pics of 914 turbo plumbing Options

[iamchappy]

I would think you could run with the existing fuel injection system by plumbing in a 5th injector that fires off a hobbs pressure switch, I am running a 7th injector on my six with great results, A MSD BTM ignition will handle the timing. I am barely retarding my ignition because the 7th injector works so well.
I like the keep it simple idea first, and move on if more is work needed. I think a type 4 engine would be a fun project to turbo on the inexpensive side with great results.

[Bruce Allert]

If someone would make a pictorial installation guide I think it'd be worth some good bucks. That's the only thing that holds me back from doing a turbo... I don't know anything about it, where to begin or how (IMG:style_emoticons/default/unsure.gif)

.....b

[Brad Smith]

Ok, I get to chime in with something I know a LITTLE about... woohoo.

To start with, someone said T4... I say that's WAY too much turbo for that itty-bitty flat 4. I'd stick with a moderate sized T3, which has the additional advantage of having the wastegate built into the turbo housing- cheaper, easier to fabricate the system, and more compact. Get them cheap from the salvage yard from a turbo T-bird or Lincoln. Or use the turbo from a late 80's RX-7, again with integral wastegate... but that may be marginally too large, depending on your power "wishes."

Second, a short exhaust and long intake is better than the other way around. You want the turbo as close to the exhaust ports as you can get it, to maximize the energy "felt" by the turbo from the exhaust pulses. It will spool quicker that way. If one were to run a divided inlet turbo with each side getting the pulses from 2 of the cylinders (the opposed ones that fire 360 degrees apart) that would help it spool even quicker, but the plumbing would be a nightmare.

Third, turbos give off a LOT of heat. I suspect having the turbo in the engine compartment of a 914 may give you some cooling grief. Shield it off as much as you can. (note that I didn't say they GENERATE a lot of heat... they generate a LITTLE heat from mechanical friction and by compresing the air, but the housing of the turbo will radiate a lot of exhaust heat.)

Fourth, GET AN INTERCOOLER. 'nuff said. Ok, maybe NOT enough. Cooling the intake charge will both give you a denser intake charge and reduce the heat that is ingested by the engine to begin with. It will make more power and be less subject to detonation.

Brad

[Sammy]

On mine I built a short header/collector that came up at the right-front side of the tranny where it conected to the turbo. That was as short as I could make the exhaust plumbing. I used a sidedraft weber on top of the engine in a draw through style (not the best but very simple and it worked).
I had the discharge of the turbo plumbed into a modified stock intake manifold.
I wrapped the turbo with muffler insulating wrap and didn't have any heat problems.
Having the turbo lower in the car creates a whole new set of problems for oil drainage but nothing that can't be solved, it just adds to the complexity. I like simple.

Intercoolers don't do squat except create more lag at boost pressures under 6 psi and can't really be justified on a 914 until you get above 7 psi IMO, plus you need to get lots O' air through it, not easy.
Heat of compression is not linear and doesn't really climb much at all for the first few psi, then gradually starts to increase as boost goes up.
Intercoolers work on differential temperature and are not efficient if the air charge is only 15 or 20 degrees hotter than ambient.

[iamchappy]

An intercooler will be needed if you plan on running 12lbs of boost or more, but significant horse power gains will be seen at 9lbs or less without an intercoooler.
The efficiency rating of a intercooler at low boost is minimal. I suppose if one was trying to extract every bit of horsepower out of an install all the things said about shorter exhaust, exhaust pulses flow and then some would be a factor, but for someone putting together an uncomplicated system that would still provide huge horsepower gains, simple straight forward easy to build designed like what I have done on my turbo 3.0 six will get the job done.
I am sure I am giving up a few horsepower here and there with my install but come take a ride with me and I doubt you will come away with the feeling that I need any extra horses.

[Mueller]

from what I understand, the stock /4 (D-Jet) has "issues" once the MPS sees positive pressure so just installing an extra injector is not as easy as one would think.....

as for the shortest length exhaust....according to Corky Bell, for a street motor, it's not that big of deal, yes you want all the plumbing to be the shortest as possible, but for a "bolt-on" kit, you'd never know the difference since you are not trying to build the most optimized system for the average person.....I don't see a huge market for this, maybe 2 or 3 people would really be interested and then when it comes time to buy it, they'd be nowhere to be found (IMG:style_emoticons/default/smile.gif)

as for making kits, I think the best way to approach this would be to at least devolop one good running example, take plenty of pictures and make instructions with the drawings and part numbers...not sure how to price it, but obviously it has to be cheap for us 914 people (IMG:style_emoticons/default/smile.gif)

[airsix]

Here are a few of my thoughts.

Injection: Jenny's brother Jeff ran D-jet on his turbo. As I recall putting boost on the stock MPS broke it eventually. Maybe my memory is wrong, but that's what I recall. Why mess with D-jet when you can go Megasquirt for around $200 total cost and have a programable system designed for forced induction? (Jeff used the D-jet as an experiment)

Intercoolers: True, 914 turbos should have intercoolers. And there should also be world peace, a free Tibet, and a restoration of the rain forests. What I'm trying to say is that I've converted my 914 to a hydraulic clutch, digital fuel injection, crank-fired ignition, and fabbed my own turbo installation.... but I still can't figure out a practical way to install an effective intercooler. I haven't given up, but I'm telling you it's been a challenge for me at least.

-Ben M.

[Brad Smith]

I can think of SEVERAL ways, but they're not really "easy."

1) 914-6 engine cover, ducting to keep the hot engine air away from the intercooler. This seems the most practical for me... probably need an e-fan to cool it. Short plumbing runs. BTW Supra intercoolers are compact, efficient, and can be had CHEAP on ebay or from the salvage yard... and they don't look like the typical intercooler for you stealth guys.

2) Hack out the trunk and mount it between the taillights. (you could do this and keep some useable trunk space... but it's not very stealthy!)

3) On cars with body kits, mount it in the fenders. (rear quarter panels I should say)

And an intercooler on a draw through setup would allow more chance for the fuel to "settle out" so I would say forget it on that.

4) If you want to get more complex, an air-to-water setup allows you to have the plumbing short on the intake tract but you can put the "radiator" anywhere you want. One of my buds did that with his RX-7. He took the notoriously inefficient (due to size and location) stock 2nd gen RX-7 intercooler and built a water box around it... then plumbed it to a tiny radiator from a civic or geo or something, and plumbed it up with a tiny electric water pump in between. It worked great- he makes 425 hp at the rear wheels with that setup. (with a big honkin' T4 based turbo and some porting on the engine, and a Haltech to manage fuel and ignition.) So how about beside the tranny with a fan directing air? Lots of options folks. This one is a bit more weight, so moving the battery up front would be an idea to mantain balance.

I joined here to learn more about the 914, since I'm looking at getting one for my daughter... but it sounds like you folks are like "gearheads" everywhere- lots of ideas and good info on here. (IMG:style_emoticons/default/smile.gif)

BTW I'm normally a "rotary" guy... hmmm... since I have a turbo rotary motor in the garage, maybe I should put THAT in a 914... nah. Too much power for a 16 year old. (IMG:style_emoticons/default/laugh.gif)

Brad