TemjinX2

Hi guys,

I was reading on the srt forums and i read about a guy that machined down his stock pulley to create more boost.

I would rather to machine down the sc pulley rather then overdrive my accessory pullies.

I was thinking of machining down the code pulley from 65mm down to 62mm..basically creating the same boost as a LET 185.

You think it would be ok or is 65mm the smallest the sc pulley can be safely run?

c32AMG-DTM

Two potential limitations I can think of: one, you need enough material for the pulley to be structurally sound, since it uses the stock S/C bearing (not sure what it's OD is), and two... you'd likely have massive belt-slip problems, unless you fashion some sort of belt-wrap kit to deal with it.

Keep us posted though - interested to hear what your results are.

jturkel

is this SLKGermany that you are referring to on the srt forum?

i dont see why you cant machine it down for more power, should work. the only problem is that belt slip may significantly increase and you may need to change the belt size.

kindafast

You would probably get lots of belt spin and besides code3 pulley is designed to run on our cars, to me you are taking risk and gains outweigh the loss ($800). Just my 2c.

Let's see what MRAMG will say

See Yeah! lol

TemjinX2

yeah, reading his post gave me the idea.

i bought my code3 pulley used for $450...so if i can machine it down to maybe $100 and get the power of a LET 185, i'll be happy.

I'm more worried about the structural integrity issues rather then belt slip.

The other issue is that i might need to switch to a higher rpm bearing? Kinda like the new LET vs old LET crank pullies?

hooleyboy

I was thinking the same thing today, except doing it on a 55k crank pulley to lower boost.

TemjinX2

do you know how much they would charge for maching it down?

CLKCLK

I personally don't think bell slip will be a bigger problem compare to LET 185mm. Well the bell slip problem is always there, but to compare between the two: The LET's "super" smaller guide pulley will also create bigger angle. To sand down the supercharger pulley you also create a bigger bell angle. Which one is bigger? I am not sure. But I think LETs will probably be bigger (I may be wrong) so take my opinion at your own risk The bigger the angle is the more bell slip occurs.

The point here is why do you want to sand down your code3? If I sand it down, I definitely sand the original pulley down

The idea is right but I think it may be too thin for the pulley. (Yes it's possible)

hooleyboy

I can try and find out, the only thing kinda putting a damper on my plans is just that the damper on the stock pulley might be in the way. IT was just an idea I tossed around to the guys who are doing the install.

I tell you what If there is enough material still on the C3P SC pulley i would think you could machine it down....I would bet a skilled machinist could do it.

Something to think about though if you do run more boost then the C3P SC pulley you may run the risk of putting your supercharger out of its efficiency range.

With my case I'm not sure a stock crank pulley could be machined down enough to lower the boost to a safe level and still stay structurely sound.

TemjinX2

yeah originally i was thinking the code3 since it already has a new bearing. But your probably right, i'll probably just use the original since its already off the car.

TemjinX2

after talking to one of my ME friends. I'll probably just use the oem pulley since its already off and i dont really have to worry about structural integrity issues as much. i'll probably call a couple of machine shops tomorrow and see what kind of pricing i can get. My friend told me it might be a couple of hundred dollars, so i'll see where the pricing is before i continue with the project.

c32AMG-DTM

Not following you here... you're going to machine down your OEM S/C pulley? Why, when you already have a C3P S/C pulley? Or do I misunderstand you...?

TemjinX2

well couple of things. I paid $450 for the code3 pulley so if the project is a dud then i lose on the $450 i spent plus the cost to machine the pulley. If I use the oem pulley and it craps out, i can keep the code3 pulley and later trade someone for a stock pulley and cash when i want to put the car back to stock.

Plus the oem pulley is probably built to a higher quality then the code3 and its already off the car. I can take the pulley and get opinions from experienced machinists on my project and see if its fesiable to machine down it down that low from there experience.

Everyone saids its doable from a theory stand point, i think this is one of the cases where talking with someone with experience can give further insight.

Fcs32amg

is anyone selling a code 3 pulley by any chance and could someone possibly direct me to a forum that has oppinions on if these wear on your motor. I have a 2002 c32 with 75k and a lot left in loans on it so i dont want to mess up my car. Please let me know thanks guys

bumpnzx3

anyone thought about the fact that code3 decided on their size for a reason? is it possible that machining the pulley will overdrive the SC too much? i would think that they have done their research.

TemjinX2

the other site states the sc can go up to 20000rpm on the supercharger, which is in line with the other ihi superchargers i've seen on the net. But the fuel injectors and fuel pump will crap out way before that.

I machined the oem pulley down to 70mm from the 74mm. I might just do with a duel stack pulley setup with a 178 asp/evo and 70mm which would be slightly higher then the 185 LET setup.

SRTpowa

just get a 178 and the code3 mid sized pulley. I'm lovin it. New track times next weekend, weather permitting.

TemjinX2

well i got my pulley machined down for free. so it didnt really cost me anything. I'm debating whether i should try to machine down further

jturkel

dont machine to where it puts you past the safe limits of the S/C

c32used

Good luck just be careful.

TemjinX2

considering the code3 pulley is at 65mm and i only have it down to 70mm. i got still got a lot of room. i'm debating whether i want to go with a duel pulley setup or not.

SRTpowa

the new Code3 mid pulley is 68mm. I'm seeing 15#'s almost instantly and 19-20#'s peak, with it and the ASP 178. Car runs strong and I hope to havve some new track times soon. There has been some talk of running the 65mm Code3 and 178 with possibly a wastgate to kepp boost at 22#'s and prevent overboost. Who will be the first to try it?

TemjinX2

So i got my buddy to machine down the stock sc pulley to 70mm. I'm thinking of maybe going with a LET 185 and a 70mm sc pulley.

going off a forza's formula,

178/65 combo would push the supercharger to 16,430rpms

185/74 = 15000rpm

178/ mid code3 pulley 68 = 15705 rpm

I'm thinking maybe

185/70 = 15857 rpm

You guys think 15800rpm would be viable for the supercharger since we know at 16400, it makes the car run too lean.

cruzinquick

I think forza still has his for sale on the cf forum.

TemjinX2

yeah i thought bout buying his evo pulley, but he sold it already.