Blower pulley or Metco lower pulley

jm35ny

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Hey guys I was looking to add some more boost to my Whipplie 2.3 Gen II. Currently I'm running a stock 3.5 pulley and stock caged lower making about 14 psi. I just wanted to add a couple more pounds boost so should I just bolt on a 3.25 upper? My tuner is recommending adding a 2lb lower, is there any benefit from adding a lower over just bolting on a new pulley?
 

stangfreak

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The only benefit is that you will have more belt wrap. If your only going for a few more lbs, just change the upper. Its easier and cheaper. You will gain hp and tq just like the lower pulley. 2 lb lower is 2 more lbs of boost. And no, the lower pulley will not magically add tq. Your adding more tq bc you are adding more boost just like the upper. I would do the upper
 

cj428mach

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The only benefit is that you will have more belt wrap. If your only going for a few more lbs, just change the upper. Its easier and cheaper. You will gain hp and tq just like the lower pulley. 2 lb lower is 2 more lbs of boost. And no, the lower pulley will not magically add tq. Your adding more tq bc you are adding more boost just like the upper. I would do the upper

I agree with this 100%. If you're running a 3.0" or bigger pulley you won't have belt slip issues in my opinion.
 

Posi

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Yeah swap the upper and make sure you have the largest idler you can have next to it with a tight belt.
 

GodStang

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The only benefit is that you will have more belt wrap. If your only going for a few more lbs, just change the upper. Its easier and cheaper. You will gain hp and tq just like the lower pulley. 2 lb lower is 2 more lbs of boost. And no, the lower pulley will not magically add tq. Your adding more tq bc you are adding more boost just like the upper. I would do the upper

This this and this. The only time I would do a lower over an upper is if you start getting too small of an upper like under 3" and you need that added belt wrap.
 

SVTFocus Noob

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This this and this. The only time I would do a lower over an upper is if you start getting too small of an upper like under 3" and you need that added belt wrap.

So question I have a upper 2.76 from previous owner I am going install should I get a bigger lower too?

Jake
 

jm35ny

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Thanks guys I'm not looking to go crazy just get a little more hp/tq so the upper sounds like the way to go. Adding a 3.25 upper and a fresh tune sounds like the way to go
 

GodStang

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So question I have a upper 2.76 from previous owner I am going install should I get a bigger lower too?

Jake

I guess I should not of said 3" exactly. It really depends if you are having belt slip or not. Depending on idler pulleys you have brand of pulleys and type of belt plus guilty of your tensioner all play into if you have belt slip or not. I was just trying to say as you get smaller you may start running into belt slip and one way to correct that is go bigger upper and then a lower.
 

e85svt

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If you run a ported eaton go with a 4lb lower and 2.93 upper. If non ported just run the upper. Adding a 2 lb lower to a non ported eaton won't add much hp but the torque gain will be significant.
 

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