Turbo & ECU Tuning: Can You Turbocharge Without Tuning?

Quick Answer – Yes. But tuning is recommended when installing a new turbo. A turbocharger significantly increases the amount of air in the combustion chamber. Tuning is required to fix the air/fuel ratio and unlock the full horsepower potential.

Personally, I have installed a bigger turbo to my Civic without ECU tuning first to test the difference. It didn’t perform as expected, not even close to the numbers I was hoping to get. The engine was not consistently powered and boost delivery felt a little off-timing.

It is a completely different story after ECU tuning. The car ran well, and I can feel the instant power delivery to the engine as I floor the throttle. 

In this article, I want to share with you some experience about ECU tuning. Especially with the most frequently asked questions like below:-

1. Why You Shouldn’t Turbocharge Without Tuning?
2. Horsepower Gain From Turbo Without Tuning
3. Cost of ECU Tuning
4. Do You Need Tuning After Upgrading Turbo?
5. Can You Install Turbo On Stock Engine & Parts?

Why You Shouldn’t Turbocharge Without Tuning

If your car already has a turbo, It is not recommended to run a newly installed turbo without a tune. The stock ECU configuration to your engine is very limited, it will not improve your car’s performance much.

You may also end up with check engine lights on due to incorrect sensor reading and even risk running lean – depending on the size of turbo.

The main reason your car will not be improving its performance is because of the stock boost rate settings, which are usually lower. 

Your bigger turbo may need more pressure to deliver power correctly. The bigger the turbo, the more air that needs to be sucked in to deliver the proper level of boost.

For best performance, you may also need some to upgrade on your other stock components like cold air intake, a bigger intercooler, bigger fuel injectors, and a fuel pump that can deliver more fuel in order for the car to run smoothly.

RELATED ARTICLE: Cold Air Intake On Turbo Cars: Does It Work? & Power Gain

Without a proper ECU tuning, even if you upgraded all these parts, you probably won’t get much from your turbo, since the air to fuel mixture can be messed up and power delivery will not be smooth.

If your car didn’t have a turbo and you just installed one, then tuning is absolutely required. Otherwise you will have a lean engine – where you lose performance and get into overheating issues.

This is because a turbocharger forces significantly more air into the combustion chamber – which will mess up your car’s air/fuel ratio.

A tune is required here to instruct your car to inject more fuel and fix the air/fuel ratio.

Data in the ECU memory

Horsepower Gain From Turbo Without Tuning

Installing a new larger turbo without tuning will not provide you with any horsepower. You even risk running lean and have reduced horsepower instead.

If you install a smaller turbo that requires less boost, you will see some reduction in turbo lag but horsepower gain will not be much.

I.e., If you place a big diesel truck turbo on a Civic, you probably won’t get much out of it. That big turbo will not spin to the required RPM to deliver power, which won’t improve your car’s horsepower rating. 

This may sound disappointing but that’s how things work when you are applying a mod more than your car can handle.

Having a bigger turbo without tuning is not recommended. It will be very unstable and it’s a little bit of a bet to have it deliver you a good boost every time you floor the throttle. Your car will run lean and you will not see any benefit at all. 

It will slow you down more than you will gain horsepower. Long story short, if you want more power from a larger turbo, tuning is absolutely necessary.

Cost Of ECU Tuning For Turbo

If you are doing ECU tuning, initial cost can start at $500 to $1,500 in your local garage with a professional technician. A remapping often costs around $500 – $1,000 in the market. 

This number will depend on several different factors such as the make of the car, any parts that are needed and additions to make it run more efficiently. 

You may find it a little expensive, because the costs are also involved with the actual tuning on the dyno which requires technicians to go through multiple diagnostic runs to determine the baseline of your engine.

 They will see the graph and how your car behaves at specific RPM and if the power delivery is consistent.

Keep in mind of your budget, sometimes you will need to upgrade some aftermarket parts to get the best tuning result. The tuning process will take a while and you probably won’t be able to see your car for some time. 

RELATED ARTICLE: Why Are Turbo Kits So Expensive? (Complete Breakdown)

Reasons Why ECU Tuning Is Not Illegal

ECU tuning is legal. No one can fine you if you ECU tune your car. But you can face some other repercussions if you opt for this mod. 

Different states around the US have different laws, some are stricter and some are not. For example, if you live in California, you will probably not be able to pass the inspection at your local DMV. 

Failing an inspection can be caused by many things, but in this case, it will be caused by your carbon footprint.

Cars from the factory have specific values that need to comply with in order to pass the smog inspection. If you have tuned your car for better performance, in some cases, you may find out that you cannot pass the inspection, until you bring it back to factory spec. 

Your car will not comply with the ecological norms that are needed for your car to be registered.

If you live elsewhere, for example in some state that does not have such strict laws when it comes to registering a vehicle. You may get away with this… But it is still not recommended to do.

Most of the modded cars to get maximum performance are not particularly safe. You’ll also need to take a note about how your car handles. If you have a big amount of horsepower, you also need a big amount of suspension and brakes upgrades to make your car street friendly.

Which means, even if tuning can help you gain more power, it doesn’t mean that your car parts can handle the extra load. 

If you tune your car for better fuel economy, you will be fine. Because tuning to increase fuel mileage will not harm the engine and is eco-friendly.

Things To Know

Sometimes, tuning is not always perfect. You might see warning lights on your dashboard. I highly recommend anyone to get this code reader just to keep in your tool box.

Having yourself a basic diagnostic code reader will be great to determine the cause and find a solution. The scanners are able to detect the engine system and read or erase error codes.

I found several affordable ones from Amazon, and I have bought this Universal OBD2 Diagnostic Tool, which works pretty amazing. 

The reader is very easy to use. You will just need to locate where the reader would plug into your car. You can choose to clear the codes after you read them which will likely turn off the Check Engine light.

Do You Need To Tune After Installing Bigger Turbo?

A tune is required after installing a bigger turbo. It is simply because the newly installed turbo does not work as your old ones. 

A bigger turbo will require more air into the intake. More air in other words translated to more fuel needs to be injected into the cylinders and also bigger and stronger piping in your turbo installation.

Depending on the turbo that you want to install, these upgrades can be very minor and solved with a simple tune if the turbo is of a similar size. 

But if the new turbo is a lot bigger, you will need to upgrade some aftermarket parts to work alongside with the bigger turbo, such as cold air intake, a bigger intercooler, bigger MAF sensor, bigger fuel injectors, and a fuel pump.

Bigger fuel injector can inject more fuel into the combustion chamber at a given time. Bigger fuel pump allows more fuel to flow into the fuel injector – where they eventually enter the combustion chamber. You need a bigger fuel pump to ensure that it’s not acting as a bottleneck for your turbo.

You may also need a bigger MAP sensor so it can accurately measure the amount of incoming air from your intake. 

RELATED ARTICLE: Cold Air Intake On Turbo Cars: Does It Work? & Power Gain

Car’s computers are very sensitive and will need specific tuning in order to make the upgrades work as they should.

Can You Install Turbo On Stock Engine & Parts?

You can install a turbocharger on a stock engine and parts. Turbochargers may sound like rocket science, it really is pretty straightforward once you figure them out. You can do this at your own garage, if you are one of the DIY car enthusiasts.

There are special kits that come with everything you need when it comes to installing a turbocharger on your car. A turbo kit can cost from $4,000 and up, check out this article to read more about why turbo kits are so expensive.

Here’s a list of things included in a turbo kit (with approximate cost).

Some engines are more susceptible to turbocharging, if you want to do a stock engine turbo upgrade the best thing is to get one of these engines.

Check out this article if you want to learn more on installing turbo on a stock engine.