Track stuff from Finland

[petrolhead]

Hi
A few videos of a 2009 Ninja 250R on different tracks and some other stuff.
https://m.youtube.com/channel/UCulqQK67M8oGiBvtr8-EoIg
The bike has:
- race fairings
-Bridgestone S22 tyres (110 & 140)
-13/47 sprockets
- lighter battery
-lighter DIY muffler
-DIY rear sets
-some cheap clip ons with soft Renthal grips
-Front brake Brembo P30/34 caliper, stock disc
-Braking 16mm radial master cylinder
-all sorts off zero-bugdet weight savings here and there.
The fairings let me mount the clip ons low enough and helped with ground clearance. Kick stand was also deleted for clearance early on. Braking feel was much improved and required force reduced with upgrades. Not a firm believer in braided hoses so I used the old brake line, nothing wrong with that.

I'm on instagram as petrolheadjj, some bike related pics there.

[petrolhead]

I repaired the forks this spring (leaks), and replaced the oil with 15W instead of the 10W recommended by shop manual. Otherwise the suspension is stock. It's mainly ridden by a 50kg person so it's not too soft.
The seat foam I cut from an old camping mattress. My son seems happy with the bike, which is the point of the whole exercise.

[petrolhead]

According to Racechrono data, he was doing 47° of lean on your hometrack, so I had to do this. In spite of the bike being at normal height and the pegs being raised by ~4cm. I had the bike lowered by quite a bit when he was starting out.
I have to say I'm impressed with the tyres. We do use tyre warmers but still, they're good for a street tyre. The edges are without grooves and softer compound.

[CaliGrrl]

Welcome to Ninjette! That's a sharp looking bike.

[petrolhead]

Thanks.
It's an ongoing project. We have winter twice a year where I live, so that leaves time for wrenching.
I cut, bent and glued some aluminium heat shield on the bottom cowl and added some alu tape. All surplus stuff . Come winter I'll take the fairings, tank and mud guard to a friend for paint.

[petrolhead]

Does anyone have experience with DIY-mufflers? The bike currently has one, made by me. It's a bit over 2 kilos at the moment. It gained some weight when I added some extra baffles and a dB-killer to get to my desired noise level. I'm not 100% sure anymore that it's nonrestrictive enough because of those parts added as an afterthought.
I have a new design in mind that would weigh 1600-1800g by my calculations. It'd have 2x26mm OD outlets. I'd anyway appreciate anyone's experiences with silencers. The noise limit for this bike at the closest big track is <95dB @4500rpm.

[DannoXYZ]

Greetings & Salutations!!! Welcome to Ninjette!!!

Mufflers don't do much on this bike for performance other than weight-savings. It's headers that make biggest gains; Tyga has highest power with their full-exhaust.

For mufflers, I played around with several aftermarket versions and modified their innards. What works best for noise-reduction with straight-through design is to have larger outer canister. When exhaust enters muffler, it expands through perforations. The more the expansion, more pulse-pressure variations are absorbed. Expansion also cools exhaust and shrinks volume. This draws flow back into centre core in 2nd-half of muffler and out rear. Also fill gap between inner core and outer chamber with fibreglass or stainless wool packing material.

I would try larger outer canister with thin wall-thickness. Aluminium or CF would give maximum weight-savings. The larger Tyga muffler was definitely quieter than smaller el-cheapo muffler I got from Ali. Smaller Ali muffler weighed 1390gm while Tyga with my Laguna Seca elbow weighs 1620gm.

Some photos and discussions here:
https://www.ninjette.org/forums/showthread.php?t=307767
https://www.ninjette.org/forums/showthread.php?t=338180

Good articles:
http://www.vaglinks.com/Docs/Misc/Mu...t_Section3.pdf
https://www.researchgate.net/publica..._vehicle_Noise


Might also consider cutting off kickstand bracket. At some point it will dig into ground and cause crashes. Great job on bike, your son is so lucky!

[petrolhead]

Hi
Yeah, not expecting to gain hp over stock by playing with silencers. Objective is just low weight, desired noise level and non-restrictiveness. I'm always skeptical about gains from dicking around with exhausts, be it car truck or a bike. Same with air filters. That being said, the bike had a loud straight thru muffler, and it felt punchier than with stock.
I did hack off the kickstand bracket early on. If memory serves it would interfere with those fairings anyway.
Thanks for the tips and kind words. My son's only request with bike mods is always "make it lighter". It's an OK bike to thrash around and practice.

[DannoXYZ]

You can gain +20% power with Tyga exhaust and DynoJet kit to lean out high-end mixtures. This has been dyno-tested and proven by numerous racers over decades. Makes my bike slightly faster than Ninja 300.

There's numerous no-budget mods I've done to shave weight:

- trim fairing-stay bracket to minimum, just 2-arms to hold upper-fairing, remove all wiring brackets, ~1.5-2kg
- remove factory dash, I used Trailtech Vapour, but Koso RX2N clones are great values
- cut off tail of rear subframe after rear seat mounts, ~4kg
- minimal wiring harness, no extra relays, wiring or unnecessary diodes, ~1.1kg

Here is what's left:


Pieces removed:


Major weight-savings require replacing heavy factory parts like handlebars & electronic controls, wheels, rearsets, etc. My bike's down to 129kg from factory 170kg. Could probably remove another 2-3kg by chopping off all unnecessary tabs and brackets on frame. I've got list of mods somewhere. I'll post it when I find it.

Next significant amounts of weight savings would be to replace largest solid fasteners with titanium versions such as F&R wheel-axles, shock-mount and linkage bolts, dog-bones, brake-mounting bolts, engine-mounting bolts, sprocket-carrier studs & nuts, etc. Another 5-6kg there. Honda uses lots of hollow chromoly bolts on their race-oriented bikes that's comparable to titanium. I might just visit Honda dealer and go through their parts bin.

https://racetechtitanium.com/
https://store.mettec.com/category/238
https://titanclassics.com/
https://www.ti64.com/

as usual, ALOC!

[petrolhead]

Yea I'm all for zero budget DIY stuff. I havent used titanium fasteners in any of my builds. Certain bolts and nuts need to be replaced because they strecth, so that'd be an expensive exercise.
Cutting off the excess length of bolts saves a meaningful amount of weight.
The battery we have at the moment is Unibat ULT2 (0,9kg). Changing that to a ULT1 would save 0,4kg. The ULT2 is big enough to start a 1000cc V4. I updated the first post.

[petrolhead]

Decent riding gear need not be expensive.
Second hand Alpinestars Supertech boots 25€
A stars GP Pro R3 gloves off ebay, once worn.
New Berik suit which has the all important hump.
HJC helmet.
A-stars lv2 back protector w/chest armour which was 60% off.

[DannoXYZ]

Awesome deals!

My wife, the expert shopper, found backup 2nd suit, boots and gloves for next to nothing!

[petrolhead]

Originally Posted by DannoXYZ

Greetings & Salutations!!! Welcome to Ninjette!!!

Mufflers don't do much on this bike for performance other than weight-savings. It's headers that make biggest gains; Tyga has highest power with their full-exhaust.

For mufflers, I played around with several aftermarket versions and modified their innards. What works best for noise-reduction with straight-through design is to have larger outer canister. When exhaust enters muffler, it expands through perforations. The more the expansion, more pulse-pressure variations are absorbed. Expansion also cools exhaust and shrinks volume. This draws flow back into centre core in 2nd-half of muffler and out rear. Also fill gap between inner core and outer chamber with fibreglass or stainless wool packing material.

I would try larger outer canister with thin wall-thickness. Aluminium or CF would give maximum weight-savings. The larger Tyga muffler was definitely quieter than smaller el-cheapo muffler I got from Ali. Smaller Ali muffler weighed 1390gm while Tyga with my Laguna Seca elbow weighs 1620gm.

Some photos and discussions here:
https://www.ninjette.org/forums/showthread.php?t=307767
https://www.ninjette.org/forums/showthread.php?t=338180

Good articles:
http://www.vaglinks.com/Docs/Misc/Mu...t_Section3.pdf
https://www.researchgate.net/publica..._vehicle_Noise


Might also consider cutting off kickstand bracket. At some point it will dig into ground and cause crashes. Great job on bike, your son is so lucky!

No need for jet kits, it's a fuel injected engine.
I'm making the silencer from 0,75mm steel. Bends easily, cheap, reasonably light and I can weld it. Inside piping is 0,9mm wall thickness 25mm pipes.
I was thinking of a section with hole pipes inside wool, then a 15cm chamber then a closed chamber with 2x26mm pipes going thru and to the exit.
edit. Unibat ULT1 is on order. Someone actually bought the previous ULT from me for 35€ .

[DannoXYZ]

FI is even better! Those were able to gain an extra +5bhp over carb bikes for +11bhp over stock! That's close to +30% and definitely faster than Ninja 300!

[petrolhead]

I checked the factory repair manual. Apparently the stock exhaust has a cat in the collector. Replacing that with a smooth non cat item.. I guess that might help power.
The bike weighs ~143kg with fuel enough for one stint.

Where possible, I use nylon bolts. Cheap and light.

[petrolhead]

This arrived. Still waiting for a second hand gear display to arrive. No clue whether it'll work on a Ninja but hey, 10€ incl. postage. Wife's kitchen scale says 539 grams.

[DannoXYZ]

Wow, where did you buy for that price? I want 10 of them!!!

Amazing light thing huh? I had one on my race bike for 3-yrs without any problems. Then I transferred it to my street-bike and accidentally left headlights on when I went to check mail. Talked to neighbor for a bit and when I got back, it was dead, kaput! Good thing race-bikes don't have headlights!

[petrolhead]

The gear display was 10€. The battery was 71€ w/ postage, from Carpimoto.
Making the new silencer. Probably won't be pretty but perhaps functional. The muffler body will be matte black.

[petrolhead]

I declare it wintertime. If you look closely you can spot a DIY coolant expansion tank I did way back. Saved a little bit of weight.

Some smithing going on with the new silencer. I found some age old heat resistant matte black spray paint, so..

[petrolhead]

Almost exactly 0,5kg lighter than the previous contraption.

[petrolhead]

Expertly drawn 😁 layout of the silencer if anyone's interested. Brown is wool.

[DannoXYZ]

Originally Posted by petrolhead

Expertly drawn �� layout of the silencer if anyone's interested. Brown is wool.

That's pretty awesome, thank you!

[petrolhead]

I started stripping useless stuff off of the wiring harness.
Takes quite a bit of work per gram saved, even with a wiring diagram to work with.

[DannoXYZ]

Yeah, took me about 3-hrs. Be sure to test harness often to make sure it still works. At some point, you actually have to bridge ground wires when removing interlock switches and diodes.

I think if I was to do it again, I would just build new harness from scratch with thinner-gauge wires and much, much smaller connectors. Here's diagram someone developed for using pre-gen engine in kart.



I actually completely removed ignition-switch and right-hand controls to replace with one of these. I bypassed starter-relay and triggered starter-solenoid directly from switch. Was worried that higher-current needed may fry switch, but it's been 4-yrs and it's held up just fine.

[petrolhead]

I think this thing already has pretty thin wires. I'm not too ambitious with the harness, just removing what I reasonably can.
You are right, a loom made from scratch would be lightest. I lack the pin tools etc for a Kawasaki.
I copypasted the wiring diagram to Paint and started making a colored version of it. My eyes hurt when trying to follow the black and white version.

[DannoXYZ]

Yeah, I like to print out on 11x17" paper and colour lines with marker.

[petrolhead]

I contemplated on cutting the last 20-30 cm off of the bike frame. I looked at it and my reasoning that'd do nothing to it's stiffness. At the very least the pillion seat bracket etc small brackets are useless. All that needs to remain are mounting points for the rear fairing and "mud guard", ie. the black plastic thing supporting battery and ECU. Not exactly worried about the bike's resale value.

Ofcourse you could go crazy with the wiring harness, do it from scratch and use aluminium wiring for weight. Right now I'm doing what I can with little cost and reasonable effort.

Wiring removed with two airbox pipes I deemed unneccessary:

[petrolhead]

https://youtu.be/3wgy3O0KZ8g
I'm calling the muffler a success. 0,5kg saved and not too loud. Also I apparently did not mess up with stripping the wiring harness since everything works.

[DannoXYZ]

That turned out great! Aside from noise regulations, I really don't like loud bikes, gives me headache after day at track.

Here's where I chopped mine, just 2-3cm after seat-mounting bracket.



Piece that came off was about 2-3kg, I don't quite remember.

[petrolhead]

That's the chunk of metal I was eyeing. Something needs to replce that to mount the fairing and mud guard to. Also the front piece where the instrument cluster mounts to, can take some chopping.
I don't like too loud cars or bikes either. If you go fast enough, you can't spare any attention to the sound quality anyway.

I measured the holes of the airbox inlet pipe, 12x29mm. My calculator says that's equal cross sectional area to two 21mm throttles. So yes, its possible it's a restriction.

[petrolhead]

Every bit counts. The bike's been ridden for 2 seasons with a faulty blower motor fuse, anyway.

[DannoXYZ]

woohoo!!

[petrolhead]

DIY foam seat v 2.0. I doubled the the thickness to account for a rider who is now taller. I calculate that the bike has lost ~2,5 kg over the winter.
The silencer mounting bracket/passenger foot peg bracket lightened by 0,25kg. So, winter weight loss totals ~2,8kg now.

[petrolhead]

First ride feedback was that the bike is quick to lean. I'm not sure if this is down to the weight savings or the fact that the rider is now taller and stronger. Anyway everything seems to still work despite all the fiddling about.
I'm betting the total winter weight drop is bit over 3kgs, there's some stuff not listed above. Like the front mudguard bracket, which I drilled to swiss cheese and bits like that.

Spring is late this year in Finland. Last year we started the season way earlier.

[DannoXYZ]

Coming along nicely! Are those factory bar-end weights? I replaced them with plastic plugs. Saved about 1kg.

[jkv45]

Originally Posted by DannoXYZ

(SNIP)

There's numerous no-budget mods I've done to shave weight:

- trim fairing-stay bracket to minimum, just 2-arms to hold upper-fairing, remove all wiring brackets, ~1.5-2kg
- remove factory dash, I used Trailtech Vapour, but Koso RX2N clones are great values
- cut off tail of rear subframe after rear seat mounts, ~4kg
- minimal wiring harness, no extra relays, wiring or unnecessary diodes, ~1.1kg

(SNIP)

Major weight-savings require replacing heavy factory parts like handlebars & electronic controls, wheels, rearsets, etc. My bike's down to 129kg from factory 170kg. Could probably remove another 2-3kg by chopping off all unnecessary tabs and brackets on frame. I've got list of mods somewhere. I'll post it when I find it.

Next significant amounts of weight savings would be to replace largest solid fasteners with titanium versions such as F&R wheel-axles, shock-mount and linkage bolts, dog-bones, brake-mounting bolts, engine-mounting bolts, sprocket-carrier studs & nuts, etc. Another 5-6kg there. Honda uses lots of hollow chromoly bolts on their race-oriented bikes that's comparable to titanium. I might just visit Honda dealer and go through their parts bin.

https://racetechtitanium.com/
https://store.mettec.com/category/238
https://titanclassics.com/
https://www.ti64.com/

as usual, ALOC!

My son is doing most that to his new Ninja 400 race bike to shave some weight. Also new slipper clutch, Ohlins cartridges and shock, ECU flash, and on and on...

Hey Danno - are you going to be racing anywhere in Cali this year? You may run into him.

[petrolhead]

Originally Posted by DannoXYZ

Coming along nicely! Are those factory bar-end weights? I replaced them with plastic plugs. Saved about 1kg.

I'm not sure ditching bar end weights is safe. The bike currently has only the one. The other is at some track's run off area, MIA.
They have already served as crash bars during couple of oops-moments.

[petrolhead]

Has anyone fabricated a radiator cowl to their bike? With the race fairings, the radiator is exposed on all sides. There's nothing to direct the airflow /force it through the radiator. I don't remember how it was with stock bodywork. My building experience is with cars. In cars atleast, the improvement to cooling is meaningful with some sort of cowls. Better yet if they're are tightly on the radiator edges.

[DannoXYZ]

On stock bodywork, there are inner pieces under fairings that seal gap around radiator. On my race-bike, I have gaps. Even with removing fan, I haven't had overheating issues, even on +45C days @ track. Just have to make sure not to run at low-speeds for very long.

[petrolhead]

Thanks, that experience is actual useful info.
I think a radiator fan has no place on a track machine. The air stream while at speed pushes 50x more air thru the radiator than any a fan so it's meaningless while at speed.

I was surprised how dark the brake fluid had gone in ~13 months. I changed it along with motor oil and coolant, can't hurt.