78sc 3.0 Can I add turbo??
 

Can you upgrade a stock 3.0 to turbo? Are the camshafts different? What's involved other than money and alot of work?

You sure can. Do a search for this topic, but tricky since you can't use 3.0 or SC in the title. I think his handle was RFNG who was designing a kit. Search Beep Beep and Juan.

Your camshafts will work for moderate boost. Compression will be the biggest issue unless you change pistons. Look at EFI conversions to in that it will give you options outside of CIS.

You have the correct block, crank, and rods. You might consider the 3.2 EFI or Tbitz's or multitudes of other custom fuel managements. It has been done and turns out successful if $$$$.

what kind of power gains can be found with the stock pistons and CIS if I add a turbo?

~250-260 HP (if you have correct US engine with lower C/R pistons).

It can be easy or it can be complicated/expensive. How handy are you?

I can rebuild the entire engine with ease if I need to.

You can also supercharge the 3.0.

Speak ..wise one !!
Did someone say supercharger??
I'm in what's the details?

Do a search on "supercharger," or "Superchargers of Knoxsville." Evidentially, it's a very competent system as long as you are prudent with the boost. They build two units;

1) a Whipple Supercharger, which isn't as torquey and a little easier on your gearbox/drivetrain; and

2) a Paxton Supercharger, which is a balls out torque monster.

Both get the early SC motor, as I recall, over 300 hp. The Whipple is fairly reasonable $$ wise, while the Paxton is about $7K, IIRC.

Either way, you'll have a very strong engine that should last if you don't drag race the car.

Of course, you know about the other liabilities with such modifications, right? I.E. upgrading the suspension and brakes.

I'm developing a turbo system for the 2.7-3.2 engines...

How soon are you looking to pull the trigger?

Check out Turbo Performance Center in MD. Mike Levitas does absolute wonders with supercharging and turbos! He also drives a mean race car.

Not a big rush. It's in the bodyshop now getting a 930 body kit..Sometime next summer would be fine by me. I have a little history with superchargers on V8 engines, Never thought about it on the 911. I just figured turbo would be the way to go since the factory did it and the parts are there.

Yeah, but the factory turbo - at least the 3.0, had 6.5:1 compression, a different block, a big intercooler (later on), and a whole bunch of other stuff. I mean, after all, if you go to a turbo, all you're doing is "sticking" stuff onto an existing powerplant designed within the parameters as it exists in your car. IMHO, very few mods make these engines much better overall.

If I wanted a turbo, I'd try to adapt a true factory turbo engine to my chassis. Or just buy a 930 and be done with it.

Sorry for not answering before, I just had a biiiig bussines exam. (covering half semester of studies).

First, it's not ordinary "rebuild by the book" skills that are required for this kind of project. It's more ability to be creative and fabricate stuff. If you have acess to good tools (TIG-welder, machines etc.) it can be dirt cheap. Otherwise you have to go to shops and it will cost more.

Second, supercharger usually cost more, is less reliable, more complicated and nets less power. I've went trough reasons many times before, it's all there in archives.

Third: there is not much "true-factor-turbo-with-extra-cheese" on turbo engine. They were built very conservativly, and have been re-done in many ways since first 930 appeared 1975.

If your SC engine is of low C/R type specced for NA market it will be able to take light boost w/o problem.

Again, I advice against supercharger...this is not V8 and fitting supercharger is troublesome and expensive. There are people here who tried and then swapped it for turbochargers. A small turbo that draws air trough CIS and boosts 0.5 bar, plus little lower control pressure should do the trick.

The low compression also makes the Turbos lug like a fat pig off boost. I know of an 3.0 that has been turbo charged since the 80's, and it has log a lot of miles...perhaps the owner will see this thread :)

What you lose in the low boost pressure is made up in the CR of the pistons, so one way or the other, you will have to be wary of detonation. If you had a low CR, you'll be cranking up the boost until you detonate!

There are other guys on this BBS that have boosted 3.0 or 3.2 without having torn the engine down to midify it.

A mildly boosted CIS or Motronic engine is viable. As long as the boost monster doesn't grab you by the throat, the engine will live a long life.

Juan Ruiz started with a stock 3.2, and Richard Fong started with a 3.0 L-jet. Both got very nice numbers out of their engine with approx. 7 psig of boost. Boosting the engine adds very little stress to the engine from a mechanical perspective.

EDIT: As I was typing this, I saw Goran posted :) ....yep, a tweak of the CIS will make the 3.0 a happy boosted engine :D

Yeah it can be done, 7 psi on a 80-83, 9 psi on a 78-79. I have a completed proto type kit for an SC that I was going to start selling, but the interest was relatively low. The proto-type was done on a 83 but I would imagine it will work on a 78. You would have to remove the air pump as its in the way.

When will the trigger be ready to pull?
jurgen

Jurgen,

I'll be fabricating and testing over the winter. I'm targeting April or May for final testing in the cars and dyno runs. Hang tight, unless I go bankrupt, I'll have a few induction, ignition and fuel control available.

Re: 78sc 3.0 Can I add turbo??
 

Yes, no and less money than work.

http://forums.pelicanparts.com/uploa...1080781098.jpg

http://forums.pelicanparts.com/uploa...1080844463.jpg

Most of the details are here:

http://forums.pelicanparts.com/showthread.php?s=&threadid=90065&perpage=20&pagenu mber=1

looking back on several turbo thread's i failed to notice why more people didnt go with the exhaust manifolds from the turbo, they are cheap!


is the turbo placed too low? do you need a scavange pump?

things not line up?

do they flow bad?

Flow is not optimal even before cat's. They end up longer than ideal before the turbo housing. Many people often are looking for minimal turbo lag in custom installs and the factory pipes/turbo setup is not optimal in today's tech in reducing lag or ultimate flow. They were designed around certain criteria and did well for their time within this.

They are cheap and would seemingly make it quicker/cheaper to convert. I differ from an earlier post in that I think WE can do it better than it was done so many years ago and we can improve these engines. We don't have the constraints of mass production, emissions, and limited tech that Porsche was limited to back then. Yes they had/have great engineers. But, we have learned from them and improved over 30 years of Turbo Porsches. Porsche didn't design a Turbo in 74 and stop developement did they, nor need we.

I would think the stock Euro 930 exhaust would be perfect for an SC conversion. There is no cat and very few mods would be needed to make it bolt right up. You may be able to get away with not using an oil pump if the mount is moddified to place the turbo up higher.

just the constraint of $$ now :(

looking for a Used BAE kit because i would like to keep from removing the heat exchangers(i dont think they have moved in 20+ years)

I DONT want a scavange pump, how much would it have to be modified, anyone have a picture were the turbo sits without modifying it? any way to just add a nice big old spacer to place the turbo up a few inches more?

Sam Gore and tsuter have BAE kits. So does pjv911. I believe neither install uses a scavenge pump. If I recall correctly, the turbo drains into the left timing chain cover. Use a big hose and aim the turbo drain straight down.

It would be relatively wasy to duplicate the BAE kit, the olny hard to make parts are the rubber boots that go on the throttle housing and air sensor thingy.
If you could get those the rest could be fabricated.
My car is running 6 psi right now and I will bump it up soon when i get a CIS issue ironed out. The A/F ratio swings a little, which it did before the turbo also.
I've played with the mixture quite a bit, replaced the O2 sendsor, etc. It may be that it is just too far out of normal range, I guess I need to buy an exhaust gas tester to nail it down.
The car runs great, but at steady cruise I feel a slight surging as the mixture swings. It's done that since I first got it, for a while I ran with the O2 sensor disconnected because it was bugging me. For all I know it could be a DAPO thing.

Couldn't these be cast from RTV Silicone? I've use this stuff make molds for casting pewter/antimony/lead/tin etc, so it's designed to take the heat and is flexible.

BTW, I replaced the 4 O2 sensors on a friends '97 993 Twin turbo (Protomotive) on Saturday....and all I can say is...Holy $hiT this car is fast.

Sam,

I had a surging / hesitation at cruise with my 79SC and it turned out to be two things.

The tip of the rotor was very worn and not providing good spark and one of my spark plug wires was not conducting well.

Once I replaced those two things the problem went away, and we had tried everything with the mixture and so on.....

With the turbo, you want to run open loop (disconnected) under boost and closed loop when not under boost.

Here is how:

http://forums.pelicanparts.com/uploa...or_Install.JPG

Tsuter is deffinatly a thinker...:D...and that car is wicked cool. Thad you owe me a ride next time I see you.

Anyone have website for Knoxville Superchargers. I've searched but have come up with nothing

alright so, 930 exhaust sytem with a spacer could put the turbo high enough to gravity drain?

yea, those boots are really what im after :(

Tsuter, I have the BAE manual and have the lambda system configured exactly as pictured, but don't run with the O2 sensor disconnected. Is that what you mean by open loop? The only difference is the BAE manual calls for the hobbs switch to close at 1.5 psig, mine is set at 3 psig rising.

A couple of years ago I ran without the O2 sensor when it was bad, the only reason I replaced it and hooked it back up because it gives better fuel mileage and better metering under certain conditions and it helped me a pass smog test . Right now I am just about ready to disconnect it and tune it manually like I did back then. I hate to give up and admit I can't make it run as designed, call me a stubborn SOB.

Sammy how do you pass the smog with such a non-stock motor? Have you been sent to a test only station? Do you have to submit to the visual inspection (like in LA and the Bay)?

My engine is completely stock, it just has a little modification to the intake and exhaust ;)
A year ago November I had to go to a test only station for my biannual smog test, which eventually I passed. Two weeks later I added the turbo.
When it comes time to test again I will take it back to stock again, prolly only take a few hours.
For those tree huggers out there, the turbo itself does not increase the level of pollution the car puts out, it just affects the visual inspection.
Oh, that and also the catalytic convertor that "fell off". ;)

The same smog rules apply to the O.C. as L.A.