Help with SC upgrade

[Carson45]

I use a 78" belt with a stock sized Metco lower, 4 piece Metco idler and 3.25" upper. A 2lb lower would add 2" and a 3.5 upper would add 0.5". So 80.5" should be in the ball park.

As for plugs, NGK TR7IX is popular if you prefer Iridium, BR7EF for copper. Start the gap at 0.035" and go down from there if you experience spark blow out.

If I got the whipple idler assembly would that effect length? Or would 80.5 be good still?

 

[cj428mach]

Buy a used 2.3 tvs, get a gt500 tb as well. The removable inlet, better pulley options, better tb options and the fact they're torque monsters really make it a no brainer.

 

[olympic]

The Whipple idler has a really small pulley so it may need a shorter belt, plus it adds quite a bit of adjustability. If you're just buying belts from the parts store down the street then start with an 80". It's easy enough to take it back and swap for a different size.

If you need it to be right the first time it's best to wait till the car is together then measure what size you need. Easiest way is to take an old belt (longer than 80", 4,6, or 8 rib, doesn't matter)) and cut it so it's 1 long piece. Then you can wrap it around all your pullies to measure the length needed. A second set of hands is useful to move the tensioner into position while you take the measurement.

 

[Stage 4.6]

Ok thanks. I was told today my 2 lb lower will make too much boost for 93 so Im just kind of confused on what pulleys to get to be safe? I would like to find a nice used blower if possible.

I had similar supporting mods, I had a 4lb lower 3.25 upper pulley with ID1050 inj, my car made 635hp with KB2.6H on 91 oct.
The KB has been in storage for a year never posted it for sale because i didn't want to deal with the shipping and haggling.

 

[Carson45]

The Whipple idler has a really small pulley so it may need a shorter belt, plus it adds quite a bit of adjustability. If you're just buying belts from the parts store down the street then start with an 80". It's easy enough to take it back and swap for a different size.

If you need it to be right the first time it's best to wait till the car is together then measure what size you need. Easiest way is to take an old belt (longer than 80", 4,6, or 8 rib, doesn't matter)) and cut it so it's 1 long piece. Then you can wrap it around all your pullies to measure the length needed. A second set of hands is useful to move the tensioner into position while you take the measurement.

I might not change them but someone suggested it to me. I dont know the benefits over my current metco idler. I would definitely like to have 2 different belts at least in hand that should work.

 

[olympic]

The Whipple idler can help with belt slip problems, plus it's adjustable to help dial in proper belt tension. But you shouldn't have any belt slip issues running a >3" upper and moderate boost levels.

 

[Carson45]

Edit...issue was fixed. Loose vacuum line on back of whipple.