For those of us that do all of our tuning on the street and/or track what are some pointers for your first dyno tuning session? The would be for someone that is proficient at tuning, but has never tuned on a dyno. Thank you.

 

The main thing I would suggest has little to do with the tune itself it has more to do with being fully prepared when you get the car on the dyno so you can maximize your time. Read to many stories where people have problems and have to spend time fixing little things that should have been done before the car was put on the rollers, Check fluid levels, Tire pressure and so on. If it's a first real run time on the engine make sure there aren't any leaks and bring an extra set of spark plugs incase your start up tune fouls them before it gets dialed in. Other than that tuning on a dyno should be easier and more accurate than the street because everything should be more consistent, Same temperature, Load, Time and so on. You'll actually have real torque and HP numbers rather than seat of the pants feel you rely on when street tuning so changes to timing aren't a guessing game.

 

You're basically using the dyno as a tool to find what afr and timing the engine likes. Then use that information to hit those afr and timing numbers on the street. The AFR will change because as hard as you try to simulate driving down the road with fans, it's just not the same. The dyno will tell you if that extra couple of degrees before the knock sensors picked it up was worth any power or not. I've found out that the difference between 29* and 26* was like 1 horsepower before. There would be no reason to run anything over 26* because there would be no gain from it. Just getting closer to detonation. You can also find out that the engine may like an afr closer to 12.5 or 13.0. Every engine is different. Just play with one thing at a time to see if it helps or not so you know which change had the effect.

 

There are alot of things that go into dyno tuning, it will depend on the type of dyno you are using, vehicle auto or manual, NA, boost or nitrous and the power level. Post what your going to tune, type of dyno, what mods and we can give you some pointers. We rented dyno's for years after selling our dynojet before building our dedicated dyno room with a dyno with a load cell.

 

Thank you for the responses. I'm mostly speaking in general terms. For a person that feels proficient at tuning on the street and track using trap speed to determine power increases what are some things he needs to change in his techniques to be successful on the dyno?

 

Use the dyno like the tool it is. Perform the testing that you really can't do as accurately on the street: I.e.: steady state testing. The better you can use the load bearing dyno to map your speed density model in steady state (where there is no transient influence from the fuel wall model), the better it will drive on the street later. Fixing this has all kinds of side benefits for things like idle control, coasting behavior, tip-in response, trans shifting, etc...

A couple hours on the loaded dyno can fix things that I have seen people waste weeks or months on the road (and forums) chasing their tails.

 

Ok so the main take away would be to learn the advantages of the dyno vs the street and take advantage of them. I'm sure with experience comes efficiency of being able to knock out a better tune more quickly. I've lost track of the amount of time I've spent tuning my current car on the street and track to get it where it is. I'm sure a good tuner would have knocked that out in a day minus some fuel system issues that would have been a delay early on. Driving clear to Mexico to do a wot pull thru 3rd gear with a 4l60e is a pain as well as stressful.

 

I have never done the dyno tuning myself, but my tuner said that it is sometimes difficult to keep the converter locked up while doing a pull. I believe he adjusts the converter lock-up (mph/percent throttle) with HP Tuners to make it lock up earlier. After tuning, he adjusts the converter lock-up and shift points on the street.

 

Oh, my tuner also sets up cameras to watch the exhaust. At some point during the pull, you might see a little puff of smoke out the tail pipe. I forget what he said that was, but it was important enough to capture it with a camera.

Let's see if this works:
https://www.dropbox.com/sh/q7j9pavsn...0914181610.mp4

 

You are on the right track, but as a previous poster mentioned, the main takeaway is to have the vehicle in pristine mechanical condition. Dyno time is expensive, and you only want to have to deal with tuning, not wrenching while the clock is ticking. Even when using my neighbor's dyno there is only so much we can do before someone calls the cops on us for a noise complaint.

 

I would be curious what he is watching for, the vid had a slight puff on decel.

 

Yeah, I forgot what he said. He did two more pulls after that one. The last two pulls didn't have that puff of smoke. I think it does that when he gets the tune close to done. He showed me some other videos of other cars, and they all had that puff of smoke just before he got the tune dialed-in.

 

That little puff of smoke is the aluminum pistons melting---kidding

 

Make sure to show up with a *full* tank of gas.