Staintune

[PowerDubs_imp]

I have been modifying engines in cars and motorcycles for a few decades.

Not to get off topic- but I have done port jobs, bigger valves, countless camshafts, custom intake manifolds, numerous headers, high flow cats, mufflers, jetted carbs, bigger carbs, bored out TB's, individual TB's, bigger injectors, ecu tunes... you name it. And yea literally hundreds of dyno runs and several hundred drag strip runs.

What I can tell you- most important, don't believe manufacturer #'s.

2nd thing- don't add #'s you see listed for products together for a lump sum.

3rd thing- most larger power gains on old engines are not available anymore from a design stand point.

The port design, valve sizing, filter/intake cfm, exhaust design/cfm, and yes even fueling and ign curves are already near optimal from the factory on just about anything- right down to a lowly Kia.

Long gone are horrible inefficiencies from log manifolds, 2b carbs, casting slag, 2v heads... all you can really do is tweak a little to get back what they factory trimmed for emissions, fuel economy, noise, and low octane fuel. Not much.

You can throw the parts you are talking about (full exhaust / ecu flash / intake mods ) and after having spent an easy $1,000+ you will end up with less than a 10whp gain. While the bike will feel and sound better- the difference in actual acceleration won't be enough to make up any difference in rider ability.

What I mean by that- take your bike when done- and another rider on a stock bike. There is a good chance the stock bike would still win a race- something as simple as launch rpm, or a difference in shift points could easily make up the difference. And that is talking best case scenario- straight line staged start. In the real world you are rolling on the throttle, in who knows what gear.

So- back to gears- an engine makes the power, all the gearing does is manipulate that power. Like a breaker bar on a ratchet or tire iron. Changing a sprocket has ZERO effect on the power the engine makes, does not change anything about how much power it makes at any rpm.

Gearing changes how that power is sent from the engine to the wheel. Like a 10-speed bicycle. You changing gears on the bicycle doesn't make your legs any stronger. Changing the sprocket on the motorcycle is the same. You know when you downshift from 4th to 3rd to accelerate? If you put a larger rear sprocket or a smaller front- you are shifting all 6 gears downward.

Also- people get confused on tq and hp. They are one and the same. In fact- engines don't make hp- they make tq and then you calculate hp from that.

HP=TQxRPM/5252

So if you know how much tq an engine makes at any rpm you can figure out the hp # for that rpm as well.

Have fun, do what you want to do..that's how you learn, but don't be surprised at the results and placebo effect of a lighter wallet. I'm not saying there isn't power potential in 1140cc, I'm saying the bottleneck is not the normal easy parts everyone is doing.

If you want to learn how an engine works, especially in the realm of hotrodding them and making power or moving power bands around- this is not the engine to start on.