FlyingFinn

I hope it is ok for me to trying to keep this old topic alive because the problem is not solved yet. Here is more info about my car (I'm sorry for my ADD)

98 T/A A4 with CompCams XR269HR (216/220 .525/.532, 114 LSA, negative overlap)
Patriot Stage II LS1 heads
LS6 intake
Hooker LTs & cat-bak w/one 3" cat
fueling mods (62 lbs Siemens high impedance injectors + Walbro 255)
AND a P-1SC-1 with standard dual (3.5"?) intercoolers and a used standard inlet filter.
Tuned for mentioned mods and 8-10 psi by PCM4Less.

I still have a boost problem. There are no boost leaks, BOV is working properly and has a right sized gap, intercoolers are ok, engine oil dipstick stays in place and hardly any fumes come out from a valve cover breather. 1 - 1,5 psi @ 6000 rpm.

It has a stock 6" crank pulley and a 4.1" S/C pulley.. So the impeller speed is 37000 rpm when engine is turning 6200 rpm, if my math is correct.

Bob from Brutespeed has helped me to rule out leaks etc, he's a gift for people addicted to boost Just trying not to bug him all the time.

My questions are:
Can those standard Intercoolers be restricting the boost in my car? (~390 rwhp N/A)

Is the filter supplied by Procharger for P1 is restricting? (I have head about 2-3 psi increase with a bigger one)

Wrong sized pulleys?

Right rotation head unit + no boost leak + no belt slip =

Should I move to 8-rib kit?

Are there any other things that I have not asked yet?

I will truly appreciate any help, dyno day is 16/5

scottsman

iTrader: (15)

Try this approach out. Look at the head unit with the pulley towards you and the impeller to the rear. As you know, the volute housing will rotate 360 degrees for lining up your outlet air to the intercoolers of choice. Rotate the volute housing (in your head is also good) to where the outlet tube is located on the top of the head unit, if the outlet tube is pointed to the left, it's standard rotation, if it's pointed to the right, it's reverse rotation, which is the one you need for a 4th gen F-body. Hope this helps, I use this approach to look at units for sale on E-bay and other sites and it works. I have a d-1sc on my car and also have a P-1SC-1 in a box. I can take a picture of mine if my explanation above doesn't help you, let me know.

tictakman

iTrader: (6)

vertical flow or horizontal flow intercooler? I couldnt boost past 2lbs with a horizontal flow and i switched to a vertical flow, boost fine now.

indyboom

iTrader: (11)

204//

Bob@BruteSpeed

iTrader: (16)

He has the standard 3.5" twin intercoolers that come with the ProCharger 6 rib kit. Bob

Bob@BruteSpeed

iTrader: (16)

Is your head unit a P-1SC or the P-1SC-1? If it is a P-1SC that I would expect it to make next to nothing for boost with your cam and a 4.10 blower pulley with the tiny 6 rib 6.0 crank pulley. In any case 37000 rpm is not much rpm for either one of the above head units. I'd say to forget that you initially saw the boost you saw when you first installed it, and assume the blower pulley is much too large to make any boost at all. 37000 rpm at 62000 engine rpm is barely turning the blower.
Back in the day I had a ProCharger D-1SC 6 rib kit on my '99 Z28, engine was stock with 110,000 miles on it, all it had was Hooker headers and an off road y pipe with a Hooker cat back. 6" crank pulley, 4.00" blower pulley and it made 7 psi at 62000 rpm at an elevation of 900 ft. The D-1SC makes more boost than the P series of blowers with any given pulley size. Bob

FlyingFinn

It's a P-1SC-1 according to that blue tag on top of the headunit. So it seems that I need to spin impeller a lot harder. Do you sell larger crank pulleys? Can I even get larger crank pulley if I use the stock balancer? I Can't afford ATI balancer, 8 rib kit or SDCE kit right now What are my options if I want to get say 8 psi of belt slip free boost with a 6 rib?

Thak you!
J-P

Bob@BruteSpeed

iTrader: (16)

Your best bet is to have a machine shop over there make you a larger 8" diameter crank pulley. No one over here makes one at the current time that I know of, I've had machine shops make them for me in the past for customer builds. Bob

FlyingFinn

Thank you for a fast reply! So an 8" crank pulley will fit ok without ATI balancer? Luckily there are couple of machine shops just a short drive away. I also have a bell shaped water pump and I've heard that sometimes it can be an issue.. Is it?

JP

Bob@BruteSpeed

iTrader: (16)

You're welcome. Yes, an 8" pulley will fit without going to an aftermarket balancer. There was company over here that use to make the exact same pulley, which I put on my Camaro back in 2003. The standard bell shaped pulley on the water pump is not a problem. Bob

ChevyChad

iTrader: (50)

As has been stated already, you are not really working the blower much at all with that pulley ratio. I'd get a smaller head unit pulley or a bigger crank pulley, or both lol.. It would be ideal to get an 8 rib setup for now if you could because it would suck to spend money on pulleys now that you know you are going to replace later.

As far as knowing if your head unit is reverse rotation or standard rotation, get the serial number off it and call procharger and ask. They can tell you when the kit was bought, what application it is set up for, and any other service records they might have on the unit. Its a nice check for any head unit that you would buy used.

FlyingFinn

You're absolutely right about getting an 8 rib straight, but unfortunately it's not possible until september and by then there are no drag racing and one mile events to attend... I try to keep the 6 rib and get it to make 7-10 psi and save money for a D1 8 rib.

I looked at the tag where the serial number is. Only three last digits of it were visible. Something rapidly moving has been in contact with the first digits of serial number. It's kind of strange that P-1SC-1 is clearly punched/carved to the tag, but serial number is not. Just painted I would be really amazed if mu head unit is standard rotation because it blows air when charge pipe is disconnected from throttle body. Impeller also rotates counterclockwise.

J-P

FlyingFinn

It's time for an update. According to TAT dyno it actually makes 3 psi of boost at 6092 rpm.

My Trans Am dyno results (engine power & tq)

433,8 Hp @ 6092 rpm
440,3 lb-ft @ 2824 rpm

It's running a bit rich, AFR is roughly 12.5 the whole rpm range.
It goes from vacuum to boost at 3750 rpm, then kind of peaks to 1,5 psi @ 4100 rpm and climbs steadily to 3 psi @ 6092 rpm

Dyno operator said that the engine is running like a swiss clock and is ready for more boost. He also said that in Dynojet I would get same numbers - at the wheels

J-P

Bob@BruteSpeed

iTrader: (16)

Above 5000 rpm you want the tune to be richer, I'd shoot for a 11.5/1 air/fuel ratio. 12.5 is going to be too lean up top. You're making boost so you know the rotation is correct, you just need more of it. Your blower pulley is way too large, something in the 3.20 range would be where I would start at. Here is a link to the pulleys. http://shop.brutespeed.com/ATI-DPxxx...-ATI-DPxxx.htm I'd still try to get a larger crank pulley made, but you could try a 3.20 pulley and see what it does. Bob

FlyingFinn

Thank you Bob, I'm still looking for a place that can make a larger crank pulley for me. I will think about that 3.2" pulley for sure.

There was a strange lean peak as you can see from the papers I scanned.. Car will be tuned in dyno after I get right sized pulleys. Now it has mail order tune.

J-P