2.4 Supercharger pulley size boost calculation

[Unholy707]

Does anyone have the chart or math that shows how much boost is expected with a 2.57 pulley, or how I can calculate it for a 2.4 supercharger?

 

[fubar569]

Stock heads, Stock bottom end, Jokerz full tilt blower with ported bearing plate, snout & runners, Kong 108 & TSP headers - a 2.50 upper and stock lower nets me 19ish or so. Before the headers I saw 20-21ish to almost 22psi on a cool night.

I am finally seeing evidence of slip at this point even with an idler. FYI.

 

[fumanchu182]

That's a spicy meatball.

 

[vortecd]

Does anyone have the chart or math that shows how much boost is expected with a 2.57 pulley, or how I can calculate it for a 2.4?

Its on the site may be in racing or drag racing. Sdg has it on their Facebook page also

 

[Unholy707]

Stock heads, Stock bottom end, Jokerz full tilt blower with ported bearing plate, snout & runners, Kong 108 & TSP headers - a 2.50 upper and stock lower nets me 19ish or so. Before the headers I saw 20-21ish to almost 22psi on a cool night.

I am finally seeing evidence of slip at this point even with an idler. FYI.

I should have pulled the trigger and sent mine to Kong for port work for their Black Friday sale, kicking myself

 

[Unholy707]

It’ll just be the party pulley. Planning on getting upgraded bearings. Hopefully she’ll hold. Too many different build paths to choose. I want 9.3 or better, stock engine stock heads on a 2.4

 

[fubar569]

It’ll just be the party pulley. Planning on getting upgraded bearings. Hopefully she’ll hold. Too many different build paths to choose. I want 9.3 or better, stock engine stock heads on a 2.4

I told myself it was just a party pulley too.

Now I tow the 4x8 enclosed to the track on the 2.5 and average about 10.5-11mpg at 900+ wheel doing so. LOL

 

[Unholy707]

I told myself it was just a party pulley too.

Now I tow the 4x8 enclosed to the track on the 2.5 and average about 10.5-11mpg at 900+ wheel doing so. LOL

Welp sounds like it’s handling it pretty well. Pics of trailer? Been contemplating that myself

 

[fubar569]

Welp sounds like it’s handling it pretty well. Pics of trailer? Been contemplating that myself

4 x 8 x 4 - bought before big dick competitors got the trailer rule changed from 4 x 8 x 4 to any single axle.

 

[Speedy!]

All track testing has shown pretty much anything smaller than a 2.7" pulley is slower. FYI.

 

[Unholy707]

4 x 8 x 4 - bought before big dick competitors got the trailer rule changed from 4 x 8 x 4 to any single axle.

View attachment 125954

I like it. What do they change? Can have a bigger trailer now?

 

[Unholy707]

All track testing has shown pretty much anything smaller than a 2.7" pulley is slower. FYI.

With chillers and additional cooling mods? I have a stock lower

 

[Unholy707]

I can get my coolant down to 28 degrees and it stays cool because I added a 1.25 gallon tank, have been testing it the last few days. I can’t see it making less power when I run e85, have a chiller and more coolant capacity. Also sealing up intake box to hood and doing more to deflect radiator fans away from intake

 

[Speedy!]

With chillers and additional cooling mods? I have a stock lower

I "think" yes even with coolers, but double check me on that. @hellno did some extensive testing on his.

 

[Unholy707]

I "think" yes even with coolers, but double check me on that. @hellno did some extensive testing on his.

@hellno only knows about chevys now he forgot all hellcat stuff 😆

 

[jonx96]

All track testing has shown pretty much anything smaller than a 2.7" pulley is slower. FYI.

I don’t agree with this if the lower is stock.
Edit.
I never recommend more than a 2.7 and 10 lower. Because of blower speeds

 

[Unholy707]

I don’t agree with this if the lower is stock.
Edit.
I never recommend more than a 2.7 and 10 lower. Because of blower speeds

Lower is stock, thanks for chiming in @jonx96!

 

[jonx96]

Stock is lower, thanks for chiming in @jonx96!

There are shoulds and shouldn’t and safe and dangerous with all decisions. Kind of like on a dyno I can add more timing and you’ll make more hp. But that wouldn’t be safe. Just because you can make a gain doesn’t mean you should.

 

[fumanchu182]

I don’t agree with this if the lower is stock.
Edit.
I never recommend more than a 2.7 and 10 lower. Because of blower speeds

If he did the Kong port and race rebuild he could spin it to the damn moon but the heat would be the issue. My blower will be back this week. Prepare for machined metal surfaces.

 

[Unholy707]

If he did the Kong port and race rebuild he could spin it to the damn moon but the heat would be the issue. My blower will be back this week. Prepare for machined metal surfaces.

I know, kicking myself for not pulling the trigger. I’m thinking I might be able to get by with the SDG snout (no bearing plate) because it has upgraded bearings on the snout, which seem to be the weak point. That might be in play, still figuring out build path for my goals