ESE's works engine tuner

[TZ350]

saw this yesterday, i edited the Valves out and added some ports. Cameron

Thanks for that Husa, the wife pulled my ear when she caught me reading your post....

Now that I know its the 1978 AMA Tech Bulletin 78-1 I should have been looking for I found this....



The rest of it can be found here:- http://books.google.co.nz/books?id=d...=onepage&q=ama technical bulletin 78-1&f=false

I had heard about the restriction imposed on the TZ750's and that Yamaha were able to use it to their advantage. I was never able to find out much about it, but the story gave me a direction to look in for developing my own inlet system.



The 24mm taper bored OKO .... with the old Suzuki GP nudging 34 crank hp the idea has pretty much made the Bucket 24mm carb restriction rule for 125 2T's redundant.

[RomeuPT]

Hi again.

Found this graph comparing an exhaust made from dif materials.

Would this difference came from just heat dissipation? Making the stainless a titanium pipe reach a higher temp?



thanks

[TZ350]

First ever (for me) EFI dyno run.



My new, smaller injectors arrived today and I got the Beast running well enough to try a first pull on the dyno.

Lots of tuning to do but its looking promising.

[koba]

Hi again.

Found this graph comparing an exhaust made from dif materials.

Would this difference came from just heat dissipation? Making the stainless a titanium pipe reach a higher temp?



thanks

Perhaps difference in resonance too?

I'm no expert but would suggest that if the design was optimised for each material one would attain the same, or a similar, power curve.

[koba]

First ever (for me) EFI dyno run.



My new, smaller injectors arrived today and I got the Beast running well enough to try a first pull on the dyno.

Lots of tuning to do but its looking promising.

Haha, awesome, out of the box it smashes what I have!

[husaberg]

Thanks for that Husa, the wife pulled my ear when she caught me reading your post....

lol that was my aim......

Now that I know its the 1978 AMA Tech Bulletin 78-1 I should have been looking for I found this....


The 24mm taper bored OKO .... with the old Suzuki GP nudging 34 crank hp the idea has pretty much made the Bucket 24mm carb restriction rule for 125 2T's redundant.

All but, you still have that air cooled limitation
The Cameron Sportbike Performance handbook is well worth a read.
I also got the tdc book for my birthday.
BTW did you soda blast the frame?

[chrisc]

First ever (for me) EFI dyno run.



My new, smaller injectors arrived today and I got the Beast running well enough to try a first pull on the dyno.

Lots of tuning to do but its looking promising.

Congrats Rob!

[Grumph]

[QUOTE=TZ350;The 24mm taper bored OKO .... with the old Suzuki GP nudging 34 crank hp the idea has pretty much made the Bucket 24mm carb restriction rule for 125 2T's redundant.[/QUOTE]

Not completely - you've still got to think about it and have the skill to make it...it's a bit harder too IMO with a reed motor as the article makes clear. My approach at present which is working quite well i'll admit is the 'lectron" answer.
If i continue with the reed motor I may well look at making up a flatslide version of an Amal GP or RN - with a remote needle. This should leave only a nozzle protruding into the bore - and of course to keep Wob happy, a powerjet too.

Have you looked at any advantage to continuing the taper inward past the rotary valve to the point where it meets the transfer wall ?

[TZ350]

Yes, on my engines I tried to carry the divergent cone from the venture restrictor right through the carb, rubber manifold, rotary valve and on into the motor itself.

With the EFI Ball Valve throttle and 24mm venture restrictor behind it, the inlet passage is to short for a nice divergent angle so its a bit abrupt I am afraid.

I like what your thinking of doing with a flat slide and remote needle.

I tried a 30mm EI (Lectron??) with a 24mm venture restrictor just in behind the slide with it extending right back into the rubber manifold.



Later I set it up with a power jet arrangement and got good results but the carb was big and made the inlet tract to long and I was hampered by a lack of needles to jet it properly. In the end I found the smaller OKO gave better results on the dyno and was much easier to work with.

I tried all sorts of carburetors like the 38 which passed an astronomical amount of air on the flow bench but made no more power on the dyno than the OKO did. I guess the power restriction was not in the carb.

And at lower rpm, if you whacked the throttle open on the 38 you would get a big flat spot, this didn't happen with carbs that were 32mm or less.

[TZ350]

The 24mm taper bored OKO .... with the old Suzuki GP nudging 34 crank hp the idea has pretty much made the Bucket 24mm carb restriction rule for 125 2T's redundant.

All but, you still have that air cooled limitation

True but that is another issue and probably the real limiting factor. Ironically, if they did away with the 24mm carb rule I probably would not bother trying to run a bigger one now because a taper bored 24 works so well.

Now what to do about that air cooling ..... .... I have a few ideas ....

[husaberg]

True but that is another issue and probably the real limiting factor.

they were a clever set of rules

[TZ350]

they were a clever set of rules

True and its what keeps me entertained by trying to get the best out of them.

To improve the air cooling I will need to data log some critical areas like the temperature under the plug, the fin area near the exhaust port duct and the gearbox oil temperature.

[Frits Overmars]

Now what to do about that air cooling ..... .... I have a few ideas ....

A little story:
there is a german racing series called SimsonGP, based on the one truly indestructible product from the former German Democratic Republic: the Simson moped, of which there are still thousands around. A friend of mine named Jan Schäffer runs a tuning company called Langtuning (www.langtuning.de/Shop2/index.php) specializing in Simsons. Jan has dominated the fastest class of the series, which has been kind of demoralizing for his competitors, so at the end of 2012 I talked him into trying his luck in the most restricted class: street tires, aircooled cylinder with cast-iron sleeve, no nikasil allowed, piston port induction, no more than two transfers, and so on.
Kind of a hopeless enterprise really, since Jan puts a 115 kilos on the scales with his helmet and boots on, so he needs every pony he can get out of the 50 cc engine. And if you're not allowed to tune it properly, what can you expect.
To cut a long story short: in spite of another team hiring a 55 kg Moto3-rider, Jan became champion. How? Take a look at his bike; there are cooling fins everywhere. Even the large fins on the clutch and ignition covers become too hot to touch. Something in line with your ideas, TZ350?

[husaberg]

A little story:
How? Take a look at his bike; there are cooling fins everywhere. Even the large fins on the clutch and ignition covers become too hot to touch. Something in line with your ideas, TZ350?

I came across something posted about how a 50 lapped many seconds quicker with a dry clutch than its original wet clutch,later i wondered if it was more to do with the cooling effect of the clutch not directly heating the oil and thus the crankcases rather than just the reduced drag.


Something else to consider is how much a sealed airbox by taking air from in front (which at bucket speeds will be 9.9/10 of zero pressure) will lead to a power boost regardless, by the virtue of the air not being preheated by the engine or rad.(cameron)

I saved these because they were pretty.but notice the cases.....

[C_Wolf]