What turbo should I buy? Options

[turnaround89]

I am getting ready to turbo my 1.8L engine. And I already know that you can't turbo a 914. But, what i would like to know is what are good cars to get turbo's off of?

I am looking for a small turbo that will spool quickly. Looking to run about 7 to 10 pounds of boost.

What turbo'd cars will give me a good turbo to use? I have been looking for ones on ebay, but don't really want to buy one there. I don't mind buying a used one, so going to the junkyard and getting one is definitely an option.

Which turbo?

[ottox914]

Reading and understanding are one thing, blowing stuff up and re-doing it is another, and leads to a more well rounded understanding of how and why. Read up, make your plans, build it, see if it breaks, come up with better ideas, build it some more.

My intent in making this comment was not to imply that you needed a large wad of cash, or a bottomless pit of stuff to break, but to get the point across that if you build it, you'll gain a better understanding of how it works, and if/when it breaks, you'll be in a better situation to understand the failure mode and how to repair/avoid it again in the future.

My SDS is a fine example. I am more interested in the overall engineering of the turbo system than the workings of the EFI. I could have built myself a mega-squirt system, but knew of others who had and ended up with problems getting the build right, then working thru the screens and screens of programing, and if one little thing is off, say the voltage range for the TPS on the system set up does not match the actual range of the TPS used, more trouble shooting to find and fix this, IF you don't pop a motor trying to tune around the problem. I elected to spend a little more and go with a proven system, and had great fun designing the layout of the wiring harness, fuel lines, linkages, and ecu location. Much more fun than I would have had tracking down a diode that I installed backwards one night at 9pm. If the SDS fails, I won't know where to start, but with the beyond excellent customer service they have shown me, I won't have to. I chose not to get more educated by the been there done that school for the efi part of the project, but I did a TON of research on what unit to buy.

Whats that got to do w/a turbo on a 914? EvilEd did not make a kit for his system, he used an idea for CIS, that I think, but may not recall completely, was a retro-fit offered as a kit for for bus engines, and morphed that into a very good 914 system, but for the most part, its a one off build. Chappy has done amazing things with his turbo system, and in his quest for fire, or rather power, had moved up into bigger and better engines. He was more interested in building the perfect 914, so he applied his efforts in that direction, farming out the motor build.

My system is loosely based on the kits from STS. Google STS turbo and you'll get to their site. My turbo car has been an evolution. I bought the ITB's from Jake several years before I used them, as I was thinking NA at that time. So step one was to mount the ITB's, get fuel and linkages figured out, install and tune the SDS. I strongly considered selling the ITB's and going CIS for the turbo, when the turbo bug bit, as I had been following Ed's build closely, but went SDS for several reasons: Its a great system that has all the features I need, and few I don't, service/support is excellent, and it controls spark and fuel. That was probably the big reason I didn't go CIS, I wanted to be able to fine tune the ignition curve for NA and boosted operation. I also liked the clean look of the engine compartment with the ITB's and the harness/fuel lines tucked up out of the way, and there was LOTS of room for an intercooler as well.

As far as the system not being reliable, well, draw your own conclusions. The motor in the car currently is probably 12 or more yrs into its last re-build, and was using some oil prior to the turbo. I was figuring that with running a dozen auto crosses and schools a year, for the last 10 yrs, that I had maybe a yr or 2 left in the motor before it would be really needing a re-build, just on general principles and accumulated beatings/mileage. If I'm finishing top 10 in 100+ car grids I'm not being any to easy on the hardware to do this. So putting the turbo on it was not at all the cause of my doing a new motor, it was part of the plan. Using a tired motor for the test subject, if I really messed up and popped it, not much lost. I have proven to myself the system as it is installed all works as it should. The turbo and motor have stood up to 11.5psi on pump gas. My school of hard knocks intercooler plenum and fan set up will be improved upon for the new motor, and with better heads and cam, the whole system should breath much better, which should spool the turbo sooner, and its all good in the end. When will it be "done"? Never. And for me, thats part of the fun.

Whose system is best? Blonde, brunette, or red head? Chappy has made the most amazing street 914 I could imagine. Trunk space has been lost, mega horse power and super-coolness found. Ed's/Nein's set up tucks into the factory location, not even loosing the raintray, and has been as reliable as gravity for 7 yrs of boost. Outstanding! And while the cost of the "used" parts is less than what I have into mine, I suspect if there was a 10 page build thread there was plenty of machine work and trial and error to get it right. Mine is a little different still, and works fine, and should be a hoot with a stronger engine as the project continues to evolve.

Back to the project at hand: Draw thru would not need a RR FPR, but the carbon seal is a must. Consider your location also- while I do not have direct experience on this, I understand the draw thru systems can be prone to iceing and other issues in temps below 40-50 degrees or so. Read up on what Bell has to say on this. I considered a draw thru as well, but thought it to be a step backward from the CIS, and 2 steps back from the SDS, however depending on the budget, and intended use of the car, draw thru could be the way to go for this build. For me, driving to events in the early spring in 30 degree temps, draw thru was not an option, but the bug guys have been doing it for a while and making it work fine.

[andys]

Back to the project at hand: Draw thru would not need a RR FPR, but the carbon seal is a must. Consider your location also- while I do not have direct experience on this, I understand the draw they systems can be prone to iceing and other issues in temps below 40-50 degrees or so. Read up on what Bell has to say on this.................

Actually, it doesn't need to even get that cold to start icing, but it was never really a problem in SoCal. However one way we solved the issue (on air cooled applications) was by circulating engine oil around the base of the carb, though only with incidental contact so as to simply add some small amount of warmth, not a lot of heat. Many times the turbo and carb were mounted far from the intake and a water heated carb manifold (on water cooled cars) helped to bring back some of the lost throttle response. The '63 Olds Jetfire, and the '63-'65 Corvair Corsa both used draw-through systems. I only ever witnessed the Corvair develop some small amount of icing, but only after some long hard runs. The Olds used a water heated impeller housing.

Andys