Track stuff from Finland

[petrolhead]

Note to myself. 27 laps around Pesämäki is 4,5 liters of 98E5 gasoline, 38 laps is ~6,5 liters. Including warming up the thing in the morning, outlaps and inlaps.
With bit less an a liter in the tank works fine.

[petrolhead]

I ordered this, hasn't arrived. Interested in how that changes things.
Thinking of ways to make the thing faster. The more speed I can coax out of it, the further I can delay getting a 600. There's the muffler bracket v. 1.1

[DannoXYZ]

Are you allowed engine upgrades?

Very, very easy to install 300 crank with ZX-6R pistons... Now we're talking 45bhp... Same as Ninja 400... very, very fast... with 150kg bike...

[petrolhead]

Originally Posted by DannoXYZ

Are you allowed engine upgrades?

Very, very easy to install 300 crank with ZX-6R pistons... Now we're talking 45bhp... Same as Ninja 400... very, very fast... with 150kg bike...

Yes, I have some moderate plans for the engine, now I have a spare one to build. Suspension is next, and that will probably cost a pretty penny.
I'm not looking to go crazy with the engine when/if that time comes. I think higher compression ratio and retarding the intake cam could be workable stage 1 solutions. Maybe come up with some sort of header without the H pipe.

[petrolhead]

There it sits. Installation itself is simple enough. The instruction talks about bluetooth connection which I spent a lot of time trying to establish. Until it turned out this is a Wifi model, yay. I finally got it working on the stands.

For future fiddling, the set could lose about 2 metres of wiring if integrated to the bike's harness properly.

[petrolhead]

Originally Posted by DannoXYZ

Are you allowed engine upgrades?

Very, very easy to install 300 crank with ZX-6R pistons... Now we're talking 45bhp... Same as Ninja 400... very, very fast... with 150kg bike...

Just for starters, I haven't even gotten around to delete the cat from the pipe. There could be 0,07 hp there plus more problems with noise limits.

[petrolhead]

Originally Posted by petrolhead

Note to myself. 27 laps around Pesämäki is 4,5 liters of 98E5 gasoline, 38 laps is ~6,5 liters. Including warming up the thing in the morning, outlaps and inlaps.
With bit less an a liter in the tank works fine.

Answering myself. 16 timed laps around Ahvenisto is 4 liters of fuel with outlaps inlaps and warm up plus noise check.

Currently at Ahvenisto track doing setup for the shifter and apparently chasing a ZX-10R.

Once I got the cut time and sensor threshold adjusted, rider reported that the quick shifter improves things. 30% seemed good, bike vibration alone causes 8-10% signal. 95 milliseconds worked, 85ms caused a jerk he told me.

Again, lap time much improved from last time.

Link to original page on YouTube.

[petrolhead]

Recap of the current specs:
- race fairings, DIY foam seat from a camping mattress
-Michelin Power Cup evos(110 & 140), Bstone R11 mediums in storage
-13/47 sprockets (14,15, 43,46,48 in storage)
- ~0,5kg Unibat ULT 1 battery
-1,5kg DIY muffler v 2.0
-0,19kg titanium muffler bracket
-DIY rear sets
-tank grips
-some cheap clip ons with soft Renthal grips
-Front brake Brembo P30/34 caliper, stock disc
-Braking 16mm radial master cylinder
- ~8% quicker throttle
-about 137kg with 3 liters of fuel. Nonessential wiring and most brackets deleted. Kickstand, its bracket and aux parts deleted. Back part of frame cut, replaced with lighter tubing.
-Stock suspension, bit thicker oil in forks.
-Rear wheel pushed as far forward as it can fit.
-Ignition lock deleted
-Replacement engine, supposedly was ridden 9800km when bought.
-Healtech IQSE W quick shifter
-Racechrono pro, Garmin Glo GPS.

[superkain]

We tried to go to Kymiring last year for MotoGP. Bummer it got cancelled, but good to se you are getting after it!

[petrolhead]

Originally Posted by superkain

We tried to go to Kymiring last year for MotoGP. Bummer it got cancelled, but good to se you are getting after it!

Until someone builds 50 million worth of facilities in there, there won't be world championship races.

Rear tyre warmer was suspect. Bit of re wiring and half an hour of sewing, done. Heats up quickly a spare tyre I tested.

[petrolhead]

I bought a used GSXR 600 rear shock. See what happens then that arrives. Wasn't expensive.

[petrolhead]

The service manuals for 250R and 300 list exactly the same degrees, timing and height for both cams. Am I correct to assume they're the same between models?

[petrolhead]

Being the safety-Sally that I am, I noticed that the current suits hip armours were very thin and flimsy. I sewed on thicker ones I had left over from some Alpinestars gear. Rider said they're unnoticeable when riding. Quite a hassle to sew them between the leather and inner lining.

Yesterday we were at Motopark. The shifter wouldn't co-operate. The bike does 157km/h and no more. The track has a 4th gear corner exit followed by 1000 metres flat out. That really reveals small bike's limitations. Most tracks in Finland are twistier.

Camera mount **** the bed so I'm not sure if anything is uploadable. Best time was 2:03 which I think is OK this being his first time there. Mid day I changed 47 to 46T rear sprocket, he was pretty close to limiter in 6th.

[petrolhead]

I just realized I'll have to cut/modify the airbox to make room for the shock.. oh well.

[petrolhead]

Originally Posted by petrolhead

I just realized I'll have to cut/modify the airbox to make room for the shock.. oh well.

I'm contemplating on modifying the upper shock mounting point. Maybe weld shut the holes and re drilling a 10mm holes a bit lower. That would help with the shock being shorter. I don't want to bring it higher by adding preload. Internet tells me both GSXR and 250R springs are about 9kg/cm. The rear is currently too stiff, because of shortened wheel base and a light rider.
Also lowered mounting would lessen the need to cut the airbox. I'm a firm believer in airboxes, plenums and such.

Unedited random clip from Motopark without data. His fastest lap isn't on that video.
https://youtu.be/0MI19IpeTfs

[petrolhead]

Note to myself. The GSXR spring is 213mm , 64mm ID, 87ish mm OD.

[petrolhead]

Does anyone know of a cheap spring for the gixxer shock? K-tech makes them , 64-210-XX but there must be cheaper alternatives than 120€ for a piece of wound steel wire. I'm looking for a ~8kg/mm spring. That'd be about 450lb/in.

20th Aug edit.. We got the shifter working. I'd previously tried to shorten the cut delay which made things worse for some odd reason. Now, I lengthened the delay to 25ms with 110ms cut time and seems to work perfectly. Go figure.

Some shaky footage from today. New personal best lap, which is number 31.
https://youtube.com/watch?v=7QzdP3q1AkI&feature=share9

[petrolhead]

I ended up ordering the K-tech 64-210-80 spring. Once that arrives I'll post some pics of the shock project.

[bruce71198]

I may have just broken my femur watching that video!! Those walls!!!!

[petrolhead]

Originally Posted by bruce71198

I may have just broken my femur watching that video!! Those walls!!!!

Yeah, it's a small track made in an old sand pit. Top speeds are 115km/h so mayde it's not too dangerous. The rider goes his maximum minus some margin. He doesn't need to ride 10/10, not practicing for racing. Still he makes some progress over time.


The shock lower end was a pain in the ass to disassemble without instructions. Took a lot of soaking, hammering and an induction heater to break a part the aluminium piece and spring plate. Difficulty being that they couldn't be removed from between other parts before broken apart. Here rust removed and painted with the first primer and color that were on the shelf.

[petrolhead]

That's all the oil that came out. Surprisingly little?
Different sources recommend different oil so I decided to try this one:

[petrolhead]

A very special tool for filling oil/getting rid of air. A cut bottle with rubber glove fingers as sealing. I rotated the compression valve thing all the way to open position and kept it under oil til I screwed it on. 30Nm tightness. It was less than 25Nm on in the beginning. The shock had 4 bar pressure when I got it. I filled now to 10,5 bar nitrogen, see how that works. GSX-R service manual doesn't give any value for it.

[petrolhead]

I ordered the softer K-tech spring. Been on it's way from England for close to three weeks.

Dont try this at home. I tried to measure how much the new/old spring compress under equal force. Didnt get any intelligible numbers. Seemed like there's not much difference between them.

[petrolhead]

I test fitted the gixxer shock. Found to my surprise that the stock one is shorter. Very little clearance for the spring through swing arm, similar findings anyone?

The airbox needs cutting to fit, hopefully all on the unfiltered size of it.
We've only been on track once this year so far, thanks to finnish spring (=18cm snow fall in end of April).

[petrolhead]

I moved the upper link hole a bit further back to clear everything, and a bit lower to achieve desired height without adding any preload. And I ground the swing arm corners a bit for clearance.

[petrolhead]

Does anyone have suggestions for base line settings on the rear shock? Spring is supposed to be 80kg/cm and the rider is probably 60kg with gear.

[petrolhead]

Anyone ^ ?
I'll then probably go with no preload, compression close to softest and rebound on the softer side of middle setting. When compressing it by hand without spring, feels like the rebound adjustment affects both directions of damping. Anyone with similar findings?

I measured the rear sag with minimal preload, still too stiff but softer than it was with original parts.

Edit. No video but he put in a 39,11 sec lap around our home circuit, kart track. Which makes him faster than me.

[petrolhead]

Quick shifter worked for once without problems, we were at Ahvenisto. Shifter was set to 50 ms delay and 100 ms cutoff time. 3rd 4th and 5th gears are in use there. He rode his personal best, 1:49. Unfortunately the video is too shaky to upload.

The internet was unable to tell me if YSS emulators are good so I'll see for myself. ⅓ of the price of Racetech emulators.

[petrolhead]

Useful info on the emulator install/setup is kinda hard to find. My thinking now is that once the parts arrive I'll measure/calculate the maximum total area of flow in them. Then drill the damper pistons to less than that by some margin. I couldn't find valve spring values for YSS emulators so probably have to take it apart and measure them. I could compare values to other manufacturer's numbers and see if they're in the ballpark.

Shortening the spring spacer pipe by less than the effective height of emulator might be a safe bet.

Thoughts^ ?

[petrolhead]

Shock upper link develops a squeak after each running. I noticed that I'd put in a bolt that juuust reaches the nut enough. I'll replace them.

We were out on track at Akaa. Rear end is now more settled going over asphalt seams while turning. Day ended in a bit of a crash. Foot peg assembly and gear shifting parts fell victim. Fairings not cracked thanks to being glassfiber, some filler and paint will do. The extra length I had left on the handlebars and steering angle limiters meant bar end weight took almost all of damage.

[Mohawk]

I use the YSS Emulators in my X300 running longer modified damper rods, they work great. I've used Racetech in previous bikes & these are just as good, so should suit your needs ��

[petrolhead]

Originally Posted by Mohawk

I use the YSS Emulators in my X300 running longer modified damper rods, they work great. I've used Racetech in previous bikes & these are just as good, so should suit your needs ��

Thanks for your comment. I see no reason why they wouldn't be an improvement, bar serious quality issue.

[sharky nrk]

Originally Posted by petrolhead

Useful info on the emulator install/setup is kinda hard to find. My thinking now is that once the parts arrive I'll measure/calculate the maximum total area of flow in them. Then drill the damper pistons to less than that by some margin. I couldn't find valve spring values for YSS emulators so probably have to take it apart and measure them. I could compare values to other manufacturer's numbers and see if they're in the ballpark.

Shortening the spring spacer pipe by less than the effective height of emulator might be a safe bet.

Thoughts^ ?

yeah, starting point would be just cut the height of the emulator from the spring preload spacer. I am interested in your findings on the quality.

[petrolhead]

Originally Posted by sharky nrk

yeah, starting point would be just cut the height of the emulator from the spring preload spacer. I am interested in your findings on the quality.

My first thought was to leave some margin, then cut more if neccessary. The bike has no preload adjusters up front. Rider has complained couple times about excessive dive under braking. I'm not sure whether I should increase preload or go to stiffer springs.Then again, might be wise to change only one thing at a time to know what affected what.

I came across an interesting thing about shock pistons and valves. Apparently if their mutual contact area is too smooth there's some sticking effect before the oil way opens up.

[engine-hear]

Hello Petrolhead,

I would like to share some infos with you.

Front Fork Ninja 250 (all values in mm)
OEM Modified
FEGV* 0,0 15,0
*FEGV = Fork Emulator Gold Valve
Spring 420,5 420,5
Washer 1,5 1,5
Collar* 100,0 85,0
*Collar is what sharky_nrk calls 'spring preload spacer'
Sum 522,0 522,0
Preload 22,0 ~14,0 with 3 turns (to start with)
If you use Preload-Adjuster take them into account.

Do NOT use 15W Fork-Oil, use 10W or even lower.
Raise the Air gap until you think it's the best for you (start with recommendation)*
*When you put the FEGV into the fork it raises the oil-level by 29mm (measured)
DO NOT FORGET to drill the bigger holes into the damping rod!

Get the following product: https://www.hks-czech.de/produkte/hks-ggv
For: Elimination of the telescopic fork breakaway torque (this works absolute great!)

Lower the front by 10mm and raise the rear also by the 10mm, this makes the cornering easy. But, if you don't like it change the values like you want.

Sag setup (from my bike)
Front: 35mm
Rear: 27mm

My computer crashed 6 years ago, I think I could safe most of my data (but must search for it, since I didn't use them since then).
I have some documents also, but I think I need some posts, before I can insert them.

[sharky nrk]

Originally Posted by petrolhead

My first thought was to leave some margin, then cut more if neccessary. The bike has no preload adjusters up front. Rider has complained couple times about excessive dive under braking. I'm not sure whether I should increase preload or go to stiffer springs.Then again, might be wise to change only one thing at a time to know what affected what.

I came across an interesting thing about shock pistons and valves. Apparently if their mutual contact area is too smooth there's some sticking effect before the oil way opens up.

just for clarity, in general, preload is not used to effect the rate at which the forks pass through their travel, that is for spring rate and in some amount compression damping

preload increases the required force needed on the spring in order to compress it further and as such, adding preload will generally cause the bike to ride higher in the stroke of the suspension but not change the way in which the spring moves once dynamic loading is placed on it

the caveat there is that if you have a great deal of preload on the springs, a large additional force will be required to get the fork to move through its first travel as that preloaded spring force must be overcome

long story short - if the forks are diving excessively but your ride height is good with a reasonable preload then a higher rate spring is the likely the best solution

a bandaid would be to dial in a little more compression damping with the GVE

[petrolhead]

Originally Posted by sharky nrk

just for clarity, in general, preload is not used to effect the rate at which the forks pass through their travel, that is for spring rate and in some amount compression damping

preload increases the required force needed on the spring in order to compress it further and as such, adding preload will generally cause the bike to ride higher in the stroke of the suspension but not change the way in which the spring moves once dynamic loading is placed on it

the caveat there is that if you have a great deal of preload on the springs, a large additional force will be required to get the fork to move through its first travel as that preloaded spring force must be overcome

long story short - if the forks are diving excessively but your ride height is good with a reasonable preload then a higher rate spring is the likely the best solution

a bandaid would be to dial in a little more compression damping with the GVE

Thanks for your comment, made me think about stuff. The bike could do with perhaps less static and rider sag up front so that's one reason to increase preload a bit. If you increase preload by x mm the forks will be x mm less compressed during braking am I right? That'd make the rider happier. But you're right, if stiffer springs are needed then they should be used. Increasing compression damping is not the correct solution. For grip, I understand that it's ideal to have as little compression damping as reasonable and stiffer rebound. To allow the suspension to do what it's there for.

Emulator package is going round Europe in a circle if parcel tracking is to be believed.
Next on the work list is to repair the foot peg assembly mounting points then bolt on new parts that arrived. I'm aiming to repair the crashed old parts and put together an "emergency back-up" set if similar crash occurs. After that, replace the worn Power Cups with Bridgestone R11 mediums.

[petrolhead]

Not going to win any prizes for the weld or paint finish, but two M8 nuts welded to the frame. Not exactly worried about resale value with this bike.

[petrolhead]

Potential problem with the emulators. Many websites list the YSS 335 to be a fit. However the diameter of them is.. 33,5mm according to couple sources. They haven't arrived yet. Ninja's fork tube ID is somewhere around 32,5mm. Whoop de fukking doo.

[petrolhead]

Always to nice put on soft fresh(er) tyres. I changed the brake fluid and the lever pretty much bottoms out now. Zero chance of air in the system before anyone asks. It's just that the pad range of movement is really small with solid calipers, takes lot of effort , pumping and stuff to get the pistons out and pads close to brake disc. Happened before also. Can't remember how I solved it back then.

Emulators arrived and yes they are 33,5mm. Got to return them and I guess try my luck with 310 items.