Basics of going faster/more power

[F5 Dave]

There’s a 970cc kit for the RF or you could look at an 1100 top end but that loses the water cooling. Apparently the run better a little hotter than they currently do & I am trialling a hotter thermostat to see.

They seem to like advancing the ignition somewhat. This can be done with a stepped ignition advancer key or rotor, but I have just rotated the pulsar plate anticlockwise & been careful to keep the clearance down to about 10thou. You need to slot the plate to do this (under RHS sidecover). I have only just done this & it seems to aid pickup, but think some detonation is heard under 2k rpm. Will try 96 to see if this goes away. Seems to aid midrange & perhaps topend.

K&N airfilter will require a bit of jetting so wouldn’t bother unless fitting a aftermarket jetkit. My bike is keeping the std pipe as it’s my touring bike. If you lower the gearing be aware that they vibrate a bit at higher speeds so this may bring it down to usual cruising speed.

The ports are huge & if I get the time (the YZF project is likely to receive more attn) I will experiment filling them in a bit. This should help topend as well as through the range. Making them bigger rarely helps, despite the folklore.

PS the bars are at a dumb angle if you get wrist ache try some adapter bars from F1. Cost $230 inc courier which seems like a lot but they are well made & worth it.

[Jackrat]

Now we're talking,big bore,big valves,Cam it up,Blue print it,Hot ignition,Lose wheight,chuck away all the heavy stuff.
Ah stuff it buy a harley, spend heaps an still go slow.

[Oscar]

OK - me waving my "I don't know shit" flag here..

I have an RF900, I got it all tuned up and it's going nice now... but it is stock standard. What are the basic/common tricks to getting more horses at the backwheel.

It also raises the question - what are the best ways of measuring that difference (other than a dyno or tracktime)...

Hmmmm???
MDU

Ahem, at the risk of being rude...why don't you just learn to ride it faster? I've met plenty of guys with more horsepower than brains...

[F5 Dave]

The logical conclusion of that argument is to buy a 10 speed & pedal like 10 bastards.

More midrange power always feels better on the road, easier & lazier to ride & although the RF has a sweet engine it’s top end overshadows it’s midrange.

[wkid_one]

I agree - in most instances you are the only limiting factor on the bike. The bike will do a hell of a lot more than your mind will lead you to believe it can.

I would only be worrying about increase performance when you are riding the pants of the bike you are on....and in that case, you would also have to weigh up whether you aren't just better off upgrading....

[jrandom]

Ahem, at the risk of being rude...why don't you just learn to ride it faster?

Ahh, he probably doesn't necessary want to break lap records or even point-to-point road records, he just wants it to make a pretty noise and try to pull his hands off the bars. Fair enough too, we only live once. If you want your toy to make as much horsepower as possible, more power to you, says I...

Of course one could argue that MDU would do better to just trade his RF in on a gixer if that's what he's after, but I understand the attachment one develops to a machine... it's funny, some guys swap bikes every year or so, never satisifed, and other guys stay with a demonstrably 'inferior' machine for ages, tweaking it, tuning it, fiddling with it, but those guys often seem happier than the ones with the latest rocket in their garage and the biggest hole in their mortgage...

[750Y]

Cheers guys...
Yup more ponies is specifically what I want - I can then gear up or down from there...
MDU

DeatchINC is right about making horsepower.
also Craig? at colemans, has an RF so he'd be a good guy to ask also.

[Oscar]

The logical conclusion of that argument is to by a 10 speed & pedal like 10 bastards.

More midrange power always feels better on the road, easier & lazier to ride & although the RF has a sweet engine it’s top end overshadows it’s midrange.

Ahhh, we're just being a bit silly now, aren't we?
He's talking about an RF900, I assume - so he ain't short of the odd pony.
He'd probably benefit more from a suspension tune up and a decent set of tyres, before looking for more berries.

[Racey Rider]

Higher octane fuels actually have a faster flame front and can in effect make the engine run cooler due to being more efficient.

Are you sure you got that the right way around? I thought we had said 91 had a faster flame front than 96. Can anyone confirm?

[jrandom]

Are you sure you got that the right way around? I thought we had said 91 had a faster flame front than 96. Can anyone confirm?

Hmmm. Faster flame front? Not sure that octane would directly affect that. It DOES affect the likelihood of an uneven burn under different pressures. If it did have something to do with overall burn speed, I'd expect a lower octane to burn faster, not slower.

Hell, I need to get me some chemistry books.

[James Deuce]

Are you sure you got that the right way around? I thought we had said 91 had a faster flame front than 96. Can anyone confirm?

That was the answer my petrologist brother -in - law gave me.

[FROSTY:Me]

might be teaching gramma to suck eggs here but I understand that rf900's vary in engine specifications depending on where it was soposed to go.
We got a lot of rf900's that were for other countries -some with much lower horsepower due to sound/smog emmission laws
The cheapest/easiest option to raise horsepower might be to find out what carb setup,cam angles,etc the south african spec bikes have and set your bike up the same

[BurnCycle]

I’m surprise no one has mentioned the one fundamental ‘rule’ when it comes to more power… How much power you want all depends on how much money you’re willing to spend!

There are simple and effective ways to make a bike fast that don’t deal with the engine. But yes, they have some adverse effects (some more minor than other), it all depends on what your willing to put up with.

1. Weight reduction. Have a good look at the bike and see what can be removed or replaced with lighter materials. Simply removing the tool kit can be around 2kg. Passenger pegs and tie down points are other things that can go (depending on bike). Plastics can be replaced with race fairings (though maybe not on the RF). Wheels are another way to utilize the existing power of the engine. Less rotating mass the engine has to move the better the power is put to the ground. A simple aftermarket rim can weigh in at half that of the stock wheel. Here’s also where a 520 chain/sprocket conversion can be a benefit with less rotating mass. Also consider the tires you use. That 190/50 weighs quite a bit, try a 180/55.

2. Driveline. As mentioned before changing the gear ratio can have a big difference in the way the bike feels. A few (2 to 3) extra teeth on the rear sprocket will make quite a noticeable difference. Yes your top speed will be down, but how often are you pushing that hard? As mentioned before, converting to a 520 weight chain/sprocket may also be beneficial.


3. Rider. Can the rider loose a few kg? For every 4-5kg lost the bike can utilize an extra HP not trying to move a lard arse around. Training also goes a long way and a simple book is a good place to start.

As for the engine (simple stuff)…

1. Exhaust. This also goes into weight reduction. The stock pipe is nothing short of a boat anchor. Ditch it.

2. Jet kit. Larger mains and pilots as well as a few shims will get the right amount of fuel you need. Most jet kit’s come with recommendations for applications. This is a bit of a shot in the dark but a good starting point. Without dyno tuning you won’t know if you’ve got it right.

3. Air filter. Also mentioned previously was the air pump… More air in combines with more fuel and a better way to get it out all equate to more power.

And the not so simple stuff…

This is where big $$$ comes into play and you may want to start considering a new bike as finding upgrades for the RF become a bit of a heart ache.

[Lou Girardin]

Fit an aftermarket can, Neptune are good value. K&N or similar filter, static timing advance plate, Dynojet kit and time with a good dyno operator.
It'll cost a bit but you'll should get 5 to 10 more hp and fatter midrange.
Then again, the RF's not exactly slow as stock.
Lou

[Eddieb]

Or another option that hasn't been mentioned but would be relatively cost effective for the gains.

Sell the 900 motor and put in a GSXR1100 motor. Huge instant power gains, up to an extra 25bhp depending on the donor model and thats before tuning.
Lots of extras available, hugely tunable with lots of info on the net and people who have tuned them before.
You must be able to get an 1100 motor for around a $1000, if that nowdays, minus whatever you can sell/trade the 900 motor for.

They are all based on the same motor so a bit of research should reveal a model that will slot into the 900 frame with little or no modification.

That would be my bet for a good gain and relatively little expenditure and still have plenty of scope to go much further. I would think it would be a lot cheaper than can, filter, dyno time etc and produce up to 5 times the power gain even before tuning..