2010 weapon

[woodyracer]

i bet some people thought your car rexhaust was stupid when you first put it on??
well if it works then who cares.......

Just like my exhaust, nobody has heard it......and nobody has seen it on the track......

It might not work, but if it dosnt what do i have to loose?.......

[Schrgd]

i bet some people thought your car rexhaust was stupid when you first put it on??
well if it works then who cares.......

Just like my exhaust, nobody has heard it......and nobody has seen it on the track......

It might not work, but if it dosnt what do i have to loose?.......

Ironically, The only reason that the car exhaust ended up on bike is at 11pm the friday before my first meeting, it was all i had in the garage, it was free, and if I didn't use it, i would't expect to turn up at most track's in NZ on any bike without no muffler and expect to be allowed on the track.

[woodyracer]

thats where you are wrong, im turnig up to the track WITH a muffler.....

[RDjase]

So Ill take that as a yes, actually I didnt know you had rebranded yourself.
You could mug me in the street and i still wouldnt know who you were.
Good luck with your bike, isnt there a rule in the general section of the rules requiring a muffler, otherwise my lc would have straight stingers, just because they sound good !

Straight Stingers , yes please, Whats the decibel reading again , 110 for LC's and 95 for everyone else

[woodyracer]

my 25cc goped used to have a straight pipe and man was it LOUD!, and that was only a 25cc weed eater motor....lol

[SS90]

Now Wooyracer, back to business.

A little research will tell you, is your injection system "closed loop", or "open loop"?

This is important, and will determine what you are able to do (and HOW you go about it) to your bucket.

[woodyracer]

i wouldnt have a clue ss90, but i know one thing, The guys from honda have a cbr125, its got an aftermarket exhaust and it dosnt seem to go like mine did because i had the standard exhaust, mine seems to no rev as high, and not have as much power on the straight, but im almost certain that i had better throttle response with the standard muffler then they did.

So its looking like i should put the standard exhaust on because when i started it today and revved it, it hesitated before reving when i pulled the accelerator, but before it didnt do that. Alothough the main reason i took the muffler off in the first place is because it weighs 3KG......and when i took the muffler off to weigh it out of curiosity, my dad dared me to start the bike without the muffler on to see how loud it would be. So i did so, and we were both suprised how quiet it was. And thats how i got to where i am now :]

[SS90]

Uh hu.

OK, so, whip out to your shed, and look at the entire length of the header system (that bulge in the middle is the restrictive CAT), anywhere along the length, is there a single wire going into what looks like a bolt, mounted on the header system.

IF yes, then it is closed loop.

[woodyracer]

nope their aint no wire......., how should i come about getting rid of the CAT?, I cant afford a new exhaust system as im saving.

Thanks for the help, its much appreciated.

[SS90]

Ok, what you have is called "open loop" (basically, this is an older system that does not use an o2 sensor to calculate, and adjust fueling, it relies on a predetermined fuel curve)

It's simply a cheaper system.

take your header in to the muffler shop, and simply get them to cut the cat out, and replace it with a straight bit if tube (inexpensive really).

I guarantee you you will gain power, and won't have problems with fueling.

It's been done before.

[woodyracer]

thanks will do. Might get pit stop to do it when the jeep gets its brakes done. -Max

[aircooled]

sensor is in head near header outlet

cbr125 13hp with pipe , power commander. 13/42 gearing.

[woodyracer]

thanks, have you had a cbr125 on a dyno?, -Max

[aircooled]

yes to sort the fuel mapping for pipe & air box mod

[SS90]

yes to sort the fuel mapping for pipe & air box mod

Well, that makes it a "closed loop" system, and will, as Aircooled says, require a power commander to get the bike running correctly..........

13HP with pipe AND air box mods?

Blegh!

I honestly don't think you will get much of a competitive machine out of this one Max....... it may well Co$t a bit just to keep up with a standard FXR150 in the power stakes

Power commander
big bore kit
header mods

probably 15 HP, maybe 16

I can't remember, but I think down in Chch Kiakaha rode an FXR with more than 20hp

that blows a grand before you even have the bike on a dyno........ may well be best advised to leave it as it is and ride the wheels off it!

Just a "heads up" as well max, but "back in the day" (cough cough) GN125/GS125 (air cooled, single OHC 2 valve) engines, could, with very little work be (reliabily) coaxed up to 14 HP with little more than a $80 muffler attached to a home bent header, a quick port job (head still on the bike, head off, and you could get 2 more HP) and a GN250 carb (no air box OR jet changes whatsoever)

Total cost (including 17 in wheels, and purchasing the bike, which was a minter)..........$700.

This was all 6 years ago, so not exactly a millenium.

People sometimes resent when others come in and go "cheque book racing" in a class that for years has promoted innovation.

There is a guy on here who goes by the name "oyster" (Pete Jones),Max, in the late eighties (maybe the early ninties......a VT would have been to new for Jonsey to get his hands on in the eighties) he built his own alloy framed bucket, with a vt250 head fitted onto (I think) a CB125 bottom end.

5 or so years ago, he pulled it out of his shed, and whipped almost everyones arse in a street race in Rakia (actually, I became famous in the sidecar world at that meeting....for all the wrong reasons)

Perhaps if you PM'd oyster, he could find some pictures of the bike, and maybe even give you some advise, he's very helpful.

BIg bore, VT250 head (I have 2 in christchurch in my mothers garage you can have if you want), then you may start making some power!

You could run the EFI, or perhaps continue with it running a carb would be easier, as a VT head does not have a camshaft position sensor, although maybe neither does the CBR125, as you can run off a crank angle sensor instead, you would have to check and find out what the EFI system uses for data collection.

A power commander would be "must have" for sure.

Even if you don't try it, learning about how you could do it (and why it would make more power) would benefit you (and your racing) massively

What sort of sensors does your CBR run?

If you don't know, take pictures of all the engine sensors you find, post them, and those of us with experience will tell you what they are, what they do, and how they work.