2# of Boost WTF?
Dealing with the MMS crank pulley......... I saw 11 psi with there crank pulley and a 4" blower pulley and my only mods were full exhaust...LT's not cats, baby cam 212/218 .522/.529 on a 114, and a LS6 intake............. How boost max to you want to see??
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Damn, no matter how much research you do You always miss something. That makes sense. You are right 3.2 is small.
How much is the pulley and where to get one?
Does Mike still sell them since he now only does E-Tune?
How much is the pulley and where to get one?
Does Mike still sell them since he now only does E-Tune?
Last edited by Ed LS1 Vert; May 12, 2004 at 11:59 AM.
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Originally Posted by NA$TY-TA
Dealing with the MMS crank pulley......... I saw 11 psi with there crank pulley and a 4" blower pulley and my only mods were full exhaust...LT's not cats, baby cam 212/218 .522/.529 on a 114, and a LS6 intake............. How boost max to you want to see??
Overall goal is 500 rwhp.
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Originally Posted by Todd2001SS
I know you will get lots of good opinions, don't be disappointed if it take a few tries to get what you want with boost. It takes time and trial and error.
Originally Posted by Todd2001SS
It soulds like ATI is stepping the pulley one size at a time (from their pulley selection) for you to safely get where you want. The 3.8 probably will not quite get you where you want, don't be up set. I am thinking 3.6 or 3.4 will do it for you. I am leaning toward you needing the 3.4 pulley.
I was running the same boost you are with the 4.1 = 2# (reading the gauge is not easy because of it's size but it was close to this) The 3.4 got me to 5# of boost. These readings were with my stock LS6 intake. When I changed to my Lingenfelter intake my boost went down, (the volume is greater in the intake) then I bought the MMS pulley to bring boost back up.
Remember, you are not experiencing anything out of the norm. Mods always change boost. It will take a little time to get it where you want.
Thanks for the compliments on my engine compartment, show has always been my first goal. Like I said before no I am getting into the tuning aspect.
Good luck!
Do I need to break-in the belt?
I also have a 3.2 pulley should I just install that?
Last edited by Ed LS1 Vert; May 14, 2004 at 10:36 PM.
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From: Marysville, WA
Originally Posted by Ed LS1 Vert
You guys are right as always. I installed the 3.7 pulley that ATI sent me. Got only 2.5# - 3#.
Do I need to break-in the belt?
I also have a 3.2 pulley should I just install that?
Do I need to break-in the belt?
I also have a 3.2 pulley should I just install that?
Isn't is a pain, Mods...
Just install the 3.2 if you have one, worst thing it can do is slip, use the belt they list for the 3.4 pulley and you will be able to tighten the adjuster almost all the way down and get a good amount of wrap. You already have your timing pulled back a lot so you should be OK.
An MMS pulley and a 4.1 is a good combo but if you have a 3.2 try it.. With a P1SC/stock crank pulley and a 3.4 you will see ~6.5psi at sea level and 7.5psi with the 3.2 @ 6500rpm if you have a decent exhaust on the car. 6000rpm will be almost 1psi less..
An MMS pulley and a 4.1 is a good combo but if you have a 3.2 try it.. With a P1SC/stock crank pulley and a 3.4 you will see ~6.5psi at sea level and 7.5psi with the 3.2 @ 6500rpm if you have a decent exhaust on the car. 6000rpm will be almost 1psi less..
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Mods a pain? Some, but I guess that is half the fun.
I will go ahead and try the 3.2 pulley. At the rate I am going, I don't think I can hit 5# with the ATI crank pulley. Where can I get a MMS pulley??
What would be the boost for:
MMS + 4.10
MMS + 3.7
MMS + 3.2
I am going to have to send one back to ATI
Thanks again guys.
I will go ahead and try the 3.2 pulley. At the rate I am going, I don't think I can hit 5# with the ATI crank pulley. Where can I get a MMS pulley??
What would be the boost for:
MMS + 4.10
MMS + 3.7
MMS + 3.2
I am going to have to send one back to ATI
Thanks again guys.
you should be able to hit 5psi with your cam with a 3.2.
Impeller speed @ 6000rpm, stock ATI crank pulley:
4.1 = 35100rpm
3.7 = 38894
3.2 = 44972
MMS pulley,
4.1 = 47100
3.7 = 52191
3.2 = 60346
I would see where you are you are at with the 3.2, if its not enough do the MMS + 4.1. Morgan Mototsports in california made those pulleys, I dont know if they are in business still but I know they quit their web part of their business a while back..
Impeller speed @ 6000rpm, stock ATI crank pulley:
4.1 = 35100rpm
3.7 = 38894
3.2 = 44972
MMS pulley,
4.1 = 47100
3.7 = 52191
3.2 = 60346
I would see where you are you are at with the 3.2, if its not enough do the MMS + 4.1. Morgan Mototsports in california made those pulleys, I dont know if they are in business still but I know they quit their web part of their business a while back..
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Verdad Gallardo Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Thanks for the info. I installed the 3.2 pulley this morning. Wasn't able to get the rpms up too high about 5900, but did see 4# of boost. I need to get a smaller belt. Belt is tight, but idler adjustment is maxed.
Time to find a MMS pulley.
Time to find a MMS pulley.
Teching In
Joined: Mar 2002
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Originally Posted by Ed LS1 Vert
Spun it to 6300.
5# boost! Finally!
I think I hit 5.5# but damn thing was moving and I had to put my eyes back on the road. 
Thanks for all the help guys!
5# boost! Finally!
I think I hit 5.5# but damn thing was moving and I had to put my eyes back on the road. Thanks for all the help guys!
Dont be so down on the 3.2, I have over 100 passes (shift the car at 65-6600rpm) and a couple thousand street miles on my stock crank pulley/3.2 and my boost is rock solid.
I do have a riechard pulley and keep it fairly tight, if you had to buy one or the other and already have a 4.1 I would go with the MMS though. Unless you you can find a good deal on a RR 3.2 like I did
I do have a riechard pulley and keep it fairly tight, if you had to buy one or the other and already have a 4.1 I would go with the MMS though. Unless you you can find a good deal on a RR 3.2 like I did