I've tried doing a search but for some reason it doesn't let me search for this. I want to buy a D-1SC for my LT1 this summer until I rebuild it with a low compression 383 with 600+ RWHP goals. I want to do 4-5 PSI on it with the D-1 on my stock longblock since I don't want to upgrade the supercharger later on. I was wondering if this low of a boost will hurt my LT1, which is in good health? It will be intercooled and have a really conservative tune. Can you even pully down the D-1 to that low of a boost?

Also, what other upgrades are going to be needed along with the kit, such as injectors and fuel system? I will only subject my stock longblock to this for about half to maybe a full year. Thanks!

 

If it is only going to be like that for 6-12 months, why not wait till you have the money to do both? 4-5 lbs of boost won't hurt the stock engine, I think some people go up to 7-9 lbs and are ok. What year is your car? You may be able to get away with the stock injectors at that low of boost, I really am not sure about that.

 

I would think you would have to step to 30# injectors, even running 4-5#'s of boost. I'm looking at running a D1SC with 14-18#'s of boost. I'm starting to gather the shortblock parts. Your car looks good with the ZR1's on the back. I'm trying to decide on what wheels to put on mine.

 

24lb injectors will work if you decide to use an FMU but I wouldn't use the factory GM ones. Use SVOs. If you decide to ditch the FMU, then I'd run at least 30's with a custom tune.

 

So is it possible to pulley down the D-1SC to make only 4-5 PSI?

 

I would think so. Use a 7.0" (IIRC) crank pulley and get a custom s/c pulley from Procharger. But, realistically, there's no reason you couldn't use 6-7 lbs of intercooled boost. When you decide to step up to high boost, you'd be better off to go to the 7.6" crank pulley.

Also, I recommend looking at upgrading your fuel pump if you haven't already done so.

 

I would love to, but where I go to school, I can only get 91 octane. I have fears of detonation which would kill my engine and I would be 500 miles from home. Definitly not the best position to be in.

 

How much PSI is a D1SC going to make on a stock LT1?

 

You can in theory pully the blower for that boost I'm not sure what kind of crazy pulleys you would need. The D1SC is not designed to work at the levels you are talking about that is why they make smaller blowers. With The amount of horse power it takes to turn the blower with 4 psi you may have almost no gain. Just wait untill you can do the whole project.

 

I definitly see what you are saying. I would be willing to do 5-6 PSI so long as I put in some octane booster in along with a conservative tune. I really just want to have the supercharger whine and a few extra ponies. I'm kind of in a rough spot because I'm going to do the 383 probably next winter so I don't want to do any motor work to the stock motor now (such as H/C) if I'm going to be pulling it soon anyways. The only other option that I could do is throw on my brothers NX kit and be happy with that for a year, but then again, I don't like knowing if the bottle runs out, so does the HP. Forced induction FTW!

 

throw on the spray now don't waste time with a big blower until you have a built bottom end. You can always leave the juice on when you have your blower ready. dual power adders are cool

 

^^^Yep, plus octane booster won't help, do a search on it, but it seams like I remember that it only raises the actual octane level by ~.2

 

Very true. I think maybe I won't have to worry about it because I found a gas station about 15 miles north of me that has both 93 and 101 nonleaded gas. I'm still not sure what I want to do!

 

Just going by experience, I was so eager to have my engine rebuilt that I waited till I had just enough money to cover everything, without factoring in machining, extras (other stock parts that needed replaced after I tore into it), etc. I didn't have my new LT4 heads and intake ported because I didn't have they money at the time. Once everything was together and I finally had the other unexpected expenses paid off, I realized that I should of waited till I could of sent the heads and intake off to LE and went 383 instead of 355.

It is better to wait, as hard as it is, it will be worth it.

I was just 18 with a hard on about building my engine up.

 

Here's HARD data from my car:

I run a 7.00" crank pulley, and a 4.50" blower pulley, with a D1SC, with the new ATI inlet. This is the SLOWEST ratio you can run on an LT1 F-body, since nobody makes a smaller crank pulley, and that's the largest blower pulley you can run without hitting the upper radiator hose.

MY ENGINE IS NOT STOCK!! It's got ported stock heads, 2.00/1.56 valves, ported intake, CC306 cam, 10.8:1 compression. The shortblock is 100% factory.

Turning the engine to 6200 rpm, I see 6 psi (on days that the temp is below ~40*, I can see up to 7 psi.

Now, take a 100% STOCK engine, with a redline of 5700, you will probably still see 6 psi.

So to answer your question, I don't see making less than 6 psi with a D1SC on a stock LT1 F-body.