Project Turbo 914 begins..., (yes, I know you can't turbo a 914) Options

[ottox914]

Just a little teaser on this winters project. Last winter I dug into this little update:

http://www.914world.com/bbs2/index.php?sho...c=53733&hl=

This winter will be phase 2. This photo will show some of the goodies under the tree, which will soon be under/on the car. The WRX intercooler has one round inlet on the back, and 2 smaller oval outlets under the opposite end tank. These will each exit and attach to some CB performance turbo "hats" for the ITB's that have 2" tubes welded to them. Some silicone elbows, and we're good. The intercooler will mount on braces running across the engine bay to support the intercooler as close to the GT lid as possible. I'll see how it goes, and probably do some yarn tuft testing to see about airflow in and around that lid, but I could always use the SDS computer to switch on either a puller or pusher fan below the intercooler based on boost, if needed. The turbo will mount on a custom flange/adaptor to be built to connect the turbo to the collector of the Kerry Hunter exhaust system. The turbo is a small Garrett VNT. The compressor map looks like a good match for this motor. I'm expecting the VNT turbo to give good low rpm thorttle response. Starting out at 5-6 psi, I'd be happy to see 10 when I'm done, but will tune to run safely on 93 pump gas and see where we end up. Off the back of the transmission, where the factory exhaust hanger mounted, I'll mount a similar hanger to support the turbo and exhaust system. A Tildon differential pump will return the oil to a willing valve cover. Oil will be taken from a "T" at the pressure sending unit on the case. There is a blow off valve to be added to the intercooler, and a mocal thermostat/sandwitch plate adaptor for the oil cooler, which has a thermostat controlled fan. I'll be adding an ignition switched relay for power to the fan and scavenge pump, so both will have power when the key is on. The pump will run continously, the fan when the thermo switch tells it to. Add some pressure side stainless or aluminum tubing from the turbo, thru the back engine tin, into the round inlet on the intercooler and we're done. Except for another trip to the LSE dyno, for some additional tuning. I'll keep posting as progress would warrent.

[ottox914]

Moving on to other work, I re-plumbed the puke tank to have an individual line from each head into it, with the lines going up from each head, no low spots to have anything condense. I also added an elbow and fitting for the oil return from the scavenge pump. The oil supply was already stubbed in when the oil pressure sender was installed. Next is a pic of the oval to round adaptors to get from the 2" round that the ITB hats need, to the oval of the subi intercooler.

[ottox914]

Final cuts of tubing, and the masked welder in action, adding beads to the aluminum ITB hats, intercooler adaptors, and to the mild steel IC piping. Good to have friends with skills... and now, just needs clamps.

914 Joke of the week. My friend Ron, the welder, goes into town to hunt down a flange to use to mount the turbo to the kerry hunter header collector. He stops at the one muffler shop in town, and runs into a guy who used to be on his fastpitch team, Steve. They catch up a little bit, and Steve asks Ron what he's looking for. Ron says he needs a flange to match a collector, shows him the collector, they find one thats close, just needs the mounting holes hogged out a little. Steve asks whats it for? Ron says "I'm putting a turbo on a 914 Porsche" Steve says "No, really, whats it for?"

Moral of the story: even in a town of 8000 with one muffler shop, a guy with a shaggy beard and no teeth knows you can't turbo a 914...

... what am I thinking?

[ottox914]

Right and left sides completed!

[ottox914]

Intercooler mounted and connected to the round to oval adaptors, connected to the ITB hats. With a VNT turbo I shouldn't really need a blow of valve, , but there was a hole in the IC for the factory valve, so now was as good a time as any to make a plate and just put a hole in it for the BOV. I have since trimmed off the plate and finished it off a little better, added some stainless bolts to class it up a little, rather than the parts box bolts in the pictures.

[ottox914]

On to the good stuff. Think we'll have to trim off that exhaust just a bit. It should look pretty stealthy when its done. We went thru several versions of the adaptor from the turbo to the header collector. The first one kept the oil in/out of the turbo verticle, for good drainage, but the angles did not favor us, as the turbo ended up 4" off the ground. Before attaching the drain. Not good. We cut, tacked, test fit, and did it again till we had the drain no lower than the engine mounting bar. The oil comes into the turbo at a little bit of an angle, but after consulting with Corky Bell a bit, as the oil drain will be "sucked" dry by the Tildon differential pump I'll be using as a scavenge pump, being off verticle will hopefully be no big deal. Due to the nature of the center section and VNT mechanicals, clocking options for this turbo are limited.

[ottox914]

Some close ups of the flanges we had to make, and the final product, which is designed to bolt right in where the supertrapp now resides.

[ottox914]

Last installment for tonight- I took and hosed down the bare metal with some black grille paint to finish it off a bit.

to do list: fix oil leak at sandwich plate adaptor to oil cooler, mount the tildon pump, wire it, plumb the pump to the engine, get the hose made to go from the engine to the turbo, get more 2" tubing to make the boost line from the turbo to the intercooler, and "T" a vaccume line to the turbo to control the VNT. Per usual, its all worked out and done in my head, just gotta get in the garage and make it happen.

[ottox914]

I just re-read the thread and see that I 2x posted some pics and info- good thing I'm not in the garage tonight... enjoy and more info as it gets done.

[ottox914]

A few more updates- over the weekend, I swapped out the oil lines to the cooler. I just couldn't stop the leaking. Oddly enough, it was not where the fittings threaded into the sandwich plate adaptor, it was at the hose to hose barb connection. I tried several different types/brands of hose, one big clamp, 2 narrower clamps, 2 big clamps, different NPT/barb fittings, still leaked. So I got some -AN fittings for the sandwich plate end of the lines, and went to the local auto parts store for some REAL hose, with NPT on one end to connect to the oil cooler, and -AN on the other to go to the sandwich plate.

[ottox914]

I also got the tildon differential pump (now scavenge pump) mounted. Made the bracket out of a piece of aluminum plate, drilled holes, and done. Well, 1/2 a day later done. I mounted it on the back of the trans where the brace for the factory muffler system would go. I also mounted the bracket thru the pinch bolt for the speedo angle drive, so I had 3 mounting points for the plate. I took another bolt from the box of old 914 bolts, and ground down the end to match the factory bolt, but be longer to accomidate the thickness of the plate. 4 bolts mount the pump to the plate, but be careful where you drill them, as the back of the plate contacts the back of the trans in several spots, and there is no room for the bolt/nut if your hole is in one of these spots.

[ottox914]

Here are some pics of the pump on the car. I found key switched power in the factory harness. There is a group of 4 wires, 1 black, 1 larger black, 1 white/blue (I think) and one black/purple (tach). The larger black was the coil wire, and after testing with a meter, was found to be hot when the key was on, so I added a 20amp fuse in line, and connected to this location for power.

[ottox914]

Couldn't fit all the pics on that last post, here is the back of the plate, showing the need to be tidy with the mounting bolts to keep it all fitting well. The ground for the pump went up to the trans ground strap bolt.

Last night I mounted the turbo, and ran the drain line from the turbo to the pump, roughed in the lines from the pump to the engine, and the oil supply to the turbo. Will add some more pics tonight. I took thursday/friday off to get this thing DONE and on the road.

Side note- shop hard for parts! I was looking for an NPT to -AN adaptor for the turbo oil line, and a 4' section of braded hose, pre built, with -AN on each end. Some of the usual big auto parts superstores (you know who they are) had such things, in the sport compact section, as nitrous bits and pieces. Would have run me 70 bucks or so, and the adaptor would have been a blingy anodized aluminim bit. At my local dirt track store, (there are plenty of dirt/clay ovals in my area) a good solid brass adaptor and 4' section of brake line with correct fittings at each end ran me, oh, $17 bucks.

[Brian Mifsud]

Dave,

Is your turbo oil circuit seperate from the engine's oil? You say you are using the scavenge pump to PULL oil out of the turbo. I don't know much about these systems, so the "obvious" question for me is why not "PUSH" the oil through? Does that cause oil leakage into the pressure side of the compressor?

[iamchappy]

It would be best to have a small sump under the turbo to catch the drain oil. oil can back up into the pump and sit after shut down you can run the pump before starting and after shut down but the little sump is helpful in de-foaming the oil coming out of the pump and helping the priming circuit for the pump.

I have and extra one I made with 8an fittings on it if you need it.

[ottox914]

Brian- the engine oil is pressurized, and I am tapping into that to supply the top of the turbo bearings w/oil. As these are bearings, and not a pump, gravity is the only force trying to move the oil out the bottom of the turbo once the initial pressure supplied by the engine is "used up" getting the oil into the turbo. So you're mostly right. The engine pumps the oil to the top side of the turbo, gravity drops it out the bottom, and now my scavenge pump sucks it out and sends it back to the engine. Thats why you want the oil in/out to be as close to verticle as possible, and to mount the turbo higher than the oil pan if possible. I chose this mounting system mainly to save the $$$ and effort of a custom exhaust.

Which brings me to chappy.

I have been talking with Corky Bell, author of "Maximum Boost", and he suggested a line directly to the pump, although his book shows some low mount turbos with a small sump as you suggest. His reasoning was that if with the VNT feature of the turbo, I couldn't get a verticle oil drain, the draw of the pump may be more important to keep the turbo bearings flowing well, and this design concern may overrule the conventional set up of a small sump. He noted the main purpose of the sump was to allow a drain for the oil in the line to the turbo, and in the turbo, after shut down, and that the de-foaming of the oil in the sump was a happy side benefit. I'll be trying things as they are, and I can always turn the key to "on" and let the scavenge pump run a second or 2 prior to starting the car, to suck the lines clear, and also leave the key "on" a second or 2 after shutting the motor off, again to clear the lines and allow some room for draining. Supposidly the pump is self priming, and has some crazy verticle draw, but the thought of having the de-foamed drain oil ready to enter the pump can only make is last longer, rather than to start out dry each time the car is run. I still may contact you for that little sump you made if the godfather of turbos isn't 100% correct on this one.

The wonders of a one off install never cease to amaze and confound me.

[iamchappy]

I had problems scavenging fast enough with the Tilton pump, but part of that was the Rayjay turbo I was using, after i switched to the cam driven 930 pump i didn't have any more problems.
I use the Tilton pump for my transmission cooler now.

Just let me know if you want the sump.

[ottox914]

chappy- pm sent.

[Aaron Cox]

looks great!

so how do you put oil in it?

[ottox914]

More updates- I'm so close now I can feel the boost- Took today and tomorrow off to get this project DONE, but have a horrible cold, so work and mental processing are progressing at about 50% efficency...

Today got alot of small things buttoned up. Here are some pics of oil lines being installed from the oil sending unit to the turbo.

When I had the motor out for the SDS install, I added a short nipple and "T" fitting to the oil pressure/temp sender, with a plug in the "T" for future use with the turbo.

Next is the line connected.

Next is the line going thru the back engine tin, and back to the turbo. There will be hose zip tied around the braded line where it touches anything to protect the hose and whatever it touches. The vaccume line to the VNT actuator will end up sharing the same hole and grommet, so I zip tied the hoses togather in front and in back of the grommet, to prevent any in/out motion.

[ottox914]

Here's a couple money shots for you- turbo, air cleaner, and tildon pump all installed and ready to go. I suspect I'll be re-doing the turbo drain, as it looks a little lame, but it is no lower than the engine mounting bar. I expect when the car is on the ground, you'll never see anything, except a factory looking little pea shooter exhaust.