Need a winter project: turbo or supercharge a stock 3.0.

[rennch]

Hi all,
I'm a complete newbie to engine building, but I'm handy with a wrench and a welder. Currently my car is a LOT of show, without the appropriate amount of "go".

I've got a stock 3 liter motor from a 79 SC. I also live at 5280 feet in Denver, so forced air is a no brainer.

I'd like to build a solid, reliable motor with a turbo or supercharger. Think "bang for the buck." I have NO idea where to start. Can anyone give me a semblance of a road map and approx. cost? Assume I'll do all the labor.

Thanks!!

[gsmith660]

Consider a 3.2 short stroke with some P/C from JE. You already have the base with the 3.0 as I have heard it the stock 3.0 is stronger than the 3.2 lower end and will hold up better and the SS will be good for 500 or so hp. Someone that knows for sure please chime in to confirm my thoughts. Whatever you do will not be cheap when I did my 2.7 I didn't do any engine work and I spent somewhere around 3-4000 on making the turbo not blow up my motor I went with Megasquirt EFI and EDIS I will be twin plugging and will be adding water/methanol injection to prevent detonation.

[Tippy]

If you can fab your own parts, putting a supercharger on would be simplest and cheapest.

I'll PM you later.

[rennch]

Tippy...do tell. Would love to hear it. I'm trying not to spend 6 grand on it.

[sjf911]

The simplest thing to do is to buy someone's complete, running 930 motor and swap it out for your 3.0. You are faily limited in amount of boost and horsepower gains by the stock compression and lack of fine control on fueling and timing with the stock SC CIS.
EFI conversion, especially utilizing a 3.2 intake, lends itself nicely to turbocharging but may not be any less expensive than an engine swap in the long run and leaves you with a system that is under capacity from an oil scavenging standpoint especially with an oil cooled turbo. G35R's or equivalent may help this.

[rennch]

Hi Steve...that's not an option for me at the moment, unfortunately. I have a very low mileage 3.0 engine. Right now I'm leaning towards supercharging, which seems to offer a lot of bang for the buck.

[sjf911]

Supercharging certainly would be fun to do . I look forward to watching your build.

[rennch]

Thanks Steve. I was looking at this thread, but there hasn't' been a follow up:

Plan for (inexpensive) 300+ hp SC motor

[TIM.G 911]

Super charger takes horsepower to make horsepower. Turbo charging is free horsepower. I am in the process of turbo charging my 82 3.0 sc and thanx to some used parts from pelican board members it will be completed under $2500.00 with used intercooler, new turbo and new msd box. But i dont think its going to reach your goal of 300-350 hp. I am hoping for 225-240 hp to the wheels at .5 bar (roughly 7 psi) boost.
Good luck with your build, post some pics and if you learn anything i need to know please pass it along

[rennch]

Hi Tim,

I never stated I was looking for 300-350 hp. That would be crazy! Do you have a thread on your build? Your numbers are right what I was aiming for.

[gsmith660]

Typically you can expect 18 hp per psi boost so 7 psi boost gives you about 120-130 hp stock 3.0 is what 180 or so I don't remember and don't have any of my tech stuff its all packed away. so you are looking at around 300 hp roughly EFI adds some hp and twin plugging and WMI make it safe Emptyo a low milage 3.0 you could bolt on a low boost turbo system and get plenty of hp I would spring for EDIS that with mega jolt to control is not that expensive as the stock dizzy isn't curved for a turbo.

[rennch]

Well, plus you have to remember that I'm at altitude, so I'm losing a GOOD 30% of my HP just because of that. So I expect a complete transformation!

[Tippy]

Originally Posted by emptyo

Tippy...do tell. Would love to hear it. I'm trying not to spend 6 grand on it.

I think you can supercharge your SC minus the CIS upgrading for no more than say $1000 - 2000.

Why I would go the SC route for simplicity and cheapness:

1. Cheapest to build hands down due to far less components than a TC.
2. SC's provide low-end grunt/torque most TC's cannot replicate without serious upper-RPM hp limitations.
3. You don't have to use an intercooler until high boost levels (say 10-12psi+).
4. Opposite of turbos, the bigger the SC is (of course a point of diminishing returns), the more power it makes due to lower exiting air temperatures on non-IC'd setups.
5. Less headaches due to less sytems like WG's, IC's, etc., and less plumbing.
6. More room due to less plumbing.
7. Keep factory heat without replacing expensive headers.

Anyways, here's what I did on a '69 Camaro that would be pretty much the same as your SC - some of it sounds really shadetree but it worked for my car:

1. Build brackets out of 3/8" to 1/2" aluminum for a centrifugal, 1/4" steel for a screwcharger........very little $$$
2. Buy used pulleys for the SC and crank from Ebay or others.....very little $$$
3. Make or buy the oil pressure feed line (for centrifugal).....very little $$$
4. Pop a whole in one of the chain housings for oil return (for centrifugal).....very little $$$
5. Go NAPA's warehouse and look for assorted heavy equipment radiator hoses for the discharge side of the SC to the CIS.....very little $$$
6. Go to Home Depot for PVC plumbing for the inlet side of the SC. You can make just about any curve you want......very little $$$
7. Acquire a BOV - minimum would probably be like 2"......these are a little $$$ but not bad
8. Belts are very little $$$
9. Assorted fittings for the oil lines.....very little $$$

There you have.

BTW, I have a perfect SC for sale for you: Vortech S-trim (680hp capable)

Regarding upgrading the CIS to handle boost, I have no idea but I am confident you can find out from these guys here.

[Tippy]

Originally Posted by TIM.G 911

Super charger takes horsepower to make horsepower. Turbo charging is free horsepower. I am in the process of turbo charging my 82 3.0 sc and thanx to some used parts from pelican board members it will be completed under $2500.00 with used intercooler, new turbo and new msd box.

$2500 is awesome!

But I want to make a point to what you said. From stop light to stop light, the SC'd car will feel more linear and responsive than a TC'd car all things equal. Boost will come in nearly instantly with the SC whereas the TC will have some lag. I prefer TC'ing to SC'ing due to hp potential, but I know they both possess limitations.

[Packy]

Originally Posted by TIM.G 911

Super charger takes horsepower to make horsepower. Turbo charging is free horsepower.

This is a myth. Do your research. Back pressure and cam timing of turbo engines use horsepower or in actuality prevent flow therefore using some potentially "free" hp. The exhaust side of a turbo motor always has higher pressure from the intake side so you have to have very little valve overlap. And obviously higher pressures to charge the turbo is naturally a bad thing. The fact that can't be denied is turbos are more efficient because they use energy or heat that otherwise would be wasted to drive a compressor. On the other hand a good supercharger doesn't use much hp to get to max boost. For example an eaten 62 only uses 15-25hp MAX at 1200 rpms with a 2:1 overdrive. this compressor can easily get you 300-350 hp.

Like others have said, what are the driving characteristics you are looking for? If you are going with an older turbo don't expect boost to come on until 3500 to 4000 rmps unless you can afford a variable geometry turbine turbo (good luck with $2,500). With a SC you get instant boost and you also don't have to rev the engine as high. Actually, it's better to not rev the engine as high and save money on expensive valve drive components. It's all about what you want. I like SCs and turbos but I'm building a SC motor for the low cost solution and high low-end torque curve of a roots blower.

There's also the other myth that porsche doesn't do SCs from the factory. They just started putting them on their V6 cayennes if I remember correctly. Do a search and you will see what I'm talking about.

The best advice I could give you is to read a few books before you boost your car with either method. This is good advice. Also see what others have done and what actually works. Turbos are obviously tried and true, but I would rather have a good SC system than a sh* tty turbo system, and a 79SC with the larger ports and lower compression is set up well for boost. Also, the timing isn't the best, but it is pretty good and will work. I have documents I can send on some kits from SoK that were sold (tried and true). I also have info from TurboKraft and others. I'm also a mechanical engineer. Let me know if I can help.

[Packy]

I also forgot to mention that you can easily stage the SC build. i think it would be harder to stage a turbo build.

[spence88mph]

If you want super cheap and little fabricating, a j-pipe and 2nd hand but in good condition k27, T03 etc would be a very cheap route, j-pipes $150ish, turbo $200-$500 (ask around in here, I'm sure there's a tonne of turbos sitting on shelves from upgrades) for your low boost level no problem.

A buddy had a supercharged 911, the sound was cute to begin with but very annoying after a while... Belts broke constantly too as I've seen happen to other members here, having to fabricate brackets etc.... well I'll leave that to you.

BTW I did my turbo conversion in a sunny afternoon and was driving it that night...

Harder to stage build a turbo, in what way?

You don't need an intercooler or BOV under 7psi .5bar.

[TIM.G 911]

STARTED A THREAD BUT IT DIDNT GO ANYWHERE. HERE A COUPLE OF CURRENT PICS. PRECISION TURBO 61-57 I HAD FROM A PREVIOUS TURBO BUICK BUILD, HAD TO CHANGE EXHAUST HOUSING (SPECS CLOSE TO A K-27), REWORKED STOCK 944 FRONT MOUNT INTERCOOLER FROM EBAY $75.00, STOCK DISTRIBUTOR WITH LOCKED ADVANCE AND AN MSD 6BTM TO PULL TIMING UNDER BOOST, I AM GOING BLOW THRU RATHER THAN DRAW THRU LIKE A STOCK 930.

[sjf911]

Originally Posted by Tippy

$2500 is awesome!

But I want to make a point to what you said. From stop light to stop light, the SC'd car will feel more linear and responsive than a TC'd car all things equal. Boost will come in nearly instantly with the SC whereas the TC will have some lag. I prefer TC'ing to SC'ing due to hp potential, but I know they both possess limitations.

Oh, but the smile on your face when that boost pipe kicks, the car squats and feels like it's going to launch you into the sky.

[Packy]

Originally Posted by spence88mph

Harder to stage build a turbo, in what way?

You don't need an intercooler or BOV under 7psi .5bar.

You still increase intake charge temperatures with .5 bar.

I guess what I'm saying is heat kills engines. I would use an intercooler even at low boost levels. But that's just me. I've had friends kill their engines with low boost and no intercooler. Not to mention the car will be quite a bit more temperamental on hotter days and you can run the risk of engine knock. In the summer time CO gets temps above 100 degrees Fahrenheit and many, many days in the 90s (i'm from Denver BTW). your choice. I know what I would risk on my motor.

There is a difference between cheap and inexpensive. Throwing a j-pipe on a non-turbo motor seems cheap to me and I wouldn't do it to my motor. I wouldn't even do it to a friends motor. That's just me. Granted porsche did have 3.0l motors with NO intercooler and twin turbochargers and they got WAY over 300 hp out of them but that was on a motor designed for turbo charging and these were on race prepped cars, etc. I'm sure others have done it too, but probably not cheaply.

The one way to find out how smart it is would be to see how many people have done it and how many motors lasted the test of time.

Staging? The exhaust on turbos work with the intake. You replace the exhaust you need to replace the intake, etc. etc...
EDIT: you could probably buy the intake first then exhaust on turbo. I guess it depends on what turbo system you go with. Stock porsche systems you need the intake and exhaust to work, but I imagine a home made system you could stage by making the intake work without the exhaust and turbo. There are still other issues with turbo charging a non-turbo motor without opening it up and changing the cam timing, etc. And you can always buy parts and not throw them on, but that's annoying.