4t tuning thread

[richban]

your bike looks the part Rich, and cheers for the brew.

though about this a bit more last night, not the most exciting evening in welly...

what about a supertrap like baffle system?
I know we had a lot of success with a similar design to quieten down a speedway chair, years ago...

a few disks and you could be away laughing???

http://www.supertrapp.com/technology/index.asp

as discussed,
silencer application: (ok designed for twostrokes but must have some uses) second to last download on this page:
http://www.mh-aerotools.de/airfoils/software.htm
audio spectrum software:
http://www.trueaudio.com/rta_abt1.htm (free) and a $5 microphone for Jcar. could also work as a knock sensor for tuning your CDI??
If you know what your main driving frequency is, then you could gain a lot more with your slit concept..
I think I've posted this up before somewhere......?


Cheers Bro

For some reason I hate supertraps it might just be the way they look but that is enough for me. I think cutting a couple more slits in the end shroud might do it. I've been told with megas you really don't want to reduce the end diameter unless the dyno tells you to. I will bodge up some reducers for testing.

Not even sure I will have enough time to setup the ignition. New engine is going to take a while.

[Bert]

Carbs for a 150 four strokes?
just looking at putting an order in and bring out a a few extras. so what size would suit the standard lonchins?? 28-30-32?

[fi5hy]

any more than 28 and your cheating:yes::yes::shit:

[richban]

Carbs for a 150 four strokes?
just looking at putting an order in and bring out a a few extras. so what size would suit the standard lonchins?? 28-30-32?

I recon the 28 for a 2 valve 150 and the 30 for a 4 valve engine. Running a 30 on my FXR and it is mint totally out performs my old 28 mikuni. They are a little brittle but work very well.

[richban]

New Wheels
Well new wheel. Front RS goes straight on just need to take a bit of the rotor and make one spacer. Rear is not such a big issue but a little more dicking around should have that sorted in the next week or so. The new engine is almost ready so time to re think exhaust and intake. What ever happens a new light muffler is in order. Going to try a slightly bigger header. And a new mega. Also looking at a brace for the front and a swing arm improvement. Quite keen to stay with the FXR and not go to another frame. Even though I have a very good option in the shed now. Got rid of the RGV and replaced it with the RS. The weight savings and power should be a big improvement and will hopefully help fend of the 2 strokes that are being developed all over the country. Now all we need are some races to compete in.



pics240052240051240050240049240048240047

[TZ350]

So you have a Team Works Mechanic helping with engine development.................

[richban]

So you have a Team Works Mechanic helping with engine development.................

Yep two actually. One has already designed the paint scheme for the RS. Orange silver and black apparently. I'm cool with that.

[F5 Dave]

Very nice er the RS. Was having a nosey at Dr Bobs a week or 3 back.

[richban]

Very nice er the RS. Was having a nosey at Dr Bobs a week or 3 back.

Yeh I could not resist. You don't see many those for sale in NZ. Bit of a work of art. Good lessons to learn from studying the frame and setup.

[koba]

Yeh I could not resist. You don't see many those for sale in NZ. Bit of a work of art. Good lessons to learn from studying the frame and setup.

Probably the bes bike I've ridden. :tugger:

[richban]

Probably the bes bike I've ridden. :tugger:

The other night after having a quite chat with the bike. It told me to save up my dollars and buy it a nice KTM 450 6 speed, and oh so gently make it fit. Then race it like it was born to do. Just the little problem of the 4k I need to do the job.

[koba]

The other night after having a quite chat with the bike. It told me to save up my dollars and buy it a nice KTM 450 6 speed, and oh so gently make it fit. Then race it like it was born to do. Just the little problem of the 4k I need to do the job.

Yum. <tencharacterers>

[Ivan]

no thats the pidgeon english it speaks!

it said copy my frame make your own version based of my geomtry put a KTM motor in! and said put a original motor back in me as I am going to be worth a shit load of moeny in a few years time since 250gp is now dead.

And the fact as a 250GP bike I am much faster and will be alot cooler to ride than what a KTM engine will ever be, and that the KTM really deserves to be in a 125gp style frame

[richban]

no thats the pidgeon english it speaks!

it said copy my frame make your own version based of my geomtry put a KTM motor in! and said put a original motor back in me as I am going to be worth a shit load of moeny in a few years time since 250gp is now dead.

And the fact as a 250GP bike I am much faster and will be alot cooler to ride than what a KTM engine will ever be, and that the KTM really deserves to be in a 125gp style frame

I see. That could have been what it was saying. It would be a shit load easier. If I had and engine.

[richban]

Well its taken a while but the new engine is now fixed and in the bike. Just took it for a spin up the road and she rips. Engine its self has lost 3kg with ditching balance shaft and lighting the shit out of the crank and flywheel. It rev's up hard and has plenty more toque. Also new wheels are nearly on just waiting for some sprockets and RS cush drive rubbers. Running the RS250 rear break made up a little spacer that holds it all together will make for easy wheel changes. Should all be done by BOB. Some pis below. Bike is more born again than a birthday. Born again faster and lighter.

244353244354244355244356244357244358

[Kendog]

Very nice.
Love the engine weigh in photo, very 'Biggest looser'

[F5 Dave]

25kg?. I think that's what my whole 50 weighs.

[koba]

25kg?. I think that's what my whole 50 weighs.

With or without fuel? :laugh:

[F5 Dave]

And depending on Tyre pressure. More air I add the lighter it gets dontchaknow.:yes:

[speedpro]

Some VERY interesting stuff in here, EFI kits, throttle bodies, turbos.

http://www.mbe-motorsports.com/catalog/index.php/cPath/21

[Moooools]

I have seen that site before. They offer slightly to little info on products to really commit to it, but it would be interesting to have a crack at a fuel injection conversion.

[richban]

Some VERY interesting stuff in here, EFI kits, throttle bodies, turbos.

http://www.mbe-motorsports.com/catalog/index.php/cPath/21

Hummmm Turbo charged, fuel injected 100. Not sure if you would get enough power with the 20mm throttle body. Will consult someone that knows.

[Moooools]

Hummmm Turbo charged, fuel injected 100. Not sure if you would get enough power with the 20mm throttle body. Will consult someone that knows.

They offer right up to a 35mm throttle body.

[richban]

They offer right up to a 35mm throttle body.

F5 rules = 20mm.

[Henk]

F5 rules = 20mm.

F4 for a turboed 100. But no carb restriction.

[richban]

F4 for a turboed 100. But no carb restriction.

Really must read them again.

[richban]

Really must read them again.

And you are right of course. Well that changes the game a little. So you could sleeve down, de stroke an FXR and wack a turbo on it. It would still need to be making 300hp per litre to be top of the heap. Coz for all the fecking around you would want it to rule the track.

Must consult the oracle. Back soon.

[richban]

Must consult the oracle. Back soon.

Apparently all you need is about 6K and you would have a lot of grunt.
Fuel Injection, Computers, Petrol tank pumps, Turbo, Water injection system. Very strong engine casings. One day maybe.

[Kickaha]

F1 qualifying engines used to run something like 75-100psi of boost and get around 1200-1500hp from 1500cc in qualifying trim (depending on who you want to believe)so no reason why you shouldn't be able to get 100hp from your 100cc engine :whistle:

[speedpro]

The engine is made, have an IHI RB31, have the Haltech ECU. Missing was all the suitable fuel system stuff. Now I know where to get it.

244913

[gav]

The engine is made, have an IHI RB31, have the Haltech ECU. Missing was all the suitable fuel system stuff. Now I know where to get it.

244913

:corn: :corn:

[Moooools]

Great plan sir. Now do it quickly so we don't have to wait to see what happens.

[richban]

The engine is made, have an IHI RB31, have the Haltech ECU. Missing was all the suitable fuel system stuff. Now I know where to get it.

244913

No fecken way. Well done that man. Kev was saying it would be a good idea to use a bigger engine like what you have done. Also said they are getting 1400hp out of a 2l honda engine with 50lb of boost. So 70hp is possible if it holds together.

Go for it. Look forward to seeing it on the track. For a 1/2 second each time I am lapped.

[speedpro]

For a 1/2 second each time I am lapped.

We've been through this before :no:

[F5 Dave]

Now all you need is the sidecar class to be rebirthed so you have something to put it in.

Onlookers will note the 2005 stamp on the photo. When I first saw this engine it was a collection of bits probably a couple of years before.

However I'm only just attempting to get my 15year MB100RS to the track so I won't cast too big of a stone.:confused:

[richban]

We've been through this before :no:

True. Well I like the turbo concept. The cool thing is that you can use a water cooled engine. For a bit I thought you had to stay air cooled. Re read the rules and no cooling restriction is mentioned.

All I need is the engine and we are all go. Cut down v twin maybe. That way when it explodes the cylinder dead will just take out the front wheel not the tank and rider.

[TZ350]

True. Well I like the turbo concept.......

A supercharger driven by a slave engine........ we are working on one now.

[TZ350]

Actually when I think about it you could have a turbocharger driven by a slave engine.

The slave could be running hard out all the time driving the turbo, that way there would be no turbo lag when changing gear on the prime mover, constant manifold pressure all the time.

[Moooools]

True. Well I like the turbo concept. The cool thing is that you can use a water cooled engine. For a bit I thought you had to stay air cooled. Re read the rules and no cooling restriction is mentioned.

All I need is the engine and we are all go. Cut down v twin maybe. That way when it explodes the cylinder dead will just take out the front wheel not the tank and rider.

Vt 250 cut down and sleeved down.
I may just try that with my sidecar after I have spent some time riding it, if I ever finish it that is. Maybe I should try and get it done by the welly north island round. Fill in the gaps in racing...

[Yow Ling]

I have repaired a few FXR cranks. Seems there are 2 common failures.
Stiffies, where the bigend cage fails and the crank grinds to a halt, usually feels like fuel starvation or some tuning problem, then it siezes.

Then the less common but far more spectacular FXRmageddon, seem to happen at full noise, no warning just crunch. Seems to fuck the whole motor, hole through the top cases, sometimes the bottom, rod snaps in half, gear shafts bend. Sound familiar?

245207

[Kickaha]

I have repaired a few FXR cranks. Seems there are 2 common failures.
Stiffies, where the bigend cage fails and the crank grinds to a halt, usually feels like fuel starvation or some tuning problem, then it siezes.

Then the less common but far more spectacular FXRmageddon, seem to happen at full noise, no warning just crunch. Seems to fuck the whole motor, hole through the top cases, sometimes the bottom, rod snaps in half, gear shafts bend. Sound familiar?


How many of those have you had now?

I had a type 1 which highsided me and got me run over on the Bren Bike

[Yow Ling]

How many of those have you had now?

I had a type 1 which highsided me and got me run over on the Bren Bike

Thats not my rod, I had one like that on my bike and repaired 3 others, sometimes the crankwebs are pretty ugly, not ones you would do on exchange.

Oh yea there is a 3rd kind of failure, when people remove the balance shaft and decide that the bearings are too hard to remove, they not going anywhere. Seems they do go somewhere, snapped rod and hole in front of motor

[kel]

Then the less common but far more spectacular FXRmageddon, seem to happen at full noise, no warning just crunch. Seems to fuck the whole motor, hole through the top cases, sometimes the bottom, rod snaps in half, gear shafts bend. Sound familiar?

So while I’m yet to witness the coming of Gog and Magog I do find myself living in fear of the FXRmageddon. While playing with cam timing I thought I had given the thing too much advance as it would hit a wall at about 10.5 to 11k rpm, set the timing back to standard but the problem is still there. This isn’t like the soft rev limiter the bike has at 12.5k which is kind of a machine gunning effect (if you hit it you know what I mean), it’s more of a hard limiter but the motor doesn’t seem to cut out electrically rather the power gives up and a hideous change of noise takes place almost like a bark (probably a better way to explain). Changed the rectifier and the CDI checked all the wiring and connections yet the problem is still there. Anyone else experienced this? Any help would be greatly appreciated. Cheers.

[Buckets4Me]

Any help would be greatly appreciated. Cheers.

get a 2 stroke :laugh::wings::drinknsin

[Yow Ling]

So while I’m yet to witness the coming of Gog and Magog I do find myself living in fear of the FXRmageddon. While playing with cam timing I thought I had given the thing too much advance as it would hit a wall at about 10.5 to 11k rpm, set the timing back to standard but the problem is still there. This isn’t like the soft rev limiter the bike has at 12.5k which is kind of a machine gunning effect (if you hit it you know what I mean), it’s more of a hard limiter but the motor doesn’t seem to cut out electrically rather the power gives up and a hideous change of noise takes place almost like a bark (probably a better way to explain). Changed the rectifier and the CDI checked all the wiring and connections yet the problem is still there. Anyone else experienced this? Any help would be greatly appreciated. Cheers.

Not much goes wrong with them except big ends and a few bent valves, has it ever had a new big end? They go weird before they die

[speedpro]

They "start" out weird, silly 4-stroke things

[F5 Dave]

in every 4 stroke is two 2 strokes trying to get out.:mellow:

[kel]

I have to admit to enjoying the banter but Im afraid the original question might get lost.

While playing with cam timing I thought I had given the thing too much advance as it would hit a wall at about 10.5 to 11k rpm, set the timing back to standard but the problem is still there. This isn’t like the soft rev limiter the bike has at 12.5k which is kind of a machine gunning effect (if you hit it you know what I mean), it’s more of a hard limiter but the motor doesn’t seem to cut out electrically rather the power gives up and a hideous change of noise takes place almost like a bark (edit: actually its better described as a cough). Changed the rectifier and the CDI checked all the wiring and connections yet the problem is still there. Anyone else experienced this? Any help would be greatly appreciated. Cheers.

[richban]

I have to admit to enjoying the banter but Im afraid the original question might get lost.

While playing with cam timing I thought I had given the thing too much advance as it would hit a wall at about 10.5 to 11k rpm, set the timing back to standard but the problem is still there. This isn’t like the soft rev limiter the bike has at 12.5k which is kind of a machine gunning effect (if you hit it you know what I mean), it’s more of a hard limiter but the motor doesn’t seem to cut out electrically rather the power gives up and a hideous change of noise takes place almost like a bark (edit: actually its better described as a cough). Changed the rectifier and the CDI checked all the wiring and connections yet the problem is still there. Anyone else experienced this? Any help would be greatly appreciated. Cheers.

Was it going ok before you played with the timing?

[kel]

Was it going ok before you played with the timing?

Pretty much, it used to suffer from the odd miss but I think that was due to not enough fuel in the tank as it never seemed to happen if I ran a higher level.

[Yow Ling]

I spoke to Brendan about this today, he had a similar problem with 1 bike and a new stator sorted it out. do you run a battery or capacitor?

[richban]

Pretty much, it used to suffer from the odd miss but I think that was due to not enough fuel in the tank as it never seemed to happen if I ran a higher level.

No clue what so ever. Never come across a problem like that.

[kel]

I spoke to Brendan about this today, he had a similar problem with 1 bike and a new stator sorted it out. do you run a battery or capacitor?

Neither a battery or capacitor.
Was thinking stator could possibly be the problem, will find a battery and give it a try.
Cheers.

[bucketracer]

If your still having problems Team ESE have an old oscilloscope you could borrow to check the AC wave form out of the stator and also from the rectifier to see how DC that really is.

[husaberg]

I have repaired a few FXR cranks. Seems there are 2 common failures.
Stiffies, where the bigend cage fails and the crank grinds to a halt, usually feels like fuel starvation or some tuning problem, then it siezes.

Then the less common but far more spectacular FXRmageddon, seem to happen at full noise, no warning just crunch. Seems to fuck the whole motor, hole through the top cases, sometimes the bottom, rod snaps in half, gear shafts bend. Sound familiar?

245207

From What I have seen the Honda 125/200 rod could be adapted to fit they (The Honda) used to Seize/snap at the top but that was a problem that could be solve by a bronze bush.Of course there are yamaha rods 200 and 225 in slighly shorter lengths with 16mm pins as well as the ktm250 but they have short rods.the Honda rods to suit are available from Carillo. mmm....mmm.shiney bits

[kel]

Im off to India, which happens to be the home of the YZF-R15. Will be looking out for motors as I figure there will be plenty of write-offs knowing Indian traffic and driving technique (lack of). If anyones interested send me a PM and Ill keep you posted with what I find.
Kel

[gav]

India is also the home of the KTM 125 Duke built by Bajaj. Looks pretty cool.

[richban]

246470
India is also the home of the KTM 125 Duke built by Bajaj. Looks pretty cool.

Made little bike. Must look at the engine more.

[richban]

Ok so been doing a bit of work on my old engine trying to make it work better. I changed the carb angel to get a more straight draft into the engine and that caused a little problem with the intake being to short. After a little search on the web I found a great little tip on making you own bell mouths. PVC pipe. I just heated it and pushed it over a small old bell-mouth and cut it to length. Worked a treat. Then ran it into a nice still air box. I had been meaning to sort a proper air box for ages and will never go back to open or slightly open carbs again. Makes jetting your bike very predictable. This is not a calculated plenum but just a big volume airbox with more than double the intake area of the carb. Keeps the shit out of the engine as well as drawing nice cool air. Cool air = more power its that simple. What is the correct intake length well here is a basic calculator to get it close. Cams and exhaust will have to match this to make it work proper of course.

I am buy no means an expert in anything to do with engine building but I have noticed what seams to work and what doesn't. Also the engine that I have been doing this on is now almost 3 years old and the same internally as the day it was build but keeps making better power with more development. It will be getting pulled down soon as I think is deserves a birthday.

http://www.bgsoflex.com/intakeln.html

I will post some pics of the PVC bell mouths tomorrow.

[timg]

Another one here http://www.velocity-of-sound.com/velocity_of_sound/calculator2.htm with a few more variables to suit your engine specs Cheers.

[Yow Ling]

Where do you measure the runner length from and to?

From the back of the valve ?

In general what effect does does the bellmouth velocity thing have on existing jetting?

[kel]

We did a whole heap of dyno runs with different length intake runners attached to the Kehin flat slide, the best result was with no bellmouth at all, the FXR/Keihin setup doesnt seem to like flared bellmouths. The intake length seemed to be best at approximately 175mm measured from the back of the valve but that maybe specific to our cams? The longer the intake length the earlier you produce peak torque (its not quite that simple but will do when considering the bikes space constraints) so less peak hp. I also run the airbox with no lid (wouldnt run with the lid on), the idea being to limit the crap the carb can suck in, not sure if it helped clean up the jetting or not? Was interesting to see Andrew Adlam runs the old Mikuni pumper I use to have, its a good carb and fairly easy to set up, glad I got rid of it :facepalm:
I believe Wallace has also done a fair amount of testing of FXR's with bellmouths and airbox.

[richban]

Where do you measure the runner length from and to?

From the back of the valve ?

In general what effect does does the bellmouth velocity thing have on existing jetting?

I think most of the time when people talk about runner length they are talking about the intake on a car that runs from the front of the car to the plenum / air box. Ram air style on a bike or like the monocoque old super bike can't remember who built it. Draws cool air from the back.

On existing jetting who knows. I have seen a cleaner power curve on the dyno after adding an open airbox to the equation. If you look at the standard FXR intake length into the air box including the rubber bit. I bet its really close to the equation below.

The simple equation for working out an intake length is 97000 divided buy peak power 11500 rpm = 8.4 inches / 213mm from valve centre. Apparently.

[kel]

If you look at the standard FXR intake length into the air box including the rubber bit. I bet its really close to the equation below.

Not that I looked at the formula but the original intake length to the airbox produced peak torque at 8500rpm, shortening the overall length to 175mm (or was it 185mm?) length lift peak torque to 10500rpm giving a handy increase in peak hp.

[richban]

Not that I looked at the formula but the original intake length to the airbox produced peak torque at 8500rpm, shortening the overall length to 175mm (or was it 185mm?) length lift peak torque to 10500rpm giving a handy increase in peak hp.

How long was the exhaust header?

[kel]

How long was the exhaust header?

That was the secret bit, its quite a bit longer than you'd expect. Bike will have the standard short 2 stage header with a nice quite muffler fitted for Easter.

[richban]

That was the secret bit, its quite a bit longer than you'd expect. Bike will have the standard short 2 stage header with a nice quite muffler fitted for Easter.

Ahhhh yes the megaphone. Haven't seen one on a moto3 bike yet. Back to the airbox thing. Before Taupo I had a bit of a desater with an needle that was almost worn through at the clip. I epoxyed it onto place and then noticed it had a couple of weid holes in the power. I had cleaned and serviced the carb and check everything. It was running pretty much open. I figured it was time to build a proper air box. 1 hour later fitted to the bike with longer intake she ran crisp and clean. The length could be out for sure but the main thing I noticed it the consistency of the engines power delivery. It just did not miss a beat. It used to.

[Bert]

interesting article:
http://motortecmagazine.net/article.asp?AID=1&AP=1

Far to many strokes for my liking; but horses for courses.

[Bert]

interesting article:
http://motortecmagazine.net/article.asp?AID=1&AP=1

Far to many strokes for my liking; but horses for courses.

Hummmm

Anyway, since I've taken a backwards step and made a tempory move to quad stroke; I thought this tread should be bumped.

What's been happening in Palmy (GPR headquarters)??

5 freshly finished GPR tuned FXR engines Have been completed
(including one very lucky welly rider).
We have managed get from 14.7hp to ~21hp. Piston, pipe, cams & carb and head mods.

Currently there is a stock fxr sitting on the dyno and are going to test out some simple bolt on mods to see what can be made easily. Pipe, carb, timing, fuel etc
The idea here is to get a simple set of mods for newbies to follow. ~18Hp is the aim which isn't bad to start with.

Too share the love we will post up our findings. And try and do some YouTube stuff show and tell.

Side notes to get things started:
1. Challenge fuel vs BP 98 (0.5 Hp gain on back to back test on full worked GPR engine)... Something to think about here (is it safe)...
2. Cam chains. Old stretched chains can move timing by up to 10 degrees. Might be why engines feel the best before they shit themselves.
They are cheap so replace them regularly to save heartache. Check and record your cam durations (opening etc). If they drift do something.
3. Clean your chains. The frictional losses on the dyno are surprising. >1Hp loss.
Make sure you get everything lined up correctly (and clean& oiled). don't over chain your bike (buckets don't need anything more than a 420, 415 DID race chain is good for 50+ hp, so think about your 520 chains and how much weight and friction you could loose).

http://www.fxr150.co.nz/forum/attachment.php?attachmentid=1910&d=1377377020
More later when I've got time.

[TZ350]

Really interesting, thanks Bert.

A way of varying the inlet tract length and picking up a couple of thousand rpm at the lower end.


254019 254020 254023

What really surprised me was the inlet with the hole closed was crap up top but with the hole open it had the tuned length (to the hole) of the carb but made better power up top than the carb did. I would have thought the plumbing of the long inlet would have been more restrictive to air flow than the naked carb and made less power.

From experiments I did with Kel and Gigglebuttons bikes I think a 4T could gain a lot from varying the inlet and exhaust header length as required by just 100mm for the inlet and 50mm in the exhaust.

[mr bucketracer]

287022getting some good breakthroughs started at 13.7 hp, half a day on the dyno wih bert and things are looking good
in the exhaurt there is alot to learn

[mr bucketracer]

not seen this thread so going to have a good look:banana: