2.3L KB pulley chart?

[03LCalgaryAB]

Hi guys,

Is there a KB pulley conversion chart?

I'm picking up a 2.3L KB :banana: and it currently has a 2.75" pulley on it. That with my current 6lb lower is going to be overkill on the stock block.

I'm hoping to run 16psi max.
I've searched and it appears a 3.5" upper + a 6# lower = 16-17psi?

Since KB pulleys are harder to come by, how much boost would I have if I put the stock lower back on? and would I get excessive belt slip due to the small upper?

Thanks!

 

[mcarbine]

I am going to subscribe to this thread because I would really like to see a chart too and if it had belt lengths too that would be bad-ass. You can get the KB pullies straight from KB or watch the classifieds like I did they pop up every once in awhile. I am installing my 2.3 in spring and right now I have a 3.5 and a 3.25 upper and a 6# and 4# lower so I am trying to figure out my best combo. If your correct on the 3.5 and 6# being 16-17psi I think I will go with the 3.5 and the 4#er since I want to be around 14-15psi since thats what I am running now with my ported blower and 6#er. Lets hope somebody has a chart or something laying around. Matt

 

[1990stanggt]

Also subscribing, just bought a truck with a 2.3 KB and it only makes 10psi, not sure of why on that, hoping a chart would help me figure it out.

 

[svtharley]

i have a 2.3 kb with 2.75 and 6# lower and im pushing 19lbs that was with a stock block...

 

[04whitesvtlight]

i have a 2.3 kb with 2.75 and 6# lower and im pushing 19lbs that was with a stock block...

damn you must have money ready for a new motor or a new motor waiting.

 

[latemodelracer2]

ill hook you up with a 3.5 just paypal me about 10-12 bucks for shipping

 

[03LCalgaryAB]

ill hook you up with a 3.5 just paypal me about 10-12 bucks for shipping

you sir have a pm!

 

[03LCalgaryAB]

So I did a little more research. I cracked open a Truckin issue back from OCT 02 and they did some pulley swaps on a L with a KB. (Wow, looking back, the Truckin issues are so much thinner now)

7.5" lower & 3.0" upper = 13.2psi
9.0" lower & 3.0" upper = 15.8psi
9.0" lower & 2.75" upper = 20.6psi
9.0" lower & 2.57" upper = 21.6psi

There is also a boost conversion chart.


Potential boost =
Blower displacement x drive ratio
----------divided by------------ X 14.7 - 14.7
1/2 of Engine displacement

The ex. provided is a Eaton M112 (112ci = 1.84L), 7.5" lower & 3.0" upper


Pot Boost =
1.84 (7.5/3.0)
-------------- x 14.7 - 14.7
1/2 x 5.4

= 4.6
---- x 14.7 - 14.7
2.7

= (1.70 x 14.7) - 14.7
= 25.04 - 14.7
= 10.34 psi*

*The difference can be attributed to inlet restrictions.
"It also states that this equation can be used for any positive-displacement supercharger, including the Autorotor from Kenne Bell, a Whipple Charger, a Magnacharger, and even an old GMC Roots-style 6-71 blower."

 

[MMShaggy]

3" upper 5# lower here @ 17lbs of boost on stock block KB 2.3

 

[PhLoBuS]

I wouldn't use anymore than 15 especially up north here. I found out the hard way...

 

[03LCalgaryAB]

I wouldn't use anymore than 15 especially up north here. I found out the hard way...

Hmm time to reconsider my options, I don't wanna join the VBC too soon.

 

[txyaloo]

I was seeing 14lbs with a 3.65" upper and 6lb lower. When I added my MP idler bracket and a 3.40" upper, I saw 16lbs. That's running a 69" belt I believe.

 

[03LCalgaryAB]

^^
Thanks.
I think I'm going to do a 3.5" upper with my existing 6lb lower.