GeneSch

I've been using the calculator on the vortex web sight but its just hard to figure out where it will be at.

My car C6Z, had a stock lower with a 3.43 blower pulley and made right at 7 lbs with a restricter. ARH 1-7/8 no cats and meth.

Now I have added a cam and lower compression and want to run this blower at max before I take the leep into a 2200.
I know the better things flow the less boost I will see.
Im looking to max out the blower with out really over spinning past any safe rpm with the motor at like 6,500 RPM

I now have a 10 over crank pulley with a 3.6 blower pulley. It makes 9#lbs with no restricter but starts to fall off at 6,000RPM. I want it to hold till 6,500 if It can. I may have a boost leak or this blower is just out of steam.

Im only asking because its safer to ask now then ask why it broke later.
With my 10 over lower, what pulley should I run on the blower for max RPM out of the blower. Im getting like 3.33 ish

Louis Gigliotti

Do you have a boost curve? Sounds like belt slip.

Spoolin8

I run a 1500 with a 3.48 pulley and no restrictor, with identical mods (minus the 10 over crank pulley) on a LS2. Right around 11-12psi

Obviously you are going to flow more with the LS7 but I would think you should be between 12-15psi with those mods and +10CP

GeneSch

I don't yet. I do hope it is that or maybe the intake isn't tight enough. I am easy on those bolts. I don't want to break one so I just snug them down. Stock intake.

GeneSch

That's about what I was thinking. Around 12 or so. I will check for leaks and slip.

MBB

I agree with Louis, belt slip. My car wouldn't make power above 5800rpm until we went with a shorter belt. The old one had too much slack and was slipping a tooth or two at a time while under load.

My LS3 is at 14psi or so, (3.25" pulley, 8" lower 10% OD pulley) but as you know boost is relative and a measure of restriction so really it doesn't matter what boost I'm at vs you because it's the boost curve that would tell you what you need to know.

lt1z

I run a TI trim (same as 1500) with a 3.47/8.0 pulley combo. It makes right at 14 psi at 6500 on my 377. That is spun to the max 55000 rpm.

GeneSch

It may be belt slip or boost leak. I will have to look at it more. I put a new belt on and it looks to be tight. I may need to go down a size on the belt but i only see like 7 to 8 lbs with a 3.6 pulley and a 10 over balancer.

I don't want to invest in a tighter belt when I know I have room to go down on the pulley. I will be sure to get one that is near imposable to get on. LOL

I think 10 over would put the LS7 at 8.25 but I'm not sure.


What is the smallest pulley I can run with a 10 over balancer and not hurt the blower. I wouldn't go over 6,750 rpm on the shifts.