Title said it all. My math must have been off a bit, so taking 5.08mm off the stock pulley actually added a full 3psi, when I was shooting for only a 2psi increase.

I was going for 22psi max thinking that anything over that would cause the dreaded over-boost code, but so far it hasn't surfaced. It's obviously too early to celebrate, but I'm cautiously optimistic.

Merry Christmas guys and gals.


EDIT: Here's the receipt from where I had the pulley machined in case anyone is interested:

fc4f5499.jpg

 

At what point does the stock supercharger spin out of effeciency? Cant wait to see some results.

 

I must be fairly close, but the SOTP results are that I'm not there during daily driving.

 

I have gotten MAP errors on the Aero at 21psi......

 

You should have bought SSB.

 

LOL

 

hmmmmmmm...... I DID have an SSB and the Aero for 2 years.... I kept the 11 second car....

 

you guys crack me up...you know Black is the fastest, but not ready to unleash it yet...so I bought an Aero for the 11 second stuff...lol.... Merry Christmas DJ.... OK, back to "overboosting"...lol......

 

Grip Grip, you just performed the mod I was planning if I could find a stock pulley. I'm definitely interested in numbers when you get them. By the way, my car threw the overboost code with just the 181. Only has done it once, I was running hard on a very cold night. Cleared the code and it hasn't came back. Merry Christmas and enjoy the extra 3 psi.

 

But black comes in a 4 cylinder..now I'm confused..

2005 Chrysler Crossfire limited with 6 month warranty - $9999

 

dealers, what do they know....lol....that means you can buy it a lot cheaper....

 

Same here, I got the code one time only.

 

Wondering if you've done a pressure test after that one time max boost moment?

 

Anthony,
did you do your math based on adding 2 psi to the 34.7 psi your supercharge had been moving (ambient air pressure plus your current boost) or adding it to 20psi? (wrong way) . Not saying you did, but many people forget to factor in the ambient air pressure (14.7) and in doing so, add more boost than they intended with pulley changes.

looking forward to seeing what you find as you explore the frontiers for us : )

Chris

 

my math suggests that a 69 mm pulley should add 2.5 psi

and a 70 mm should add 2 psi (to a motor running a 181 crank pulley)


(20 + 14.7) x 74/69 - 14.7 = 22.5

(20 + 14.7) x 74/70 -14.7 = 22

Chris

 

In all these post no one has ask about the ARF's ,,,,,,,I hope you have a air fuel ratio gauge,, if no, there is a spare engine on e bay you may need it . if you AFR is at wot higher than 13.2 in about 50 runs ,,you will need that engine.,,,,and do you have enough fuel to support both pulleys?

please post your AFR. !!

jim

 

I'm hoping this works and for the 1/4 mile it may. I'm more interested in when you get the IAT's under control but from my limited experiments the only way is what Jim has resorted to. A heat exchanger with a strong fan. Super subscribed to what your trying. I'll be doing some trial and error when my manifolds arrive ..... and before the next racing season begins. I hope to contribute to the what works and whats a waste of time archives.

Les

 

Looks like my math was off, but I don't mind. As long as I don't see any codes I'm happy. I can deal with track IAT's when I cross that bridge. I've already added a larger H/E as well as the stocker, so I've got a head-start on getting the temps under control.

 

Like others, I have thrown an overboost code with the 181 (with the sl55 intake) .. only on a cold morning (3 or 4 times). If you are not throwing codes at 23, that is surprising, but good news.

If you want to start over, cutting on a stock sc pulley .... I have an original one that I would happily trade for yours (if you cut it down to 65 first : ) .... I will even cover the shipping.

Chris

 

I don't believe a stock pulley can be machined that small. If you send me your stock pulley I can have my local shop machine it for you. It cost me $178 to have it machined. I would even send you the receipt.

Actually, I can send you their contact info and you can work directly with them and save me the drive.