I love the reliability and drive ability of my completely stock 1.8L. . . However, it's just got no balls and w/ approx 160K on it, it's going through oil about 1 quart every 2-3K (burning, not dripping).

I have a completely stock 1.7L block with which to use as a base that has perfect 371Q heads (that will be rebuilt) as well as a spare set of Q heads. My desire is to remove the 1.8L and keep it as is in storage and build a small displacement turbo motor using MS EFI to run it. The goal is to make a completely street drive able motor that when needed can pump out around 140ish HP and plenty of torque without going too exotic. I'm not looking to get 200+ hp by boosting to the moon so one must think fairly mild turbo application. . . It must be affordable.

I've got a perfect TD04 turbo that I plan to use that only has about 10K miles on it. At this time, I'm unsure of the turbine and compressor specs but it's not a large turbo and should spool-up pretty quick and the waste gate is adjustable for tune ability. The car it came off of boosted around 10-12 psi if I recall. Pretty standard.

The quandary mainly lies in the basic internals of the motor. I'm planning to use a 66 stroke crank and have it welded and ground w/ type-1 journals and use 5.4" H-beam rods. I want the motor to rev easily to 6K. The bore at this point is unclear though. I could have the stock 90mm cylinders bored to 90.5 or 92 OR use a set of 93s I have and bore those to 94 all using forged VW type-1 "B" spec pistons. All these can be done for effectively the same price however for the 94s I would have to have the heads bored. I'm looking for good head sealing and conventional wisdom says keep it smallish to get the thickest walls possible. What think you folks??

Next is cam choice. . . I've never built a turbo motor so the requirements are new to me here. What lobe center is best for turbo?? Again conventional wisdom leads me to a fairly mild grind since it will be force fed anyway, but I defer to turbo experts on this.

For heads, I'm leaning toward a more stock rebuild w/ stock sized S/S valves, HD springs, chromoly retainers and light, Manton push rods. Again having never built a turbo specific motor, I'm open to any and all suggestions. What do you turbo experts suggest??

I'm planning to retain the SSI heater boxes and Sebring 4 into 1 header so that I can retain heat (this is a street car that routinely carries my wife) and plumb the exhaust forward to a turbo outside the engine sheet metal.

I plan to run an intercooler either under the car with a ducted dedicated fan, or in the engine compartment. I would prefer to have less "stuff" in the engine compartment and have heat sources away from the cooling air, but I'm pretty flexible at this point.

EFI will be the latest MS w/ EDIS ignition. I already have made some turbo end-castings and plan to connect them with a custom "T" and have a late model car TB (around 50-60mm in size). Any suggestions on what car to get said TB??

Well that's enough for now. Any suggestions folks can give would be appreciated.

it common knowledge that you can't turbo a 914

I always liked the turbo setup in my '86 Subie (RX)...ran sweet!

See the links in my sig.

Talk to Jake about a turbo cam. Have Len do the heads. Get ready to pay, as doing it right the first time isn't cheep at first, but will save you $$$ in the long run.

Turbos on our motors are a challenge, as the turbo is driven as much by exhaust heat as it is by velocity. Do some searching on turbo maps and educate yourself on turbo sizing- then think smaller. Our 2 valve heads don't flow as much as a 4 valve, so a turbo from a 2.0 subie will be to big for a stock 2.0 type IV, it will work, but you won't get much boost below 3.5K-4k rpm. If you go to small, you'll get a quicker spool and more boost at lower rpms, but to much heat and back pressure will cook the heads, your intake temps at higher rpm's will be scorching, and thats all bad.

Be ready to fabricate just about everything, as no one currently makes a bolt on kit.

http://lowbugget.com/turbo_mid_kit.html

T4 turbo bolt on kit- they will bend tubes to your spec and behind the engine under the trunk. Proven 150hp-300hp has been done on strongly prepared engines. There are many others that cater to the T4 Sand Rail community with decades of proven turbo setups on our 914 engine. A secret; don't tell anyone...Enjoy(!)

I have a PERFECT dual ceramic ball bearing turbo for a small displacement engine for sale.. It would only work for a blow through arrangement, but it is a super nice, fast spooling animal!

Its only seen dyno time!

I just read through your thread. . . Thanks for the link and sharing what you experienced. I'm definitely going to do my homework. I can't afford to do this twice. The turbo I have looks to be just a slightly different configuration (as in exhaust flange mount) of your smaller 3000GT unit on page 6. The one I have is a TD04-09.

Will an under the car intercooler get enough air? Won't it be getting all the waste hot air from the engine cooling tin?
zach

There is/was a turbo kit for the MR2 spyder that had a thin, wide intercooler mounted in back below the floorpan of the car, the mfg stated with ducting they had great cooling, equal to, if not better than a front mount.

But. The MR2 is water cooled, and has (relatively) cool and smooth airflow from the front of the car to the back. With the cooling air of our motors going top down, and exiting the bottom of the motor, I would expect, but have no numbers to prove this, that a low and rear mounted intercooler, would not be all that efficient. I went with a top mount, ducted puller fan set up, and with the smaller turbo and 10-11 psi, have had no problems with it for auto cross. On a 3-4 hr highway drive, in 90 degree + temps, even with the fan on, it will heat soak and intake temps will rise, but not dangerously, and on the highway I'm not heavy into the boost for an extended period anyway.

When the new motor is done, the next evolution of the top mount IC will be ducted again, with dual fans pulling air thru it, with more than double the CFM of the single fan now used. I'm considering a tiny bit of water injection as well, more to "steam clean" the heads and chambers and keep any carbon build up/detonation at a minimum. With the SDS I can program this to come in at any PSI that I would choose, so I could, say, run 15 psi max, and have the WI come in at 12 or 13 psi.

Without a built motor, 10-12 psi is a good maximum. At that rate, a well designed water injection system may be enough to do what you need it to, with 93+ gas.

Read Maximum Boost by corky bell- he's not so keen on water injection, but it works for the WRC cars, it can work for you. I used it on a focus I boosted to 8psi and it was fine for that purpose, low boost, stock internals. When I cranked the boost up and developed it further, I ditched the WI and went with an air/water system.

I'd love to build an auto cross only 914 with a wicked boosted motor- build it a 100 pounds or so under weight, and install a 5 gal or so spare tire fuel cell up front, use that to hold ice water for an air/water intercooler. For short auto cross runs, that would be great, having intake air temps below the ambient air temps, oh could you boost that beast. Drain little water and add another bag of ice for each run...

some of my bookmarks from playing with turbo stuff:

http://www.lovehorsepower.com/CFM1.htm

http://hondaswap.com/forced-induction/comp...dummies-129194/

http://www.dsmtuners.com/forums/articles-t...ressor-map.html

http://www.not2fast.com/turbo/glossary/turbo_calc.shtml

David,

Have you seen the setups where they are spraying CO2 on the intercooler for an instant freeze?

I wonder if there would be a weight difference in comparison to hauling around that much extra water/ice in the front trunk.

I'd have to check the rules to see if that was legal- You'd be blowing alot of CO2 per weekend. Lots of the drag guys do this prior to a 12 second run. Our events are 60-90 seconds per lap, 6-8 laps per event, thats alot of blowing. My thought was to build the car under weight and use the air/water system to make weight. Putting the weight over the front end and low would help balance the chassis. The 914T is slightly underweight so I can leave the spare tire in place for just that reason. I'll never have the $$$, time, or spousal support for another 914, so its a build in my dreams, but its still fun to think about.

78.4 x 91 = 1995cc's. Lot's of torque at low speeds. Use Q heads with the proper valve sizes (the propper valve sizes are not stock) with the appropriate port work, relocate the spark plugs to the 2.0 914 position. Have custom pistons made with the correct dish volume to achieve the desired compression ratio, as opposed to hogging the chambers on the heads and thereby weakening a head that is already damn near to weak for a turbo.

For best results, and the greatest hope for success, use LNEngineerings Nickies. Iron cylinders with a turbo will leak, it's just a matter of time. Have your case decked to ensure all of the cylinders are perfectly square and even. I deck a lot of cases and EVERY case I have ever decked has been out some. Some are worse than others, but they all have been uneven to some extent.

Do a lot of research regarding induction, exhaust and tuning. One well timed, well placed mistake and POOF! it's toast.

I'm not a big fan of turbo charged T4's. But if it is done right and with reasonable expectations it does work. A long stroke, small bore, low rev engine with modest output could actually achieve a decent life span.