Steps After Cam Change?
Seasoned HDF Member
Joined: Sep 2008
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From: San Diego, CA
Hello again y'all,
I haven't made any decisions yet, but I'm leaning towards getting a 2 into 1 with O2 ports and then getting either the powervision with the autotune kit or the thundermax with autotune. I just wanted to clarify some things about how these tuners work first.
Is it possible to install the tuner and use the O2 ports on the new exhaust to tune the bike, and then remove them and plug the ports after flashing the ECM? Or would I have them hooked in all the time?
I haven't made any decisions yet, but I'm leaning towards getting a 2 into 1 with O2 ports and then getting either the powervision with the autotune kit or the thundermax with autotune. I just wanted to clarify some things about how these tuners work first.
Is it possible to install the tuner and use the O2 ports on the new exhaust to tune the bike, and then remove them and plug the ports after flashing the ECM? Or would I have them hooked in all the time?
I've never used them, but IIRC, the DynoJet Target tune and the Thundermax ECM basically use wide band O2 sensors full time. I believe they convert the open loop tune to closed loop for real time adjustments after any "tuning" is done. The O2 sensors stay connected.
Others more knowledgeable than I about Target Tune & the Thundermax ECM will correct me if I'm mistaken, and/or give better info about how they work than I can.
I have the DynoJet Auto Tune Pro Module. It can be used on both bikes with no O2 sesnors, or the newer bikes with O2 sensor feedback, as long as you can connect the wide band O2 sensors. It connects between the PV tuner and the data port, to allow for auto tune runs, using wide band O2 sensors. The Auto Tune session changes are then saved to a new tune. That new tune is then flashed to the ECM to replace the original tune, and both the PowerVision Tuner, Auto Tune Pro module, and AT module O2 sensors are removed. On the pre-O2 sensor bikes, it will then run a new tune, but it will still be an all open loop tune with no O2 sensor feedback.
You can do several Auto Tune Pro sessions, each one starting with the new tune that the previous AT session made. They recommend once you reach an average cell change of 4% or less, you're done with auto tuning.
I have started with a base MAP from FuelMoto, done one AT Pro session, and had an average cell change of only 1%... That's a really good tune right from the start...
You could give FuelMoto a call, or a trusted shop of your choice, and discuss your goals, then what the best tune strategy would be for you use....
Keep us posted...
Last edited by hattitude; Feb 28, 2025 at 09:04 PM.
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Joined: Sep 2020
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From: Southeast
...I'm leaning towards getting a 2 into 1 with O2 ports and then getting either the powervision with the autotune kit or the thundermax with autotune. I just wanted to clarify some things about how these tuners work first...Is it possible to install the tuner and use the O2 ports on the new exhaust to tune the bike, and then remove them and plug the ports after flashing the ECM? Or would I have them hooked in all the time?
T-max does allow you to "turn off" auto-tune, but there are just a few reasons someone might want to do that. Besides, when you add the cost of tuning devices that allow for wide-band sensors, it seems counter-intuitive to turn the feature off.
If you're looking to optimize the bike to its new configuration and that is all, then @hattitude 's suggestion of buying a license is the most cost-effective route. You could also still use the bungs in the new 2-into-1 exhaust at the dyno and then put the plugs in and forget about running oxygen sensors once the tune is set. Either way will get you there. The hard part is deciding which way is the best for you!
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I see, sounds like a good deal then. I called one of the shops near me about getting a tune yesterday and they said they'd call me back. They never did lol. But, ultimately, my goal is to get her tuned well enough to drive and have fun. I'm not necessarily looking to wring every ounce of performance out of her.
The reason why I was asking about running the tmax or PV with the O2 sensors removed is because I was worried about routing the sensors on my bike when they didn't come on it from the factory. I'm cool with leaving them hooked up all the time, I just didn't know if there was going to be some extra fixturing I'd have to do to get the cables routed to the headers. Otherwise, I'm cool with hooking them up and letting them do their thing
The reason why I was asking about running the tmax or PV with the O2 sensors removed is because I was worried about routing the sensors on my bike when they didn't come on it from the factory. I'm cool with leaving them hooked up all the time, I just didn't know if there was going to be some extra fixturing I'd have to do to get the cables routed to the headers. Otherwise, I'm cool with hooking them up and letting them do their thing
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From: Southeast
I've put a T-max on a few bikes. There's a lot of stuff crammed into the frames and under the tanks of these bikes, but all in all, the wiring tucks in pretty well. The hardest part is finding the best place for the connectors for each sensor. They're kinda large, but they do tuck in beside or inside the frame rail pretty good. Just make sure that all the wires are above the frame rails. You don't want to scrub one off if you high-center the bike somehow.
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From: Indiana, USA
I have done both and with Dynojet Power Commander I removed both the AutoTune Module and the O2 Sensors after Completing my Tune. The Thundermax system needs the O2 sensors installed at all times because it is actually auto adjusting at all times to compensate for altitude and temperature changes. Older TMax's would allow 15% change per cell but I believe the newer units are clamped down to 10% change per cell.
I have ran both of these scenarios on the same bike and today that '03 is running the T-Max only because it is such a radical build. - The only draw back to this option is when something goes wrong, who is gonna fix it? BTW - My '03 with TMax has been ridden from Indy to Sturgis and back no problems.
I run PV on my '13 because it is simply a cam and exhaust change and should I be away from my shop any Dealership in the USA can fix me when I break. I have O2 Ports for tuning but they are usually plugged.
I have ran both of these scenarios on the same bike and today that '03 is running the T-Max only because it is such a radical build. - The only draw back to this option is when something goes wrong, who is gonna fix it? BTW - My '03 with TMax has been ridden from Indy to Sturgis and back no problems.
I run PV on my '13 because it is simply a cam and exhaust change and should I be away from my shop any Dealership in the USA can fix me when I break. I have O2 Ports for tuning but they are usually plugged.
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Okay, so I've decided to take my bike to get tuned at the shop near me. I got the new exhaust on and the bike all buttoned up. Started it up and everything sounds great. It definitely needs a tune, I let it idle for for a bit and it idles really low when the bike warms up. I also putted around the parking lot for a bit and it has a good bit of pop on deccel. My original plan was to put it on a trailer and take it to the tuner, but I feel like it runs well enough to ride it to the shop about 10 minutes up the road. All the threads I've seen of people doing cam swaps say not to ride it to the shop, but I'm not sure why exactly. What's the worst that happens if I ride it on the stock tune?
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Joined: Sep 2008
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From: San Diego, CA
Okay, so I've decided to take my bike to get tuned at the shop near me. I got the new exhaust on and the bike all buttoned up. Started it up and everything sounds great. It definitely needs a tune, I let it idle for for a bit and it idles really low when the bike warms up. I also putted around the parking lot for a bit and it has a good bit of pop on deccel. My original plan was to put it on a trailer and take it to the tuner, but I feel like it runs well enough to ride it to the shop about 10 minutes up the road. All the threads I've seen of people doing cam swaps say not to ride it to the shop, but I'm not sure why exactly. What's the worst that happens if I ride it on the stock tune?
You can damage your engine...
Think about it..... You have made changes that will increase the power. To increase the power, the engine needs to move more air. You will be riding on a tune that is safe/proper for an engine that moves less air... maybe much less air.
You will be running lean to very lean. Hard to tell just how bad that will be on the engine.... but why chance it?
Your bike, your call.....
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Yeah, I'll trailer it over there. I did some reading and didn't realize running lean could do that much damage. My mistake
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Seasoned HDF Member
Joined: Sep 2008
Posts: 14,156
Likes: 11,247
From: San Diego, CA
Not really a mistake.... I'm sure numerous people do it...
It's just impossible to tell how/when/where the lean condition could bite you in the butt... A lot of it has to do with the cam, the conditions, how you ride it, etc, etc, etc..
IMHO, it could cause minor damage, not to surface until a later time & mileage by way of a premature need for a rebuild... Or... something could happen, causing the need for immediate attention..
I believe it's one of those situations where it's not necessarily high odds that something WILL happen, but rather, what's at STAKE if something does happen....
For my part, I agree with your decision to trailer it.... Be sure to share how it runs after the tune...
Enjoy...!
Last edited by hattitude; Mar 15, 2025 at 07:40 PM.
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