I have my dad's 2002 Fatboy over the winter with almost 50,000 miles.
I'm getting into the cam chest to inspect and likely replace the cam tensioners and inner cam bearings.


While in there I mentioned it would be a good time to put some bolt in cams in and he agreed. Andrews TW26A is what I will likely use. I have read several times from builders that the TW26 from Andrews is a great stage 1 cam. He does not ride hard and I think he would benefit from a low rpm torque increase more than a high rpm cam.


QUESTION; He is running a stage 1 Screamin Eagle air cleaner and V&H long shots. To my knowledge he has had no mapping done and the bike runs really well and cool. If I add these cams to the mix will I require a remap or tune? I KNOW to get the full benefit, a tune would be best but is it required?


Also is it worth shaving the heads a little and using .030 head gasket since I will have it torn down that far? He has no interest in going 95 at this point. I think if the compression increases the tuning part would become more critical.


Thanks, I have searched for hours and cannot find much information.

 

I would say yes to remapping it.The cams and compression increase are big changes and you don't want to burn it up by running really lean.

 

They are bolt in cams & don't really need compression bumps. I wouldn't worry about shaving the heads, but definitely use the .030 gaskets if you're there. Or you could cut the oem pushrods out and put some good adjustables in. No need to pull the heads.

As for the tune, IMO, if the bike's running good & cool as stated it's not going to get any hotter with those cams. You guys would've already noticed that with the AC & slip ons. But if you want to throw time and money at it, you know the skies the limit!

Good luck!

 

I installed them in my 95" Stage II (from the factory,) replacing the already upgraded 203's that came stock. The difference between those 2 cams wasn't big enough to warrant tuning, but remember the Stage II from the factory came with a Stage II download already. My bike runs fine.

But going to 26's from the stock 88" cams might be a reach without a tuner.

 

Yes, you will have to tune it. I put the same cams in a 2004 88ci and took it for a test ride just to see how it was running. The bike already had the HD Stage 1 download. It did not run good at all. You could immediately tell it wasn't running right.

 

Okay so a tune is probably needed. Thanks
Next question, can someone dyno tune the bike and download the mapping or will we need to buy a tuner?

From what I have read the dealer can do a download but I'm wondering if the aftermarket world can do this without buying a tuner? The bike wont continue to get changes. Once done he will probably ride it another 50,000 with regular maintenance.

 

Forget the dealer download; worthless, particularly with aftermarket cams. You will need to buy a tuner; several options from the Power Commander III to the TTS Mastertune or the Dynojet Powervision. The difference will be whether or not you want a "flash" tuner like the TTS or the Powervision that can reprogram the ECM or a "piggy back" tuner like the Dyonjet PCIII that must be attached to the bike and does not reprogram the ECM but reads a program or map and sends the appropriate signals to the ECM. The piggy back systems are old technology but do cost less; all can be tuned on a dyno.

There is a third option; a "fueler" like the Dobeck TFI that will allow you to add fuel and richen up the mixture at various throttle positions. Does not require dyno time and the operator can adjust the added fuel, test ride and fine tune by tweaking the amount of fuel added.

Sounds like you just need to spend some time reading about the various tuning options and decide which is best for your situation. IMHO, there is no replacement for a proper dyno tune by a competent tuner. You might visit your local independent tuner and consult with him to see which system he prefers.

 

I agree 100% dyno time is very beneficial. My personal carb bike gained 6 hp and 4 lbft just from a proper air/fuel mix. I never would have guessed that much increase on a carb bike.

Just trying to save my dad some money. He is happy with the bike as is I just want him to be REALLY happy.

Thanks for the help.