LocostUSA.com

Okay, you want locost? Use a carb.
Done laughing yet? Well, actually, it works. I had a 57 Dodge with a low compression big block, so I decided to turbo it. The first thing I did was melt the Electromotive ECU. So, put back the 4 barrel intake, and here we go. After all sorts of misadventures, I met someone with a 20psi race Pinto. The trick is suck thru. Modify the carb so the manifold pressure/vacuum is referenced externally. Reference it downstream of the turbo. Jet rich as heck. Then, using your O2 sensor, you can jet for close to stoich at vacuum, keeping it pretty rich under boost. The rich mixture evaporates a little, cooling things a little. Obviously, no intercooler, short intake/exhaust runs. No trick fuel pump/regulator needed. Not smog legal. But it works.

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It's my leg, Jack. The string's gone out of my leg.

As you know, the locost would accelerate much faster. No "terrain. turn. turn now" warning, no smile and a cup of coffee either! Seat of pants all the way.

6spd?

An early small metro would make a great high-mpg 2f1r trike build.

As for small engines, I'm interested in the 1.8L v6 option in the Mazda MX3.

Banks built a lot of twinturbo camaros and firebirds in the early pre Bosch efi 80's with draw thru 4 barrel carbs behind each headlight. Such a system draws fuel through the compressor so the bushing seal needs consideration, to prevent fuel from being forced into the supporting oil film.

Blow thru makes more sense to me, pressurizing the entire carb in a box. Just pressurizing the top causes fuel leakage at the throttle shaft bushings. Paxton has a similar carb box system for their centrifigal blower. The floats need to be able to withstand the pressure, but they make special floats for that.

Ok, I know Im gonna get bashed but here goes
We upgrade turbos and up boost pres all the time on the Porsche's
They dont even have ecu's on the older 911's (that do much anyway) they use CIS injection (not electronic injectors)
We use micro fuelers.

If your rods/pistons can take it then seems to me your only fear is lean out, cant you plumb an extra injector into the plenum thats tripped by a micro switch? an A/F qauge should be able to tell you when its needed? May have to experiment with various flow/rate injectors but would be fun to try.
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I was at Mid Ohio once and a guy had an old 2002 BMW with a giant turbo (went by me like I was parked) anyway he was using a 8 cyl fuel distributor from a 928 Porsche with the extra injectors drilled/mounted in the intake runners.
Just a thought?
BTW you can use a cold start injector (they are not pulsed just on or off) and they even have a mount flange.
also can you trick the coolant temp sensor at full load? wouldnt that increase fuel pulse width and retard the timing...?(dont know much about Japan electronics so just throwing stuff out there?

The best af ratio isn't 14.7:1. It varies with load and temp.

The Greddy 1.8L turbo kit uses temp sensor manipulation instead of a rising rate regulator.

A piggyback ecu with an add on injector that considers af, load, temp, etc but it would need to be setup only to augment(versus conflict with) the stock ecu in warm cruise.

Those interest me as well. Of course from the research I've done, those engines dont seem to take North/South mounting very well nor do they take well to FI. I'm sure that can be addressed with enough time/money.

Maypo on Miata.net converted one to rwd, using a block adapter, rx7 front transmission housing, and the miata transmission internals with tailhousing. Too much work IMHO. I was talking about a middy application.

http://majica.net/JNR/major.htm

The only problem I see with the MX3 V6 is that it's the same basic engine as the much more common 2.5 V6 from the Probe/MX-6. If the engine were physically smaller than the 2.5 version, then there would be a reason to use it.

As it is, it's just an exercise in small displacement for small displacement's sake.

If you are trying to get into a certain race class and must stay below 1.8 liters but want a V6, then it makes sense, but if you are just going small for packaging sake, why bother with the 150(?)hp rare bird 1.8, when the 180(?)hp dime-a-dozen 2.5 is the same overall size and weight???

IIRC there are some oiling issues that come into play when mounting it N-S. Based on my readings of that miata swapper guy's website. There's a thread about it somewhere here if you do a search. I was considering buying one for my build before I bought the 1.8.

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He is a wise man who does not grieve for the things which he has not, but rejoices for those which he has.

I'm not in a competition. I'm more interested in something that is fun to "work" at legal speeds. The hp for the K8 ranged from 130 to 140 or so, but that is still 11.5 lbs per hp at 1500 lbs with only 130 hp. A shorter stroke and smaller bore equal less reciprocating weight, so it should be smoother running and more free reving than the 2.5. Less hp equals fewer btu generated, less fuel burned, less radiator capacity required, smaller fuel tank for desired range, etc.

No certain racing class here. Nor do I care about packaging. Its more of a love of oddball engine designs. Mazda's famous for them Rotary, Miller cycle

This is why the 1JZ and/or 2JZ have captured my heart. I love a rare engine (or rare in that particular car), and I love the sound of straight 6's. Yeah, its a little more heavy, and little long, but hell, the car is custom anyway, right?


The KL v6 is the engine in question, and from what I've heard it sounds amazing, makes decent power, but doesn't easily go N-S. Custom this and that, and even then its just a battle. It can be done, like almost anything of course.

Top motors that I've been spying have been turbo 4's and 6's. The RB's (think Skyline) the SR's (think 200SX), the CA's (think 180sx), the JZ's (think Supras), etc. All of them have a certain reason to be used, of course. Out of them, I feel the JZ's, have the most durability, the CA's have the best weight and packaging, and the JZ's have the most potential in case you want a nightmare car. Factory turbocharged cars are generally the best to run a turbo on. Now, that probably sounds really, really obvious, but a lot of people will try to add a turbo to an engine not made for it before they will buy an engine designed from the ground up to be turbo. The factory builds in oil squirters, stronger headgaskets, better block designs, more durable bearings, etc. for their turbo cars. Any N/A engine can add a turbo, just about. But, what must be considered is just how much extra work is it worth vs. picking up an engine that was built for it from the get-go.

Something to think about!

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Old car restoration experts, help me out. I've got a 1977 Capri that will need some serious attention. Pics of the restoration project http://1977caprirestoration.shutterfly.com

I guess Chet's question didn't get answered.

If I were going homebrewed, I would use the turbo, turbine housing, exhaust head pipe flange, bov, and waste gate components from a Mitsubishi Eclipse. I would pass on any turbo I could'nt turn the impeller on. I would plan on overhauling it. Push the waste gate rod in, cover the vacuum port with your finger to test the seal.

I would make the manifold from weld Ls and weld a turbine housing mounting flange from strips of 1"X 3/8" steel. The head flange would be 1/4-3/8" thick by 3" strip, opened up to match the gasket with a vertical band saw, then welded back together and ground flat.

I'd get the MSD boost retard unit.

I'd go with no more than 5 psi and a rising rate regulator, adjusted with a data logging wideband 02. I wouldn't add an intercooler.

The stock water to oil cooler may be adequate.

A hose is fine for use as an oil return as long as it designed handle hot oil. Most oems use a flexible metal pipe. It needs to be vertical as possible. If it isn't, the oil will backup into the exhaust.

The pressure side can be stainless brake line with a banjo. Reuse as much as you can from the eclipse.

chetcpo - i have a cheap and reliable turbo in my 1.6 miata.

http://miataturbo.net/forum/showthread.php?t=21808





I spent about $1000 for all the parts, and the final setup, I am sure everyone will agree, is in no way "ghetto" or a junkyard build. It could have been cheaper if I had access to a proper garage or fabrication facilities, but I did all the work in my apartment parking lot!

I have since raised the boost to 10 psi which on this turbo is in the neighborhood of 200 hp at the wheels. I get positive pressure at 1500 rpm, full boost by 2700 rpm and there is no fall-off at the top end. The torque curve is like that of a big V6 engine, there is no sudden spike anywhere. Lag is almost supercharger-like. Ideal for an auto-x car since that was the target application originally. It would also make a kickass track car since it is ridiculously easy to drive.

Oh, and its been running great for the past 2500 miles without a glitch. The only thing is my engine is past 154k miles and was already drinking oil in fair amounts. The turbo has only accelerated that and I might need to rebuild or buy a newer used engine shortly.

My homebuilt Megasquirt (not PNP) along with wideband was most critical to the success of the whole thing. I did all of that when the car was bone-stock, down to the exhaust and airbox. I got it running reliably on megasquirt, dialed in everything, then upgraded to larger injectors. Then I did the turbo, and re-tuned the spark and fuel maps.

My advice to you would be, if you want to go "locost", do so by all means on the hardware, but not on engine management. There is no way you can get the throttle response and OEM-like drivability with a fuel pressure regulator or what we in the miataturbo community call "bandaids" (various devices which retard spark or add fuel or fool the stock ECU).

Another tip would be to shop around other car forums, particularly those that came with turbos from the factory. People get rid of stock turbos at ridiculous prices - my turbo with 35k miles and clean enough to eat off of, cost me only $130 shipped.

Hope this helps.