ESE's works engine tuner

[koba]

Quickly burnt out ......

Damn, 'twould be fantastic to have the power to do that!

Is the gearing as good as it can be for drive out of the important corners on the track?

Just throwing a few more ideas into the mix, I'm sure you have thought of it already anyway.

[husaberg]

Koba Is the gearing as good as it can be for drive out of the important corners on the track?
Just throwing a few more ideas into the mix, I'm sure you have thought of it already anyway

I was wondering the same thing as the gp100 is 5 speed and I am sure the top 3 ratios will be the closest in terms of spacing between the gears.
Are you geared at the track to take advantage of this.ie the top three ratios.

F5Dave Wasn't aware that they were supposed to stick out a bit.

Neither was I.
I was always was lead to believe that it could cause preignition. Obviously only an old wifes tale.
is it better to have the plug protruding more into the combustion chamber becaue it it is more in the center of where the mixture is concentrated?

Also maybe Wobbly could also enlighten us on how much power increase from the new small cranks engines power increase, would/could be atributed to the less tortorious path of the mixture past the crank.Rather than say a larger crankcase volume.

[bucketracer]

One point to remember is that the best radius on the squish corner into the bowl is no radius at all.A sharp corner with just with a rub of sandpaper to get rid of the ragged knife edge, works best.

And with any of the race type plugs we are using approx 1mm of unthreaded plug end should be protruding into the chamber.
The old B10EGV was originally designed to be used this way by NGK, but nowdays the trick plug is a R7376-10, this plug makes more power than any other tested with around +2 Hp better than an expensive Denso equivalent, here is the test i have shown before.

4 NGK Spark Plugs R7376-10 on Ebay



About $13 NZ each plus shipping

http://cgi.ebay.com/ebaymotors/ws/eB...K%3AMEWAX%3AIT

[TZ350]

Is the gearing as good as it can be for drive out of the important corners on the track? Just throwing a few more ideas into the mix,

All good ideas, was running a 14 on the front, 13 seemed to be, too big a jump and was running out of revs before the next corner, so may try half way by putting a couple of extra teeth on the back. The FXR's seemed like they could easily run corner to corner without changing gears, so you can see why I wan't to increase the power spread of the GP.

And clean low end carburation would be a help too. I have ordered a 24mm pumper kart carb. It is much shorter than the Keihin I am using now so I hope there is enough room so that I can use the pumper with the V Tec inlet for sharper low end carburation and keep the inlet tract length below the 135mm limit suggested by Wobbly.

I was wondering the same thing as the gp100 is 5 speed and I am sure the top 3 ratios will be the closest in terms of spacing between the gears.
Are you geared at the track to take advantage of this ie the top three ratios.

One of the reasons I am trying to develop enough power spread to only need two gears is to be able to only need 4th and 5th and drop down to 3rd for emergencies when I have truly cocked things up or been baulked in a corner.

[husaberg]

All good ideas, was running a 14 on the front, 13 seemed to be, too big a jump and was running out of revs before the next corner, so may try half way by putting a couple of extra teeth on the back. The FXR's seemed like they could easily run corner to corner without changing gears, so you can see why I wan't to increase the power spread of the GP.

Gearing guide attached nice and simple.

No doubt if anyone could be bothered a programe could be found written etc
.
As you can see the options are endless 1/10 of a tooth on the rear etc not to mention the effects on on handling squat etc
I used to spend hours on speed calulations for rev drops between gears changes to overal ratios etc etc.Should have spent more time actualy riding.
Failing that, if the fxr is still holding you could always "ram him"Just how tight is Mt Welly.

[TZ350]

Thanks for the chart.

Should have spent more time actualy riding.

Some at work have said the same thing about me........

.... Just how tight is Mt Welly.

Google map "1 Tainui Rd Mt Wellington NZ"

http://maps.google.co.nz/maps?client...ed=0CBwQ8gEwAA

Av was taking all 7 corners around the longer infield track in 30.2 to 30.6 sec depending on traffic .......

... I am about a 1/2 hour slower.

[husaberg]

Av was taking all 7 corners in 30.2 to 30.6 sec depending on traffic ....... ... I was about a 1/2 hour slower.

In fairness to your riding I am guessing she is maybe a few KGs lighter.
What did the kt100 use to lap in or still lap in?

[TZ350]

In fairness to your riding I am guessing she is maybe a few KGs lighter.

All up, Av and her bike is 90kg lighter than me and my bike.

What did the kt100 use to lap in or still lap in?

Not sure what the Karters do but one day a Kart Girl who had come down for some practice laps let Karl Morgan out in her Kart, from memory after a bit he was doing 26 sec laps.

[Buckets4Me]

from memory after a bit he was doing 26 sec laps.

and still a second slower then her
I thought he was going to throw her brand new kart away trying to beat it

[F5 Dave]

Thanks to Koba who came around last night & helped me grind up a reasonable curved cutter & we found a bit of slop to take out of the cross plate doofer. Plus he's making up a better flange type holder that will facilitate skimming some off the gasket face without chatter hopefully.

Heck after he left I even cleaned away a bucket of swarf as I was feeling guilty about the mess around the area.

[wobbly]

Some bastard got in and swiped those plugs - me.

The case com being bigger works better and better as the inlet is optimized to fill that volume to the same pressure ratio, and subsequently the ducts/transfers are able to move the extra vol available into the cylinder.
This then increases the delivery ratio and ultimately the dynamic com.
I dont really see much gain from reducing the cranks effect on intake streams - Jan Thiel found 1 Hp in 50 by covering over the crank wheels as is done by all the Italian 125 kart engines.

Here is a gearing chart with rev drops I did.

It may be a better way forward to look at keeping the same powerband width, but simply moving it all up a thousand revs or more.
Then with the adjusted gearing, to achieve the same terminal speed, you will accelerate alot quicker due to torque multiplication of the extra teeth on the back.

[Bert]

some of us handle metric better.

I think I posted this before its been converted back from excel 2010 so I hope it works.
Gearing_V3.xls

[ac3_snow]

Had my bike on the track in the weekend During the first few laps on saturday morning I almost had to pinch myself, was great punting around on something I had built myself, very satisfying

Bike went very well, after the exhaust vibrated its self in half, huge thanks to chambers for the help mending it! Sunday was a cracker day and the start of a new season in A grade. Two finishes at the back of the pack due to very foolish mistakes. Rest of the time finished around middle of the pack, hopefully can improve on this through the season!

Gearing seemed good, most of the track was spent in third then a quick chop up to 4 and 5 as I came onto the straight. Might put the cbr250 standard front springs in for the next meeting and see how that goes. Also with any luck will have a new pipe mounted properly for the next round. But all in all very happy with the weekend only a few minor issues to work on.

[husaberg]

we found a bit of slop to take out of the cross plate doofer. ............ I was feeling guilty about the mess around the area.Abridged slightly

Slop in the cross plate doofer, I am not in the urology industry, But I hear it happens to some people later in life?

Quote Originally Posted by Bert

I think I posted this before its been converted back from excel 2010 so I hope it works.

Great work,I always did mine with a calculator I like yours sooo much better.

Originally Posted by Wobbly - Jan Thiel found 1 Hp in 50 by covering over the crank wheels as is done by all the Italian 125 kart engines.

Thanks Wobbly
I was just musing that the smaller Dia crank wheels as well as increasing the crank volume may offer a straighter less torturous path for the air fuel mixture in the disk valve gp125 engine.As it would not have to go up over and arround the crankwheel to such a great extent.

[TZ350]

Start of the grandsons F5 bike.

Recycling my old GP125 rolling chassis with a CB100 engine for young Rob to ride in F5.