Last winter I did a build on my 09 Fatboy. 103 big bore, high compression 10.5:1 pistons, perfect fit pushrods, high lift valve springs, 259e cam. Huge difference. Made 95 HP and 102 Torque. Now doing headwork, 50mm throttle body, and D & D Fatcat exhaust bought from Dr. V-Twin. I hope like hell I am in the 115 HP and 120 Torque range. Everyone I read on here with headwork and Fatcats are making great performance numbers. Am I going to also?

 

Where are the Fatcats at?

 

I think you're going to be disappointed. If you're at 95HP and 102TQ with what you've done to this point, I seriously doubt you're going to get to 115HP and 120TQ with head work, a 50mm throttle body, and a D&D Fatcat. If you did, I'd be really, really surprised and very impressed - unless your current tuning at 95 and 102 is off a bit. Personally, I think the most you could reasonably expect given where you're starting from is 105HP and 110TQ. Even that might be a little ambitious. I'll make a SWAG and say 103HP and 108TQ.

It'll be interesting to see your final numbers. I just changed out my Hypercharger and V&H Big Shots for a Forcewinder and D&D Fatcat and will be going back to the dyno soon for a new baseline and tuning session. I'll post the final dyno charts once everything is done.

 

I'm at about 106.7hp and 116.2 ft-lbs without a throttle body or injectors. I have stage 1 Tman head work and a little more aggressive cam T-man (TR590). My builder thinks I should pick up about 6-10 more hp and about the same for torque with throttle body and injectors. So if done right there is no reason you shouldn't be in the 110-115 range

 

You know what FBFletch, those were the numbers I was initially expecting. And those were the numbers my builder said I SHOULD SEE, 10 HP and 10 TQ. But damn, I am seeing people on here within 10 HP and 10 TQ with a Fatcat, and not anything near my build. I guess my expection grew a little bit. That's why I am asking.

 

You've got to remember that dyno numbers are subjective... one dyno can read on the high side, some dyno's read on the low side. They're just numbers, and only reflect WOT readings.

Bottom line is how it feels to the butt dyno, unless you're planning on doing some barroom drags. I'm sure it feels great now, and will feel even better once you get the next round finished.

You can only get so much out of a given size build... nothing beats cubes. Presuming your tune was decent on your last pull, it would not be realistic to get 20hp and 18 tq on your peak, although you'll certainly pick up some. I guarantee your butt dyno will be able to tell the difference, though, and your bike should run a lot better throughout the ranges while picking up a certain percentage on the overall numbers.

Enjoy!
Roger

 

100hp & 107 tq...can't wait to see!

 

I don't think those numbers are too far out of reach.. I finally took the time to put mine on a dyno this winter (actually 2) after riding for 2 years on my TTS V-tune.. The place I took it said their dyno was 8-10% low and that they were in the process of having Dynojet recalibrate it. Went with them anyway as I had heard nothing but great things about them. Base run showed 92hp 100 torque.. After tuning sheet showed 101hp and 114 torque.. Took it to another shop with a Dynojet and had them do 2 runs just to see. They showed 110hp and 123 torque.. The numbers were right at 8% above the tune run. Which ones are right? I don't know..

My build is with 103", forged flat tops, GMR Stage III heads, SE211 cam, 10.4-1 compression, D&D Lowcat w/ perf baffle. Maybe they're happy dynos or maybe they're right but I can tell you, I took it out last week on a "decent day" and i was lovin it now.. Wish I had done it when I 1st built the motor.

PS: Before ya'll rip my a$$ about the torque with 211 cam, we were all as surprised as anyone... lol

 

Dammmmm, just when I started feeling good with the power my simple cams gives me.

U go and do all that.....


REALLY----I be thinking if not, U'll be right around those #'s..

One question for Ya.. I've read that when U take a B motor and go over 100 HP U should be thinking about beefing up Ur crank also..

So have U also looked into that.??? Hate to see a great build like Ur doing all busted up.


.

 

Builder never said anything about the crank. Good question. Whatever the numbers are, and as someone mentioned earlier, I should feel this in the seat of my pants for sure. It would still be nice to see some gains on paper though. I am reall looking to the sound of the Fatcat. Never thought I would run a 2 into 1.