Howdy all,

I've recently had SE Stage 2 Kit 29893-07A Black Installed in my 08 SB.
I now would like to take it to the next level and upgrade to SE Stage 4 Kit. 27516-08a

Both kits are designed to be fitted to a stock standard twin cam harley engine. While Stage 4 kit has number of new parts (heads, throttle body) there are number of parts (e.g cylinders) that are common between Stage 2 and Stage 4. Obviously I don't want to buy a complete Stage 4 kit since I already have some of the parts that came with Stage 2. Does Harley do an "upgrade" kit, designed for customers who already have Stage 2 and wants to upgrade to Stage 4?

Cheers
vladt

The 29893-07A Black kit has the following:

SCREAMIN’ EAGLE® PRO
STAGE II KIT – 103 CUBIC INCHES*
The Stage II Big Bore Kit provides the parts you need to
improve the track performance and horsepower of your
EFI-equipped model. The kit increases the displacement
of your Twin Cam-equipped model from 96 cubic inches
(1584cc) to 103 cubic inches (1690cc). Kit includes Stage
II (SE-255) cams, 3-7/8" Big Bore cylinders, 3-7/8" Big Bore
flat top pistons a high performance clutch spring, and all
mounting hardware and gaskets.
Fits ’07-later Twin Cam models (except FLHTCUTG).

The 27516-08a kit has the following:
High performance / high flow Screamin’ Eagle Performance
110+ Heads which include large intake valves at 2.120" diameter
(our biggest ever), high compression forged aluminum
10.5:1 pistons matched to the 110+ heads, an SE260 cam to
open the valves appropriately, allowing the right balance of
air and fuel to enter, Perfect-Fit Pushrods to accommodate
the higher cam lift, a 58mm EFi throttle body to get that air
flow to the heads, big 3-7/8" diameter highlighted cylinders,
then topping off this kit off with a “must have” Super Tuner
to provide the right tuning capabilities. Kit includes gaskets.

 

I don't know if they have a upgrade kit, but you don't really need half the parts that are in the stage 4 kit. Go with a higher lift cam along with having your heads reworked will put you right up there with the stage 4 for a lot less. As for the 58mm throttle body, IMHO I think that is way to big for a 103" motor.

 

I agree about the TB, you have a lot of cubes between now and need.

 

2008 fxdse recall not done yet. i have 17,000 miles on it now. when i have the rework done i want more out of the motor but keeping it drivable. i have big city thunder baffles and the sert already. would the 50mm throtle body with around a 600 lift cam ,clean up the heads and roller rockers be resonable?

 

How do you like the 255 cam? I know it adds alot of torque but since the dyna is so light I've heard it's kinda overkill and that the top end falls off a bit.

I've got the same stage 2 still in the boxes with a 50mm throttle body sitting beside it. I was thinking of a 259 cam and still haven't chosen a direction for the heads. I already had the heavy breather, intake and tuner so I decided to go the same route with the stage 2 and add ons.

 

The 255's IMO are better suited for baggers looking for more low end or someone who rides 2-up more than not. There made for torque not horsepower(I got 110/tq). I ran them for about a year and liked them, but they do fall off a little too soon for my riding style. As for the 259's, I haven't heard of anyone using them yet. Which ever cam you decide on, get your heads worked to match them. I'm running the 110" pro heads now and they're being reworked to match the woods tw-8's I'm putting in. As for the 50mm throttle body, everyone I talked to agree it's not really necessary unless your building a high horsepower motor. Your stock one will do fine.

 

I have a Stage 4 Big bore kit for sale. Check on my post in Touring for sale. Do you a good deal.