sschoeffler

iTrader: (24)

I can easily feel when the boost kicks in, at around 3800 rpm but it feels like it bleeds off at higher RPM. According to the boost gauge I am holding 4psi at the higher RPMs. But the question is, why does it not feel like it pulls hard all the way up top. It feels like it pulls hard in 2nd gear and the beginning of 3rd when the boots starts but by about 4600 rpm the set my *** in my seat seems to fade quite a bit. 4th gear shows that I am boosting but it doesnt feel like it at all. Is that the for sure method of knowing your supercharger is too small or should it pull just as hard all the way once the car is in boost?

Bob@BruteSpeed

iTrader: (16)

It should continue to feel like it is pulling hard, it sounds like you may have belt slippage. Do you see black belt dust on the blower?
Feeling the boost come in at 3800 rpm is pretty far up in the rpm range, what pulley do you have on the head unit?
What air filter do you have on the ProCharger? Bob

Packy

iTrader: (11)

I would think it is probably belt slip as well. Check for the things Bob mentioned but I would also think that your P1SC is not enough blower for a 408ci. What size of pulley do you have on the S/C?

Aster

iTrader: (9)

When I originally had my 383 built and maxed out the old P1 I had it would start to fall off early on the dyno. The power would stop climbing around 5200 RPM. The blower just couldn't keep up with the motor to keep building power, just kind of flat lined. You could be feeling that effect, otherwise like Bob said it could be belt slip.

LS1RedZ

iTrader: (19)

That 408 is making that P1SC its bitch. Man you need a F1 on that 408 or at least upgrade to a D1, that is if you have the funds to allow it! Are you running a 6 or 8 rib system?

Detoxx03

iTrader: (14)

Exactly

sschoeffler

iTrader: (24)

Found the problem. It was in the tune and running extremely lean. Fattened up the fuel tables quite a bit. I hit 131 MPH in a bit less than 11 seconds now and the tune still needs more work. This is off some 42lb injectors. Here is a video.

b727pic

iTrader: (1)

Unless your base fuel pressure is extremely high and or your running 16 of them instead of 8, I don't see any way those 42's are going to support your setup.

Before you spend a ton of time tuning, you might as well throw on a set of 60's minimum. depending on your power goals might even step up to 80's.

sschoeffler

iTrader: (24)

Well I have found several problems. First off though. I went to Lowes to get some stuff to block both ends of my charge pipe. Just after the supercharger and right before the throttle body. Started to pressurize it with an air pump and it would not hold pressure. Ran my hands all across the pipe and found an obvious spot which was at the air temp sensor. Wrapped some electrical tape around the end of the sensor and slipped it back into the rubber grommet. Still wouldn't hold pressure so I got to checking the Vortech Mondo bypass valve and it was leaking out the side where you can put the filter on it. Put my hand on it to create a seal and bingo it was holding 20psi and I got tired of holding it. So I pulled the bypass valve off and there is no gasket that goes between the plunger and the plunger seat. So now I have got to find a gasket for it... It would not hold 1psi without holding my hand over it. I called summit racing and they don't sell one for it so I am going to Lowes again tomorrow and maybe they will have a rubber gasket that goes between a tub and the drain pipe and glue that baby in there. I will post back and let you know the results.

Bob@BruteSpeed

iTrader: (16)

I'm glad to see you found the problem, that's always a good feeling! Bob

sschoeffler

iTrader: (24)

The pulley is a 3.25
I have 2 pullies for it and there is an oddness between the two. Both pullies have an offset on opposite side. The 3.25 pulley has the offset on the front side(the side where the pulley size is located) The 3.45 pulley has the offset on the back side (the side the pulley size is not indicated) When I say offset you can take a straightedge to one side of the pulley down the middle and it's even. Turn the pully around and the straightedge will sit on top of the offset of the pulley. When I received the supercharger the 3.25 pulley was bolted on. There is no spacer between the pulley and the supercharger but there is one between the retaining nut and the pulley. Bob at Brutespeed sAid there must be one there but spacers are also sometimes needed between the pulley and the head unit. The reason this came up is because I noticed the belt was rubbing on the J-Bracket.

Aster

iTrader: (9)

If you have an 8 rib system then you need to shim the pulley away from the head unit .2". You can order two .1" shims directly from procharger for fairly cheap. Without that as you have found the belt rubs the bracket and the pulley is out of alignment.

Bob@BruteSpeed

iTrader: (16)

The pulley on an F Body should not have an offset, and I'll bet that is where your problem is. I didn't think of that when you called me last week. Here is a link to the pulleys that are used on these cars. http://shop.brutespeed.com/ATI-DPxxx...-ATI-DPxxx.htm The pulley comes with the washer/shim. Here are extra shims should you need them. http://shop.brutespeed.com/ATI-PDW01...PDW01C-100.htm Bob