How To Prepare For a Tuning Session

[Mach V Dan]

This post is in response to a few recent threads I've read, plus a number of tuning experiences I've had lately. Basically, I want to give some simple Do's and Don'ts when you're getting ready for your custom tuning session. For many of you, these items may be completely obvious. But judging from my experience, some of you may learn something.

By "tuning session," I mean an appointment with a professional tuner on a dyno, where the tuner will use some kind of engine management system to adjust ECU parameters to get more power from your car. Generally, this kind of service costs several hundred dollars. When I'm tuning, I'm very conscious of time -- my time is valuable, and the dyno I'm using is also a costly asset. One of my goals is to get the tune done in a reasonable amount of time, without wasting an undo amount of time on things unrelated to ECU tuning. I prefer NOT to have to troubleshoot basic mechanical problems on the dyno -- these kinds of things should be done at normal shop rates, which are roughly half of dyno rates.

So, with that in mind:

DO:

• Check your fluids! I always tell people this, but I keep finding cars short of oil when I get 'em on the dyno. WHY? It's not difficult, people. Top up your oil.
• Bring all your hardware. Got a boost controller that uses a special allen wrench? Engine management with a little plug-in electrical part or special cable? Bring all those things. Sure, we can dig them up, but if it's already in your car, that will make things more efficient. If it's an AccessPort tune, BRING the AccessPort!
• Clean out your car. We'll be using both front seats, maybe getting into the glove box (to grab a UTEC cable, say), moving cabling around the inside of the car. Not having to maneuver around your dry cleaning and Slurpee cups makes things easier.
• Buy NEW parts if possible! I cannot tell you how many dyno problems come from USED parts. Think about it: At $200/hour, it's no bargain if your used part costs you two hours of tuning time.
• Even better, think about having us supply the parts AND install them, then dyno. It's easy! No muss, no fuss. We sell you parts that we know will work, we install them, and if there's any trouble with the parts, you're not paying for it. But since we know and use these parts all the time, there's not likely to BE any problem.
• Bring extra money. I know, this sounds like me being a salesman, but it's not uncommon for us to advise a parts purchase during a tune. "Your throttle body coupler is split open. We can sell you a replacement, or you can come back another time..." To be able to afford the parts you need when the time comes might keep you from having to come back to complete your tune at another time. Most common purchases while on the dyno: Boost controllers, boost gauges, intakes, couplers and clamps.
• Have your car running as perfectly as possible. That means fix fluid, exhaust and intake leaks, bolt down any loose parts (heat shields, intercoolers, body parts). Air up the tires. If you can, verify that your car will make the boost you desire, although that's not always practical before the car is tuned. If you've got CEL's, figure out what they are and what is most likely causing them. Fix those problems if possible BEFORE your tune.
• Bring a camera or video recorder if you want, for recording those special memories. . Bring your USB key to take away digital files or graphs.

DON'T:

• Install stuff the night before your dyno appointment. You WILL be in too much of a hurry, and your parts WILL cause problems. It's Murphy's Law. If you don't have more than eight hours between your install and your drive to the tuning shop, postpone your tune. You'll thank me later.
• Buy JUNK. Arrrgh! How many problems have I seen that came from junk parts? Too many to count. There's the intercooler pipe that pressed against the timing belt cover so hard it rubbed on the timing belt and melted the cover. The induction pipe that collapsed under suction. The intercooler pipes that had no beads and blew off constantly. The crapola couplers. The junk boost controllers. Junk BOV's. No-brand intakes. The list goes on. Buy good parts. They work, and in doing so they actually SAVE YOU MONEY! Hint: We do not sell junk. If we DON'T sell it, the reason MIGHT be that it's JUNK.
• Be late. I try to reserve a good block of time for this work, so I can work carefully and with full concentration. Being pressed for time does not make for good tuning, and if you're late I may ask that we postpone the tune to another day where I can allot the proper amount of time.
• Forget that there IS risk involved in this process. We have you sign a waiver that basically says if your car burns up on the dyno, it's not our responsibility. I think every dyno shop has a similar waiver. Serious problems are extremely rare, but dyno runs are HARD use, and we are tinkering with the built-in safety margins the factory designed your car around. These are risks we all work under when we're tuning; although nobody's ever happy when a car goes south, it CAN happen. If you are not prepared for this -- or cannot afford major repairs -- I advise that you not have your car custom-tuned.

Well-tuned cars are fast and fun. Hopefully this little list will help some of your have a more efficient, enjoyable and rewarding custom tuning experience.

--Dan
Mach V
FastWRX.com

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[Unabomber]

I take it the genesis behind this post was due to that douche who was in your shop today getting tuned?

[Mach V Dan]

Originally Posted by Unabomber

I take it the genesis behind this post was due to that douche who was in your shop today getting tuned?

Heh! No.

Today's tune went nicely. Good parts, nice running car, good conversation. I'm glad you came up.

--Dan
Mach V
FastWRX.com

[varacr69]

You should sticky this one!!!

Spending $$$$$ + time = saving you $$$$$$$$$$$$$$$$$$$$$$$$$$$$$ and your car!!!

[jrskeen]

good post Dan. Def should be made a sticky, great information.

I think this might have been in response to the hilarious post someone made slamming Agile Auto. Long story short, he came unprepared for the tune with a broken car and had the nerve to complain that Agile was unfair. People need to know this kind of stuff Dan posted ahead of time!

[xcntrk75]

Did you guys ever investigate your wideband O2 sensor for accuracy on your Dynojet?

You may recall at your last dyno day we had some pretty significant discrepancies between my on-board WB and your chassis dyno WB. Trusting your equipment far more then my own; I went ahead and replaced my sensor with a new one, fully calibrated it and captured some new AFR numbers. Yeah no change on my end, same AFR in my logs with my old bosch sensor as with my new VW sensor; so that can only mean your chassis WB sensor was the source of our discrepancy. You may recall the difference was pretty significant with your sensor reading 10:1 dropping down into the 9.x:1 range up top, while mine was a solid 11:1 throughout each pull.

Just thought you should know***8230;

[jagcars26]

Originally Posted by jrskeen

good post Dan. Def should be made a sticky, great information.

I think this might have been in response to the hilarious post someone made slamming Agile Auto. Long story short, he came unprepared for the tune with a broken car and had the nerve to complain that Agile was unfair. People need to know this kind of stuff Dan posted ahead of time!

+1 great post Dan

[OMEGA SUPREME]

its sad that this needs to be posted, for lack of others common sense

[nhluhr]

RiftsWRX posted a similar pre-tune checklist LONG AGO and it seems the community has forgotten.

Originally Posted by CaringForYourVehicle

Anything I should do before my tune?
The most important part is to make sure you have a SOLID platform for your tuner to work off of. Tuners are not mechanics, and vice versa. So you can’t realistically expect your tuner to spend your dyno time trying to diagnose and fix your car. If most tuners are like me, they’re busy, always busy….

Thankfully, there is a very simple list of things you should look into prior to your tune. I’ve updated this list over the years, and I’ll include it here for reference.

1: Pressure test your system.
Build a small compression tester by taking a PVC cap the size of your inlet hose, drilling a hole large enough for a tire valve stem, and cementing it to it. Then you can simply clamp it to the inlet hose and plug off your evaporative purge lines. As you fill the system with air, you want to make sure you don't have any air escaping at all from the inlet hose, BOV return line, BOV itself, etc. If you hear a leak in a congested area, grab a spray bottle of soapy water, and mist the area. See bubbles? Fix or repair the clamp.

2: Check plugs and gap.
What we've found, is that stock turbo WRX's are fine with their factory gaps, but anything over the stock turbo should be at .028" gap. Any turbo over 650 CFM should seriously consider running as far down as a .025" gap. 2.5L's are different. Seriously consider running at least .028" on any car setup aggressively with their stock turbo's (FXT's, Baja's, STI's, etc.) Same rule applies to turbos over 650 CFM. They've been shown to work better at a .028"-.025" gap. Something else to keep in mind about plugs is that tuners are embracing copper plugs for high pressure environments. Frankly, if you’re pushing 22+ PSI, seriously consider them. Reason being that the electrode on a Iridium or Platinum plug is so small that it will continue to glow after the
combustion event, setting the cylinder up for a pre-ignition issue on the next stroke. Avoid this situation at all costs! High RPM misfire, and pre-ignition will quickly spell the end of an engine. Work with your tuner to properly select the spark plug for your application.

3: Check coils.
If the car suffers from misfires, stutters, etc, and a plug swap hasn't cleaned them up, consider swapping coils around. This is especially valid if the problem persists in one cylinder. Misfires and detonation cause the electrical energy of the coil to go to ground, and as a result it can quickly overheat and damage a coil. Try swapping the coil first with a cylinder known to be OK. If the problem follows it, you know it's a coil. If not, check the back of the plug with a volt meter on the supply wire. It should have around 12 volts. If it does, and the front of the plug doesn't, you may need to rebuild the weather pack. I've seen at least half a dozen examples of corroded pins in the weather packs themselves.

4: Check Compression.
If the car is erratic, and #3 was fruitless, check your compression. If you find that you have good ring seal, and you've not successfully found your problem, do a leak down test. I've seen a few cars skip teeth on their belts, which wouldn't necessarily affect the compression numbers too bad, but dramatically affect performance.

5: Consider your mod path, and how it relates to boost control.
Subaru superceded the parts used for their boost control restrictor pills sometime for the '05 MY. What this means, is that it's VERY difficult for turbochargers on said vehicles to exceed 15-17 PSI on a factory equipped IHI. Stock WRX's will achieve even less. If you've found that your in this category. You have 3 options. (If you are trying to sustain over 20PSI at redline, just go to option C)
A: Leave it alone and tune the car for what you can get out of it.
B: If you have an adjustable waste gate arm, you can preload it based on conversations with your tuner.
C: Install a GM boost control solenoid (part number 1997152). A search on NASIOC can yield quite a few threads on the proper installation of this part. Again, it's very important that you do this with the guidance of your tuner. If not, you WILL suffer from boost spiking, or worse.

6: Check all fluids and ancillary items.
Oil, coolant, radiator cap, alcohol for injection kits, fuses, tire pressures, leaks, etc. Imagine you're going on a huge cross country road trip, and the LAST thing you want is to break down in the middle of no where.

Again, remember the old computer saying… “Garbage in, garbage out…” If you present your tuner with a car in poor shape, you’re going to get a tune that is also going to be in poor shape. If you’re tuner is a god, at best you’ll have a band-aid over a bullet wound, and the car will drive fine. But if you wrench on the car later, and fix whatever was wrong, you’ll compromise your tune. Finally, in my opinion, no… it’s NOT the tuners fault either, when it blows up!
Owner beware…

The full text of the "Caring For Your Vehicle" article is available at: http://www.pandlmotorsports.com/cari...ourvehicle.pdf

[Mach V Dan]

Originally Posted by xcntrk75

Did you guys ever investigate your wideband O2 sensor for accuracy on your Dynojet?

The sensor gets replaced periodically. I've also calibrated it vs. other sensors, and it's pretty reliable. On-board sensors (like in the downpipe) WILL vary compared to tailpipe sensors, though. Normally the difference is a few tenths. I don't know why yours was more.

This thread is about preparing your car for a tuning session, though. If you want to discuss widebands more, shoot me a PM.

--Dan
Mach V
FastWRX.com