Pulley size for LESS boost on eaton?

[88silvergt]

OK, please dont flame me too bad. I have a 68 camaro I put a LT1/T56 combo in. Now I am about to do a custom intall of a M112 Eaton of a 03/04 cobra. A couple people have already done this with great results at a great price. The problem is they are running 7 to 8 pounds of boost with the stock pulley which with my engine needs to be intercooled or meth/alchohol injected at that level. I am going to be driving the car alot and would rather lower the boost around 5 to 6 lbs and not run the extra stuff. So what is the size of the stock pulley on a 04 cobra? And does anybody make one that will effectively lower my boost? It shouldnt take much of change to do 1 to 2 psi but on a pump gas engine its worth it to me to not risk hurting something. Please do not get angry for asking on this site but you guys are the most knowledgable on these superchargers so I figured you would be who to ask. I still own 3 mustangs so im not a trader, just playing frankenstein lol. I'm in the army and currently deployed to afghanistan so I am just collecting info/parts for when I get home in 5 months to get this done. Thank you for any info/help you can provide.

CW2 Watkins, Thieman L
U.S.Army

 

[03DOHC]

So what is the size of the stock pulley on a 04 cobra?

3.65"

And does anybody make one that will effectively lower my boost?

That's a good question and I don't have an answer. Most people try to get more boost than stock not less. You could try contacting BilletFlow and ask Doug if he can make you a larger custom size upper pulley.

 

[01yellercobra]

Would it be possible to run an under drive crank pulley to lower the boost?

 

[88silvergt]

That was actually going to be my second choice depending on cost of a bigger s/c pulley. Seems possible but I would prefer to not slow down my alternator. Would just be easier with a diff s/c pulley but we will see.

 

[92z28]

You know it is possible to put a Gen 1 SBC blower like a weiand on an LT1, if you want fuel injection thats possible too. This maybe a simpler route then to try to place the Eaton meant for a mod motor on a chevy pushrod engine.

 

[88silvergt]

I've already seen most of how its done and i've already purchased the M112. Its really not as bad as it sounds. Some good sheets of 3/8 alum and a good tig welder and a good imagination is all thats needed lol. Only thing I really need right now is to find a slightly bigger pulley for the eaton and I will be happy. Thanks.

 

[mysteed]

As far as I know the 3.65" stock pulley is the largest pulley available. You can ask a company like ASP to make you one that's a little larger (a 3.8" should be what you are looking for). What some v6's are doing when running the m112 is to utilize a stock pulley and a 25% UDP, which underdrives the blower and it makes a mere 5psi.

Do you have any links to installs like you are wanting to do?