c32kompressor

I'm getting milled down to 69mm, what kind of gain do you think ill get? I'm hope for 10+ HP and around the same tq. It's my birthday present. I wanted to go with a c3p pulley but can't find them anywhere! Hope to hear back from you all

Newzchspy

I am thinking with a tune that you would get 30-40 HP, not just 10.

buffyclk500

who is doing it for u

Robert AMG

iTrader: (1)

+1, get a tune from Jerry you will get much more from only machine down the sc pulley, plus you can get free remap if you will go more upgrading.

Newzchspy

My AF's were all wrong when I installed my Code 3 SC pulley about 30 months ago. Not only that, I shredded a belt since the original pulley's grooves were so aggressive to prevent slippage.(he subsequently fixed that problem) . Anyway, the engine was lean and Jerry retuned it to run a bit on the rich side. I wouldn't do a Code 3 pulley or a shaved pulley without a tune, despite Brandon's original assertions back in March 2008 that you didn't need a tune for it??

320 dreamer

c3 is 65mm and tune nets 20 hp and 30 ft/lb range

c32kompressor

should i be worried about this? i will be getting a tune in a month or so and i will go with jerry, but i dont want to severely damage the car. im having it done by a local machine shop

jturkel

if the code3 pulley is a 65mm and you're only going down to a 69mm, then there should be nothing to worry about tune wise.

like stated above, sometimes the grooves on the earlier c3 pullies may have caused wear and tear and broken belts. inspect the grooves carefully after it's machined down

c32kompressor

thank you jturkel, im was worried about it for a little while but i feel a little better. im getting it back right after school tomorrow so im a little excited too. i didnt go down to the c3p size (65mm) because i heard you needed a new bearing??

jturkel

for sure, a tune won't be a problem. you can run the code 3 and the 178 (i've run both) without a tune. you aren't near a code3, so you have nothing to worry about.

regarding a bearing, i suppose you could possibly need a new bearing since it will have a smaller circumference and will therefore spin more quickly, but i'm not familiar with the specifications or capacities of bearings on the oem or code3 s/c pulleys

saer1one

You should also replace the bearing while you have the pulley off.. Do you mind sharing the price with the rest of us..? Haven't heard of anyone else doing this to a c32.. Good luck..

320 dreamer

regarding the grooves in the c3. i have a first gen c3. the grooves run horizontal to the belt . this was to ensure better grab. and it did! shredded some belts due to the sharp edges. after the pulley wore in no more issues. never hurt a belt on mine with 19 psi boost logged. the parallel grooves should be the same depth as oem when machined down.

you might want to hollar at rob at needswings and order a c3 pulley saver kit. bigger idler pullies by 10mm and they spin slower so less bearing wear. inc. belt wrap also. oem idler by s/c was replaced 3 times in 1 yr with c3. after psk not a single pulley failure

c32kompressor

i wanted to be unique in modding the car and this is one way to do it! i will definatley share with everyone my outcome. i dynoed last at 330.2whp and 327.4wtq, i will be getting an after dyno soon

c32kompressor

I got it back today and wow, it really made a difference I'm very happy with the outcome. The only thing is I'm noticing some rubber residue on the outside of the pulley. Idk if it's slipping a little or the groves are wearing to the new size? I did a check to see if it was slipping by holding the brake like a break stand but only reving to 1700 rpm and it didn't slip?? Any ideas?

silverjimm

Who did your machine work on your pulley?

southernwake

Very curious about who did your machine work. I was just thinking about doing this to mine as well this weekend because I can not find the C3 pulley anywhere. I had not heard of anyone doing this though. Keep us updated because if this works for you I will definitely be machining mine down.

Andrew

c32kompressor

As for the butt dyno it worked, I haven't gotten any dyno results yet, I had a local machine shop do it for 60$ I milled it down go 69mm because I didnt know if the belt would slip.

AMG3.2

wow, this is sick! I really want to do this. If it only costs a around $60 at a local shop I'd be stoked. Could I machine it down to 65 mm like the code 3 and then get a tune immediately after?

AMG3.2

wait come to think of it... how exactly do they machine the pulley down if there are grooves? Do they machine it and then re-groove the pulley?

c32kompressor

They machine down each grove individually, I went down to 69 mm to be safe but I'm sure you could get away with 65. And yeah just tune it after

AMG3.2

Nice. I'm so stoked to do this. How hard is removal and installation of the pulley itself? Also, did you replace the bearing?

c32kompressor

Removal and instalation is super easy. Just look at the instructions for the c3. And no the bearing is stock

AMG3.2

nice, thanks for your help!

positronicC32

There's a groove apparently that limits the turn down on the stock pulley. I don't think 65mm is achievable because of this. Here's a cross-section that I found (props to whoever owns it). You can see the groove in this image. Up where the bearing sits, adjacent to the belt grooves. It's some plastic/rubber compound by the looks. Would like to have someone confirm...or at least what tolerance there is with turning down this pulley.





Tom2112 measured the pulley dimensions over on the crossfire forums...

http://www.crossfireforum.org/forum/...tml#post609606

Been discussing what the minimum mm is that the stock sc pulley can turn down too. I'm thinking 68mm at best without better evidence. I've read of a keen forum member that has machined down to 66.8mm.

Any thoughts?

AMG3.2

wow thats a good find (the pic). I'll want to go lower than 69 mm because I'm going to get a tune at the same time. I want to go as low as possible without compromising structural integrity.