I have an 05 fatboy that initially had a screaming eagle race tuner to dyno the bike when it had a 95 engine upgrade. Flash forward several years and a put in a new cam(585 easy start) and went to have the bike tuned again. I had to send in my old race tuner for a new TTS unit and the tune was completed and I was happy.

Currently, the bike is being upgrade to a 106 with D&D Lowcat exhaust. The builder will be finished with the bike this coming week, He does not use TTS and told me I should probably stick with this unit and have the TTS dyno guy tune the bike.

I called the TTS guy and have an appointment for June 12th...he is booked solid till then. Herein lies the problem...bike will be completed on Tuesday and it will be 2 weeks until I can get it into the dyno. Dyno guy told me that riding it un-tuned could cause damage if the bike is running to lean. He also told me that until the bike has 1000 miles he would not push it hard on the Dyno and my HP/Torque numbers would be lower than expected.

I called my builder and he told me he will hook it up to his dyno, he uses Power Commander, and just "sniff" the exhaust to see if it is running acceptable to ride. If it is not, I should park the bike and have it towed down to the dyno guy in two weeks. He also confirmed with me that he does not run new engine build bikes hard on the dyno till the 1000 miles mark too.

I understand that TTS flashes over the original settings and if I would switch to another tuner the bike would have to be set back to stock. My builder does not do this procedure and said I would have to take it to a Harley dealer.

So my question, what would you guys do in this situation? Stick with TTS or go with Power Commander and all the BS switching over to a new unit?

It does seem that if I really want accurate HP/TQ numbers it will have to go back on the dyno after a good break-in period. I just want to ride.

 

There's no reason that you can't add a power commander to the tts tuned ecm, if you need to go that route for 2 weeks anyways. Power commander piggy backs the ecm so it doesn't matter if it's getting fed from a stock or modified ecm (it will just take the tuner more work because he won't be able to start with a canned map), being on a dyno Is the only way I would add a power commander to a tuned ecm just invade it is way off to start.

when your builder runs it on the Dyno the air fuel ratio may be close enough (safe) to run as is, if your new cams are more aggressive then the previous ones then that can actually richen your mixture in the lower part of the rev range, because they will cause less vacuum. It won't be an optimized tune but you will be having that done in a couple weeks anyways.

It's all speculation until your builder gets it on the dyno to see where it stands. If you do need to run a power commander for a couple weeks you shouldn't have any problem unloading it afterwards and recouping most of your cash. My 2 cents anyways (from ase certified (a8 engine performance)auto mechanic

that sounds like it's gonna be a fun bike when it's done, I'm thinking about going a similar direction with my fxst when it's ready for another rebuild

 

Thanks for the input, Camaro. I am sticking with the cam already in the bike....585 easy start. I will talk with the builder about running a Power Commander for the breakin and then get it to the TTS guy to put it on the Dyno. Perhaps I can hold off until the bike has 1000 miles for a proper Dyno with TTS.

I pick up the tins from the painter today and will drop them off at the builder tomorrow. Hoping that it can get sorted out and I can start riding the bike this coming weekend.

 

What compression are you running with your S&S 585?

 

The builder bored the stock barrels from 3 ¾ to 3 7/8 inches and increased the stroke from 4 inches to 4.5. I think the compression is around 10:1 ratio with the stock heads. My heads are getting worked over so I am not sure what the final compression ratio will be.

Here is an article about his build process..

http://www.bikernet.com/pages/Bennet...106Incher.aspx

 

Cool, a stroker motor! We don't see many of those these days...Just make sure you get the compression up with those cams, they have a super late intake close and will be super soft off the bottom without it. I speak from experience. In my 95" with Branch heads and 585's the power didn't come on until 3k (actually 3200k) rpm. out of the hole the bike was a dog, but from 50mph+ I would pull and pull and pull. My bike hit 119mph on the dyno is 4th gear while doing some tuning work...Build the engine properly and you will have a blast with her!

 

I am a weird Harley guy...grew up riding minibikes, raced motocross, rode street bikes before getting into Harleys. I ride the fatboy like she is a sports bike up in the canyons...always in the higher rpms. This past year, I have had to replace the outer primary cover twice because it scraped hard on a turn and was leaking oil. After the first time, I bumped up the rear height by an inch but still managed to destroy the cover again.

I loved the 585s in the 95 build...can't wait to see how they perform with 65 to 70% more HP/TQ.

 

You are going from a 90 hp/tq motor to a 150 hp/tq motor buy upping the displace from 95 to 106? wow..

 

No, the 95 build in the bike was done by Harley Davidson at the point of purchase, no head work, weak hp pipes etc. It only produced about 70hp/80tq ...even after putting in the 585 cam a few years later.

These 106 builds easily hit 115/120...which would be 65 to 70% more power than previous. I am expecting better results.

 

Builder called me last evening and says the bike is ready to pick up today....it runs great but it will not idle for more than 20 to 30 seconds. He replaced a hose in the fuel pump that he thought might have a pinhole...it idled better but still shuts down. He checked the fuel air ratio and said it is fine and the bike is not running lean.

He is sure it is a tune issue and wants me to try and get it into the dyno guy early...to just adjust the idle for now so I can ride it and break it in properly before a full dyno tune.

I mentioned to him about running a power commander over the TTS and he said that he did this once and will not try it again...was a major headache. The build will have a one year warranty ...so if the the tune does not fix the idle issue I will just bring it back.

A question for you knowledgeable folks...does this sound like a tune issue...where the bike runs fine but will not hold an idle? Heading down to pick up the bike in an hour or so...guess I will be one of those guys blipping the throttle at stop lights for awhile...dyno guy takes the weekends off.