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103b se performance upgrade

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r1dave

New Member
Hi all. New to this site so please bear with me! Originally posted this in the 'Engine and Fuel' section but realised it may be better placed in here.

I have an 04 Softail Standard FXSTI which the previous owner fitted with a 103" se motor. After riding it for a season I'd now like to get a little extra performance from the bike. I know I need to look at headwork, cams, and pistons but being new to the Harley brand I'm unsure of the best route to take. I can't find any specs at all on my current motor so don't really have an idea of what I have to start with. I've come across plenty of 'upgrade' kits to take a stock 88/96 motor to 103, but I figure thats my starting point, so where do I go from here? I'm in the UK and there aren't that many avenues for Harley tuning advice and there seem to be some really tech savvy guys on this site so I thought I'd ask for some constructive advice. I tend to ride fairly quickly having come from a background of years of jap sports bike so would like to have a motor that produces good power throughout the rev range while maybe improving the low end response too. A recent dyna run shows the bike is currently producing 86hp and 96ft lbs torque. From some of the posts on here its seems I can realistically expect 100bhp if the right work is undertaken. Anyone out there help me at all?
Cheers
Dave
 
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Re: 103B performance upgrade

Cheers Hobbit
Its the full SE motor fitted as a complete new unit by a HD dealer over here in the UK. Bigger cams sounds great, its just that I don't know what cams the motor came with as standard! As for a 110 upgrade, not sure about that yet. I figure I should be able to get enough from what I've got with the right mods, although more cc's is always an option!
 
If you want big performance form a simple installation without cracking open your engine. Look into ProCharger super chargers.
I installed one last winter on my 2003 Roadking that already had been taken up to 103CI.
I have 145hp to the rear wheel of reliable, ride-able performance. Have ridden it all summer with no problems. Bang for the buck it’s perfect.
 
II also went with a 6-speed trany to help with fuel economy. If you ride it smooth and not jump into the throttle it does well. Depending on riding style 35 to 38 mpg.
But when you really crank the throttle it will suck the fuel quick.
And its hard to hold back sometimes with all that power setting under you!

Also my 103CI engine configuration compression is higher then stock, which meant the boost from the supercharger, needed to be lowered to work well with my setup.
The ProCharger super charger's love stock compression and I wish I would have done the ProCharger to my stock engine prior to spending all the coin on the 103CI engine work I had done.
My recommendation is a stock HD engine with a ProCharger. You'll spend as much money as all the engine work costs with about half the results to the rear wheel.
And no need to break the cases or do any internal work to the engine other then new injectors. And if you do not like it you can take it off and go back to stock very easily.
But from my experience you wont want to take it off!
And if you like attention this thing will get it. I was up in Milwaukee for the 105th and I had a crowd around my bike every time it was parked.
 
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Another popular way that folks go, is to have the heads re-worked, install a Wood 6, or 7H, and set the squeeze at 10.2:1. That, along with boring the cylinders to 103"-107". Great little combination.
Of course, if the cases were bored to accept a cylinder kit from Axtell, the engine size pops up to 117". Ya-hoo!!
 
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