Searched, but couldn't find what I needed. I've got a 2010 aluminum 5.3 (799 heads, 10:1 compression) with an LS6 cam in a 2006 Colorado. 1 3/4" longtube headers, 2.5" true duals. Stock truck crank pulley (pinned). I've got a 3.4" pulley right now which came with the blower. Truck will run E85. Has head studs and LS9 gaskets. I'm looking to not go with an 8-rib setup so I want to keep the boost reasonable. Truck has a McLeod RST clutch and T56 trans. I was hoping to make around 9-10lbs (or maybe a bit lower?). Will my 3.4" pulley get me there or will I need a 3.6"? Right now I've got dual 100mm idler pullies and I plan on a Gates belt. Right now primarily worried about pulley size. Looking to make 550whp/550wtq give or take.

 

That's a big charger for a 5.3, what boost does it make now?

 

I bought it used off a forum member. I've never had it running before.

 

I would start with the 3.4" and go from there. You might have to swap it a time or to to end up exactly where you want.

 

The 3.4 should be around 9psi and the 3.6" around 7psi.

5.3, stock crank pulley, 2300 w/ 3.4" pulley

 

Thanks! I had downloaded that spreadsheet ions ago but couldn't find it.

 

@Atomic sorry to dredge up old posts. I have your spreadsheet downloaded and am looking at it and had a question.

I'll also be putting a 2300 on a 5.3
I have a "jack shaft" 2300
I see your spreadsheet has cells in the lower right to calculate for this, but I don't note any change in the rest of the table when I input that.

So, I've just been taking pulley diameter and multiplying by .86 because the jackshaft has that for an underdrive ratio
Is this how you'd recommend I do it for proper calcs in your table? the SC rpm matches up when done that way so I believe it to be the right way to go about it.

if you care on the setup:
2007 GMC Envoy Denali
LH6 5.3
9.9:1 compression
218/224 .553/.553 113+3
Stock 799 heads
TVS 2300 "radix" jackshaft kit
Flex fuel, plan to run e85 as often as possible

Currently have a 3.2 front pulley
3.0/3.49 rear pulleys for a .86 UD ratio
plugging that into your fantastic excel grid, that looks like it should net 6-7 psi

flipping the rear pullies around to have a 1.16 OD would have me at around 16 psi (I think that's a bit much!)

So, I'll plan on leaving the 3.2 and the .86 UD rear setup
any guesses on what that might make for AWD hp?
Am I using your excel sheet properly?
Thanks very much

 

Yes that is fine. That jackshaft calculator part is basically just to find an equivalent conventional pulley setup, then youll use that size in the main part of the spreadsheet. Hard to say how much power, but a cammed 5.3 at 7psi would probably be in the 450rwhp range.

 

Awesome.
I figured that's how you had it setup to calculate but wanted to be sure

Thanks!

I'm shooting for the 450-500 whp area, I'll be on e85, so we will see how it goes with the current pullies and I'll go from there

 

i've used that sheet so many times over the last decade

also made the mistake of running my jackshaft 2300 in an underdrive configuration for the first few years. if you ain't ready to pull the trigger on an 8rib, pulley size & belt wrap are your friends above 8-10psi. i started with a 3.3 while underdriven for ~8psi on my LS1 & was fine, but when i dropped to a 2.9, it slipped like a mug above 9-10psi. i ended up trading a friend for his 1:1 rear setup (he wanted ribbed overdrive) & put my 3.3 back on for the same RPM - it made 11psi just fine.

now, i'm using an OD crank, 3.8 front, and OD cogged rear to make 13psi through a built top end... no slip with the 6rib belt.

but getting back to your original question, inputting the front & rear pulley sizes in green gives you the non-jackshaft number to use up top (which calculates as if it was a direct drive unit). also don't forget to account for your elevation's typical barometric pressure; 14.7 is standard for sea level, but up here where i live is ~13.8 and will change the expected boost numbers.






and unless you're timing the crap out of it, i don't see the need for e85 at a measly 7psi (unless you've ramped up the compression). my car above's still on pump 93 with 10.6 SCR, a high-LSA cam (something like upper 8s DCR, if i remember right), and 13psi.