max impeller speed equations and quickly realised that I am a long way from the max. Case in point the P1SC-1 enjoys a 65000 rpm limit. These kits shipped with a 3.85 Pulley even @ 6500 rpm the impeller is only spinning @ 48454 RPM.....I can get close to max speed with around a 2.9" blower pulley. The problem is ATI states anything much lower than a 3.25 is going to have belt slip issues. EPP confirms this and does not recommend anything lower than the 3.25.
The problem stems from the ATI crank pulley only being 7" in diameter. I have spoken with ASP they quoted me a custom pulley for around $250.00 if we come up with 30 sets the price point may come down to around $175.00
You guys with the D1SC-1 have a similar issue as your impeller limit is 62000 you still have to run a pretty small blower pulley to achieve this.
As my engine bay is completely empty right now I cant even check for clearance issues. I would like to see an 8" or 8.25" Anyone who's car is intact let me know if there is room for an additional .5 or .75 all around the ATI lower pulley.
if any of you are interested in this let me know, I doubt we can come up with 30 but I would like to go to ASP with more than just a couple.
Those of you who think maxing out the impeller will get you more boost than you want....the advantage is the boost comes on at a lower engine RPM. A restrictor plate can be utilized to maximize the torque at an earlier rpm yet keep boost levels at an acceptable level......
Just some things to think about.....
05-04-2006, 03:44 AM
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I did exactly this on my Vortech supercharged Honda years ago. Then again, I enjoyed a large factory parts supply and found that a stock CRV crank pulley was a full inch larger in diameter than the stock B16 crank pulley. After calculating the change in blower speed was within the limits with the 3.125" (10psi @ 8000rpm) pulley I already had on the car, boost increased to 13psi at 8000rpm and 15psi at 9000rpm. Then again, I still had extreme belt slip due to the limited grip of a 4 rib belt. Eventualy a company developed a "race" belt and pulley system for my application which was a full 8 rib drive belt. Even though the crank pulley was slightly smaller than the CRV pulley I had replaced with this custom part, the increased grip on the belt resulted in 15psi at 8000rpm and 18-20psi at 9000rpm depending on conditions. Needless to say, the car was crazy fast at that point. (It ran a best of 12.3 @ 116mph on 15psi with the 4 rib setup and massive tire spin with 23" slicks (ie: too small). I never got to run it on the 8 rib belt at 18psi but from the datalog comparisons on the street before and after the swap, I estimated mid 11's at over 120mph.)
Good luck getting enough people interested, but I doubt their are even 30 people who frequent these forums running a Procharger interested in increasing boost by that much considering factory internals and fuel limitations of the factory systems.
My point is, you might check around and see if any other factory parts will fit and have a larger diameter to overdrive the supercharger.
Good luck getting enough people interested, but I doubt their are even 30 people who frequent these forums running a Procharger interested in increasing boost by that much considering factory internals and fuel limitations of the factory systems.
My point is, you might check around and see if any other factory parts will fit and have a larger diameter to overdrive the supercharger.
05-04-2006, 08:30 AM
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I hear ya.....
Not really trying to round up 30, I am prepared to pony up what it takes to do this even if it is a one off. Just sharing and getting the info out. If there is just a handful of us that is ok as well.
Your example is a good one, I wish there were "other" options. seems the fluidampr is kind of an animal unto its own..but the hunt shall continue!
Not really trying to round up 30, I am prepared to pony up what it takes to do this even if it is a one off. Just sharing and getting the info out. If there is just a handful of us that is ok as well.
Your example is a good one, I wish there were "other" options. seems the fluidampr is kind of an animal unto its own..but the hunt shall continue!
05-04-2006, 08:37 AM
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I'm in but not for the above reasons. In fact I don't intend on increasing my boost at all. A group buy of a larger crank pulley if it happens means we can get a part never made before and maybe not ever again. If it is produced I would buy one just to have for future applications of my GTO. I would install it and then pulley up the blower pulley to provide the same level of boost I am seeing right now. Future growth is the name of the game......
