Upper and lower pulley questions, what the....??

[Black_Noise]

So Ive been already looking at the next step in the power ladder, and why or what would the difference be in doing a smaller upper VS. doing the metco ring to run an oversized lower pulley?

is this basically like motorcycle sprocket ideas of changing up or down the front or rear sprockets?

Explain this all please!

[SC Cheesehead]

So Ive been already looking at the next step in the power ladder, and why or what would the difference be in doing a smaller upper VS. doing the metco ring to run an oversized lower pulley?

is this basically like motorcycle sprocket ideas of changing up or down the front or rear sprockets?

Explain this all please!

Good analogy. Changing the pulley ratio will increase or decrease blower RPM with a resultant increase (or decrease) in boost. Key point is that going too small on the upper pulley will decrease contact area of the belt on the pulley which can lead to belt slippage, so going with a larger lower pulley ring is preferable to running a real small upper pulley.

What boost range are you targeting? A stock upper and 2 lb lower will bet you about 10 -11 lbs boost, which is a great set up for a street car.

[Black_Noise]

I'm not sure what I'm shooting for but a littler more would be awsome... got a buddy with a lightning with a ported blower and were about dead even... just trying to figure out the next step when I do go there. So would a 3.0 upper be too small and maybe slip? I have a buddy with one from a terminator cobra, would it fit the trilogy snout?

Also with more boost do I need a new tune?

[MOTOWN]

Still in the building stages, but i have a 3.0 upper, and a 4lb lower metco ring/hub

[SC Cheesehead]

I'm not sure what I'm shooting for but a littler more would be awsome... got a buddy with a lightning with a ported blower and were about dead even... just trying to figure out the next step when I do go there. So would a 3.0 upper be too small and maybe slip? I have a buddy with one from a terminator cobra, would it fit the trilogy snout?

Also with more boost do I need a new tune?

PM sent.

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[guspech750]

I'm not sure what I'm shooting for but a littler more would be awsome... got a buddy with a lightning with a ported blower and were about dead even... just trying to figure out the next step when I do go there. So would a 3.0 upper be too small and maybe slip? I have a buddy with one from a terminator cobra, would it fit the trilogy snout?

Also with more boost do I need a new tune?

I have a 3" upper and 2lb lower with not belt slip. And I beat the snot out of it.


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[BODYMAN]

Properly tighten belt/size you shouldnt have concerns of belt slip. Iam pushing 20lbs boost with 0 belt slip. except when really cold out.

[Black_Noise]

tune needed when adding more boost?

[1 Bad Merc]

YES.........I would dyno it and tweek the tune.

[guspech750]

tune needed when adding more boost?

FOR SURE!!!


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