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So now that I have 90% of my remaining parts in transit for my LSA build I need to figure out my pulley situation. The snout is currently still disassembled for my solid isolator, so I can swap pulleys there no problem, or go lower pulley and leave the upper alone.

Now my motor is on stock internals so I'm not looking to beat any HP records.

Money is not the deciding factor for me, but as with any mod where I have multiple options I will always consider the most cost effective means vs easiest means.

So lets talk features and benefits. I'm all eyes and ears for feed back. Holla back!
 

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I kept mine simple. Metco interchangeable 2.4" upper with the stock lower. No slippage using the green belt and 100mm metco idler.
 

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I'll give my usual LSA advice - head on over to ctsvowners and search a bit. Much larger pool of experience.

FWIW, I'm stock upper, 5 or 10% lower (forgot) on a ati dampener. For me, no need to push it, it blows the tires off most any time.
 

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Discussion Starter #4
I kept mine simple. Metco interchangeable 2.4" upper with the stock lower. No slippage using the green belt and 100mm metco idler.
Nice. I looked it up and the fact you don't have to machine the snout in order to benefit from the interchangeable sizes seems legit.

I'll give my usual LSA advice - head on over to ctsvowners and search a bit. Much larger pool of experience.

FWIW, I'm stock upper, 5 or 10% lower (forgot) on a ati dampener. For me, no need to push it, it blows the tires off most any time.
Oh I have been there. I have been all over the web. Just wanted to engage with a community of owners that knows me well and has been through the struggle with the G8s.
 

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I think the 2.4 is a good choice if you're not looking at maxing everything out. I'm running the Lingenfelter 2.38 but it requires machining the snout. I've got the 8.66 lower on ATI damper and it makes around 16 psi of boost just for reference. The 2.4 and stock lower I think would give you all you want on a stock bottom end...and maybe more!
 

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Not quite running yet but i have an interchangeable 2.55 upper and stock lower on a stock bottom LS3 with a small cam and e85 fuel system. I'm nervous to pulley up anymore right now until i get it dialed in like this, don't want it on the ragged edge. Hoping to break into the 10's.
 

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Forgot to mention. My combo makes exactly 11 psi.
 

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Stock pulley on stock motor I made 6 - 7 psi, with a 2.5 I do 12 - 13. Haven't looked to see if you have a build thread or anything but do you have fuel system to support it all? With just the stock pulley I was running out of fuel on stock system. Ran the Vaporworx stuff and had enough until I went to the 2.5, then needed injectors.

If you want to get really crazy you can do the overdrive lower pulley and keep it easy up top. What my buddy did until he stroked it, now is maxxing out the blower.
 

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Discussion Starter #10
I think the 2.4 is a good choice if you're not looking at maxing everything out. I'm running the Lingenfelter 2.38 but it requires machining the snout. I've got the 8.66 lower on ATI damper and it makes around 16 psi of boost just for reference. The 2.4 and stock lower I think would give you all you want on a stock bottom end...and maybe more!
Right on Doug. I'm going to make it easy on myself and not do anything requiring machining lol. I think you are right about the 2.4 being optimal based on everyones feedback. I don't want to blow the motor for at least another 18 months haha. I don't track the car really anymore so I should be able to keep it rolling for a while under modest boost levels.

Not quite running yet but i have an interchangeable 2.55 upper and stock lower on a stock bottom LS3 with a small cam and e85 fuel system. I'm nervous to pulley up anymore right now until i get it dialed in like this, don't want it on the ragged edge. Hoping to break into the 10's.
The LS3 is a nice foundation to build that LSA blower on. Better than my 94k plus mile engine haha

Hi are you retaining the existing valvetrain? If not what alterations in the detail?
Same valve train. No alterations until I destroy something some day and go with a full on rebuild.

Stock pulley on stock motor I made 6 - 7 psi, with a 2.5 I do 12 - 13. Haven't looked to see if you have a build thread or anything but do you have fuel system to support it all? With just the stock pulley I was running out of fuel on stock system. Ran the Vaporworx stuff and had enough until I went to the 2.5, then needed injectors.

If you want to get really crazy you can do the overdrive lower pulley and keep it easy up top. What my buddy did until he stroked it, now is maxxing out the blower.
I have a ZL1 pump and 60lb injectors. Should be plenty of fuel for my plans based on feedback from my tuner.
 

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Discussion Starter #12
OK so keeping Custom AFM cam and 1.85 rr?
Exactly. My setup is ultra mild and will be fine with boost. Just need to swap valley covers and I'm golden.
 

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I'm running metco interchangeable 2.4 upper and 9.1 lower currently making 770whp 700tq running out of fuel . But like previously stated the cts-v forum has way more info
 

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Discussion Starter #15

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I'm going back to a W-body company I used to deal with, Smooth Flow Pulleys.
Dial the boost in. Even might do a larger pulley just for the Winter to make traction easier
 

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my plan was to run a 10 or 10.5 lower , and keep the stock upper , little more stealthy for the mexico races
 

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9.55 is as big as you can run on the lower without hitting the AC line. Nothing stealth about a huge lower pulley. It's right there and everyone notices it first. 9.55/2.55 combo is good for #17. Toss on a 2.38 if you are feel like rolling the dice.

Stock idlers on a relocation bracket with a good belt and it won't slip.

Cam selection, tuning, idle speed is all key too to running a sporty pulley combo. Idle vacuum over 75 kpa won't allow the bypass to function properly at idle.
 

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the area infront of my pulley is wide open , granted its been a while since i opened the hood

with the rest of the stuff around the crank pulley , and being blacked out , most will over look its size
 

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Discussion Starter #20
SO I went with the Metco 2.5 pulley. Since they are interchangable I will swap out down the road to a 2.4 if I can support the power. Just gonna play it safe for now until I get the car dialed in 100%

Big shot out to everyone who pitched in on the conversation!
 
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