In trouble...turbocharged 911SC

[turbo6bar]

I bought a turbo 'kit' of sorts off Ebay.

turbo kit from Ebay

It is basically a 930 CIS system from a '76 turbo + a Sparco intercooler. My plan is to bolt on the 930 exhaust manifold. Perhaps the crossover pipes will bolt to my SC heat exchangers, and then install the 930 CIS system in place of the stock Euro CIS setup. Well, I suppose I need to start calling myself Jüng and Stupid once again.

I have the need for speed. I just want to get this setup running & NOT blow the engine (rebuilt with less than 10k miles). Then, I can start thinking about EFI and other goodies.

Anyone been there, done that, except with stock 930 parts? If it all bolts together, my primary concern is ensuring the ignition is properly tuned (J&S Safeguard is a good possibility). Plus, I will need to install a rear 930 fuel pump or a high quality aftermarket FI pump, and maybe a new set of fuel lines.

Yeah, I know I'm stupid. Now, what else ya got to say to me?

I consider myself good mechanically, and I have a good understanding of what I am doing. What scares me is tuning EFI, and that's one of the benefits of the 930 CIS setup. Plus, the CIS is just plain cheaper to get into. If I can merge cheap with reliable, then I am happy. I do not need 400 HP. OK, at least not now.

Jurgen

[thabaer]

I pondered bidding on that gear, nice little pile of bits but I had no intention of using the CIS metering, only the plumbing.

limit the boost until you drop compression or get a smarter/faster control system. (I mean REALLY limit it until you get some metrics and know you won't burn it up) Instrument the hell out of what you start running with so you can learn what it's doing.

I was on a similar track years ago, before 9:1 and higher compression turbo cars were commonplace, I think I still have a 7.something 3.0l P&C set around ...somewhere...

[sammyg2]

DON"T DO IT! You run the risk of serious damage. I suggest you package it all up and ship it to me so I can help you resist the temptation
Since I'm such a nice guy i'll even chip in to help cover shipping. I know, I'm a giver

[thabaer]

Originally posted by sammyg2
... ship it to me so I can help you resist the temptation...

NOW I feel stupid, gee why didn't I think of that ? Yah know, shipping to Boulder would be cheaper than all the way to the coast

[turbo6bar]

I would feel bad shipping all the parts to either of you guys, so here's what I can do. I have a cutting torch with low hours, and I really need some practice. I can cut everything in half, and then you each have a piece of this HUGE mess. Plus, shipping will be a lot less. The intercooler will probably be severely melted, but superglue and a few well placed SCWDP stickers should fix it pretty darn well.

I don't know what I'd do without you guys.

[dd74]

Ahhh, bidding with emotion. It's like bombing Middle Eastern countries with emotion...

Here's what I'd do (seriously).

Sell it, get your money back, and go one of the two following routes:

1) Call Imagine Auto and see if they can track down a real 930 motor for you. It most probably will be a 3.3, but you can handle that.

2) If you're intent on the 3.0, get hold of RFNG for his turbo kit. It's nice, but pretty green still. Nonetheless, if your motor is fine and you can hold down the boost, I think you'll be okay.

Beware, however, that the first route is probably better suited with a real turbo car around the engine - I know, you don't want to hear that.

Addendum: Supercharger of Knoxsville.

The best: 3.6.

[rfng]

It looks like your missing about $2-3K worth of parts to complete it. Those are early thermal reactor headers without the thermal part. There suppose to be very restrictive.

Looks like you'll need a warm up regulator about 4/5 bills for that year.
All the fuel lines 4/5 bills, Hard to see in the picture.
The turbocharger. 1K- I have a t-3 if interested.
A new wastgate spring .8 bar is too high if its a euro- 80-83 you'll be on the border/ 78 or 79 no problem.
Have your distributor recurved or modified if euro/80-83.
All the connector hoses/clamps 4/5 bills
Muffler system.
Gaskets set intake and exhaust.
Oil feed line and return line.
Rear sheet metal.
Early heater deflectors or turbo ones.
Correct accumulator and hook ups.
Oil pump electric or mechanical if not gravity fed.
And probably at least a 100 hours of fab.

[cowtown]

So you're the guy who won. I made a halfhearted bid, but could never get the seller to tell me exactly what was included. It looks like a fun pile of stuff. I've rebuilt and installed a '77 930 engine into a '75, and was just out looking for spares.

Sure, you could buy a Turbo engine, but what's the fun in that? The SC engine is verrry close to a 93 3.0 engine already.

Random thoughts:

What if you try to find a set of 6.5:1 compression early 930 P/Cs? After that it looks like you are getting close to the real thing. You might need a new distributor (not sure, though. My '77 930's just has one port for vacuum/boost advance - is the SC the same?).

6-pin Bosch ignition box or your choice of MSD or Crane. I'm using a Crane HI-6 with the free Crane coil.

New Turbo fuel pump in back. Days and days of measuring and converting metric to AN and back again. Lying under the car talking to yourself loudly enough to make your wife wonder if you've lost it.

I have read that the Turbo heat exchangers are actually different construction from the 930 ones, due to the higher heat of the 930, but I haven't confirmed this. Might be important if you get rid of the TR replacements and go with a Euro exhaust system.

Engine sheetmetal for the fan side of the engine, to accomodate the pipes.

Turbo sump and cam-driven oil pump if they are not included in your Ebay pile.

Do it! You only live once.

[turbo6bar]

Thanks for the comments. Running a 930 mill would be a good route, but I already have a good 3.0. I'd be trading a known quantity for who knows what used 930 engine. If I had unlimited dollars, I'd buy a 930, but at this point I cannot afford the insurance (single and 27 years old).

It looks like I still need a lot of parts to make it all work. I definitely do not plan to use the 76 turbo thermal reactor exhaust. 3.6L sounds nice, but $$$ and not a match for a good turbo engine (can you say torque, baby!!!).

I need to talk to Stephen at Imagine Auto. I can explain my budget, needs, and wants and hopefully it is a possible mission. Worst case scenario, I part out the 'kit' from Ebay. I know the Sparco intercooler is worth a few hundred, and I can wait until I'm ready to spend more money or learn how to TIG weld. At least I admit my need for speed, instead of "wasting" dollars on SSIs, and other goodies knowing they will not satisfy my craving.

jurgen

[thabaer]

You started out by saying you have the knack....don't stop now.

As far as compression ratio, I was just throwing out alternative routes in my earlier post. Having both 7.0 and 9.3:1 turbo engines, I would definitely go for the higher compression ratio for a street driver. With the newer ECUs (heh, the last DECADE) and a decent array of sensors, you can safely go beyond 1bar of boost. What you want is a quick spoolup that doesn't choke as you go over 6000rpm.

EDIT: Oh, I forgot to say that means twins , just the thing to attach on both sides of a flat six!

[turbo6bar]

I want to stick with the stock compression ratio. The car is a '78SC, but the engine is from a '83SC, so it has higher compression in the range of 9:1. The car is street driven, and I need good off-boost performance.

I do not want to abandon it, but I do need to rethink the project. If I spend hundreds of dollars on additional CIS 930 parts and another $600 on a J&S Safeguard, would it not be better to just make the entire leap to programmable EFI and a simple Carrera manifold. I admit the tuning scares me and so does fabrication of plumbing from scratch. I do not have a TIG welder, and MIG welding tubiing is still no easy task.

Again, I need to think things through, because I don't want a half-baked finished product. I was hoping to just bolt on a majority of the 930 components and run like a mad fool AS LONG AS I don't blow the engine. That is my major goal: DO NOT BLOW THE ENGINE.

I have been slowly working my way upwards with new projects on the 911, and I get confidence when I take the work to completion. It would be immensely satisfying to build a turbo car from a pile of parts, and the only drawback would be needing plastic surgery to remove the ear to ear grin.

Catch ya later when I've received the parts,
jurgen

[beepbeep]

Well I suggest you to sell the parts (there enough parts there to get all money back, and they look like remains of something that's left over from 930 EFI-conversion) and do it the right way instead.

There is nothing magical about 930 parts...they are actually pretty bad. OEM 3DLZ turbo is just plain bad, thermal reactors don't flow too well, CIS is just a big obstacle in the air-path etc.

I suggest you to go the right way, weld a custom headers (or fabricate them from OEM heat-exchangers), get yourself a decent modern turbo (even if it's a used one) and decent fuel system (used SDS ord Haltech can be found cheap).

That way you'll be able to to it the right from the beggining. I believe that attempt to bolt on those 930 parts (that were probably for sale just beacuse they were replaced with something better) will just produce frustration and cost lot's of money.

Even if you suceed (and it WILL cost you alot more that you believe) you'll still be left with low boosted engine with 930's all disadvantages and no advantages.


Get rid of it...

[turbo6bar]

OK, so we know that EFI is the real way to go. Here's another question: Aside from the slightly elevated compression ratio, is a fresh 3.0L a good point from which to start on a turbo project? I think so, as long as the ignition and fueling are adjusted properly, and boost is maintained under 1 bar. That is my totally uneducated opinion.

Just got an idea. Miller sells a cheaper TIG welder that handles light gauge stainless and mild steel tubing. It won't do aluminum, but it would be a cheap way to learn fabrication with tubing...

Thinking a lot while smoke billows from the ears,
jurgen

[cowtown]

Jurgen, what is it that you need to fabricate? The extra pipes you need are:

1)turbo pipe in
2)turbo pipe out
3)crossover pipe that mounts to the exchangers, wastegate, and turbo

You'll also need a muffler, airbox, oil pump, sheet metal etc. But I'm not sure what you're thinking you need to fabricate? You can pick up a Euro exhaust system (sans wastegate) for 300-400, a muffler for 100-300, and it looks like you have the turbo pipes.

I'm also not so sure a jump right to EFI is wise...if you're budget is tight, you can always get the thing up and running with the CIS you have, then sell it off later. I like CIS just because it's simple and was easy for me to understand once I read up. I don't doubt EFI is better-performing, and I might want to move to it in the future, but it's also a lot more complexity to add into your engine conversion.

[dean]

I don't think SC pistons are forged and that might be a problem with a boosted engine in the long run.
If I were you I would not even bother with the CIS. Go EFI now. I don't think it is that hard to tune. I use to tune carbs back in the dark ages, now that was a pain