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]

This may take a while, so get comfy.

Recap: Ever since I turbo'd my Ford Focus I wanted to do the 914. Phase one was to get some ITB's (from Jake) and SDS fuel injection (direct from the SDS guys in Canada) and get that all working. I sizes the ITB's for a 2316 as I thought I might like to build one some day, so they're a little big for my current 2.0. The 2.0 is a slightly warmed over motor built by Brad Mayeur, with euro P/C's, and a little head shaving to up the CR, stock cam and valve sizes. Kerry Hunter exhaust.

I picked up a VNT turbo from a VW TDI. The turbo I put on the Focus was a VNT, but by a company called "Aerocharger" which has gone out of business. The new turbo was a Garrett. My thinking was, the TDI is a 1.8, mine is a 2.0. The TDI revs to around 4500, the stock cam'd 914 dies off at around 5-5200. After picking up the ebay gem of a turbo, I finally found a compressor map for it. Not the best match for the pressure ratios I would be running, but it was paid for, and maybe the VNT features would broaden the operating range of the turbo, and it would work out all right.

Early October 2007 I got it all set up, custom making flanges, piping, mounts. I had thought about pre-lubing the bearings, pulling the fuel pump fuse, turning the motor over w/the starter to prime everything, but in all the research I did, I never once saw anyone make a big deal of pre-lubing. After years of research, planning, I was at my moment of victory! Rather than wait another 5 minutes, I turned the key, let it idle a while, and took a test drive. After a short bit the turbo was screaming, sounding more like a mad dremel tool than a turbo. There was oil out the tail pipe. There was virtually no boost, no matter how I set the vane controller for the VNT system.

I think I fried the seals/bearings.

I put the supertrapp back on, and finished the auto cross season. A crushing blow, enough was enough.

For the month of November I searched and researched turbos, and even picked up a junk turbo off a late 80's subie, (for free) but it was so rusted togather I couldn't get the hot and cold side housings off the center section to clock it to work for me. Studying compressor maps, I decided the stock WRX turbo, a TD04-13G would be a good match, so I joined some subie boards and looked for a low mileage take off. Turbo secured, I went ebay shopping for flanges and other bits needed.

Now we're up to the present, and on to the pictures-

First is a photo of the turbo, after clocking the center section. This is a process by which you basically take both compressor housings, exhaust and cold side, off the turbo, rotate the center section as you need it to be for oil flow in /out of the bearings, and put it all back togather. Except that in an orientation other than the OEM, the waste gate actuator will not line up with the waste gate. Hmmmm.... I found that the SRT Neon had a wastegate actuator that would start to open at 5psi, and be fully open by 7psi. The stock WRX actuator worked at higher pressures, and I wanted to start out small with psi. As a bonus, the SRT actuator had an odd bend in it, that just might work for me. Well, it did, thanks to Ebay.

The next pic is the adaptor to join the turbo and the exhaust header. Initially I thought I could just weld the header flange, a triangle shape, to the turbo flange, an odd trapizoid shape, and bolt things up. Looked like it would work. Didn't. There was all kinds of turbo housing/collector issues that prevented getting the right bolts thru. We were going to have to do alot work to tap and stud the flanges to make it all work. And to top it all off, I didn't get the flanges lined up right before welding, so the whole turbo was slanted when we tried to test fit it. Hmmmm... back to the muffler shop to look for more ideas. We thought an extention of 1 1/2" would move the turbo back under the factory exhaust heat shield. Steve at the muffler shop suggested a flaired end to the extention, then we could rotate the turbo any which way we needed. Genuis. Thus was born the flange adaptor.

Next pic is the adaptor installed.

Next pic is the turbo, looking at the exhaust side. I still need to make the exhaust pipe, which will be an "L" shape, with a tab to mount it where the super trapp was mounted to the chassis on a slightly flexable mount. This will help support the turbo, so all the weight of the turbo is not on the head bolts.

Next pic is the turbo from below, and the last pic of this section is the turbo and tildon scavenge pump, viewing from the cold side of the turbo. I still need to get an air cleaner over the compressor inlet.