jon_volk

on a relatively stock l98 (just forged pistons) w/ a crane powermax 2032 what would be the diff in real world hp between a p1sc and a d1sc if they were both running at 12psi w/ a 3 core intercooler? i know the d1 will have more future potential but i dont plan on running more than 12psi to keep engine build costs down..not to mention i want to keep a cam thatll alow the car to idle no more than 750rpm and be happy w/ a stock converter so im not sure how much of an advantage that larger blower would be in my situation. also for cylinder heads they would be no more than self ported iron l98's

soooooo, what would be the HP diff between the two and which is better suited to my application?

unknown_host

iTrader: (1)

http://www.procharger.com/models.shtml

That is ATI's side by side chart of the models. The only thing that the chart shows is that the D1SC will take 32 psi as opposed to the P1SC's 30 psi. Its hard for me to believe that is the only difference, I thought they had a different internal step up but apparently not.

jeffsbluez

Build both and we will all find out To be serious, The D1 will move more volume, wich should, make more power.?! I know the D1 is going to be more efficient, wich will make better power over all. I don't know if the price diff is worth the advantage? Good luck in your decision-Jeff

B4Ctom1

I think if the volume is different it is in the impeller because the dimensions of these are the same even the impeller is the same size (P1-sc and D1-sc) but the impeller blade anlges are different. I was going to do the D-1sc upgrade ($1000) if I send in my head unit but they are so close I dont think it would be worth it...

unknown_host

iTrader: (1)

There must be something we are missing from the chart, who would pay an extra 1000 dollars for the possibility of making 2 more pounds of boost at a level that none of us could probably realistically run on a non-sponsored budget.

B4Ctom1

Thats because it is more than just 2#'s boost, that max boost is a case seal o-ring leak with max pressure and a test plug at max RPM. it would not be acheivable with anykind of motor I could imagine. the "volute" of the impeller is the different thing. Just like in turbos there are different trims of volute there are in blowers as well. In the world of engineering "you cant get something for nothing" the angle of the blades It moves the RPM efficiency around. P1-sc's are (supposedly) more efficient right off the bat and the D1-sc trades some bottom end for some higher RPM efficiency and flow.

89ProchargedROC

the important # between the two is the cfm:

P-1SC = 1200cfm
D-1SC = 1400cfm

1200cfm * x = 1400cfm

x = 1.166666

so........the D-1SC is capable of 16.66% more airflow than the
P-1SC.

B4Ctom1

there we have it.

mypontiac

One big difference I was told by ATI and Tenacious Performance is that the power curve on the D-1SC is exponential and the power curve on the P-1SC is linear. So you hit max. power much faster on the D-1SC. Less lag.

I love mine!!!

89ProchargedROC

there is no such thing as "lag" with a superchager.

i dont care what ATI told you, every centrifugal blower on this earth builds boost linearally because it is connected by the crankshaft

NOW

you can design the impeller to compress the air faster to get the psi readings faster but it is still going to read linearally because of the belt

maybe with the D-1SC you stomp on the gas and it jumps to 8psi and with the P-1SC you stomp on the gas and it only jumps to 6psi. Maybe that is what they were trying to explain to you

BUT

if reality that is going to happen anyway because the larger blower is going to more than likely going to be pushing out more cfm than the smaller one at the same point in the boost curve and the extra cfm the the larger blower is putting out is going to show up as psi on your boost gauge and therefore be a bigger number

----One thing i can help you with is the difference between the
P-1SC-H and the P-1SC. The P-1SC-H is a helixed impeller, i dont know quite how to explain it but the jist of it from what i've read is that it is more of a track blower than a street blower because the impeller is designed to be more of a peaky design than a smooth boost curve as the P-1SC. Maybe possibly they were trying to explain that to you

in all honestly, the only one @ ATI i would ever talk to is Dorian and Jim Summers

mypontiac

Sorry 89ProchargedROC,

Just going of the power curve charts I was sent.

Dorian was actually the one that described it too me.

So maybe "lag" is the wrong term. But I was told that with the D-1SC you fell the boost come on quicker than with the P-1SC. The two units use different impeller designs.

Not making this up, just explaining what I have been told.

89ProchargedROC

hey no need to be sorry, we all learn things here. I just dont want you trying to explain it to someone else and have people look at you like an idiot

The reason why you'd "feel" the boost faster (i bet what he meant is the feeling of the car taking off) is because the D-1SC puts out more CFM than the P-1SC so at almost any given point, the D-1SC should be putting out more CFM than the P-1SC and start registering boost (psi) sooner on the gauge

mypontiac

Name calling???

I used to have better respect for you 89Prochargedroc.

Here is the text from what I was explaining. Used to have a graph too showing a linear curve for the P-1SC and the exponential curve for the D-1SC.

Text as follows:

The differences between the P-1SC and D-1SC are not many. The housing is the same, the step-up is the same, but the bearings are heavier duty in the D-1SC, I believe. The main difference is the helical impeller in the D-1SC, as opposed to the radial impeller in the P-1SC. The helical impeller provides for a sharper boost curve (more boost at lower RPM). The radial impeller in the P-1SC provides a smoother, flatter boost curve and is more appropriate for milder applications and mainly street-driven cars. For stock or mildly modified motors, the D-1SC is quite often unusable because its boost output will be too high for the motor to handle, even with the lowest pulley ratio. ATI generally specifies that the D-1SC is for modified motors only. Depending on the motor and current modifications, if any, you can sometimes use the D-1SC and use a pulley combination that will result in a low enough (and safe enough) boost level. If your motor is modified and you have the option to use either, you then need to decide which one would be better for you to use.

The P-1SC produces a flatter boost curve due to the radial impeller . Whether that's better or not depends on what you're looking to get out of it. For enjoyable street performance I would say it is better. The flatter curve means a more gradual boost increase as the RPMs increase. This is generally better for stock or mildly modified motors as it is easier on the motor at lower RPM than the D-1SC. It also helps keep too much power from coming on quickly--something that can often be undesirable on the street, where traction can often be less than decent (in terms of wheelspin). n a stock or mild motor, either unit can easily make the same maximum boost output and the power gains will be similar. You will probably be less likely to overboost the motor and cause internal damage with the P-1SC. Besides being a few hundred dollars cheaper, the kits that include the P-1SC typically include longer warranties on the unit, as well. For a street car that will see infrequent track time (if any) the P-1SC probably makes more sense.

The D-1SC's helical impeller just brings the boost on more quickly at low RPM , which is better for making power for the track (where you have more traction to make good use of it). hat's why the D-1SC is considered to be more of a street/strip blower where the P-1SC is considered to be more of a street blower. Both units are rated to have very similar maximum HP limits, but what differs is the level of strain it will place on the unit itself. It is advised to use the D-1SC over the P-1SC for high power applications. Even if you pulley either unit to make the same maximum boost (say 12 PSI at 5000 RPM just for example) the D-1SC is more efficient and therefore does not need to work as hard (spin as fast) to make that power. This is easier on the supercharger itself, which will aid in the longevity of the unit. It also cuts down on heat output levels by not working the unit as hard. If you already have a built up motor or have big plans to go with higher boost and forged internals, then you probably would be best to get the D-1SC along with the most capable intercooler available.

Obvisouly you are ignorant too concernining the whole picture.

We can both learn from each other.

By the way, what are you currently running. Have not seen your latest upgrades???

Just moved up to 15 # boost. Expect 450 FWHP on the little 305!!!!

Not too ignorant.

89ProchargedROC

LOL...wonders of the internet

i didn't mean YOU were the idiot...i meant i wanted YOU to be able to explain what you were trying to WELL so that NO ONE ELSE would think you were an idiot

THATS what i meant

Sometimes its hard to understand what people mean when it is only "typed" out

hope that clears that up

as for my setup...well...

lets just say that it will be motivated by a decent amount of boost from an XXmm wheel or wheels

mypontiac

Ha!!!

Cool.

Just needed some fun 89ProchargedROC.

It's late and I came across your reply.

So what is this code for your mods??? XXmm

How much boost?? Are you at 15# now??

89ProchargedROC

i'll give you a hint:

mm stands for "milimeter"

mypontiac

OK :lala: :lala: :lala: