GregMB

All,

With the release of the newest fixed supercharger pulleys, it seemed like a good time to go back and rework my old pulley matrix to make it more complete.

My last chart also indicated that the smaller upper "clutch style" pulley was 83mm, when most people agree that it's actually 84mm.... a small difference, but it was worth correcting this time around.




This chart is missing one extra column of data that I'd love to incorporate, which is the actual boost (psi) for a given pulley combination. If someone can help me with the formula to derive those values from the information here, or provide a table of values based on SC RPM, I will update this table and repost it. Please let me know if you see any errors on this table as well... I think I've captured everything accurately, but you never know!

I hope this helps everyone out. There are a LOT of options now for both the upper and lower pulleys so it's not that easy to figure out how to combine them to hit a particular ratio (or boost) target.

Enjoy!

-G

Style_Front

Hard to determine the last factor unless the same car was used. With improvements to breathing efficiencies naturally there will be many nuances in actual pressure. Some guys report a drop of 1.5 psi with a good set of headers.

ginger55k

many thanks to GregMB

shardul

iTrader: (1)

Nice info!

Exotic-metal55

Nice chart and it will help out with all the questions and combos!

You may need an algorithm to come up with a boost chart Every mod done to the intake side will increase boost some over the pulley ratio, like larger air intakes, larger Tb and porting the blower, while porting heads and exhaust work will lower boost in general. Then last, blower effeciency drops off a lot, as you speed up the blower ratio and with that comes more heat.

G_Money

Wow great info! Thanks for taking the time to put this together and share it with us!

BagMan

Interesting that the 84mm clutched pulley is nowhere near a 172 crank as some vendors claim. It's not even as aggressive as a 168mm crank.

GregMB

I did some digging and found a Lysholm chart on an old MBWorld thread (looks kind of like a topographic map), but have no idea how to use all the data on that to extrapolate boost in any kind of meaningful way....

This thing:



I guess the best I could do it solicit feedback from people who actually do datalogging and get their peak boost (psi) numbers and try to add them to this chart? I'd probably need to put some footnotes to call out other "mods" like headers which would affect total boost...


From the MBWorld Archives: (need to validate)


stock==========154mm=10psi (number depends on gear and rpm)
Rentech/kleeman=168mm=12.8psi=+42rwhp
Various========172mm=13.6psi=+54rwhp
VRP===========175mm=14.2psi=+63rwhp
Various========178mm=14.8psi=+72rwhp
Evosport=======180mm=15.2psi=+78rwhp

-G

GregMB

Black Friday sales are happening soon..... I am trying to prepare myself when the deals appear!!!!

I figure there are probably a few other guys out there who are ready to spend some $$$ but just aren't 100% sure how all of these new products stack up against each other.....


-G

Style_Front

Interesting, top of that chart says max rpm is 13,500 rpm. I wonder if that's the limit Lysholm imposed to ensure longevity. It's already at 13,000 with just the 180 crank pulley. The numbers associated with the rings usually express efficiency. For instance the inner most ring expresses that the compressor has a pretty narrow peak efficiency window of 66% at just under 9psi while flowing about 15 cubic meters per minute. To me that's odd, most maps I've seen measure pounds per minute. Density is a better indication of potential Hp rather than space.

GregMB

I'm not 100% convinced that the chart I posted is an exact match to the supercharger on the M113K motors....

It was just one that I found in old threads, but the displacement appears to be larger than what is actually on our cars.

-G

99lightning

as i posted last week tested a car 2 weeks ago kleemans, and a 172mm pulley split intercooler 03 res like mine 54deg rise in aircharge on the dyno. My car stock pulley 27deg rise in intake temp same split. I started both cars at 63deg on the air charge to keep the test equal. and for my car at the track stock pulley 50deg rise in temp start to finish line.

Robert AMG

iTrader: (1)

i have measured the stock sc pulley many times, it is 91mm not 90mm and it is measured from groove to groove, so also the crank pulley must be measured from groove to groove, outer ring crank pulley is 156mm so from groove to groove is 150-151mm.
i have a question for everyone, when you say ex you have a 180mm pulley, is it from outer ring or groove to groove?,
just my thought to be more specific.

Koru_Kinshi

Suppose I'll just stick with a 175 max.

sircl55amg

nice info !!!!

thank's !!!

m3j0n

+1000000000

Ls1toAMG

Can't have a post with boost in the title without the boost

GregMB

Boost psi based on what assumptions?

It's almost impossible to say what the boost psi is unless you know every other component on the target engine (headers, no headers, ported heads) even a BWK can affect whether you get all the boost you "think" you should be getting.... Otherwise you might just be creating belt dust!!!

-G

Ls1toAMG

GregMG I agree. It's a chart that's been out here for years. Many vets have posted it. That being said its a general baseline. Helps compare increases with different pulleys. It's like comparing mods/dynnos in different locations. It's not to undermine your chart. It is interesting however.

dchl21

I heard too much boost triggers limp mode ? whats too much ?

BagMan

I think over 17psi

HeissRod

A bottle of Jack Daniels

sircl55amg

https://mbworld.org/forums/w211-amg/...alculator.html

cnterline

Can somebody convert that chart/graph so a 2 year old can read it ?

NafisC

Awesome!