I have a 18K mile, stock bottom ended LT1 car.

I am likely going to be buying an D1SC, with twins, and hard tubing (Instead of that chinsey flex stuff ) with a spare pulley. Right now, there is a 9PSI, and a 15PSI pulley with all related accessories.

I wanted to run it down at around 7-8PSI since I will be on the stock bottom for a little while. I understand it may last 10 miles, or 10 years, its a hit and miss thing, namely due to tuning. So that aside, I wanted to do everything else I can to still be able to run a D1SC ( Which I will need later, when I make a low comp stroker for boost ) on the stock bottom end at as low a PSI as I can get.

So anyone know if ATI makes pulleys to run in the 6-8PSI on a D1SC?

 

I've done them at 7# without problem. 6# sould be possible as well.

 

What pulleys did you need to get it down to 7? I think 6-7PSI is the safe limit on a stock bottom end, tune issues aside. There are a few guys running 6PSI non intercooled, so I think I am going to shoot for 7PSI ...

Thanks Lonnie.

 

I have a 4.25'' pully somewhere in my garage...that might get you down that low.

 

Selling it? Ill have to check some things out first, but if that would put me in the 7PSI range, I would be interested.

 

I can sell it but i rather trade for a smaller pully...i need more boost!
I will check what size i need...hopefully the one in you kit will be what im looking for

 

if I remember right ATI told me run a 7.0 crank pulley and a 4.5inch Blower pulley on a stock LT1 D1SC setup to see about 5lbs.

But here is the question, what would happen with a FMIC, 90 degree Elbow on the inlet, and a FULL BOLT-on LT1 (Exhaust, 1.7RR's, EWP, Tuning, ETC) WOULD I still see about 5lbs or not???

I see the more mods you have it gives you less boost on a Given pulley setup.
I would figure that we need to find what RPM the Blower needs to spin in order to calculate the boost that is needed for a Certain boost range.
Lonnie you care to share your experiences

 

Ok thanks for all the info guys.

Camarossguy2 ~ As long as the deal goes through, I will PM you and let you know so we can maybe work something out trading ...

Hopefulyl someone with a little more knowledge about ProChargers can get on here ...

And yes you do loose boost the free-er flowing the intake/heads are. Im not too concerned what the actual loss # wise will be, because ultimately, freeer flowing and forced induction = more power ... So really I guess I should have been a little more specific, I want to make some half decent gains with it, without pushing the stock bottom too hard. On an otherwise stock car I would shoot for the 7PSI range. And I figure if I loose a little boost, its no biggie.

Thanks for all the replies though everyone

 

With my car, I have mildly ported heads, 2.00/1.56 valves, ported intake, CC306 with 1.6 rockers, headers and 3" dual exhaust. With a D1SC, revving the engine to 6200, a 7.00" crank pulley, and a 4.50 blower pulley, it makes 6 psi.

On a stock engine spinning to 5700 or so, you will be about the same- 6-7 psi.

 

Hmm ... OK.

I was hoping to stay right around 7-8 so I may go this route for now. I wonder if they make a pulley slightly smaller than 4.5 that will get me in the 7-8PSI range on a 7.00" crank pulley.

The 7.00" crank pulley is the pulley that comes with a D1SC LT1 kit isnt it?

 

Yes, ATI offers many different pulleys for the blower to make the appropriate amount of boost.

No, the D1SC comes with a 7.65" crank pulley. The 4.50 blower pulley is the largest you can put on an LT1 F-body (the upper radiator hose gets in the way), so that's why I had to go with the 7.00.

 

Ahhh, I got you now.

Any idea what your getting into with a 7.65" Crank pulley, and the 4.50" blower pulley? Would that put me in the 7-8PSI range?

 

Probably, but the only real way to tell is to put it on the car and find out.

 

Yea ... I hope that should put me close to where I want to be. I figure between that, using 30# SVO's,a 255, and pulling a few degrees of timing & gettin a box, I should be somewhat more "reliable" than just bolting a kit on.

I think I am going to wait until around christmas time to actually set it all up and get the car running. Then I will have all winter to possibly play around with LT1 Edit myself, or save some cash to get her dynotuned for when the weather breaks ...

 

TTT...I really want to have the exact same setup as you do. Just wondering if anyone else has some opinions on this. My motor is healthy (I would do a compression check first) and I have plans in a year to do a 383 with 600 RWHP goals. Would a D1SC be the right supercharger for me?