Pro Charger P-1SC or D1 for my application ??

Hoping somebody can point me in the right direction here. I have an '88 Iroc-Z with the L98 350. Internally, the motor is still stock but has been well maintained. (Doesn't burn oil or anything). Mods thus far have been limited to headers, cat-back exhaust and 1.6 roller rockers. I also have an after market TPI set-up waiting to be installed, when the weather warms up a bit.

I was looking to buy an ATI ProCharger but can't decide on which route to take. There seem to be so many differing opinions on which head unit to go with, I hoped someone on here could suggest something.

Right now, I'm torn between the P-1SC and the D1.

As I said earlier, my L98 is internally stock so I'm well aware of the risks of running too much boost into a motor with cast pistons/rods. ATI says that these motors can only take about 9psi at most. Anything more than that and you'd be seriously pressing your luck. I'm not looking to build a 1000hp race car or run 9's or anything crazy like that, I just want to have a fast little TPI 3rd gen with a tonne of low-end torque ;)

According to ATI's spec's the P-1SC is rated to 825hp. This is a lot more than what I hope to make (I think it's also safe to assume that's more than TPI would ever allow for :D ) and is designed to operate on engines with a base hp of between 200-500hp. The P1SC is also self contained which eliminates the need to punch a hole in the oil pan. Makes for an easier and cleaner installation and cost roughly $500 less.

I was going for the P-1SC but after doing some research on this and other boards, a lot of people are telling me to skip the P-1SC and go straight to the D1. Basically, I'm told that it has a lot more potential to make more HP and can handle whatever mods I plan to make to my engine down the line (stroker build-up). That's not so much an issue for me because like I said, I'll be retaining the TPI set-up on this motor which is going to limit my HP output anyways and besides, the P-1SC can handle 825hp so I think that about covers it.

What does concern me is that people are saying that the D1 is supposedly build with much heavier duty parts and will last longer. I'm told that because it flows 200cfm more air, it can make the same/more power as the P-1SC at the same boost levels without having to work as hard, thus, emitting less heat and increasing the engine (and superchargers) life span. Since I've never seen any direct head to head longevity comparisons between these two units, I don't know who to believe. I definitely want my Procharger to last a long time since it will be on a daily driven street car. Is the P-1SC really that badly built compared to the D1?

Also the P-1SC ranges from 6/9/12 psi where as the D1 ranges from 15-20psi. Should I end up going with the D1, does ATI offer 9 or even a 10# pully which would make it more compatible with a stock(ish) motor?

Finally, there's the issue of whether to go with a self contained unit, or tapping the oil pan. Again, there are mixed opinions here to. As mentioned above, a self contained unit is easier to install and if the motor ever lets go, or the supercharger itself for that matter, there's no risk of the engine oil getting contaminated with metal shaving or debree and causing even more damage.

Of coarse, others argue that using the engine's oil is better because there's a lot more of it circulating through the system which ultimately keeps the temperature down and prolongs the superchargers life.

I'd really like to hear from those with experience with either of these two superchargers or better still, from anyone with a Pro Charged 3rd gen.

Thanks in advance.

I would consider it serious mis-information if people are posting messages saying that ATI's D1 is not built with as much quality as some of their other units are. EVERYTHING that I have seen that ATI makes is nothing but top quality and they are far and above their competitors products...most anyone on this board will confirm that.

With that being said, as you probably already know, the secret to any type of longevity regarding a motor that uses cast parts and/or is not originally designed for boost, is intercooling. So whatever your choice is concerning any type of F.I., your choice should include intercooling. The dilemma that you face is the fact that you want a "safe" F.I. set-up now yet want room to grow.

Most people that have gone the forced induction route will probably confess that they became addicted to boost and as a result have continously opted for more. The real problem is that at some point you will need to make the decision that it is time to build a boost friendly motor before the current one gives out. If you are willing to pay the added cost to "upgrade" to the D1, then just beware that as long as you run it on the stock motor you should have a very conserative tune-up in it and keep the boost levels reasonable if you want to motor to last any length of time.

I think you should forge the bottom end BEFORE any boost. If you boost now, then forge the bottom end, you'll want a bigger SC'er and you'll kick yourself for not waiting. Forge now and get a SC'er to match your engine's capabilities, not the other way around. You'll save a lot of $$ that way and won't run as much risk of blowing your engine(which will cost even more $$)

Both are built very well and are self contained. None of their kits come with certain # pulleys. You can order different setups, but it will depend on your cars setup as to what boost amount you will end up with. Take my car for expample. I am running the pulley combo for the highest boost level available for the D1SC, and I can't do more than 15.3#'s of boost. I have seen others hit 18-20#s with their D1, it just all depends.

You pretty much have to ask yourself what power level you are looking for. I am not as familiar with the 3rd Gen stuff, but the P1SC will only put out up to about 10#'s from what I have seen, and that's totally maxed, so probably more like 6-8#'s on average. This would be good for an additional 100-150 RWHP to your car. Not enough for you? Go with the D1SC, as it will have more potential. If you are not sure, you can always go with the P1SC, and later have it upgraded to a D1SC.

I'd go with the D1. Pulley it to run lower boost, and when you build it stronger to handle more boost, (which will be inevitable at some point after you put this charger on), you'll already have a head unit that will support what you've done.

Ken R.