Practical Reflash Tuning: Step 2: What Modification Have Been Performed?
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Step 2: What Modification Have Been Performed?
05.11
| 00:00 | - So now that we've downloaded and reviewed the stock ROM file, let's start to think about the modifications on the vehicle and what changes we might want to make to the calibration based on those modifications. |
| 00:10 | For example, this vehicle has an aftermarket air intake and it has an upgraded supercharger lid. |
| 00:18 | Now the supercharger lid incorporates some airflow improvements as well as improved charge air cooling through a more advanced and larger water to air heat exchanger. |
| 00:28 | Other than that, the vehicle is mechanically stock so this is going to be pretty straightforward for this particular vehicle but let's review some other items you might want to check on to make sure you have a full picture of what's going on in the vehicle before you start making your calibration changes. |
| 00:43 | For example, if the vehicle has a wheel and tyre package which has a different diameter than stock, you might want to make a change to correct the speedometer. |
| 00:52 | Also this can have an impact on shift points on an automatic transmission, making it even more critical. |
| 01:00 | Another common change on a rear wheel drive vehicle would be a rear end gear change. |
| 01:05 | So you want to account for that as well for the same reasons. |
| 01:08 | Looking further, if you changed any engine sensors, or you've changed different injectors, fitted other aftermarket fuel system items or anything that touches airflow, that's likely something you're going to need to account for in the calibration. |
| 01:25 | In order to understand the full scope of changes that have been made to the vehicle, it's important to really look the car over in addition to talking to the owner if you're not working with your own vehicle. |
| 01:37 | In many cases, the vehicle may have been purchased second or third hand, in which case the current owner may not totally understand all that's been done in the past. |
| 01:47 | I find it really key to give the car a thorough lookover myself just to make sure any items the owner may not currently be aware of are caught before we get into our tuning process. |
| 01:59 | This becomes really important because if you're not aware of the full scope of the modifications, it's possible the vehicle may behave in a manner that doesn't really make sense and you can end up chasing your tail only to find out later that there wasn't really an issue per se with the vehicle, simply that it had modifications that you weren't aware of, didn't account for and now you might need to even go back and start over with that new information. |
| 02:26 | Another thing to watch out for is of course the mechanical condition of the vehicle. |
| 02:32 | Have the fluids been changed? Are sensors aged out? These are critical items you really want to handle up front before getting the car on the dyno. |
| 02:40 | I like to come up with a good checklist, including spark plugs, sensors, and other key items that I can ask the owner about, get a feel for how many years old they are, how many miles are on them and determine whether any of the need change before the calibration begins. |
| 02:55 | For example, when it comes to spark plugs, you might even want to fit a one step colder or more spark plug based on the other modifications or perhaps increased boost pressure that you intend to run. |
| 03:09 | As I've mentioned, this vehicle has an aftermarket air intake. |
| 03:12 | And depending on your air intake that you're working with, it may have a MAF housing diameter that's similar to stock or be larger, or perhaps even smaller than stock. |
| 03:22 | Now in our case the diameter is about the same as stock but if yours is let's say, 5 mm larger than stock, you're going to know that right off the bat, you'lll need to make a base change to your entire MAF calibration table to account for that at least in part. |
| 03:38 | And that will get you a little bit closer to having accurate fuel trends right off the bat. |
| 03:43 | For me, a rule I like to think of is if the part touches air or fuel or is the fuel, because we certainly want to know what type of fuel or fuels we'll be tuning for, or if it relates to the engine, we want to know about it up front. |
| 03:59 | So engine displacement, engine compression, camshaft, whether the heads have been worked, these are all items we really want to have a good handle on before we start making our changes. |
| 04:10 | Last but but not least, we want to cover safety. |
| 04:12 | So you want to look the vehicle over for tyre pressure, any corded tyres, anything loose or rattling, just make sure it's going to be safe to operate at high speed. |
| 04:23 | Also make sure the car tracks straight, something you can do in the parking lot before strapping it down on the dyno. |
| 04:30 | In this particular instance, we noticed that one of the rear axles had a little bit of grease that had flung out of a CV boot, however the boot was intact, there was still plenty of grease, the axle didn't have any significant play, was not clicking and we determined that it was going to be safe to operate today. |
| 04:48 | However, had it had play, have been clicking or anything of that nature, we would have stopped at that point, rectified the situation and then brought the vehicle back for dyno tuning. |
| 04:58 | Now that we have reviewed getting the modifications list, talking about what fuel or fuels we're going to be tuning for, checking over maintenance and safety factors, we're ready to start making changes to our calibration. |
| 05:10 | Let's go ahead and do that. |
