FAQ

1.   How much does a tune cost and how do I contact you?

Pricing for all tuning services, regardless of vehicle, software, fuel type, and licensing can all be found on the “services” page of our website. I will link it here: https://www.cstuned.com/services/. The best way to contact us is to submit a contact form on our website. This is also where you can apply for a tune. I will link that here.

2.   What modifications should I add to my car?

We have an entire article that goes over almost every modification out there for the Subaru DIT platform as well as how they work and what brands we prefer. Please read it. I will link it here: https://www.cstuned.com/2015-subaru-wrx-op-ed/. For the Subaru EJ platform, we do not have a formal write-up at this time. However, please contact us and we will be more than happy to steer you in the right direction.

3.   What maintenance should I perform before tuning?

We recommend always changing your engine oil before tuning. A fresh set of spark plugs is also a good idea. However, spark plugs with less than 40,000 miles on them should be up to the task. For DIT clients, we recommend a walnut blast if your engine has completed more than 40,000 miles since the last walnut blast; and no – a chemical carbon cleaning treatment is not an effective alternative.

4.   What do I need to safely run E30? E60? E85?

For the Subaru DIT platform, the answer to the question varies based on who you ask. Some tuners recommend an upgraded fuel pump at E30. Some say that you can run E100 on the stock fuel system. We think that anything greater than E30 requires an upgraded low-pressure fuel pump. Likewise, anything greater than E60 requires an upgraded high-pressure fuel pump. This is to prevent stock fuel system components from failing due to lack of lubrication. Alcohol-based fuels can strip lubrication from fuel system components, resulting in drops in fuel pressure. If these drops in fuel pressure happen during aggressive driving, the result may be damaging to your engine. For how inexpensive an upgraded low-pressure fuel pump is, it is very cheap insurance for vehicles using potent ethanol blends.

5.   I want to tune my car on EcuTek. What do I need?

For on-site tuning, you require nothing except the vehicle itself. For remote tuning, you are required to obtain an ECU Connect Kit. We can ship this kit to you for $259 USD + tax and shipping. You are welcome to obtain an ECU Connect Kit elsewhere or use any kit that is already in your possession. However, we do not recommend this, since you may purchase an incorrect kit and waste your money.

6.   Can I run flex fuel on EcuTek?

Flex fuel on EcuTek is a complicated topic. Flex fuel on EcuTek requires a flex fuel kit that taps into the rear oxygen sensor output. Not every flex fuel kit has this capability. For questions regarding flex fuel kit rear oxygen sensor capabilities, please contact the company that manufactured your flex fuel kit. Flex Fuel on EcuTek also relies on your ECU’s (engine control unit’s) ROM (read only memory). Flex fuel on EcuTek requires use of custom maps. These custom maps are not available on every ROM due to memory limitations. For on-site clients, we can swap out one ROM for another in order to enable flex fuel capabilities. For remote clients, we cannot swap out one ROM for another. Either your ROM has the necessary storage, or it doesn’t. This is out of our control.

7.   Can I run flex fuel on COBB AccessPort post Green Speed?

Yes. Delicious Tuning makes a fully compliant flex fuel kit designed to work with post Green Speed COBB software. You can purchase this flex fuel kit at www.newprovisionsracing.com or directly from Delicious Tuning.

8.   Should I use an OTS (off the shelf) tune?

Personally, I wouldn’t. There’s no denying that OTS tunes typically work well when used with the correct modifications. However, not every engine is created equal. Two identical vehicles running two identical setups may require two different tunes to perform the same. Equivalently, two identical ‘Stage1’ cars using the same ‘Stage1’ OTS tune may perform completely differently from one another. The stock tune is essentially an OTS tune, by definition. This is one reason why we see so much performance variance from one stock car to another.

9.   What do I monitor on my COBB AccessPort or ECU Connect app?

Personally, I like to track the following 6 parameters: Air/Fuel Ratio (AFR in COBB / Lambda in EcuTek), Intake Temperature Maifold (Charge Air Temperature in EcuTek), Boost (Boost Extened in COBB / Boost Actual in EcuTek), Dynamic Advance Multiplier (Advance Multiplier in EcuTek), Feedback Knock Correction (Knock Correction in EcuTek), and Fine Knock Learn Correction (Learned Knock Correction in EcuTek). For flex fuel users, it may be beneficial to monitor ethanol content after a fill up. For those experiencing drivability issues, it may be useful to monitor Long Term Fuel Trim (AF Learning 1 on COBB AccessPort) to help diagnose any vacuum leaks.

10.   Are these numbers on my AccessPort or ECU Connect app okay?

COBB has a great chart explaining what is and isn’t desirable when it comes to numbers on your AccessPort screen. The same can be applied to EcuTek. I will paraphrase this chart here. Short term an long term fuel trims generally shouldn’t exceed an absolute value of 20% during low load engine operation. At WOT (wide open throttle), these numbers generally should not exceed 10%. Ignition advance multipliers should generally read between 0.688 and 1.000. Feedback and learned knock corrections should generally not exceed a negative value of 4 degrees.

11.   What are my tuning options besides COBB?

Currently, the only truly equivalent option to COBB is EcuTek. EcuTek allows you to ditch the AccessPort and its cable in exchange for an app on your smartphone or other bluetooth device. With EcuTek, everything can be done wirelessly; flashing maps, logging data, etc. In some cases, people have set up EcuTek data monitoring through their aftermarket headunit, allowing them to read engine data in real time from their infotainment system. For more information on EcuTek, please reach out to us. We are happy to help get you set up.

12.   My DAM dropped. What’s going on?

COBB has a fantastic article explaining dynamic advance multiplier, feedback knock, fine knock learn, and how it all works together. Please read it. I will link it here: https://www.cobbtuning.com/subaru-knock-monitoring-and-dit-knock-logic-changes/

13.   Do I need a tune for … ?

We have an entire article that goes over almost every modification out there and whether or not it requires a tune. Please read it. I will link it here: https://www.cstuned.com/2015-subaru-wrx-op-ed/. Keep in mind that, while a tune may not be “required” for a certain modification, a tune is almost always beneficial.

14.   What modifications are required for a tune?

Modifying your vehicle is not a prerequisite for tuning it. Even a bone stock WRX can pick up close to 30 WHP (wheel horsepower) with nothing but a custom tune alone. In most cases, a custom tune will also increase both drivability and reliability, so there really is no reason to avoid tuning, even when your vehicle is unmodified.

15.   How does ethanol affect my oil change interval?

We recommend an oil change interval of 3000 miles on <E10, 2500 miles on E30, 2000 miles on E60, and 1500 miles on E85+. Higher concentrations of ethanol lead to a faster rate of oil contamination and/or dilution. This is why oil change intervals are shorter when using alcohol-based fuels, such as ethanol or methanol.

16.   What’s the best way to remove heat soak?

Just like with tuning a car on a dyno, heat soak can affect tuning a car on the street as well. Heat soak happens when either the engine, an engine component, the surrounding air, or the intake charge becomes so hot that it has a negative effect on engine performance. On a dyno, we combat this by simply turning the engine off and allowing it to cool down. The same method can be applied in the real world as well. However, the tried and true method of simply driving the vehicle also works well. Heat soak is at its worst when the engine is idling and the vehicle is not moving. Opening that throttle body and introducing moving air into the engine, radiator, and other components is a great way to help cool down the engine when fighting against heat soak.

17.   Why is my boost lower in colder weather or during “boost season”?

Built into most tunes is a temperature compensation for boost pressure. In colder weather, air is more dense. This means that, to flow the same volume of air, less pressure is required. More pressure does not always equal more power. They key to tuning an engine is finding that perfect balance between boost, fuel, and ignition. Rest assured, you are not down on power during “boost season”.

This is a live document and will continue to be updated as more questions / answers are added.