Jesse_Bolt
1st November 2005, 11:02
As the cool riding season approaches, it is time to formulate a plan for my next phase of upgrades. The cornerstone of this plan is going to be centered around headwork. My thoughts right this minute is to remove the heads and send them to Nallins Racing Head Service for their state-of-the-art CNC porting sometime after Thanksgiving. As I layout my objective and where I'm at right now, performance wise, that thought may change. I have read the NRHS FAQ (http://xlforum.net/vbportal/forums/showthread.php?t=1846) and I'm ready to start laying down the groundwork on this project. My target application may not meet the needs and/or demands of the average rider. As there are many knowledgable people on this forum whom I respect, you may find me leaning towards the advice of Aaron and the resources of NRHS. With that outta the way, I welcome advice and opinions from everyone whom wants to chime in.
The Bike
2004 XL1200R aka Roadster.
The Objective
When I purchased this bike used last November, my intention was for it to become my second bike. Up to this minute, its been my primary bike. Actually, the bike is a lot of fun to ride. Soon to play second fiddle, this bike will be used to cut-up on the country roads, pushing the limits around tight corners, holeshots from stoplight to stoplight in town, wheelies and the run-of-the-mill aggressive riding including changing gears at high RPMs.
What I'm NOT looking for is a dyno record breaker, attempting to eek out every smidgen of horsepower possible. I certainly don't want to build it against the threshold of detonation. And I don't want the bike to become violent, ¿If you understand what I'm asking? What I prefer is usable power within the RPM range identified using pump gasoline. I want to maintain some semblance of reliability.
What's Been Done To The Bike Thus Far
The bike, pre-owned, came with a Screaming Eagle air cleaner and large diameter drag pipes without baffles. Ungodly loud with the feeling of dragging cinder blocks, the first thing I did was replace the drag pipes with slash cut Cycle Shacks. That alone woke the bike up; I mean a lot. I could see where the previous owner wanted to sell the bike with less than 3,000 miles on the clock. The SotP response prior to this exhaust change was extremely disappointing.
Next, I was surprised to find first gear wound out over 40 mph. On most Sportsters, the first gear tops out around 20 mph. With wheelies being an important aspect I want to achieve, 40 mph is a tad bit too fast for me to start a first to second gear wheelie. At this point, a knee high wheel hop is the best the bike could muster. So reducing the gear ratios became my next step. With a newly revised model, rubber mounted, there wasn't a lot of choices available. The MoCo changed the splines on the transmission shaft. I cannot remember the deal with the engine shaft. My choices were very limited. Here are the gear changes...
Primary Stock 38~57 Modified 34~57
Secondary Stock 29~68 Modified 28~70
Now first gear winds out at 33 mph. The bike will raise the front tire high with a first to second gear shift, but lacks authority to continue to ride the wheelie. The obvious symptom is needing more power. I would like to reduce the gear ratios lower but I'm cruising in fifth gear in the 4,000 to 4,500 rpm range at 55 to 70 mph. What I like about fifth gear is, it responds (SotP) very similar to what a normal third gear feels like, only at a faster speed.
Getting side tracked here, I would like to move my fifth gear in the fourth gear position and replace the fifth gear with a taller ratio gear. Netting out a transmission with three close ratio gears, 1st, 2nd and 3rd, and two wide ratio gears, 4th and 5th. I don't know if that is possible or feasible.
Next the speedometer needed to be recalibrated. I replaced the stock ignition module with a Daytona Twin Tec TC88A only because of the recalibration feature. It's a nice module that allows the engine to rev faster over the stock module; again SotP. Other than the speedometer calibration feature, I don't see any difference between a Daytona Twin Tec and a Screaming Eagle ignition module upgrade.
Next came the suggestion to replace the CV carburetor with a Screaming Eagle Mikuni HSR42. The thought was a quicker throttle response would help bring the front tire up. It may have helped bring the front tire up easier, the bike still lacked the authority to ride a wheelie. That help was barely noticable. Where the rapid throttle response showed up was at holeshots and anytime I rolled on the throttle anywhere throughout the entire power band.
The Screaming Eagle air filter was replaced with a Forcewinder XR; only for leg room. I'm keeping the mid-set foot pegs and controls.
Screaming Eagle spark plug wires were added.
The Next Upgrade
Headwork
Headwork seems like the next logical step being I'm searching in the horsepower department. ¿Or is it headwork along with a cam change? I want to create a "Happy Family" with every component working in unison.
Reading the NRHS Evolution Sportster and Buell Head Porting (http://www.nrhsperformance.com/headworkbuell.shtml) and the OEM Cylinder Heads (http://www.nrhsperformance.com/partsoemheads.shtml), the Stage 2 CNC Service looks like the way to go. Producing more power over the entire rpm range is very appealing.
Being my application will see consistent RPMs in the 4,000 to 4,500 range, I'm wondering if special attention should be given to the valve springs, especially the exhaust valves; being the piston chases the exhaust valve closed.
Cams
This is an area I haven't paid much attention to, not even on this forum. I'm not certain which one to choose, hydraulic or solid lifters. Given the information I've supplied, ¿What cam do you recommend? Being I'm cruising in the high RPM range, I'm thinking longer duration and carefully set degrees would be more reliable than high lift.
Ponderables
Areas that may need attention...
¿Is there an intake manifold modification I should consider?
¿What head gaskets do you recommend?
¿Should I replace the pushrod tubes?
¿What about the rocker arms?
¿Will I need a different spark plug from the recommended stock 6R12?
And while I'm at it, ¿Is there anything else I should do?
Being I'm right at the pistons. ¿Is there an advantage to replace the pistons?
¿Boring to a larger size?
JB
The Bike
2004 XL1200R aka Roadster.
The Objective
When I purchased this bike used last November, my intention was for it to become my second bike. Up to this minute, its been my primary bike. Actually, the bike is a lot of fun to ride. Soon to play second fiddle, this bike will be used to cut-up on the country roads, pushing the limits around tight corners, holeshots from stoplight to stoplight in town, wheelies and the run-of-the-mill aggressive riding including changing gears at high RPMs.
What I'm NOT looking for is a dyno record breaker, attempting to eek out every smidgen of horsepower possible. I certainly don't want to build it against the threshold of detonation. And I don't want the bike to become violent, ¿If you understand what I'm asking? What I prefer is usable power within the RPM range identified using pump gasoline. I want to maintain some semblance of reliability.
What's Been Done To The Bike Thus Far
The bike, pre-owned, came with a Screaming Eagle air cleaner and large diameter drag pipes without baffles. Ungodly loud with the feeling of dragging cinder blocks, the first thing I did was replace the drag pipes with slash cut Cycle Shacks. That alone woke the bike up; I mean a lot. I could see where the previous owner wanted to sell the bike with less than 3,000 miles on the clock. The SotP response prior to this exhaust change was extremely disappointing.
Next, I was surprised to find first gear wound out over 40 mph. On most Sportsters, the first gear tops out around 20 mph. With wheelies being an important aspect I want to achieve, 40 mph is a tad bit too fast for me to start a first to second gear wheelie. At this point, a knee high wheel hop is the best the bike could muster. So reducing the gear ratios became my next step. With a newly revised model, rubber mounted, there wasn't a lot of choices available. The MoCo changed the splines on the transmission shaft. I cannot remember the deal with the engine shaft. My choices were very limited. Here are the gear changes...
Primary Stock 38~57 Modified 34~57
Secondary Stock 29~68 Modified 28~70
Now first gear winds out at 33 mph. The bike will raise the front tire high with a first to second gear shift, but lacks authority to continue to ride the wheelie. The obvious symptom is needing more power. I would like to reduce the gear ratios lower but I'm cruising in fifth gear in the 4,000 to 4,500 rpm range at 55 to 70 mph. What I like about fifth gear is, it responds (SotP) very similar to what a normal third gear feels like, only at a faster speed.
Getting side tracked here, I would like to move my fifth gear in the fourth gear position and replace the fifth gear with a taller ratio gear. Netting out a transmission with three close ratio gears, 1st, 2nd and 3rd, and two wide ratio gears, 4th and 5th. I don't know if that is possible or feasible.
Next the speedometer needed to be recalibrated. I replaced the stock ignition module with a Daytona Twin Tec TC88A only because of the recalibration feature. It's a nice module that allows the engine to rev faster over the stock module; again SotP. Other than the speedometer calibration feature, I don't see any difference between a Daytona Twin Tec and a Screaming Eagle ignition module upgrade.
Next came the suggestion to replace the CV carburetor with a Screaming Eagle Mikuni HSR42. The thought was a quicker throttle response would help bring the front tire up. It may have helped bring the front tire up easier, the bike still lacked the authority to ride a wheelie. That help was barely noticable. Where the rapid throttle response showed up was at holeshots and anytime I rolled on the throttle anywhere throughout the entire power band.
The Screaming Eagle air filter was replaced with a Forcewinder XR; only for leg room. I'm keeping the mid-set foot pegs and controls.
Screaming Eagle spark plug wires were added.
The Next Upgrade
Headwork
Headwork seems like the next logical step being I'm searching in the horsepower department. ¿Or is it headwork along with a cam change? I want to create a "Happy Family" with every component working in unison.
Reading the NRHS Evolution Sportster and Buell Head Porting (http://www.nrhsperformance.com/headworkbuell.shtml) and the OEM Cylinder Heads (http://www.nrhsperformance.com/partsoemheads.shtml), the Stage 2 CNC Service looks like the way to go. Producing more power over the entire rpm range is very appealing.
Being my application will see consistent RPMs in the 4,000 to 4,500 range, I'm wondering if special attention should be given to the valve springs, especially the exhaust valves; being the piston chases the exhaust valve closed.
Cams
This is an area I haven't paid much attention to, not even on this forum. I'm not certain which one to choose, hydraulic or solid lifters. Given the information I've supplied, ¿What cam do you recommend? Being I'm cruising in the high RPM range, I'm thinking longer duration and carefully set degrees would be more reliable than high lift.
Ponderables
Areas that may need attention...
¿Is there an intake manifold modification I should consider?
¿What head gaskets do you recommend?
¿Should I replace the pushrod tubes?
¿What about the rocker arms?
¿Will I need a different spark plug from the recommended stock 6R12?
And while I'm at it, ¿Is there anything else I should do?
Being I'm right at the pistons. ¿Is there an advantage to replace the pistons?
¿Boring to a larger size?
JB