The only time I have not signed a waiver is when the motor builder is the dyno tuner and he has built the engine from the inside-out with his own hands and tools. That was part of his warranty.

The waiver comes to question when a dyno tuner is delivered a bike with miles already on the engine, no known history to him about the condition of the engine, or knowledge if any aftermarket parts were correctly installed. If you were the dyno tuner I am sure you would do the same and make some stranger sign the waiver too. Why warranty someone elses work?

 

I figured I would join the passions around this subject. I've been efi tuning since 2003 with HDs. I've tuned using the SERT, SEPST and now DynoJet's Powervision. I've also had no less than 6 dynotunes from 4 different highly qualified dyno-tuners after different engine modifications over the past 10 years of owning efi bikes (could actually be more if I dug through the files for all the receipts).

Here's the simple truth about whether a dyno-tune is worth it and some folks aren't going to like it because it's also how they make a living .... the answer is...it depends!!

What I've learned from thousands of $s and hours of time spent in shops, is that the vast majority of the time a dynotune is not the best and certainly not the most economical way to get great performance from an HD's engine. If you asked me 3-10 years ago, my answer would have been different. A dyno tune was not only the best way to go it was the only way to go. The tuning software technology was just too rudimentary and the algorithyms for software to do the tuning just weren't good enough yet. And for some exotic engine builds, its still not good enough.

A dyno tune does not necessarily result in perfection. Even the most qualified and diligent tuner simply won't have the time and you won't have enough money for the tuner to test every cell in both the VE tables, the spark tables and all the other parameters to get a perfect map for your bike. It just isn't possible unless the tuner is going to spend days with your bike on the dyno and you're prepared to shell out thousands $s. Will a tuner deliver a better map then you started with ... yes, most of the time but not always.

For most guys that have some basic computer skills and have done a cam and pipes upgrade, you'll get just as good a result using SEPST, TTS or PowerVision and their built-in autotuning capabilities as you will with a professional dyno tune. This assumes you start with a custom map from their library that closely matches your bike as a starting point.

I would recommend autotuning with any of these 3 tuning software options, even for bikes with headwork, larger throttlebody, plus cam and pipes.

Whether you are going to autotune or dyno tune, you're going to need to buy one of the software packages from TTS, Harley Davidson or Dynojet. So why not try to autotune with the software you just bought before throwing another $500 at a shop for dynotuning that may not get you any better results. You might even enjoy the tuning experience (I certainly do).

If you're looking for a recommendation in software, my view is that the PowerVision is the best of the current choices on the market for the guy that wants to tune his bike on his own. While I haven't tuned with TTS, I'm not a big fan of their business model that locks TTS to your bike and prevents even a dealer from accessing the ECM unless you revert back to the stock map. Kinda defeats the purpose if a dealer or an Indy shop can't access your ECM to diagnose a problem. Plus it requires you to strap a laptop on the bike to conduct any autotuning which is the same reason I'm no longer a fan of Harley's SEPST.

I've used the PowerVision for datalogging, observing engine operation while riding and autotuning. For my $, this is the best option on the market today for ease of autotuning and best bang for the $.

If you're not interested in learning the basics of tuning software, you're probably best off doing some research, find out where the most qualified dynotuner is in your area, buy the tuning software recommended by the shop, drop the bike off, pick it up in a week, pull out your credit card and pay what the man asks.

IMO, anyone planning a dynotune should consider that they have to pony up the $ for the tuning software regardless. Based on my decade of experience with self-tuning and paying for professional dyno-tuning, I would now recommend putting miles on your bike with YOU in the saddle versus the 500-1000 miles a "proper" dyno tune is likely to add to your bike's odometer with a tech in the saddle. Any good dynotune is likely to add alot of miles to the bike. If they don't, you're getting ripped off since that means there's no way they could have tuned most areas of the bike's map. Check your odometer before and after a "full" dynotune and you'll see just how many miles you just added to the bike. You'll be shocked.

The PowerVision software evaluates every cell that you ride in and makes adjustments based on the data collected. Its just a matter of collecting enough data while riding the bike the way YOU ride it on the road versus the artificial conditions on a dyno.

Consider this, Dynojet makes almost all the motorcycle dynos in the country. They also make the PowerVision which now provides the bike owner the ability to tune their bike with relative ease while enjoying the time in the saddle on their favorite roads. Which direction do you think they see the marketplace heading?

 

All this theorizing about dyno tuning is really silly. Every engine manufacturer in existence depends fully on using a dynamometer for testing and tuning its engines. And guess what? No harm to the engines.