2002 T/A

I am noticing that this valve never closes unless you are really under full load, so I ordered the 9 psi pulley lol. Has anyone ever limited the amount that this valve will open or created a restiction? I would like to see some boost at part throttle so its a little more usable. And please no comments on how I need a bigger S/C, I want to keep it under 10 psi, thanks.

conan

iTrader: (5)

Do you have the smaller pro flow or the big red bypass ?

2002 T/A

The smaller one that came with the, black.

2002 T/A

The smaller one that came with the kit, black.

conan

iTrader: (5)

Is there a adjustment screw on that one ? I have the big red bypass so I'm not sure on the smaller black unit.

If there is a adjustment screw, you want to start the car and pull the vac line off the bypass. It should close all the way with the vac disconnected. If its not adjust the screw untill there is no more air comming out and reconnect the vac line.

2002 T/A

Don't think so but I will have it up to check tomorrow. I am more concerned with part throttle boost, don't want to raise the IAT but seems like a lot is being lost!

95-1LE-Z28

iTrader: (33)

What size pulley are you running? I'm currently running a 3.85 pulley and I'm battling the same issue you are..I'm only seeing 5psi at full throttle and my part throttle response is subpar(a lot of that could be attributed to my 3600 stall)...Just feels like a turd until I,m in the 4k rpm range..I'm about to order order 3.70 to see if a bit more boost will improve throttle response.

2002 T/A

Really, at least I'm not alone with this, I was wondering if there was something wrong? Bob from Brute Speed say's it should be pulling from 2,800, he had an f-body in 02 with 4:10 gears, was sideways in 3rd? But, that was the older style impeller and I don't know what he was using for a surge valve? And 4:10 gears would help with that too! My kit came with a 3.4 pulley, I am installing a 3.2 this weekend, PC told me these are the only 2 options for the P1SC-1. I also have the 4.5in ICs, their inlet/outlet are 3.5 rather than 2.5in so there may be some combined losses there? PC told me with the P1SC-1 compressor map, I won't see much below 5,000? I think that this is high even for a centrifugal? I am going to "pin" my surge valve to limit its opening position, allowing some relief but more boost. At 4,000 with moderate acceleration, I'm still at 85kpa? Would like to know what others have done?

2002 T/A

Ok, so I did a quick mod to the valve that is simple, non intrusive and can easily be undone. I don't have a comparison because I also installed the 3.2 pulley, but I will get back if anyone is interested, just waiting on a tune.

Bob@BruteSpeed

iTrader: (16)

There is a huge difference in when the power comes in between your 5 psi and 7 to 8 psi. 5 psi would hardly make it worthwhile for the cost of a blower. Combined with your 3600 stall I'll bet it does feel like you can't feel it until 4k. Bob

Bob@BruteSpeed

iTrader: (16)

Les, do you have your car tuned now and you're going wide open throttle? Bob

Slowhawk

iTrader: (12)

5psi is pretty much nothing for a blower car, very lazy in the low rpm area's.

Going by the pulley sizes I'm guessing this is a 6 rib setup with the small crank pulley.

Any p1 kit we do gets 10-12psi. You just detune timing a bit in the high rpm area. This way you get plenty of midrange power.

Never had an issue with the bypass valves. Is it hooked up to the correct vacuum source?

The Alchemist

iTrader: (19)

So what did you do?

2002 T/A

No Bob, still waiting, have not heard back from PC either?

2002 T/A

Yes, it does work, just waiting for a tune so can't put my foot down!

2002 T/A

I didn't want to do anything intrusive or permanent, so I used a couple of tie wraps aroung the diphram shaft below the linkage. The valve will still work but is now limited to 50% travel. Once I get my tune I can play around now that the 3.2 pulley if on. If I get ant surging or high IATs I can just cut them off!

Bob@BruteSpeed

iTrader: (16)

I am confused as to why you started this thread when your car isn't tuned yet and you haven't been going wide open throttle. You're not going to know when the boost comes in until that time. Bob

11SECSS

iTrader: (199)

Why would you want any boost if you have no tune for it yet thats asking for trouble.

2002 T/A

I guess Bob as you know, even with the tune I was working with there was not much boost below 4000, which is where most of the driving is and where I'm logging fuel trims. So I wanted to know from others what their systems ran like so I would know what to expect, and gives me something to do as I have been kept in a holding pattern for the last 3 weeks! So, I have made some changes on my own and when I get this thing tuned I hopfully will be in a good place mechanicaly as well. So, I went for a little drive with the changes made, and feel a difference. LTFT still short of course, no detonation and hopefully a little closer to my goal! Thanks for your help with the other matter, I will let you know how it ends up, Les.

95-1LE-Z28

iTrader: (33)

I got into an accident in the rain last week and the insurance company decided to total my car. As such, I ended up pulling the trigger on a new roller with the intention of swapping my entire setup. As part of the swap, I've decided to switch from the twin intercoolers to a front mount and also step down to a 3.70 pulley....I just ordered an open race valve from your site...Hopefully the intercooler change and the smaller pulley will yield 3 or 4 additional psi of boost..I'm also going to send my 3600 stall back to RPM and have them re-stall it to 3000.....I'm excited to see how the car responds to the minor changes......