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Practical Diesel Tuning: 2. Prepare Vehicle For Tuning

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2. Prepare Vehicle For Tuning

03.23

00:00 - Our next step in the tuning process is to prepare the vehicle for tuning.
00:03 Now on the older trucks, this takes a little bit more as far as the truck because there's a lot that can go wrong after 200,000 miles of driving.
00:11 I'm going to break it up into two parts here.
00:13 One is the truck, so I like to walk around the truck and give the thing a look through.
00:17 Does it look like it's been abused, does it look like its been maintained? Oil change, transmission filter, transmission fluid, give it a smell, what's it look like? If you can drive the truck, great.
00:28 Talk to the customer, you need to really understand the mods.
00:31 So the stuff that I'm asking the customer about is, injectors, are they stock, are they bigger than stock? Any major engine failure stuff, does it have head gasket issues, does it have transmission limp mode issues, does it have any maintenance issues or performance issues that I need to know before I strap the thing down to the dyno or start adding power? If it's not in good mechanical shape to start, we're not going to end with a good product.
00:54 Then I like to do a boost test.
00:56 So how I do that is I hook the compressed air, regulated compressed air up to the face of the turbocharger inlet.
01:02 We sell some tools for this, they're available online but really we just want to put about 20 pounds of compressed air to the face of the turbocharger.
01:10 Now this is a non overlap engine so you don't have to plug anywhere else.
01:13 Once you do that, you put that 20 pounds of air to it and you can fill the system and listen for leaks.
01:19 If you have an intercooler leak or a boot leak or any sort of boost leak whatsoever, it's going to dramatically impact the way that the vehicle runs.
01:26 It's going to impact exhaust gas temperatures, turbocharger overspeed, just the performance in general.
01:31 Smokiness, anything like that's going to be contributed to greatly by a boost leak, so we want to really eliminate boost leaks.
01:38 The reason I dwell on this is because almost 85% of the vehicles that come to our tuning shop have boost leaks.
01:43 You need to get those sorted out.
01:45 Then I get the mod list, so if the truck has injectors of course I'm going to approach the fuelling curve differently.
01:51 If it has a built transmission I'm going to approach the torque curve differently.
01:55 If it has a stock transmission I want to be a little softer on the way I ramp the torque in and I certainly want to cap the torque limit so that I don't injure the stock torque converter or gear set or clutches.
02:05 Then I want to know what the customer's doing with the truck.
02:08 Are they sled pulling with it, are they drag racing with it, is it their daily driver, are they just towing with it? That'll impact the way that I build the torque curve, that'll impact the safeties that I leave in or take off.
02:18 So it's really important to understand the customer there as well.
02:21 This is an abbreviated version but if the truck is in good shape and the customer's given you good information, and you know exactly where you're going with the thing, it's going to turn out a lot better than the truck got dropped off and the customer wants a race tune.
02:33 Now the next thing is the dyno, when I get the truck on the dyno, important to make sure that the tyres look good, important to make sure that things are secure up front.
02:43 I have a 15 horsepower fan that I run on the dyno to make sure that my intercooler gets good air through it.
02:48 Of course if the shroud's blown off or if there's insulation or anything that's not attached under the hood, it's going to be a problem.
02:55 Once I've established that the truck is in good physical condition, I also like to read diagnostic trouble codes and see if there's anything stored.
03:01 This will give me any indication if there's any lingering fuel system problems or diagnostic issues that the customer hasn't figured out.
03:08 The last thing I want to do is tune the truck and give it back to the customer and have a problem.
03:12 So if there's a problem that's underlying and it exists already, let's identify it and get that sorted out first.