Stacked pulleys - 23 psi with no codes. :)
Stacked pulleys - 23 psi with no codes. :)
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
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
Last edited by grip grip; 12-27-2011 at 01:27 PM.
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Re: Stacked pulleys - 23psi with no codes. :)
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.
Re: Stacked pulleys - 23psi with no codes. :)
Originally Posted by oledoc2u
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......
2005 Chrysler Crossfire limited with 6 month warranty - $9999
Re: Stacked pulleys - 23psi with no codes. :)
Originally Posted by rtmopar85
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.
Re: Stacked pulleys - 23psi with no codes. :)
Originally Posted by grip grip
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.
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.
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
Re: Stacked pulleys - 23psi with no codes. :)
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
please post your AFR. !!
jim
Re: Stacked pulleys - 23psi with no codes. :)
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
Les
Re: Stacked pulleys - 23psi with no codes. :)
Originally Posted by latemodel21
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
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
Re: Stacked pulleys - 23psi with no codes. :)
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
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
Re: Stacked pulleys - 23psi with no codes. :)
Originally Posted by latemodel21
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
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
Actually, I can send you their contact info and you can work directly with them and save me the drive.
Last edited by grip grip; 12-26-2011 at 09:15 PM.