Turbo Time!

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Right so I've been fooling around with the idea of throwing an electric turbo on my car (1980 124 FI), probably making around 4-5 psi of boost. I've been thinking about how the ECU handles the air and fuel relationship on the car, and from my knowledge I should be fine to just throw a turbo on there and hope for the best right? How I see the ECU working is that it merely strives for the set air fuel ratio that it was programmed for, therefore if it sees an excess of air, it'll just dump more fuel in right? My questions are am I right in my predictions, and if I'm not what other mods will I have to do to make some real power. Side note how much power until my transmission shears off 4th XD.

[18Fiatsandcounting]

I'm not very familiar with turbo setups, but I'm thinking that a lot of other things would have to change to keep the engine stable and reliable. Compression ratio, boost regulator, making sure you don't go way lean on backing off on the throttle (can burn holes in pistons), camshaft timing, ignition advance, etc.

I'm sure there are "speed shops" that know about all this stuff, and some on this forum might, but my general impression is that there are easier ways to get more HP out of these engines than a turbo setup. High compression pistons, cams, good manifolds, etc. should get you in the neighborhood of 130 HP. And that's more than you'll see with the turbo. By the way, 130 HP is about the most that you can get away with, without having issues with transmission and drivetrain reliability.

My $0.02, inflation adjusted.

-Bryan

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I mostly just want the turbo to have one. I'm not looking at serious horsepower or anything, mostly just a bragging right and maybe a few extra horses. So I think I should be able to get away with it without any major mods, maybe a tweak or two to the timing. I don't think I'll have an issue with going too lean when backing off the throttle because my setup will consist of an electric turbo, which will use regenerative braking to slow down the turbine while backing off the throttle or under brakes. My real concern is the engine running too lean while driving in general because I don't exactly have concrete info telling me how the ECU will behave, just my understanding and logic. Is there anything you can say to that?

[18Fiatsandcounting]

My real concern is the engine running too lean while driving in general because I don't exactly have concrete info telling me how the ECU will behave, just my understanding and logic. Is there anything you can say to that?

I can't offer much as I don't have much experience with turbos, but I agree that the ECU should sense (via the oxygen sensor in the exhaust) when the engine is running too lean and then adjust the fuel injection accordingly.

I am curious to see how an electric turbo in the spiders would work, so let us know if you go that route. Suggest going cautiously until you see how the engine behaves. Maybe drive really gentle for a few dozen miles and then check the spark plugs to make sure they don't show signs of overheating or being too lean (white, glazed or glassy appearance). Also listen very carefully for pinging or knocking and back off if you hear any. As you gain more confidence that the engine is behaving, you can progressively push it harder.

-Bryan

[redcars]

The compression ratio is fine for a turbo. The problem is with a normal setup the ECU adds fuel with decreasing facuum . With a turbo the ECU needs to do this and add more when it sees pressure. The fuel air meter may not be able to meter the extra air flow. I would add a fuel ratio meter that uses a wide band sensor . The way to go is with a fully program able after market ECU. This is not a cheap nor easy under taking.

[alternative]

I would add a fuel ratio meter that uses a wide band sensor . The way to go is with a fully program able after market ECU. This is not a cheap nor easy under taking.

This is something I definitely did not want to do considering how expensive it is and complicated to set up. These cars are already unreliable enough lmao. I think I should be good to get by with the stock meter (if you are referring to the AFM in the intake), and the computer should be able to adjust the ratios accordingly from the oxygen sensor in the exhaust, as I read somewhere that sensor was the first in the computer's line of command to adjust.

listen very carefully for pinging or knocking

Could you tell me a little more about what you mean by pinging or knocking?

[18Fiatsandcounting]

Could you tell me a little more about what you mean by pinging or knocking?

You can probably find some YouTube videos or the like, but it's a common occurrence in engines that have high compression, or using gas with too low an octane rating for the engine, or have the ignition timing too far advanced.

It sounds like a very rapid metallic knock, usually under heavy acceleration. Going uphill is a common situation where it occurs. Some people compare the sound to that metallic clinking sound you hear when you're in a swimming pool with your head underwater and you strike the pool cement with a hard object.

Normally, you want the flame front to be initiated only by the spark plug, so the fuel combusts evenly and pushes the piston down. Detonation occurs right after the spark plug fires when a second flame front, caused by too high a temperature in the cylinder's air/fuel mixture, collides with the spark flame front. When the two shock waves collide, you get that knocking sound.

Pre-ignition is when your air-fuel mixture ignites before the spark plug fires, as the piston is still on the upward stroke, and the combustion pressure wants to push the piston back down but the inertia of the rotating crankshaft forces the piston upward, causing damage.

Neither is good and can rapidly destroy an engine if excessive. Turbocharged engines are susceptible to this which is why they are designed to not get into an operating regime where detonation or pre-ignition can occur. Common ways to do this are to retard the spark timing or back off on the boost pressure if knocking is sensed in the engine. Another way is to require high octane gas, but high octane gas (95 or above) is not as easy to find as it was several decades ago.

-Bryan

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Thank you so much for that amazing explanation, I'll be sure to look out for that knocking. Speaking of the different octanes, which do you regularly use in your 124? I've been using 87 and was wondering if that was good enough for these motors.

[18Fiatsandcounting]

The Fiat twin cam engines are not overly prone to knocking, and so I've always been able to get away with 87 octane gas (regular). However, this is for the stock compression ratio, and people with higher compression pistons often have to run 91 octane or higher. Used to be that some stations would sell high octane gas, but other than at racetracks, I haven't seen this for years. There just aren't a lot of cars that require 95+ octane any more. Guys with 50s and 60s hot rods could probably tell you where to get high octane gas in your area, if it's available.

You can also buy cans of octane booster for your tank, but that gets expensive.

By the way, diesel engines depend on pre-ignition since they don't have spark plugs. That's why diesels have that particular clattering sound, which is a form of knocking. That's the way they're supposed to work and so the engines are massively beefier than a gasoline engine so they don't blow apart.

-Bryan

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Thanks for all your help with this research, however I think I have to sort out another issue with this car first before I begin turboing lmao, I now have a recurring no start issue that has suddenly reappeared and started anther thread about it if you'd like to take a look.

[ORFORD2004]

Electric turbo Lolllll
I try one years ago and it was nothing more than a boat engine compartiment fan. Piece of shit.
You will need a lot of ampere for that motor.

you can go north of 200HP with a real turbo but you will need a ECU, intercooler, bigger valves etc.

Remember that on boost you will need more fuel and to retard the timing.

Check Youtube, there is a guy who install 2 electric leaf blower on is hood as blower.
https://www.youtube.com/watch?v=cbGWgvJ ... htyCarMods