Mein racer

[KTy]

Ok, that's it, I don't speak german

Here is a little update on my 50 special...

Exhaust port 70% for GS piston

http://ktylife.free.fr/vespa/KTy133/KTy134.Echap70%25.jpg

Chamfreins

http://ktylife.free.fr/vespa/KTy133/KTy134...hanfrein%e9.jpg

Work on Grand-Sport piston 58mm

http://ktylife.free.fr/vespa/KTy133/KTy134...Pr%e9par%e9.jpg

Reminder :)

http://ktylife.free.fr/vespa/KTy133/200603...%E9Frais%E9.jpg

Mazzu 20/20 full-circle partially smoothed during admission phase

http://ktylife.free.fr/vespa/KTy133/KTy134...ravaill%E91.jpg

http://ktylife.free.fr/vespa/KTy133/KTy134...ravaill%E92.jpg

Specs:

Engine:

Polini 133 machined in a lot of way

Edited; 185°/130°/28° exhaust 70%

Piston GS 58mm

Malossi Head adapted to GS piston

Squish 0.8mm

Mazu 20/20 full circle

ET3 stator + HP4 (PK50 stator + flywheel for this week-end !)

2.56 straight primary + Zirri short 4th

GSF repair kit

PK XL2 clutch, 4 disks 6 springs

Reedvalve vForce3 (RD350/Banshee)

KOSO 32 carb (142/40)

Zirri silent exhaust (touching in left curves )

NGK RED sparkplug wire

Chassis:

Straight and reinforced rear spring SIP/Worb5

Dropbar from Bad Man Nico (French scooterist)

Rear tyre Raceman 100/80-10 on normal rims with 3mm spacers *between* the two half rims...

Front tyre Raceman 110/80-10

Yamaha Booster NG fork

In action this week-end near Avignon, south of France ;)

Calm...

No power diagram yet... Strugling to find a place...

Very funny to drive, wheelies in 2nd gear, powerful front brake, the front tyre is obviously a bit wide, but anyway...

The seat is maybe a little bit high for racing, anyway, my driving skills need to improve first :) Even if I manage to get the second best time of the whole day, but it's because my scooter was over-prepared compared to most of the others...

EDIT: Damn' IE !!! :veryangry:

Bearbeitet 15. Mai 2007 von KTy

[Crisk]

Really nice work. :love:

198° Exhaust.... woohooo!

Bearbeitet 27. Juni 2006 von Crisk

[merlin-eins]

nice setup.

[motor2rad]

very fine, i love the color :love:

very fine your fork and your brake clutch.

Your are from France ???

Have u more Pictures from Vepsa racers in France ???

[KTy]

very fine, i love the color :love:

very fine your fork and your brake clutch.

Your are from France ???

Have u more Pictures from Vepsa racers in France ???

Have a look here and there:

http://www.legru.net/scootentole/Mormoiron-2005

http://www.legru.net/scootentole/album09

http://www.legru.net/scootentole/C-R-D

We have less "racers" because it's totally forbiden :puke: to change anything normally... :wasntme:

[100 spezial]

34° pre auslass

[KTy]

34° pre auslass

http://ktylife.free.fr/vespa/KTy133/KTy134.xls

(Was before exhaust enlarged to 70%, I didn't have the time to measure again).

EDIT: As pointed out by Olli ETS, there is a mistake in my XLS file. The conrod length is 97mm not 93mm... It will reduce a little bit my timing (hopefully :) )

Bearbeitet 28. Juni 2006 von KTy

[Hackfresse]

Verry nice

The Fork with the original frontfender looks verry good :grins: :grins:

Wat a fork do you ride?

jAn

[Pepper]

nice job, the fork looks great. my congratulations.

[albert]

nice knee-pads

albert

[KTy]

KTy - Cheap SC

[rasputin]

can i buy that turquoise scooter?

r

p.s. congratulations on your german, bytheway. really "geil"...

Bearbeitet 27. Juni 2006 von rasputin

[KTy]

das ist nicht turquoise, das ist hellblau.

[Erbse]

das ist nicht turquoise, das ist hellblau.

I think he means this one.

I dont like racers, but this is a nice one, even for a reacer...

Greetz,

Erbse²

[Luccio]

Schaden, den dein Koso ist so gierig .... :wasntme:

[meisterbo]

why did you change from the carb-to-frame-tube to a filter? less performance??

[KTy]

why did you change from the carb-to-frame-tube to a filter? less performance??

I'm not sure at all, I have the feeling it gives slightly better performance at high RPM and, for sure, more noise :)

The other point is that it's not everyday that you can ride and make all the noise that you want !

Actually, it was more to impress my opponents with a loud Boooaoaaaaaaaaah when I was overtaking them !

Schaden, den dein Koso ist so gierig .... :wasntme:

I ran out of fuel in the last lap of the race while having a very large advantage on the 2nd... And the second was Luccio :grr: :grins:

Bearbeitet 28. Juni 2006 von KTy

[Luccio]

very large?

Bearbeitet 28. Juni 2006 von Luccio

[KTy]

very large?

Yes indeed...

I cheked, you were at the chicane when I ran out of fuel...

Anyway, you won (

[Dicker]

Salut!

J´essaye d´écrire en francais cette fois.

Vachement beau cours vous avez là bas et toujours beaux temps aussi n´est-ce pas?

N´importe quoi, vraiment cool ton scooter! Raconte moi plus concernant le cours s.t.p.

[KTy]

I don't live where the race took place, but it seems it is always sunny and hot !

The race was very "unformal"; Practice in the morning and race by categories in the afternoon. We were too few, so in the end there was only two categories; Up to 177 (!) and over 177 (!).

Each category had a first 15 minutes race, then we had another 15 minutes session with all scooter (we were 35 I think), and in the end another 15 minutes race per session. Most of us are just regular vespa-daily-user so it was very friendly with no crash *between* peoples. Some people manage to crash by themselves while attacking a lot

Anyway, great fun

[100 spezial]

you have a gsf dyno run?? :haeh:

[KTy]

Still no (

[lindy]

The front mudguard fitted in the tele-fork looks very nice. I don't like the plastic-scooter mudguards most people use to fit.

Fine piece of work!

[oli-san]

nice piece of kit.

and ever nicer: beautyful engine timing. do you have a rev counter fitted? what does it say?

what diameter has your exhaust flange to the pipe?

how could you get the cylinder exhaust area match the exhaust flange area?

[KTy]

I am in the active process of finding a dyno run !

As for the exhaust flange (manifold ?), I enlarged it a lot, I think it remains something like 3mm all around but unfortunately I have no picture... Next time !

[amazombi]

nice piece of kit.

and ever nicer: beautyful engine timing. do you have a rev counter fitted? what does it say?

what diameter has your exhaust flange to the pipe?

how could you get the cylinder exhaust area match the exhaust flange area?

tried anything from 29 to 36, there is power to be found up to say 32, 33, beyond that gains in peak power were not as significant as one would hope, whereas a loss of bandwith started playing quite a role. with a higher revving engine this may be different, up to say 10 500 or so i doubt it though. just as a point of reference: a different engine i'm working on pumps our a healthy 27,8 bhp at just under 14 grand, and it runs best with 29,5, possible 30mm downpipe diameter. as increases in diameter are slightly missleading as far as their significance is concerned (remember you need to consider the square) i'd say 32 with the resulting increase of "stable door size" to get the horses out of the barrely is plenty for most smallframe applications. one of my pipes with a 32mm downpipe mounted on gerhard's 121 malossi made 24 bhp (with flywheel fan and a 10% engine capacity handicap compared to 136 malossi). as far as i understand there will be some people with my pipes ready for marl, one or more of them will be using a dyno, i guess, and i'm quite sure the abovementioned result will be corroborated by his/their curves.

ps: keep in mind that with some more complex pipe designs it may not be possible to change the downpipe size without major redesigns of the rest of the pipe.

[KTy]

tried anything from 29 to 36, there is power to be found up to say 32, 33, beyond that gains in peak power were not as significant as one would hope, whereas a loss of bandwith started playing quite a role. with a higher revving engine this may be different, up to say 10 500 or so i doubt it though. just as a point of reference: a different engine i'm working on pumps our a healthy 27,8 bhp at just under 14 grand, and it runs best with 29,5, possible 30mm downpipe diameter. as increases in diameter are slightly missleading as far as their significance is concerned (remember you need to consider the square) i'd say 32 with the resulting increase of "stable door size" to get the horses out of the barrely is plenty for most smallframe applications. one of my pipes with a 32mm downpipe mounted on gerhard's 121 malossi made 24 bhp (with flywheel fan and a 10% engine capacity handicap compared to 136 malossi). as far as i understand there will be some people with my pipes ready for marl, one or more of them will be using a dyno, i guess, and i'm quite sure the abovementioned result will be corroborated by his/their curves.

ps: keep in mind that with some more complex pipe designs it may not be possible to change the downpipe size without major redesigns of the rest of the pipe.

Alright.... :plemplem:

As far as I have understood you're talking about the "first part" of the pipe that has a constant diameter... Am I right ?

(The part that has an outside diameter of 32mm here, http://ktylife.free.fr/vespa/KTy133/zirriDimension.jpg)

Is there some known modifications to do to my zirri exhaust or downpipe ?

If I make a 32mm (inner diameter) downpipe for my zirri, how one recommend making the junction with the rest of the exhaust ??

Okay, first I have to do a dyno... okay... :grr:

Thanks

KTy

Bearbeitet 30. Juni 2006 von KTy

[amazombi]

Alright.... :plemplem:

As far as I have understood you're talking about the "first part" of the pipe that has a constant diameter... Am I right ?

(The part that has an outside diameter of 32mm here, http://ktylife.free.fr/vespa/KTy133/zirriDimension.jpg)

Is there some known modifications to do to my zirri exhaust or downpipe ?

If I make a 32mm (inner diameter) downpipe for my zirri, how one recommend making the junction with the rest of the exhaust ??

Okay, first I have to do a dyno... okay... :grr:

Thanks

KTy

chances are that if you simply weld it to the smaller diameter part you will get good power. it may also result in a complete piece of shit. you'll never know untill you try. actually one may even argue the point that a pipe needs a paralell downpipe section. some people have been known to take the point that it actually is detrimental to the engines performance.

[oli-san]

the diameter of the exhaust at your zirri INSIDE with 32mm outside should be about 29 to 30mm. OK. This relates to a flange area of 707 mm^2. This should be equal to your area at the flange of the exhaust mounting surface.

now from there you could calculate back to your exhaust window area in the cyclinder bore. some people take the same value there in projection of the exhaust gases. this would mean, the portmap window size could be bigger than that.

what that all means, is that the bigger the better is not necessary, when your exhaust is restricting the complete system of the big holes.