I would really like to supercharge my 93 auto lt1 formula. Heres what my goal is: approx 400 - 450 hp at the wheels through the use of a supercharger. I will be satisfied with that. I'd be fine with even a tad less than 400. The reason i'd rather go with this instead of a head/cam package is because i dont want to have to rev to the moon to make power, and i like driveability, plus id like to pass emissions.

Right now, my car is stock minus exhaust. from reading, i realize there is danger is supercharging a stock car. some get away with, some don't. my car isnt my daily driver(have a 96 lt1 for that ) , i drive it maybe 3-4 times a month(not winters either), and i rarely get on it. I just like to cruise in it and show it off at shows. if the engine needs to be rebuilt, so be it.

I am considering either vortech, or powerdyne at about 6# of boost. i dont care that vortech has more potential to make 80000 hp, and yadda yadda..i have no need to ever go above the approx 400 hp barrier. Will either of these with about 6#'s of boost get me to my goal with a full exhaust(long-tubes)? or with at least a supporting mild blower cam?

If i want to add some more insurance to my motor, can i get away with just replacing the pistons and rings for some upgraded ones? What pistons do you recommend for my power level? would they bolt right up to the stock connecting rods? also, should i upgrade my stock injectors while im at it?


thanks

 

You should easily be able to pick up 150 horsepower at 8 PSI. I wouldn't recommend 8 PSI on an LT1 with miles though--if you're not objectionable to needing a rebuild, then by all means go for it. You should also be able to pick up well over 100 horsepower at 6 PSI, which would be a lot safer for your motor. Those are specs on an intercooled P-1SC ProCharger system, I'm not sure what the comparable Vortech/Powerdyne specs are.

Without an intercooler system you won't be able to run as much boost or as much timing without putting the engine at more risk, so I would assume you'll see less of a power gain. You wouldn't have to drill and tap the oil pan for the ProCharger system, which is a plus.

If you wanted to do a semi-rebuild, you could throw a set of dished forged pistons in there (yes, they'll work with the stock rods). There are plenty of good brands out there. You would lower the compression which will help reduce the detonation threshold, plus those pistons would take the extra heat a lot better. You could do all that with the engine in-car, but it's a lot easier if you pull it.

Granted, you could do all of that later on after you beat the snot out of it. Either or.

I always recommend the lower boost to start. Learn the ins and outs of forced induction firsthand. Work through all the bugs and tweak everything just right. You'll have a lot of fun with it for a while, and can then do a rebuild at your leisure. Since this car isn't your daily driver, you have a lot more options than some others, though. Still, it's always better to not break anything.

Most systems come with an FMU to increase fuel pressure and provide for the added fuel needs. I might still recommend going with larger injectors and having the car properly tuned though. The FMU will probably be running your injectors wide open (100% duty cycle) and increasing the line pressure so you get more fuel through them. It's better in the long run to upgrade the injectors. 30# SVO injectors are only like $220, and you can get a set of 36# injectors for not a whole lot more.

HTH!

Dave

 

cool . good info. Few more questions while im at it:

I would probably start out at a mild 6 psi at first and figure out this whole supercharger deal as i go. i will have headers and eventually a mild blower cam, so i should see 400 rwhp with just that alone, and that should hit my goal. at the same time, i would like to do my pistons/injectors so i dont have to break the engine down within the first week of having fun so...

If i were to get the dished pistons and lower my compression, wouldn't i lose NA power..and therefore have to crank up the boost even more to see the power level im looking for? How much should i lower my compression if all i want to see is relatively reliably HP at the 400-450rwhp (i realize thats a big discrepancy) barrier? with a good set of forged pistons at a lower CR, but stock rods and crank, how much more time does that give me before I should dump in a stronger crank and rods? If i have to upgrade the boost to 8# or 10#, wouldnt that also decrease the life of my crank and rods even with the lower CR?

I really don't know much about where I can buy pistons, recommendation..links? this will be my first venture into the internal engine, i know a good amount about the engine through reading and asking questions, but never physical application. I also know a good tuner who does superchargers all the time, so i should be able to get a good dyno tune to make sure the fuel is on the safe side.

With the power level im looking it, would it be worth going up to 36# injectors as opposed to the 30#? is having too big of an injector a negative hit against my setup?

So i will be getting a mild blower, forged pistongs, and bigger injectors and putting them in my engine at the same time. how much % more reliable overall does that make my engine over a completely stock engine?

sorry for the marathon of questions, but i want to do this as right as i can the first time.

 

While in comparison to boost on a modified motor, 6 PSI may not seem like much. However, I personally consider 6 PSI to be the maximum "safe" limit on a stock LT1 with miles. More boost is possible without enormous risk, but it's still pretty risky, in my opinion. Ultimately, it's always better to build the engine to specs that are suitable for a supercharger--but it's not always that easy financially, of course.

If you went with dished pistons and lowered your compression ratio without a blower, yes you would lose NA power. However, with a supercharger you can now raise the boost pressure and make more power without as much risk of detonation. Where you want your CR to be varies. I would say anywhere in the neighborhood of 9:1 to 9.5:1 would be good. If you were using a more powerful supercharger and wanted to make significantly higher boost levels, then you would probably want to shoot for 8.5:1 to 9:1. I would take your goals and compare them to the vehicles that other people on the forums have. If you want a reliable setup, a good idea is to find a combination that someone else already has proven to be reliable.

Making more power will always put more stress on your crank and rods. I forget what the LT1 crank and rods are rated to, but I think there are some pretty decently documented limits. Definitely a concern to keep in mind, though.

As far as which injectors to use, I'd think you'd be better off with the 36# injectors to be honest. The 30# ones will keep you at a decent injector duty cycle when used along with an FMU, but that's talking 6 PSI on a stock motor. If you're going to force more air through with a bigger cam and a lowered CR, you'll need more fuel to go along with that and the 36 #ers might be called for.

The list could go on and on though, you need to decide how much you want to spend at once and what you want to plan for the future. If 400-450 rwhp is your ultimate goal, then you may want to shoot for it all in one shot. Do the pistons and injectors, get it tuned up, and you'll be good to go for a while. Eventually, a more complete rebuild will be necessary though--even if you just fix it up and put it back together the way it was.

If you want to just throw a 6 PSI blower on it and call it a day, you can be making roughly 360-380 rwhp no problem. It will be quite safe and you can then save up for a more complete rebuild--you can do forged internals (maybe even stroke it) and the injectors and what not. You can turn up the boost to a safe level for that motor and easily be making the kind of power you're looking for and then some. The engine will be a fresh build and should last a good while.

Dave

 

Again, great advice. I think maybe i will go with the partial rebuild, and see how long that lasts. 360-380 rwhp, emissions complient, with streetability, sounds good to me. and I always have the potential to go so much bigger with the forced induction..and plus i already have the pistons, and injectors installed. I could always add a mild cam, and port heads to get me at the 400+ barrier. I will see how long that lasts, and then

A: if i want more power I can forge the rods/crank,intercool and crank it up or
B: rebuild it back to what i had before if i was happy with my current power level.

I did some reading before, and i think a traditional cast rod and crank are supposedly able to hold about 450 hp...so i might be pushing it with the 400+ at the wheels.

Sounds like a plan to me. I see you are in NJ. I am also located in NJ, Colts neck, near redbank/freehold. I saw on your website that you know some tuners who do ati prochargers. Let me know if you would be willing to consult with me offline to help me get setup, supercharger from you, and install/tune from them.

Thanks

 

Sounds like you've got it pretty straight.

I agree that at the 400 rwhp mark you're probably starting to creep up on the limits of the crank and rods. A lot of it will depend on how often and how hard you beat on it, too. Keeping the revs under control can be helpful in that respect.

If you want to email me at at dback(at)tenperf.com I'll be happy to help you get set up with whatever you need as well as set you up with my tuner. You can always shoot me a PM here as well. If you want to check it out, I set my pricing at the lowest that ATI permits their dealers to sell at, and it's all always up on the website.

Later!

Dave

 

TenaciousDB, I posted a question several days ago with no replies, so I'll ask someone who'd know directly since it's kinda related to this post. Anyhow, I'm interested in the Procharger P-1SC H.O. 4.5psi, non-intercooled kit on my 120K mile LT1. Since you recommend 6psi as the max safe amount for an LT1 with miles, I'm assuming it's even safer to run 4.5. But what kind of power gains can someone expect off this particular kit? This kit is also priced within the 4.5psi Powerdyne system, and after the searching I've done on the Powerdyne unit, I'm not so sure I'd want one. Thanx.

 

With 120k miles, you may need to start concerning yourself with the reliability of the motor period, nevermind with a supercharger. That being said, the less boost you run the safer it's going to be.

However, if you run less boost but non-intercooled, it may not necessarily be safer. It may even be riskier for you to run 4.5 PSI without an intercooler then 6 PSI with one. It's hard for me to say, others may possibly have some input in regards to that.

Be wary of putting boost on that motor at all, but especially without an intercooler. The wear on the more sensitive internal parts makes a motor with miles even more sensitive to increased heat levels. That being said--if you're prepared to do a rebuild at some point soon anyway, you don't stand to lose too much.

Regardless, if you're picking between a P-1SC ProCharger system and a Powerdyne system, the ProCharger wins hands down. I haven't personally heard much in the way of bad things about Powerdyne, but you have a lot of room for expansion with the P-1SC. It will support 800+ horsepower (even though you're better off with an upgraded unit to do THAT, of course).

HTH!

Dave