Help with Powerdyne 9psi kit

[fidstang]

First off, I had underdrive pullies when I bought the car so when I installed the supercharger I had to use the underdrive water pump pulley. Now I have a over heating problem! Any ways around this?
Second problem is I'm only seeing 5psi of boost from a 9psi pulley. Anyone have any idea's as to why. The damn belt is a tight as I can get it. What would cause a smaller amount of boost then the kit is supposed to supplly?
I did have to replace the belts for both accessory and blower with longer ones because the stock acc. belt was about a 1/2" to short and the blower belt I couldn't muscle onto the blower pulley.
So I went with a 1/4" longer belt for the blower.

View attachment 444818

 

[just4bob50]

First off, I had underdrive pullies when I bought the car so when I installed the supercharger I had to use the underdrive water pump pulley. Now I have a over heating problem! Any ways around this?
Second problem is I'm only seeing 5psi of boost from a 9psi pulley. Anyone have any idea's as to why. The damn belt is a tight as I can get it. What would cause a smaller amount of boost then the kit is supposed to supplly?
I did have to replace the belts for both accessory and blower with longer ones because the stock acc. belt was about a 1/2" to short and the blower belt I couldn't muscle onto the blower pulley.
So I went with a 1/4" longer belt for the blower.

View attachment 444808

I bought the summit racing hi-flo water pump for 60 bucks new and then put in a duralast 180 t-stat with the check ball removed from the bypass hole. This made a huge improvement in temps. As for the the 5psi thing, Im not sure, with my 6psi pulley I was making 6psi. If you have the the 9 psi pulley it should measure 2.93". The 6psi is 3.12" Also I know you said the belt was as tight as you could get it, but I found that the belt has the best tension when you cant flip it over past the 180 deg. point. check the belt in the middle of the longest section. I found that with the new belts that I used I had to tighten them up every couple hundred miles because of belt stretch. After about the time all the stretch is out. All belt are different though, mine were from AutoZone and were the cheap ones. I would usually see a 2-3 psi drop and new it was time to tighten up. Of course check the obvious like vac. leaks and all clamps are tight.

One other thing is this. PowerDyne rates there boost at 6000 rpms on a stock motor. So if your rpms are say 5500 and you have a good breathing modded motor you will see far less boost. My friend has the same pulley set up on his blower and crank as me but he has AFR 165 heads and mine are stock. At 5000 rpms he makes 391hp with 7psi while I make 368hp with 10psi.

 

[PoopDawg]

Do you have heads or an intake? The more port volume= less PSI. 9 psi is based on a totally stock engine./

 

[fidstang]

I have edelbrock rpm head, RPM II intake and a stage one cam. Full exhaust and still only getting 4-5psi of boost. The belt is tight, I'm leaning towards the bosch bypass valve. But, I still need to measure the pulley, which I did when I first got it but forgot what I measured it at. I think it was 2.98 or 2.99. I do spin the motor up to 6250-6500rpm. If the bypass valve doesn't work I may try a smaller pulley for the 12psi. The car dosen't see very many miles per year, 600miles if I'm lucky.
Just need some idea's as I've been over the vaccum fittings and clamps 200times. I did have to go with a bigger belt then what cam with the kit as the original belt would not go on no matter what I did.
Sorry for digging this old post up but I've been bussy here and there working.

 

[bentley429]

It sounds like you have a good flowing h/i setup which like everyone else said flows better so you will be seeing less psi. Are you sure you have the 2.93/6.5 pulley combo? If your looking for more I would suggest getting a bigger crank pulley thats a 1 peice verus the 3 peice spacer idea that powerdyne wants you to run.

 

[fidstang]

It sounds like you have a good flowing h/i setup which like everyone else said flows better so you will be seeing less psi. Are you sure you have the 2.93/6.5 pulley combo? If your looking for more I would suggest getting a bigger crank pulley thats a 1 peice verus the 3 peice spacer idea that powerdyne wants you to run.

I was expecting to see a little bit less but not only 5psi. I did measure the pulley and it is 2.95. So I think I might try a quick run without the bypass valve to see if I get more boost. Would doing this damage the internal belt even if it was for only one first gear run?