I have done a lot of reading and I think my next bike will be a 2005 or 2006 Sportster.
I like the idea of the dual front discs of the R model.
I read somewhere that the R version has a few more HP than the C. Is that accurate?
Are there other differences in the R and the C model?
I am primarily interested in a 1200.
Does the C have a larger gas tank ?
I have read that if I want to go to a better HP cam that I would need an aftermarket ignition to raise the rev limiter. Is that correct?
As long as I'm asking
What kind of HP numbers are y'all getting with just slipons, air filter and mild cam?
Any other info is greatly appreciated.
Thanks
Alex
2005 and 2006 XL1200C and 1200R motors use the same heads, the same cams, the same pistons, the same ignition and carb and air cleaner and exhaust. So they make the same power. However, they may dyno very differently based on the rear wheel. Spokes dyno the best, mags are in the middle, and the solid wheel (as found on many "C" models) dyno the worst. I'm talking about an inertia dyno here, which is the most common. On a brake dyno that does a steady state measurement, you won't see a difference based on wheel type.
The big difference in the motors between those two years is the tappet anti-rotation method. From 2000-2005 Sportsters used screw-in tappet pins. It's a solid, robust setup. In 2006 they went to a plastic anti-rotation device (cost reduction) that flexes with cams over about .600 lift. The 2005 setup is better.
Also there are differences in the transmissions between those two years. In 2006 the gear cut was changed to reduce noise and also the ratios got changed. I don't have all the details handy.
The stock cams are the "W" grind, which has very early intake valve close (IVC) timing at 25 degrees ABDC, which means it's a low rpm oriented design. In fact that's the earliest IVC of any Evolution Sportster cams available. So any cam swap you make will have a later IVC and thus a higher rpm range. Therefore if you do a cam swap without also swapping the ignition, you'll be missing out on much of the benefit of the new cams because your stock 6000rpm limiter won't let you get there.
For some dyno sheets showing what can be accomplished with good stage 1 pieces and bolt-in cams, go here: http://www.hammerperf.com/tthoppingup1200.shtml#camsalone . Those were taken on a 2007 which has an identical motor except it's EFI, and the EFI makes a bit more power. Derate those numbers 10% or so for a realistic expectation. Also, the EFI throttle body is bigger (45mm) as compared to the CV40 carb and it'll support more power. You'll find the CV40 starts choking the motor above 90hp. So above 90hp, you need to be thinking about a bigger carb. We like the Mik HSR series carbs.
Watch this video to learn more about IVC as it relates to rpm range and compression: http://www.hammerperf.com/ttvideos.shtml#compressionratio
Excellent video. :up:
I had downloaded your compression utility a few years ago. It's very helpful.
My local shop "thinks" he has a tuner that works on his laptop that will let him raise the rev limiter to 6500
Whether or not that can be done
What is the best cam, intake, slip on exhaust combination for an otherwise stock 1200 pre FI engine?
Is it reasonable to think I can get about 80 HP?
What is the stock HP of a 2005 1200...?
I want to get the best performance I can without changing the bike very far from stock.
Thank y'all
Quote from: Alexintenn on August 27, 2022, 12:24:16 AMMy local shop "thinks" he has a tuner that works on his laptop that will let him raise the rev limiter to 6500
Whether or not that can be done
What is the best cam, intake, slip on exhaust combination for an otherwise stock 1200 pre FI engine?
Is it reasonable to think I can get about 80 HP?
What is the stock HP of a 2005 1200...?
I want to get the best performance I can without changing the bike very far from stock.
Thank y'all
Well, I can't really answer you without sounding like a sales pitch, and I'd rather not do that. I
like the non-commercial nature of this site.
But in my previous post I provided a link to some dyno results. That page has a boatload of information that answer the kinds of questions you're asking.
Thank you
I found the Dyno run with slip ons and your 570 cam.
If I can get over 85 HP I'll be very happy.